unofficial mirror of bug-gnu-emacs@gnu.org 
 help / color / mirror / code / Atom feed
blob cb63ca51c541cf43b8089b4010000775ea11b269 115561 bytes (raw)
name: lisp/mouse.el 	 # note: path name is non-authoritative(*)

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
 
;;; mouse.el --- window system-independent mouse support  -*- lexical-binding: t -*-

;; Copyright (C) 1993-1995, 1999-2018 Free Software Foundation, Inc.

;; Maintainer: emacs-devel@gnu.org
;; Keywords: hardware, mouse
;; Package: emacs

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; This package provides various useful commands (including help
;; system access) through the mouse.  All this code assumes that mouse
;; interpretation has been abstracted into Emacs input events.

;;; Code:

;;; Utility functions.

;; Indent track-mouse like progn.
(put 'track-mouse 'lisp-indent-function 0)

(defgroup mouse nil
  "Input from the mouse."  ;; "Mouse support."
  :group 'environment
  :group 'editing)

(defcustom mouse-yank-at-point nil
  "If non-nil, mouse yank commands yank at point instead of at click."
  :type 'boolean)

(defcustom mouse-drag-copy-region nil
  "If non-nil, copy to kill-ring upon mouse adjustments of the region.

This affects `mouse-save-then-kill' (\\[mouse-save-then-kill]) in
addition to mouse drags."
  :type 'boolean
  :version "24.1")

(defcustom mouse-1-click-follows-link 450
  "Non-nil means that clicking Mouse-1 on a link follows the link.

With the default setting, an ordinary Mouse-1 click on a link
performs the same action as Mouse-2 on that link, while a longer
Mouse-1 click (hold down the Mouse-1 button for more than 450
milliseconds) performs the original Mouse-1 binding (which
typically sets point where you click the mouse).

If value is an integer, the time elapsed between pressing and
releasing the mouse button determines whether to follow the link
or perform the normal Mouse-1 action (typically set point).
The absolute numeric value specifies the maximum duration of a
\"short click\" in milliseconds.  A positive value means that a
short click follows the link, and a longer click performs the
normal action.  A negative value gives the opposite behavior.

If value is `double', a double click follows the link.

Otherwise, a single Mouse-1 click unconditionally follows the link.

Note that dragging the mouse never follows the link.

This feature only works in modes that specifically identify
clickable text as links, so it may not work with some external
packages.  See `mouse-on-link-p' for details."
  :version "22.1"
  :type '(choice (const :tag "Disabled" nil)
		 (const :tag "Double click" double)
                 (number :tag "Single click time limit" :value 450)
                 (other :tag "Single click" t)))

(defcustom mouse-1-click-in-non-selected-windows t
  "If non-nil, a Mouse-1 click also follows links in non-selected windows.

If nil, a Mouse-1 click on a link in a non-selected window performs
the normal mouse-1 binding, typically selects the window and sets
point at the click position."
  :type 'boolean
  :version "22.1")

(defvar mouse--last-down nil)

(defun mouse--down-1-maybe-follows-link (&optional _prompt)
  (when mouse-1-click-follows-link
    (setq mouse--last-down (cons (car-safe last-input-event) (float-time))))
  nil)

(defun mouse--click-1-maybe-follows-link (&optional _prompt)
  "Turn `mouse-1' events into `mouse-2' events if follows-link.
Expects to be bound to `(double-)mouse-1' in `key-translation-map'."
  (and mouse--last-down
       (pcase mouse-1-click-follows-link
         ('nil nil)
         ('double (eq 'double-mouse-1 (car-safe last-input-event)))
         (_ (and (eq 'mouse-1 (car-safe last-input-event))
                 (or (not (numberp mouse-1-click-follows-link))
                     (funcall (if (< mouse-1-click-follows-link 0) #'> #'<)
                              (- (float-time) (cdr mouse--last-down))
                              (/ (abs mouse-1-click-follows-link) 1000.0))))))
       (eq (car mouse--last-down)
           (event-convert-list (list 'down (car-safe last-input-event))))
       (let* ((action (mouse-on-link-p (event-start last-input-event))))
         (when (and action
                    (or mouse-1-click-in-non-selected-windows
                        (eq (selected-window)
                            (posn-window (event-start last-input-event)))))
           ;; Turn the mouse-1 into a mouse-2 to follow links,
           ;; but only if ‘mouse-on-link-p’ hasn’t returned a
           ;; string or vector (see its docstring).
           (if (arrayp action)
               (vector (aref action 0))
             (let ((newup (if (eq mouse-1-click-follows-link 'double)
                              'double-mouse-2 'mouse-2)))
               ;; If mouse-2 has never been done by the user, it
               ;; doesn't have the necessary property to be
               ;; interpreted correctly.
               (unless (get newup 'event-kind)
                 (put newup 'event-kind
                      (get (car last-input-event) 'event-kind)))
               ;; Modify the event in-place, otherwise we can get a prefix
               ;; added again, so a click on the header-line turns
               ;; into a [header-line header-line mouse-2] :-(.
               ;; See fake_prefixed_keys in src/keyboard.c's.
               (setf (car last-input-event) newup)
               (vector last-input-event)))))))

(define-key key-translation-map [down-mouse-1]
  #'mouse--down-1-maybe-follows-link)
(define-key key-translation-map [double-down-mouse-1]
  #'mouse--down-1-maybe-follows-link)
(define-key key-translation-map [mouse-1]
  #'mouse--click-1-maybe-follows-link)
(define-key key-translation-map [double-mouse-1]
  #'mouse--click-1-maybe-follows-link)

\f
;; Provide a mode-specific menu on a mouse button.

(defun minor-mode-menu-from-indicator (indicator)
  "Show menu for minor mode specified by INDICATOR.
Interactively, INDICATOR is read using completion.
If there is no menu defined for the minor mode, then create one with
items `Turn Off' and `Help'."
  (interactive
   (list (completing-read
	  "Minor mode indicator: "
	  (describe-minor-mode-completion-table-for-indicator))))
  (let* ((minor-mode (lookup-minor-mode-from-indicator indicator))
         (mm-fun (or (get minor-mode :minor-mode-function) minor-mode)))
    (unless minor-mode (error "Cannot find minor mode for `%s'" indicator))
    (let* ((map (cdr-safe (assq minor-mode minor-mode-map-alist)))
           (menu (and (keymapp map) (lookup-key map [menu-bar]))))
      (setq menu
            (if menu
                (mouse-menu-non-singleton menu)
              (if (fboundp mm-fun)      ; bug#20201
                  `(keymap
                    ,indicator
                    (turn-off menu-item "Turn off minor mode" ,mm-fun)
                    (help menu-item "Help for minor mode"
                          (lambda () (interactive)
                            (describe-function ',mm-fun)))))))
      (if menu
          (popup-menu menu)
        (message "No menu available")))))

(defun mouse-minor-mode-menu (event)
  "Show minor-mode menu for EVENT on minor modes area of the mode line."
  (interactive "@e")
  (let ((indicator (car (nth 4 (car (cdr event))))))
    (minor-mode-menu-from-indicator indicator)))

(defun mouse-menu-major-mode-map ()
  (run-hooks 'activate-menubar-hook 'menu-bar-update-hook)
  (let* (;; Keymap from which to inherit; may be null.
	 (ancestor (mouse-menu-non-singleton
		    (and (current-local-map)
			 (local-key-binding [menu-bar]))))
	 ;; Make a keymap in which our last command leads to a menu or
	 ;; default to the edit menu.
	 (newmap (if ancestor
		     (make-sparse-keymap (concat (format-mode-line mode-name)
                                                 " Mode"))
		   menu-bar-edit-menu)))
    (if ancestor
	(set-keymap-parent newmap ancestor))
    newmap))

(defun mouse-menu-non-singleton (menubar)
  "Return menu keybar MENUBAR, or a lone submenu inside it.
If MENUBAR defines exactly one submenu, return just that submenu.
Otherwise, return MENUBAR."
  (if menubar
      (let (submap)
        (map-keymap
         (lambda (k v) (setq submap (if submap t (cons k v))))
         (keymap-canonicalize menubar))
        (if (eq submap t)
            menubar
          (lookup-key menubar (vector (car submap)))))))

(defun mouse-menu-bar-map ()
  "Return a keymap equivalent to the menu bar.
The contents are the items that would be in the menu bar whether or
not it is actually displayed."
  (run-hooks 'activate-menubar-hook 'menu-bar-update-hook)
  (let* ((local-menu (and (current-local-map)
			  (lookup-key (current-local-map) [menu-bar])))
	 (global-menu (lookup-key global-map [menu-bar]))
	 ;; If a keymap doesn't have a prompt string (a lazy
	 ;; programmer didn't bother to provide one), create it and
	 ;; insert it into the keymap; each keymap gets its own
	 ;; prompt.  This is required for non-toolkit versions to
	 ;; display non-empty menu pane names.
	 (minor-mode-menus
	  (mapcar
           (lambda (menu)
             (let* ((minor-mode (car menu))
                    (menu (cdr menu))
                    (title-or-map (cadr menu)))
               (or (stringp title-or-map)
                   (setq menu
                         (cons 'keymap
                               (cons (concat
                                      (capitalize (subst-char-in-string
                                                   ?- ?\s (symbol-name
                                                           minor-mode)))
                                      " Menu")
                                     (cdr menu)))))
               menu))
	   (minor-mode-key-binding [menu-bar])))
	 (local-title-or-map (and local-menu (cadr local-menu)))
	 (global-title-or-map (cadr global-menu)))
    (or (null local-menu)
	(stringp local-title-or-map)
	(setq local-menu (cons 'keymap
			       (cons (concat (format-mode-line mode-name)
                                             " Mode Menu")
				     (cdr local-menu)))))
    (or (stringp global-title-or-map)
	(setq global-menu (cons 'keymap
			        (cons "Global Menu"
				      (cdr global-menu)))))
    ;; Supplying the list is faster than making a new map.
    ;; FIXME: We have a problem here: we have to use the global/local/minor
    ;; so they're displayed in the expected order, but later on in the command
    ;; loop, they're actually looked up in the opposite order.
    (apply 'append
           global-menu
           local-menu
           minor-mode-menus)))

(defun mouse-major-mode-menu (event &optional prefix)
  "Pop up a mode-specific menu of mouse commands.
Default to the Edit menu if the major mode doesn't define a menu."
  (declare (obsolete mouse-menu-major-mode-map "23.1"))
  (interactive "@e\nP")
  (run-hooks 'activate-menubar-hook 'menu-bar-update-hook)
  (popup-menu (mouse-menu-major-mode-map) event prefix))

(defun mouse-popup-menubar (event prefix)
  "Pop up a menu equivalent to the menu bar for keyboard EVENT with PREFIX.
The contents are the items that would be in the menu bar whether or
not it is actually displayed."
  (declare (obsolete mouse-menu-bar-map "23.1"))
  (interactive "@e \nP")
  (run-hooks 'activate-menubar-hook 'menu-bar-update-hook)
  (popup-menu (mouse-menu-bar-map) (unless (integerp event) event) prefix))

(defun mouse-popup-menubar-stuff (event prefix)
  "Popup a menu like either `mouse-major-mode-menu' or `mouse-popup-menubar'.
Use the former if the menu bar is showing, otherwise the latter."
  (declare (obsolete nil "23.1"))
  (interactive "@e\nP")
  (run-hooks 'activate-menubar-hook 'menu-bar-update-hook)
  (popup-menu
   (if (zerop (or (frame-parameter nil 'menu-bar-lines) 0))
       (mouse-menu-bar-map)
     (mouse-menu-major-mode-map))
   event prefix))
\f
;; Commands that operate on windows.

(defun mouse-minibuffer-check (event)
  (let ((w (posn-window (event-start event))))
    (and (window-minibuffer-p w)
	 (not (minibuffer-window-active-p w))
	 (user-error "Minibuffer window is not active")))
  ;; Give temporary modes such as isearch a chance to turn off.
  (run-hooks 'mouse-leave-buffer-hook))

(defun mouse-delete-window (click)
  "Delete the window you click on.
Do nothing if the frame has just one window.
This command must be bound to a mouse click."
  (interactive "e")
  (unless (one-window-p t)
    (mouse-minibuffer-check click)
    (delete-window (posn-window (event-start click)))))

(defun mouse-select-window (click)
  "Select the window clicked on; don't move point."
  (interactive "e")
  (mouse-minibuffer-check click)
  (let ((oframe (selected-frame))
	(frame (window-frame (posn-window (event-start click)))))
    (select-window (posn-window (event-start click)))
    (raise-frame frame)
    (select-frame frame)
    (or (eq frame oframe)
	(set-mouse-position (selected-frame) (1- (frame-width)) 0))))

(define-obsolete-function-alias 'mouse-tear-off-window 'tear-off-window "24.4")
(defun tear-off-window (click)
  "Delete the selected window, and create a new frame displaying its buffer."
  (interactive (list last-nonmenu-event))
  (mouse-minibuffer-check click)
  (let* ((window (posn-window (event-start click)))
	 (buf (window-buffer window))
	 (frame (make-frame)))          ;FIXME: Use pop-to-buffer.
    (select-frame frame)
    (switch-to-buffer buf)
    (delete-window window)))

(defun mouse-delete-other-windows ()
  "Delete all windows except the one you click on."
  (interactive "@")
  (delete-other-windows))

(defun mouse-split-window-vertically (click)
  "Select Emacs window mouse is on, then split it vertically in half.
The window is split at the line clicked on.
This command must be bound to a mouse click."
  (interactive "@e")
  (mouse-minibuffer-check click)
  (let ((start (event-start click)))
    (select-window (posn-window start))
    (let ((new-height (1+ (cdr (posn-col-row (event-end click)))))
	  (first-line window-min-height)
	  (last-line (- (window-height) window-min-height)))
      (if (< last-line first-line)
	  (user-error "Window too short to split")
        ;; Bind `window-combination-resize' to nil so we are sure to get
        ;; the split right at the line clicked on.
        (let (window-combination-resize)
          (split-window-vertically
           (min (max new-height first-line) last-line)))))))

(defun mouse-split-window-horizontally (click)
  "Select Emacs window mouse is on, then split it horizontally in half.
The window is split at the column clicked on.
This command must be bound to a mouse click."
  (interactive "@e")
  (mouse-minibuffer-check click)
  (let ((start (event-start click)))
    (select-window (posn-window start))
    (let ((new-width (1+ (car (posn-col-row (event-end click)))))
	  (first-col window-min-width)
	  (last-col (- (window-width) window-min-width)))
      (if (< last-col first-col)
	  (user-error "Window too narrow to split")
        ;; Bind `window-combination-resize' to nil so we are sure to get
        ;; the split right at the column clicked on.
	(let (window-combination-resize)
          (split-window-horizontally
           (min (max new-width first-col) last-col)))))))

(defun mouse-drag-line (start-event line)
  "Drag a mode line, header line, or vertical line with the mouse.
START-EVENT is the starting mouse event of the drag action.  LINE
must be one of the symbols `header', `mode', or `vertical'."
  ;; Give temporary modes such as isearch a chance to turn off.
  (run-hooks 'mouse-leave-buffer-hook)
  (let* ((echo-keystrokes 0)
	 (start (event-start start-event))
	 (window (posn-window start))
	 (frame (window-frame window))
	 ;; `position' records the x- or y-coordinate of the last
	 ;; sampled position.
	 (position (if (eq line 'vertical)
		       (+ (window-pixel-left window)
			  (car (posn-x-y start)))
		     (+ (window-pixel-top window)
			(cdr (posn-x-y start)))))
	 ;; `last-position' records the x- or y-coordinate of the
	 ;; previously sampled position.  The difference of `position'
	 ;; and `last-position' determines the size change of WINDOW.
	 (last-position position)
	 (draggable t)
	 posn-window growth dragged)
    ;; Decide on whether we are allowed to track at all and whose
    ;; window's edge we drag.
    (cond
     ((eq line 'header)
      ;; Drag bottom edge of window above the header line.
      (setq window (window-in-direction 'above window t)))
     ((eq line 'mode))
     ((eq line 'vertical)
      (let ((divider-width (frame-right-divider-width frame)))
        (when (and (or (not (numberp divider-width))
                       (zerop divider-width))
                   (eq (frame-parameter frame 'vertical-scroll-bars) 'left))
          (setq window (window-in-direction 'left window t))))))
    (let* ((exitfun nil)
           (move
	    (lambda (event) (interactive "e")
	      (cond
	       ((not (consp event))
		nil)
	       ((eq line 'vertical)
		;; Drag right edge of `window'.
		(setq start (event-start event))
		(setq position (car (posn-x-y start)))
		;; Set `posn-window' to the window where `event' was recorded.
		;; This can be `window' or the window on the left or right of
		;; `window'.
		(when (window-live-p (setq posn-window (posn-window start)))
		  ;; Add left edge of `posn-window' to `position'.
		  (setq position (+ (window-pixel-left posn-window) position))
		  (unless (nth 1 start)
		    ;; Add width of objects on the left of the text area to
		    ;; `position'.
		    (when (eq (window-current-scroll-bars posn-window) 'left)
		      (setq position (+ (window-scroll-bar-width posn-window)
					position)))
		    (setq position (+ (car (window-fringes posn-window))
				      (or (car (window-margins posn-window)) 0)
				      position))))
		;; When the cursor overshoots after shrinking a window to its
		;; minimum size and the dragging direction changes, have the
		;; cursor first catch up with the window edge.
		(unless (or (zerop (setq growth (- position last-position)))
			    (and (> growth 0)
				 (< position (+ (window-pixel-left window)
						(window-pixel-width window))))
			    (and (< growth 0)
				 (> position (+ (window-pixel-left window)
						(window-pixel-width window)))))
		  (setq dragged t)
		  (adjust-window-trailing-edge window growth t t))
		(setq last-position position))
	       (draggable
		;; Drag bottom edge of `window'.
		(setq start (event-start event))
		;; Set `posn-window' to the window where `event' was recorded.
		;; This can be either `window' or the window above or below of
		;; `window'.
		(setq posn-window (posn-window start))
		(setq position (cdr (posn-x-y start)))
		(when (window-live-p posn-window)
		  ;; Add top edge of `posn-window' to `position'.
		  (setq position (+ (window-pixel-top posn-window) position))
		  ;; If necessary, add height of header line to `position'
		  (when (memq (posn-area start)
			      '(nil left-fringe right-fringe left-margin right-margin))
		    (setq position (+ (window-header-line-height posn-window) position))))
		;; When the cursor overshoots after shrinking a window to its
		;; minimum size and the dragging direction changes, have the
		;; cursor first catch up with the window edge.
		(unless (or (zerop (setq growth (- position last-position)))
			    (and (> growth 0)
				 (< position (+ (window-pixel-top window)
						(window-pixel-height window))))
			    (and (< growth 0)
				 (> position (+ (window-pixel-top window)
						(window-pixel-height window)))))
		  (setq dragged t)
		  (adjust-window-trailing-edge window growth nil t))
		(setq last-position position)))))
           (old-track-mouse track-mouse))
      ;; Start tracking.  The special value 'dragging' signals the
      ;; display engine to freeze the mouse pointer shape for as long
      ;; as we drag.
      (setq track-mouse 'dragging)
      ;; Loop reading events and sampling the position of the mouse.
      (setq exitfun
	    (set-transient-map
	     (let ((map (make-sparse-keymap)))
	       (define-key map [switch-frame] #'ignore)
	       (define-key map [select-window] #'ignore)
	       (define-key map [scroll-bar-movement] #'ignore)
	       (define-key map [mouse-movement] move)
	       ;; Swallow drag-mouse-1 events to avoid selecting some other window.
	       (define-key map [drag-mouse-1]
		 (lambda () (interactive) (funcall exitfun)))
	       ;; For vertical line dragging swallow also a mouse-1
	       ;; event (but only if we dragged at least once to allow mouse-1
	       ;; clicks to get through).
	       (when (eq line 'vertical)
		 (define-key map [mouse-1]
		   `(menu-item "" ,(lambda () (interactive) (funcall exitfun))
			       :filter ,(lambda (cmd) (if dragged cmd)))))
	       ;; Some of the events will of course end up looked up
	       ;; with a mode-line, header-line or vertical-line prefix ...
	       (define-key map [mode-line] map)
	       (define-key map [header-line] map)
	       (define-key map [vertical-line] map)
	       ;; ... and some maybe even with a right- or bottom-divider
	       ;; prefix.
	       (define-key map [right-divider] map)
	       (define-key map [bottom-divider] map)
	       map)
	     t (lambda () (setq track-mouse old-track-mouse)))))))

(defun mouse-drag-mode-line (start-event)
  "Change the height of a window by dragging on its mode line.
START-EVENT is the starting mouse event of the drag action.

If the drag happens in a mode line on the bottom of a frame and
that frame's `drag-with-mode-line' parameter is non-nil, drag the
frame instead."
  (interactive "e")
  (let* ((start (event-start start-event))
	 (window (posn-window start))
         (frame (window-frame window)))
    (cond
     ((not (window-live-p window)))
     ((or (not (window-at-side-p window 'bottom))
          ;; Allow resizing the minibuffer window if it's on the
          ;; same frame as and immediately below `window', and it's
          ;; either active or `resize-mini-windows' is nil.
          (let ((minibuffer-window (minibuffer-window frame)))
            (and (eq (window-frame minibuffer-window) frame)
                 (or (not resize-mini-windows)
                     (eq minibuffer-window
                         (active-minibuffer-window))))))
      (mouse-drag-line start-event 'mode))
     ((and (frame-parameter frame 'drag-with-mode-line)
           (window-at-side-p window 'bottom)
           (let ((minibuffer-window (minibuffer-window frame)))
             (not (eq (window-frame minibuffer-window) frame))))
      ;; Drag frame when the window is on the bottom of its frame and
      ;; there is no minibuffer window below.
      (mouse-drag-frame start-event 'move)))))

(defun mouse-drag-header-line (start-event)
  "Change the height of a window by dragging on its header line.
START-EVENT is the starting mouse event of the drag action.

If the drag happens in a header line on the top of a frame and
that frame's `drag-with-header-line' parameter is non-nil, drag
the frame instead."
  (interactive "e")
  (let* ((start (event-start start-event))
	 (window (posn-window start)))
    (if (and (window-live-p window)
             (not (window-at-side-p window 'top)))
        (mouse-drag-line start-event 'header)
      (let ((frame (window-frame window)))
        (when (frame-parameter frame 'drag-with-header-line)
          (mouse-drag-frame start-event 'move))))))

(defun mouse-drag-vertical-line (start-event)
  "Change the width of a window by dragging on a vertical line.
START-EVENT is the starting mouse event of the drag action."
  (interactive "e")
  (mouse-drag-line start-event 'vertical))
\f
(defun mouse-resize-frame (frame x-diff y-diff &optional x-move y-move)
  "Helper function for `mouse-drag-frame'."
  (let* ((frame-x-y (frame-position frame))
         (frame-x (car frame-x-y))
         (frame-y (cdr frame-x-y))
         alist)
    (if (> x-diff 0)
        (when x-move
          (setq x-diff (min x-diff frame-x))
          (setq x-move (- frame-x x-diff)))
      (let* ((min-width (frame-windows-min-size frame t nil t))
             (min-diff (max 0 (- (frame-inner-width frame) min-width))))
        (setq x-diff (max x-diff (- min-diff)))
        (when x-move
          (setq x-move (+ frame-x (- x-diff))))))

    (if (> y-diff 0)
        (when y-move
          (setq y-diff (min y-diff frame-y))
          (setq y-move (- frame-y y-diff)))
      (let* ((min-height (frame-windows-min-size frame nil nil t))
             (min-diff (max 0 (- (frame-inner-height frame) min-height))))
        (setq y-diff (max y-diff (- min-diff)))
        (when y-move
          (setq y-move (+ frame-y (- y-diff))))))

    (unless (zerop x-diff)
      (when x-move
        (push `(left . ,x-move) alist))
      (push `(width . (text-pixels . ,(+ (frame-text-width frame) x-diff)))
            alist))
    (unless (zerop y-diff)
      (when y-move
        (push `(top . ,y-move) alist))
      (push `(height . (text-pixels . ,(+ (frame-text-height frame) y-diff)))
            alist))
    (when alist
      (modify-frame-parameters frame alist))))

(defun mouse-drag-frame (start-event part)
  "Drag a frame or one of its edges with the mouse.
START-EVENT is the starting mouse event of the drag action.  Its
position window denotes the frame that will be dragged.

PART specifies the part that has been dragged and must be one of
the symbols 'left', 'top', 'right', 'bottom', 'top-left',
'top-right', 'bottom-left', 'bottom-right' to drag an internal
border or edge.  If PART equals 'move', this means to move the
frame with the mouse."
  ;; Give temporary modes such as isearch a chance to turn off.
  (run-hooks 'mouse-leave-buffer-hook)
  (let* ((echo-keystrokes 0)
	 (start (event-start start-event))
         (window (posn-window start))
         ;; FRAME is the frame to drag.
         (frame (if (window-live-p window)
                    (window-frame window)
                  window))
         (width (frame-native-width frame))
         (height (frame-native-height frame))
         ;; PARENT is the parent frame of FRAME or, if FRAME is a
         ;; top-level frame, FRAME's workarea.
         (parent (frame-parent frame))
         (parent-edges
          (if parent
              `(0 0 ,(frame-native-width parent) ,(frame-native-height parent))
            (let* ((attributes
                    (car (display-monitor-attributes-list)))
                   (workarea (assq 'workarea attributes)))
              (and workarea
                   `(,(nth 1 workarea) ,(nth 2 workarea)
                     ,(+ (nth 1 workarea) (nth 3 workarea))
                     ,(+ (nth 2 workarea) (nth 4 workarea)))))))
         (parent-left (and parent-edges (nth 0 parent-edges)))
         (parent-top (and parent-edges (nth 1 parent-edges)))
         (parent-right (and parent-edges (nth 2 parent-edges)))
         (parent-bottom (and parent-edges (nth 3 parent-edges)))
         ;; `pos-x' and `pos-y' record the x- and y-coordinates of the
	 ;; last sampled mouse position.  Note that we sample absolute
	 ;; mouse positions to avoid that moving the mouse from one
	 ;; frame into another gets into our way.  `last-x' and `last-y'
	 ;; records the x- and y-coordinates of the previously sampled
	 ;; position.  The differences between `last-x' and `pos-x' as
	 ;; well as `last-y' and `pos-y' determine the amount the mouse
	 ;; has been dragged between the last two samples.
         pos-x-y pos-x pos-y
         (last-x-y (mouse-absolute-pixel-position))
         (last-x (car last-x-y))
         (last-y (cdr last-x-y))
         ;; `snap-x' and `snap-y' record the x- and y-coordinates of the
         ;; mouse position when FRAME snapped.  As soon as the
         ;; difference between `pos-x' and `snap-x' (or `pos-y' and
         ;; `snap-y') exceeds the value of FRAME's `snap-width'
         ;; parameter, unsnap FRAME (at the respective side).  `snap-x'
         ;; and `snap-y' nil mean FRAME is currently not snapped.
         snap-x snap-y
         (exitfun nil)
         (move
          (lambda (event)
            (interactive "e")
            (when (consp event)
              (setq pos-x-y (mouse-absolute-pixel-position))
              (setq pos-x (car pos-x-y))
              (setq pos-y (cdr pos-x-y))
              (cond
               ((eq part 'left)
                (mouse-resize-frame frame (- last-x pos-x) 0 t))
               ((eq part 'top)
                (mouse-resize-frame frame 0 (- last-y pos-y) nil t))
               ((eq part 'right)
                (mouse-resize-frame frame (- pos-x last-x) 0))
               ((eq part 'bottom)
                (mouse-resize-frame frame 0 (- pos-y last-y)))
               ((eq part 'top-left)
                (mouse-resize-frame
                 frame (- last-x pos-x) (- last-y pos-y) t t))
               ((eq part 'top-right)
                (mouse-resize-frame
                 frame (- pos-x last-x) (- last-y pos-y) nil t))
               ((eq part 'bottom-left)
                (mouse-resize-frame
                 frame (- last-x pos-x) (- pos-y last-y) t))
               ((eq part 'bottom-right)
                (mouse-resize-frame
                 frame (- pos-x last-x) (- pos-y last-y)))
               ((eq part 'move)
                (let* ((old-position (frame-position frame))
                       (old-left (car old-position))
                       (old-top (cdr old-position))
                       (left (+ old-left (- pos-x last-x)))
                       (top (+ old-top (- pos-y last-y)))
                       right bottom
                       ;; `snap-width' (maybe also a yet to be provided
                       ;; `snap-height') could become floats to handle
                       ;; proportionality wrt PARENT.  We don't do any
                       ;; checks on this parameter so far.
                       (snap-width (frame-parameter frame 'snap-width)))
                  ;; Docking and constraining.
                  (when (and (numberp snap-width) parent-edges)
                    (cond
                     ;; Docking at the left parent edge.
                     ((< pos-x last-x)
                      (cond
                       ((and (> left parent-left)
                             (<= (- left parent-left) snap-width))
                        ;; Snap when the mouse moved leftward and
                        ;; FRAME's left edge would end up within
                        ;; `snap-width' pixels from PARENT's left edge.
                        (setq snap-x pos-x)
                        (setq left parent-left))
                       ((and (<= left parent-left)
                             (<= (- parent-left left) snap-width)
                             snap-x (<= (- snap-x pos-x) snap-width))
                        ;; Stay snapped when the mouse moved leftward
                        ;; but not more than `snap-width' pixels from
                        ;; the time FRAME snapped.
                        (setq left parent-left))
                       (t
                        ;; Unsnap when the mouse moved more than
                        ;; `snap-width' pixels leftward from the time
                        ;; FRAME snapped.
                        (setq snap-x nil))))
                     ((> pos-x last-x)
                      (setq right (+ left width))
                      (cond
                       ((and (< right parent-right)
                             (<= (- parent-right right) snap-width))
                        ;; Snap when the mouse moved rightward and
                        ;; FRAME's right edge would end up within
                        ;; `snap-width' pixels from PARENT's right edge.
                        (setq snap-x pos-x)
                        (setq left (- parent-right width)))
                       ((and (>= right parent-right)
                             (<= (- right parent-right) snap-width)
                             snap-x (<= (- pos-x snap-x) snap-width))
                        ;; Stay snapped when the mouse moved rightward
                        ;; but not more more than `snap-width' pixels
                        ;; from the time FRAME snapped.
                        (setq left (- parent-right width)))
                       (t
                        ;; Unsnap when the mouse moved rightward more
                        ;; than `snap-width' pixels from the time FRAME
                        ;; snapped.
                        (setq snap-x nil)))))

                    (cond
                     ((< pos-y last-y)
                      (cond
                       ((and (> top parent-top)
                             (<= (- top parent-top) snap-width))
                        ;; Snap when the mouse moved upward and FRAME's
                        ;; top edge would end up within `snap-width'
                        ;; pixels from PARENT's top edge.
                        (setq snap-y pos-y)
                        (setq top parent-top))
                       ((and (<= top parent-top)
                             (<= (- parent-top top) snap-width)
                             snap-y (<= (- snap-y pos-y) snap-width))
                        ;; Stay snapped when the mouse moved upward but
                        ;; not more more than `snap-width' pixels from
                        ;; the time FRAME snapped.
                        (setq top parent-top))
                       (t
                        ;; Unsnap when the mouse moved upward more than
                        ;; `snap-width' pixels from the time FRAME
                        ;; snapped.
                        (setq snap-y nil))))
                     ((> pos-y last-y)
                      (setq bottom (+ top height))
                      (cond
                       ((and (< bottom parent-bottom)
                             (<= (- parent-bottom bottom) snap-width))
                        ;; Snap when the mouse moved downward and
                        ;; FRAME's bottom edge would end up within
                        ;; `snap-width' pixels from PARENT's bottom
                        ;; edge.
                        (setq snap-y pos-y)
                        (setq top (- parent-bottom height)))
                       ((and (>= bottom parent-bottom)
                             (<= (- bottom parent-bottom) snap-width)
                             snap-y (<= (- pos-y snap-y) snap-width))
                        ;; Stay snapped when the mouse moved downward
                        ;; but not more more than `snap-width' pixels
                        ;; from the time FRAME snapped.
                        (setq top (- parent-bottom height)))
                       (t
                        ;; Unsnap when the mouse moved downward more
                        ;; than `snap-width' pixels from the time FRAME
                        ;; snapped.
                        (setq snap-y nil))))))

                  ;; If requested, constrain FRAME's draggable areas to
                  ;; PARENT's edges.  The `top-visible' parameter should
                  ;; be set when FRAME has a draggable header-line.  If
                  ;; set to a number, it ascertains that the top of
                  ;; FRAME is always constrained to the top of PARENT
                  ;; and that at least as many pixels of FRAME as
                  ;; specified by that number are visible on each of the
                  ;; three remaining sides of PARENT.
                  ;;
                  ;; The `bottom-visible' parameter should be set when
                  ;; FRAME has a draggable mode-line.  If set to a
                  ;; number, it ascertains that the bottom of FRAME is
                  ;; always constrained to the bottom of PARENT and that
                  ;; at least as many pixels of FRAME as specified by
                  ;; that number are visible on each of the three
                  ;; remaining sides of PARENT.
                  (let ((par (frame-parameter frame 'top-visible))
                        bottom-visible)
                    (unless par
                      (setq par (frame-parameter frame 'bottom-visible))
                      (setq bottom-visible t))
                    (when (and (numberp par) parent-edges)
                      (setq left
                            (max (min (- parent-right par) left)
                                 (+ (- parent-left width) par)))
                      (setq top
                            (if bottom-visible
                                (min (max top (- parent-top (- height par)))
                                     (- parent-bottom height))
                              (min (max top parent-top)
                                   (- parent-bottom par))))))

                  ;; Use `modify-frame-parameters' since `left' and
                  ;; `top' may want to move FRAME out of its PARENT.
                  (modify-frame-parameters
                   frame
                   `((left . (+ ,left)) (top . (+ ,top)))))))
              (setq last-x pos-x)
              (setq last-y pos-y))))
         (old-track-mouse track-mouse))
    ;; Start tracking.  The special value 'dragging' signals the
    ;; display engine to freeze the mouse pointer shape for as long
    ;; as we drag.
    (setq track-mouse 'dragging)
    ;; Loop reading events and sampling the position of the mouse.
    (setq exitfun
          (set-transient-map
           (let ((map (make-sparse-keymap)))
             (define-key map [switch-frame] #'ignore)
             (define-key map [select-window] #'ignore)
             (define-key map [scroll-bar-movement] #'ignore)
             (define-key map [mouse-movement] move)
             ;; Swallow drag-mouse-1 events to avoid selecting some other window.
             (define-key map [drag-mouse-1]
               (lambda () (interactive) (funcall exitfun)))
             ;; Some of the events will of course end up looked up
             ;; with a mode-line, header-line or vertical-line prefix ...
             (define-key map [mode-line] map)
             (define-key map [header-line] map)
             (define-key map [vertical-line] map)
             ;; ... and some maybe even with a right- or bottom-divider
             ;; prefix.
             (define-key map [right-divider] map)
             (define-key map [bottom-divider] map)
             map)
           t (lambda () (setq track-mouse old-track-mouse))))))

(defun mouse-drag-left-edge (start-event)
  "Drag left edge of a frame with the mouse.
START-EVENT is the starting mouse event of the drag action."
  (interactive "e")
  (mouse-drag-frame start-event 'left))

(defun mouse-drag-top-left-corner (start-event)
  "Drag top left corner of a frame with the mouse.
START-EVENT is the starting mouse event of the drag action."
  (interactive "e")
  (mouse-drag-frame start-event 'top-left))

(defun mouse-drag-top-edge (start-event)
  "Drag top edge of a frame with the mouse.
START-EVENT is the starting mouse event of the drag action."
  (interactive "e")
  (mouse-drag-frame start-event 'top))

(defun mouse-drag-top-right-corner (start-event)
  "Drag top right corner of a frame with the mouse.
START-EVENT is the starting mouse event of the drag action."
  (interactive "e")
  (mouse-drag-frame start-event 'top-right))

(defun mouse-drag-right-edge (start-event)
  "Drag right edge of a frame with the mouse.
START-EVENT is the starting mouse event of the drag action."
  (interactive "e")
  (mouse-drag-frame start-event 'right))

(defun mouse-drag-bottom-right-corner (start-event)
  "Drag bottom right corner of a frame with the mouse.
START-EVENT is the starting mouse event of the drag action."
  (interactive "e")
  (mouse-drag-frame start-event 'bottom-right))

(defun mouse-drag-bottom-edge (start-event)
  "Drag bottom edge of a frame with the mouse.
START-EVENT is the starting mouse event of the drag action."
  (interactive "e")
  (mouse-drag-frame start-event 'bottom))

(defun mouse-drag-bottom-left-corner (start-event)
  "Drag bottom left corner of a frame with the mouse.
START-EVENT is the starting mouse event of the drag action."
  (interactive "e")
  (mouse-drag-frame start-event 'bottom-left))

(defcustom mouse-select-region-move-to-beginning nil
  "Effect of selecting a region extending backward from double click.
Nil means keep point at the position clicked (region end);
non-nil means move point to beginning of region."
  :type '(choice (const :tag "Don't move point" nil)
		 (const :tag "Move point to beginning of region" t))
  :version "26.1")

(defun mouse-set-point (event &optional promote-to-region)
  "Move point to the position clicked on with the mouse.
This should be bound to a mouse click event type.
If PROMOTE-TO-REGION is non-nil and event is a multiple-click, select
the corresponding element around point, with the resulting position of
point determined by `mouse-select-region-move-to-beginning'."
  (interactive "e\np")
  (mouse-minibuffer-check event)
  (if (and promote-to-region (> (event-click-count event) 1))
      (progn
        (mouse-set-region event)
        (when mouse-select-region-move-to-beginning
          (when (> (posn-point (event-start event)) (region-beginning))
            (exchange-point-and-mark))))
    ;; Use event-end in case called from mouse-drag-region.
    ;; If EVENT is a click, event-end and event-start give same value.
    (posn-set-point (event-end event))))

(defvar mouse-last-region-beg nil)
(defvar mouse-last-region-end nil)
(defvar mouse-last-region-tick nil)

(defun mouse-region-match ()
  "Return non-nil if there's an active region that was set with the mouse."
  (and (mark t) mark-active
       (eq mouse-last-region-beg (region-beginning))
       (eq mouse-last-region-end (region-end))
       (eq mouse-last-region-tick (buffer-modified-tick))))

(defvar mouse--drag-start-event nil)

(defun mouse-set-region (click)
  "Set the region to the text dragged over, and copy to kill ring.
This should be bound to a mouse drag event.
See the `mouse-drag-copy-region' variable to control whether this
command alters the kill ring or not."
  (interactive "e")
  (mouse-minibuffer-check click)
  (select-window (posn-window (event-start click)))
  (let ((beg (posn-point (event-start click)))
        (end
         (if (eq (posn-window (event-end click)) (selected-window))
             (posn-point (event-end click))
           ;; If the mouse ends up in any other window or on the menu
           ;; bar, use `window-point' of selected window (Bug#23707).
           (window-point)))
        (click-count (event-click-count click)))
    (let ((drag-start (terminal-parameter nil 'mouse-drag-start)))
      (when drag-start
        ;; Drag events don't come with a click count, sadly, so we hack
        ;; our way around this problem by remembering the start-event in
        ;; `mouse-drag-start' and fetching the click-count from there.
        (when (and (<= click-count 1)
                   (equal beg (posn-point (event-start drag-start))))
          (setq click-count (event-click-count drag-start)))
        ;; Occasionally we get spurious drag events where the user hasn't
        ;; dragged his mouse, but instead Emacs has dragged the text under the
        ;; user's mouse.  Try to recover those cases (bug#17562).
        (when (and (equal (posn-x-y (event-start click))
                          (posn-x-y (event-end click)))
                   (not (eq (car drag-start) 'mouse-movement)))
          (setq end beg))
        (setf (terminal-parameter nil 'mouse-drag-start) nil)))
    (when (and (integerp beg) (integerp end))
      (let ((range (mouse-start-end beg end (1- click-count))))
        (if (< end beg)
            (setq end (nth 0 range) beg (nth 1 range))
          (setq beg (nth 0 range) end (nth 1 range)))))
    (and mouse-drag-copy-region (integerp beg) (integerp end)
	 ;; Don't set this-command to `kill-region', so a following
	 ;; C-w won't double the text in the kill ring.  Ignore
	 ;; `last-command' so we don't append to a preceding kill.
	 (let (this-command last-command deactivate-mark)
	   (copy-region-as-kill beg end)))
    (if (numberp beg) (goto-char beg))
    ;; On a text terminal, bounce the cursor.
    (or transient-mark-mode
	(window-system)
	(sit-for 1))
    (push-mark)
    (set-mark (point))
    (if (numberp end) (goto-char end))
    (mouse-set-region-1)))

(defun mouse-set-region-1 ()
  ;; Set transient-mark-mode for a little while.
  (unless (eq (car-safe transient-mark-mode) 'only)
    (setq-local transient-mark-mode
                (cons 'only
                      (unless (eq transient-mark-mode 'lambda)
                        transient-mark-mode))))
  (setq mouse-last-region-beg (region-beginning))
  (setq mouse-last-region-end (region-end))
  (setq mouse-last-region-tick (buffer-modified-tick)))

(defcustom mouse-scroll-delay 0.25
  "The pause between scroll steps caused by mouse drags, in seconds.
If you drag the mouse beyond the edge of a window, Emacs scrolls the
window to bring the text beyond that edge into view, with a delay of
this many seconds between scroll steps.  Scrolling stops when you move
the mouse back into the window, or release the button.
This variable's value may be non-integral.
Setting this to zero causes Emacs to scroll as fast as it can."
  :type 'number)

(defcustom mouse-scroll-min-lines 1
  "The minimum number of lines scrolled by dragging mouse out of window.
Moving the mouse out the top or bottom edge of the window begins
scrolling repeatedly.  The number of lines scrolled per repetition
is normally equal to the number of lines beyond the window edge that
the mouse has moved.  However, it always scrolls at least the number
of lines specified by this variable."
  :type 'integer)

(defun mouse-scroll-subr (window jump &optional overlay start)
  "Scroll the window WINDOW, JUMP lines at a time, until new input arrives.
If OVERLAY is an overlay, let it stretch from START to the far edge of
the newly visible text.
Upon exit, point is at the far edge of the newly visible text."
  (cond
   ((and (> jump 0) (< jump mouse-scroll-min-lines))
    (setq jump mouse-scroll-min-lines))
   ((and (< jump 0) (< (- jump) mouse-scroll-min-lines))
    (setq jump (- mouse-scroll-min-lines))))
  (let ((opoint (point)))
    (while (progn
	     (goto-char (window-start window))
	     (if (not (zerop (vertical-motion jump window)))
		 (progn
		   (set-window-start window (point))
		   (if (natnump jump)
		       (if (window-end window)
			   (progn
			     (goto-char (window-end window))
			     ;; window-end doesn't reflect the window's new
			     ;; start position until the next redisplay.
			     (vertical-motion (1- jump) window))
			 (vertical-motion (- (window-height window) 2)))
		     (goto-char (window-start window)))
		   (if overlay
		       (move-overlay overlay start (point)))
		   ;; Now that we have scrolled WINDOW properly,
		   ;; put point back where it was for the redisplay
		   ;; so that we don't mess up the selected window.
		   (or (eq window (selected-window))
		       (goto-char opoint))
		   (sit-for mouse-scroll-delay)))))
    (or (eq window (selected-window))
	(goto-char opoint))))

(defvar mouse-selection-click-count 0)

(defvar mouse-selection-click-count-buffer nil)

(defun mouse-drag-region (start-event)
  "Set the region to the text that the mouse is dragged over.
Highlight the drag area as you move the mouse.
This must be bound to a button-down mouse event.
In Transient Mark mode, the highlighting remains as long as the mark
remains active.  Otherwise, it remains until the next input event.

When the region already exists and `mouse-drag-and-drop-region'
is non-nil, this moves the entire region of text to where mouse
is dragged over to."
  (interactive "e")
  (if (and mouse-drag-and-drop-region
           (not (member 'triple (event-modifiers start-event)))
           (equal (mouse-posn-property (event-start start-event) 'face) 'region))
      (mouse-drag-and-drop-region start-event)
    ;; Give temporary modes such as isearch a chance to turn off.
    (run-hooks 'mouse-leave-buffer-hook)
    (mouse-drag-track start-event)))

(defun mouse-posn-property (pos property)
  "Look for a property at click position.
POS may be either a buffer position or a click position like
those returned from `event-start'.  If the click position is on
a string, the text property PROPERTY is examined.
If this is nil or the click is not on a string, then
the corresponding buffer position is searched for PROPERTY.
If PROPERTY is encountered in one of those places,
its value is returned."
  (if (consp pos)
      (let ((w (posn-window pos)) (pt (posn-point pos))
	    (str (posn-string pos)))
	(or (and str
		 (get-text-property (cdr str) property (car str)))
            ;; Mouse clicks in the fringe come with a position in
            ;; (nth 5).  This is useful but is not exactly where we clicked, so
            ;; don't look up that position's properties!
	    (and pt (not (memq (posn-area pos) '(left-fringe right-fringe
                                                 left-margin right-margin)))
		 (get-char-property pt property w))))
    (get-char-property pos property)))

(defun mouse-on-link-p (pos)
  "Return non-nil if POS is on a link in the current buffer.
POS must specify a buffer position in the current buffer, as a list
of the form returned by the `event-start' and `event-end' functions,
or a mouse event location in the selected window (see `event-start').
However, if `mouse-1-click-in-non-selected-windows' is non-nil,
POS may be a mouse event location in any window.

A clickable link is identified by one of the following methods:

- If the character at POS has a non-nil `follow-link' text or
overlay property, the value of that property determines what to do.

- If there is a local key-binding or a keybinding at position POS
for the `follow-link' event, the binding of that event determines
what to do.

The resulting value determine whether POS is inside a link:

- If the value is `mouse-face', POS is inside a link if there
is a non-nil `mouse-face' property at POS.  Return t in this case.

- If the value is a function, FUNC, POS is inside a link if
the call (FUNC POS) returns non-nil.  Return the return value
from that call.  Arg is (posn-point POS) if POS is a mouse event.

- Otherwise, return the value itself.

The return value is interpreted as follows:

- If it is an array, the mouse-1 event is translated into the
first element of that array, i.e. the action of the mouse-1
click is the local or global binding of that event.

- Otherwise, the mouse-1 event is translated into a mouse-2 event
at the same position."
  (let ((action
	 (and (or (not (consp pos))
		  mouse-1-click-in-non-selected-windows
		  (eq (selected-window) (posn-window pos)))
	      (or (mouse-posn-property pos 'follow-link)
                  (let ((area (posn-area pos)))
                    (when area
                      (key-binding (vector area 'follow-link) nil t pos)))
		  (key-binding [follow-link] nil t pos)))))
    (cond
     ((eq action 'mouse-face)
      (and (mouse-posn-property pos 'mouse-face) t))
     ((functionp action)
      ;; FIXME: This seems questionable if the click is not in a buffer.
      ;; Should we instead decide that `action' takes a `posn'?
      (if (consp pos)
	  (with-current-buffer (window-buffer (posn-window pos))
	    (funcall action (posn-point pos)))
	(funcall action pos)))
     (t action))))

(defun mouse-fixup-help-message (msg)
  "Fix help message MSG for `mouse-1-click-follows-link'."
  (let (mp pos)
    (if (and mouse-1-click-follows-link
	     (stringp msg)
	     (string-match-p "\\`mouse-2" msg)
	     (setq mp (mouse-pixel-position))
	     (consp (setq pos (cdr mp)))
	     (car pos) (>= (car pos) 0)
	     (cdr pos) (>= (cdr pos) 0)
	     (setq pos (posn-at-x-y (car pos) (cdr pos) (car mp)))
	     (windowp (posn-window pos)))
	(with-current-buffer (window-buffer (posn-window pos))
	  (if (mouse-on-link-p pos)
	      (setq msg (concat
		    (cond
		     ((eq mouse-1-click-follows-link 'double) "double-")
		     ((and (integerp mouse-1-click-follows-link)
			   (< mouse-1-click-follows-link 0)) "Long ")
		     (t ""))
		    "mouse-1" (substring msg 7)))))))
  msg)

(defun mouse-drag-track (start-event)
    "Track mouse drags by highlighting area between point and cursor.
The region will be defined with mark and point."
  (mouse-minibuffer-check start-event)
  (setq mouse-selection-click-count-buffer (current-buffer))
  (deactivate-mark)
  (let* ((scroll-margin 0) ; Avoid margin scrolling (Bug#9541).
	 (start-posn (event-start start-event))
	 (start-point (posn-point start-posn))
	 (start-window (posn-window start-posn))
	 (_ (with-current-buffer (window-buffer start-window)
	      (setq deactivate-mark nil)))
         ;; We've recorded what we needed from the current buffer and
         ;; window, now let's jump to the place of the event, where things
         ;; are happening.
         (_ (mouse-set-point start-event))
         (echo-keystrokes 0)
	 (bounds (window-edges start-window))
	 (make-cursor-line-fully-visible nil)
	 (top (nth 1 bounds))
	 (bottom (if (or (window-minibuffer-p start-window)
                         ;; Do not account for the mode line if there
                         ;; is no mode line, which is common for child
                         ;; frames.
                         (not mode-line-format))
		     (nth 3 bounds)
		   ;; Don't count the mode line.
		   (1- (nth 3 bounds))))
	 (click-count (1- (event-click-count start-event)))
	 ;; Suppress automatic hscrolling, because that is a nuisance
	 ;; when setting point near the right fringe (but see below).
	 (auto-hscroll-mode-saved auto-hscroll-mode)
         (old-track-mouse track-mouse))

    (setq mouse-selection-click-count click-count)
    ;; In case the down click is in the middle of some intangible text,
    ;; use the end of that text, and put it in START-POINT.
    (if (< (point) start-point)
	(goto-char start-point))
    (setq start-point (point))

    ;; Activate the region, using `mouse-start-end' to determine where
    ;; to put point and mark (e.g., double-click will select a word).
    (setq-local transient-mark-mode
                (if (eq transient-mark-mode 'lambda)
                    '(only)
                  (cons 'only transient-mark-mode)))
    (let ((range (mouse-start-end start-point start-point click-count)))
      (push-mark (nth 0 range) t t)
      (goto-char (nth 1 range)))

    (setf (terminal-parameter nil 'mouse-drag-start) start-event)
    (setq track-mouse t)
    (setq auto-hscroll-mode nil)

    (set-transient-map
     (let ((map (make-sparse-keymap)))
       (define-key map [switch-frame] #'ignore)
       (define-key map [select-window] #'ignore)
       (define-key map [mouse-movement]
         (lambda (event) (interactive "e")
           (let* ((end (event-end event))
                  (end-point (posn-point end)))
             (unless (eq end-point start-point)
               ;; As soon as the user moves, we can re-enable auto-hscroll.
               (setq auto-hscroll-mode auto-hscroll-mode-saved)
               ;; And remember that we have moved, so mouse-set-region can know
               ;; its event is really a drag event.
               (setcar start-event 'mouse-movement))
             (if (and (eq (posn-window end) start-window)
                      (integer-or-marker-p end-point))
                 (mouse--drag-set-mark-and-point start-point
                                                 end-point click-count)
               (let ((mouse-row (cdr (cdr (mouse-position)))))
                 (cond
                  ((null mouse-row))
                  ((< mouse-row top)
                   (mouse-scroll-subr start-window (- mouse-row top)
                                      nil start-point))
                  ((>= mouse-row bottom)
                   (mouse-scroll-subr start-window (1+ (- mouse-row bottom))
                                      nil start-point))))))))
       map)
     t (lambda ()
         (setq track-mouse old-track-mouse)
         (setq auto-hscroll-mode auto-hscroll-mode-saved)
          (deactivate-mark)
         (pop-mark)))))

(defun mouse--drag-set-mark-and-point (start click click-count)
  (let* ((range (mouse-start-end start click click-count))
	 (beg (nth 0 range))
	 (end (nth 1 range)))
    (cond ((eq (mark) beg)
	   (goto-char end))
	  ((eq (mark) end)
	   (goto-char beg))
	  ((< click (mark))
	   (set-mark end)
	   (goto-char beg))
	  (t
	   (set-mark beg)
	   (goto-char end)))))

;; Commands to handle xterm-style multiple clicks.
(defun mouse-skip-word (dir)
  "Skip over word, over whitespace, or over identical punctuation.
If DIR is positive skip forward; if negative, skip backward."
  (let* ((char (following-char))
	 (syntax (char-to-string (char-syntax char))))
    (cond ((string= syntax "w")
	   ;; Here, we can't use skip-syntax-forward/backward because
	   ;; they don't pay attention to word-separating-categories,
	   ;; and thus they will skip over a true word boundary.  So,
	   ;; we simulate the original behavior by using forward-word.
	   (if (< dir 0)
	       (if (not (looking-at "\\<"))
		   (forward-word -1))
	     (if (or (looking-at "\\<") (not (looking-at "\\>")))
		 (forward-word 1))))
	  ((string= syntax " ")
	   (if (< dir 0)
	       (skip-syntax-backward syntax)
	     (skip-syntax-forward syntax)))
	  ((string= syntax "_")
	   (if (< dir 0)
	       (skip-syntax-backward "w_")
	     (skip-syntax-forward "w_")))
	  ((< dir 0)
	   (while (and (not (bobp)) (= (preceding-char) char))
	     (forward-char -1)))
	  (t
	   (while (and (not (eobp)) (= (following-char) char))
	     (forward-char 1))))))

(defun mouse-start-end (start end mode)
  "Return a list of region bounds based on START and END according to MODE.
If MODE is 0 then set point to (min START END), mark to (max START END).
If MODE is 1 then set point to start of word at (min START END),
mark to end of word at (max START END).
If MODE is 2 then do the same for lines."
  (if (> start end)
      (let ((temp start))
        (setq start end
              end temp)))
  (setq mode (mod mode 3))
  (cond ((= mode 0)
	 (list start end))
        ((and (= mode 1)
              (= start end)
	      (char-after start)
              (= (char-syntax (char-after start)) ?\())
         (if (/= (syntax-class (syntax-after start)) 4) ; raw syntax code for ?\(
             ;; This happens in CC Mode when unbalanced parens in CPP
             ;; constructs are given punctuation syntax with
             ;; syntax-table text properties.  (2016-02-21).
             (signal 'scan-error (list "Containing expression ends prematurely"
                                       start start))
           (list start
                 (save-excursion
                   (goto-char start)
                   (forward-sexp 1)
                   (point)))))
        ((and (= mode 1)
              (= start end)
	      (char-after start)
              (= (char-syntax (char-after start)) ?\)))
         (if (/= (syntax-class (syntax-after start)) 5) ; raw syntax code for ?\)
             ;; See above comment about CC Mode.
             (signal 'scan-error (list "Unbalanced parentheses" start start))
           (list (save-excursion
                   (goto-char (1+ start))
                   (backward-sexp 1)
                   (point))
                 (1+ start))))
	((and (= mode 1)
              (= start end)
	      (char-after start)
              (= (char-syntax (char-after start)) ?\"))
	 (let ((open (or (eq start (point-min))
			 (save-excursion
			   (goto-char (- start 1))
			   (looking-at "\\s(\\|\\s \\|\\s>")))))
	   (if open
	       (list start
		     (save-excursion
		       (condition-case nil
			   (progn
			     (goto-char start)
			     (forward-sexp 1)
			     (point))
			 (error end))))
	     (list (save-excursion
		     (condition-case nil
			 (progn
			   (goto-char (1+ start))
			   (backward-sexp 1)
			   (point))
		       (error end)))
		   (1+ start)))))
        ((= mode 1)
	 (list (save-excursion
		 (goto-char start)
		 (mouse-skip-word -1)
		 (point))
	       (save-excursion
		 (goto-char end)
		 (mouse-skip-word 1)
		 (point))))
        ((= mode 2)
	 (list (save-excursion
		 (goto-char start)
		 (line-beginning-position 1))
	       (save-excursion
		 (goto-char end)
		 (forward-line 1)
		 (point))))))
\f
;; Subroutine: set the mark where CLICK happened,
;; but don't do anything else.
(defun mouse-set-mark-fast (click)
  (mouse-minibuffer-check click)
  (let ((posn (event-start click)))
    (select-window (posn-window posn))
    (if (numberp (posn-point posn))
	(push-mark (posn-point posn) t t))))

(defun mouse-undouble-last-event (events)
  (let* ((index (1- (length events)))
	 (last (nthcdr index events))
	 (event (car last))
	 (basic (event-basic-type event))
	 (old-modifiers (event-modifiers event))
	 (modifiers (delq 'double (delq 'triple (copy-sequence old-modifiers))))
	 (new
	  (if (consp event)
	      ;; Use reverse, not nreverse, since event-modifiers
	      ;; does not copy the list it returns.
	      (cons (event-convert-list (reverse (cons basic modifiers)))
		    (cdr event))
	    event)))
    (setcar last new)
    (if (and (not (equal modifiers old-modifiers))
	     (key-binding (apply 'vector events)))
	t
      (setcar last event)
      nil)))

;; Momentarily show where the mark is, if highlighting doesn't show it.

(defun mouse-set-mark (click)
  "Set mark at the position clicked on with the mouse.
Display cursor at that position for a second.
This must be bound to a mouse click."
  (interactive "e")
  (mouse-minibuffer-check click)
  (select-window (posn-window (event-start click)))
  ;; FIXME: Use save-excursion
  (let ((point-save (point)))
    (unwind-protect
	(progn (mouse-set-point click)
	       (push-mark nil t t)
	       (or transient-mark-mode
		   (sit-for 1)))
      (goto-char point-save))))

(defun mouse-kill (click)
  "Kill the region between point and the mouse click.
The text is saved in the kill ring, as with \\[kill-region]."
  (interactive "e")
  (mouse-minibuffer-check click)
  (let* ((posn (event-start click))
	 (click-posn (posn-point posn)))
    (select-window (posn-window posn))
    (if (numberp click-posn)
	(kill-region (min (point) click-posn)
		     (max (point) click-posn)))))

(defun mouse-yank-at-click (click arg)
  "Insert the last stretch of killed text at the position clicked on.
Also move point to one end of the text thus inserted (normally the end),
and set mark at the beginning.
Prefix arguments are interpreted as with \\[yank].
If `mouse-yank-at-point' is non-nil, insert at point
regardless of where you click."
  (interactive "e\nP")
  ;; Give temporary modes such as isearch a chance to turn off.
  (run-hooks 'mouse-leave-buffer-hook)
  (when select-active-regions
    ;; Without this, confusing things happen upon e.g. inserting into
    ;; the middle of an active region.
    (deactivate-mark))
  (or mouse-yank-at-point (mouse-set-point click))
  (setq this-command 'yank)
  (setq mouse-selection-click-count 0)
  (yank arg))

(defun mouse-yank-primary (click)
  "Insert the primary selection at the position clicked on.
Move point to the end of the inserted text, and set mark at
beginning.  If `mouse-yank-at-point' is non-nil, insert at point
regardless of where you click."
  (interactive "e")
  ;; Give temporary modes such as isearch a chance to turn off.
  (run-hooks 'mouse-leave-buffer-hook)
  ;; Without this, confusing things happen upon e.g. inserting into
  ;; the middle of an active region.
  (when select-active-regions
    (let (select-active-regions)
      (deactivate-mark)))
  (or mouse-yank-at-point (mouse-set-point click))
  (let ((primary (gui-get-primary-selection)))
    (push-mark)
    (insert-for-yank primary)))

(defun mouse-kill-ring-save (click)
  "Copy the region between point and the mouse click in the kill ring.
This does not delete the region; it acts like \\[kill-ring-save]."
  (interactive "e")
  (mouse-set-mark-fast click)
  (let (this-command last-command)
    (kill-ring-save (point) (mark t))))

;; This function used to delete the text between point and the mouse
;; whenever it was equal to the front of the kill ring, but some
;; people found that confusing.

;; The position of the last invocation of `mouse-save-then-kill'.
(defvar mouse-save-then-kill-posn nil)

(defun mouse-save-then-kill-delete-region (beg end)
  ;; We must make our own undo boundaries
  ;; because they happen automatically only for the current buffer.
  (undo-boundary)
  (if (or (= beg end) (eq buffer-undo-list t))
      ;; If we have no undo list in this buffer,
      ;; just delete.
      (delete-region beg end)
    ;; Delete, but make the undo-list entry share with the kill ring.
    ;; First, delete just one char, so in case buffer is being modified
    ;; for the first time, the undo list records that fact.
    (let ((inhibit-modification-hooks t))
      (delete-region beg
		     (+ beg (if (> end beg) 1 -1))))
    (let ((buffer-undo-list buffer-undo-list))
      ;; Undo that deletion--but don't change the undo list!
      (let ((inhibit-modification-hooks t))
	(primitive-undo 1 buffer-undo-list))
      ;; Now delete the rest of the specified region,
      ;; but don't record it.
      (setq buffer-undo-list t)
      (if (/= (length (car kill-ring)) (- (max end beg) (min end beg)))
	  (error "Lossage in mouse-save-then-kill-delete-region"))
      (delete-region beg end))
    (let ((tail buffer-undo-list))
      ;; Search back in buffer-undo-list for the string
      ;; that came from deleting one character.
      (while (and tail (not (stringp (car (car tail)))))
	(setq tail (cdr tail)))
      ;; Replace it with an entry for the entire deleted text.
      (and tail
	   (setcar tail (cons (car kill-ring) (min beg end))))))
  (undo-boundary))

(defun mouse-save-then-kill (click)
  "Set the region according to CLICK; the second time, kill it.
CLICK should be a mouse click event.

If the region is inactive, activate it temporarily.  Set mark at
the original point, and move point to the position of CLICK.

If the region is already active, adjust it.  Normally, do this by
moving point or mark, whichever is closer, to CLICK.  But if you
have selected whole words or lines, move point or mark to the
word or line boundary closest to CLICK instead.

If `mouse-drag-copy-region' is non-nil, this command also saves the
new region to the kill ring (replacing the previous kill if the
previous region was just saved to the kill ring).

If this command is called a second consecutive time with the same
CLICK position, kill the region (or delete it
if `mouse-drag-copy-region' is non-nil)"
  (interactive "e")
  (mouse-minibuffer-check click)
  (let* ((posn     (event-start click))
	 (click-pt (posn-point posn))
	 (window   (posn-window posn))
	 (buf      (window-buffer window))
	 ;; Don't let a subsequent kill command append to this one.
	 (this-command this-command)
	 ;; Check if the user has multi-clicked to select words/lines.
	 (click-count
	  (if (and (eq mouse-selection-click-count-buffer buf)
		   (with-current-buffer buf (mark t)))
	      mouse-selection-click-count
	    0)))
    (cond
     ((not (numberp click-pt)) nil)
     ;; If the user clicked without moving point, kill the region.
     ;; This also resets `mouse-selection-click-count'.
     ((and (eq last-command 'mouse-save-then-kill)
	   (eq click-pt mouse-save-then-kill-posn)
	   (eq window (selected-window)))
      (if mouse-drag-copy-region
          ;; Region already saved in the previous click;
          ;; don't make a duplicate entry, just delete.
          (delete-region (mark t) (point))
        (kill-region (mark t) (point)))
      (setq mouse-selection-click-count 0)
      (setq mouse-save-then-kill-posn nil))

     ;; Otherwise, if there is a suitable region, adjust it by moving
     ;; one end (whichever is closer) to CLICK-PT.
     ((or (with-current-buffer buf (region-active-p))
	  (and (eq window (selected-window))
	       (mark t)
	       (or (and (eq last-command 'mouse-save-then-kill)
			mouse-save-then-kill-posn)
		   (and (memq last-command '(mouse-drag-region
					     mouse-set-region))
			(or mark-even-if-inactive
			    (not transient-mark-mode))))))
      (select-window window)
      (let* ((range (mouse-start-end click-pt click-pt click-count)))
	(if (< (abs (- click-pt (mark t)))
	       (abs (- click-pt (point))))
	    (set-mark (car range))
	  (goto-char (nth 1 range)))
	(setq deactivate-mark nil)
	(mouse-set-region-1)
        (when mouse-drag-copy-region
          ;; Region already copied to kill-ring once, so replace.
          (kill-new (filter-buffer-substring (mark t) (point)) t))
	;; Arrange for a repeated mouse-3 to kill the region.
	(setq mouse-save-then-kill-posn click-pt)))

     ;; Otherwise, set the mark where point is and move to CLICK-PT.
     (t
      (select-window window)
      (mouse-set-mark-fast click)
      (let ((before-scroll (with-current-buffer buf point-before-scroll)))
	(if before-scroll (goto-char before-scroll)))
      (exchange-point-and-mark)
      (mouse-set-region-1)
      (when mouse-drag-copy-region
        (kill-new (filter-buffer-substring (mark t) (point))))
      (setq mouse-save-then-kill-posn click-pt)))))

\f
(global-set-key [M-mouse-1] 'mouse-start-secondary)
(global-set-key [M-drag-mouse-1] 'mouse-set-secondary)
(global-set-key [M-down-mouse-1] 'mouse-drag-secondary)
(global-set-key [M-mouse-3] 'mouse-secondary-save-then-kill)
(global-set-key [M-mouse-2] 'mouse-yank-secondary)

(defconst mouse-secondary-overlay
  (let ((ol (make-overlay (point-min) (point-min))))
    (delete-overlay ol)
    (overlay-put ol 'face 'secondary-selection)
    ol)
  "An overlay which records the current secondary selection.
It is deleted when there is no secondary selection.")

(defvar mouse-secondary-click-count 0)

;; A marker which records the specified first end for a secondary selection.
;; May be nil.
(defvar mouse-secondary-start nil)

(defun mouse-start-secondary (click)
  "Set one end of the secondary selection to the position clicked on.
Use \\[mouse-secondary-save-then-kill] to set the other end
and complete the secondary selection."
  (interactive "e")
  (mouse-minibuffer-check click)
  (let ((posn (event-start click)))
    (with-current-buffer (window-buffer (posn-window posn))
      ;; Cancel any preexisting secondary selection.
      (delete-overlay mouse-secondary-overlay)
      (if (numberp (posn-point posn))
	  (progn
	    (or mouse-secondary-start
		(setq mouse-secondary-start (make-marker)))
	    (move-marker mouse-secondary-start (posn-point posn)))))))

(defun mouse-set-secondary (click)
  "Set the secondary selection to the text that the mouse is dragged over.
This must be bound to a mouse drag event."
  (interactive "e")
  (mouse-minibuffer-check click)
  (let ((posn (event-start click))
	beg
	(end (event-end click)))
    (with-current-buffer (window-buffer (posn-window posn))
      (if (numberp (posn-point posn))
	  (setq beg (posn-point posn)))
      (move-overlay mouse-secondary-overlay beg (posn-point end))
      (gui-set-selection
       'SECONDARY
       (buffer-substring (overlay-start mouse-secondary-overlay)
			 (overlay-end mouse-secondary-overlay))))))

(defun mouse-drag-secondary (start-event)
  "Set the secondary selection to the text that the mouse is dragged over.
Highlight the drag area as you move the mouse.
This must be bound to a button-down mouse event.
The function returns a non-nil value if it creates a secondary selection."
  (interactive "e")
  (mouse-minibuffer-check start-event)
  (let* ((echo-keystrokes 0)
	 (start-posn (event-start start-event))
	 (start-point (posn-point start-posn))
	 (start-window (posn-window start-posn))
	 (bounds (window-edges start-window))
	 (top (nth 1 bounds))
	 (bottom (if (window-minibuffer-p start-window)
		     (nth 3 bounds)
		   ;; Don't count the mode line.
		   (1- (nth 3 bounds))))
	 (click-count (1- (event-click-count start-event))))
    (with-current-buffer (window-buffer start-window)
      (setq mouse-secondary-click-count click-count)
      (if (> (mod click-count 3) 0)
	  ;; Double or triple press: make an initial selection
	  ;; of one word or line.
	  (let ((range (mouse-start-end start-point start-point click-count)))
	    (set-marker mouse-secondary-start nil)
	    (move-overlay mouse-secondary-overlay (car range) (nth 1 range)
			  (window-buffer start-window)))
	;; Single-press: cancel any preexisting secondary selection.
	(or mouse-secondary-start
	    (setq mouse-secondary-start (make-marker)))
	(set-marker mouse-secondary-start start-point)
	(delete-overlay mouse-secondary-overlay))
      ;; FIXME: Use mouse-drag-track!
      (let (event end end-point)
	(track-mouse
	  (while (progn
		   (setq event (read-event))
		   (or (mouse-movement-p event)
		       (memq (car-safe event) '(switch-frame select-window))))

	    (if (memq (car-safe event) '(switch-frame select-window))
		nil
	      (setq end (event-end event)
		    end-point (posn-point end))
	      (cond
	       ;; Are we moving within the original window?
	       ((and (eq (posn-window end) start-window)
		     (integer-or-marker-p end-point))
		(let ((range (mouse-start-end start-point end-point
					      click-count)))
		  (if (or (/= start-point end-point)
			  (null (marker-position mouse-secondary-start)))
		      (progn
			(set-marker mouse-secondary-start nil)
			(move-overlay mouse-secondary-overlay
				      (car range) (nth 1 range))))))
               (t
                (let ((mouse-row (cdr (cdr (mouse-position)))))
                  (cond
                   ((null mouse-row))
                   ((< mouse-row top)
                    (mouse-scroll-subr start-window (- mouse-row top)
				       mouse-secondary-overlay start-point))
                   ((>= mouse-row bottom)
                    (mouse-scroll-subr start-window (1+ (- mouse-row bottom))
                                       mouse-secondary-overlay start-point)))))))))

	(if (consp event)
	    (if (marker-position mouse-secondary-start)
		(save-window-excursion
		  (delete-overlay mouse-secondary-overlay)
		  (gui-set-selection 'SECONDARY nil)
		  (select-window start-window)
		  (save-excursion
		    (goto-char mouse-secondary-start)
		    (sit-for 1)
		    nil))
	      (gui-set-selection
	       'SECONDARY
	       (buffer-substring (overlay-start mouse-secondary-overlay)
				 (overlay-end mouse-secondary-overlay)))))))))

(defun mouse-yank-secondary (click)
  "Insert the secondary selection at the position clicked on.
Move point to the end of the inserted text.
If `mouse-yank-at-point' is non-nil, insert at point
regardless of where you click."
  (interactive "e")
  ;; Give temporary modes such as isearch a chance to turn off.
  (run-hooks 'mouse-leave-buffer-hook)
  (or mouse-yank-at-point (mouse-set-point click))
  (let ((secondary (gui-get-selection 'SECONDARY)))
    (if secondary
        (insert-for-yank secondary)
      (error "No secondary selection"))))

(defun mouse-kill-secondary ()
  "Kill the text in the secondary selection.
This is intended more as a keyboard command than as a mouse command
but it can work as either one.

The current buffer (in case of keyboard use), or the buffer clicked on,
must be the one that the secondary selection is in.  This requirement
is to prevent accidents."
  (interactive)
  (let* ((keys (this-command-keys))
	 (click (elt keys (1- (length keys)))))
    (or (eq (overlay-buffer mouse-secondary-overlay)
	    (if (listp click)
		(window-buffer (posn-window (event-start click)))
	      (current-buffer)))
	(error "Select or click on the buffer where the secondary selection is")))
  (let (this-command)
    (with-current-buffer (overlay-buffer mouse-secondary-overlay)
      (kill-region (overlay-start mouse-secondary-overlay)
		   (overlay-end mouse-secondary-overlay))))
  (delete-overlay mouse-secondary-overlay))

(defun mouse-secondary-save-then-kill (click)
  "Set the secondary selection and save it to the kill ring.
The second time, kill it.  CLICK should be a mouse click event.

If you have not called `mouse-start-secondary' in the clicked
buffer, activate the secondary selection and set it between point
and the click position CLICK.

Otherwise, adjust the bounds of the secondary selection.
Normally, do this by moving its beginning or end, whichever is
closer, to CLICK.  But if you have selected whole words or lines,
adjust to the word or line boundary closest to CLICK instead.

If this command is called a second consecutive time with the same
CLICK position, kill the secondary selection."
  (interactive "e")
  (mouse-minibuffer-check click)
  (let* ((posn     (event-start click))
	 (click-pt (posn-point posn))
	 (window   (posn-window posn))
	 (buf      (window-buffer window))
	 ;; Don't let a subsequent kill command append to this one.
	 (this-command this-command)
	 ;; Check if the user has multi-clicked to select words/lines.
	 (click-count
	  (if (eq (overlay-buffer mouse-secondary-overlay) buf)
	      mouse-secondary-click-count
	    0))
	 (beg (overlay-start mouse-secondary-overlay))
	 (end (overlay-end mouse-secondary-overlay)))

    (cond
     ((not (numberp click-pt)) nil)

     ;; If the secondary selection is not active in BUF, activate it.
     ((not (eq buf (or (overlay-buffer mouse-secondary-overlay)
		       (if mouse-secondary-start
			   (marker-buffer mouse-secondary-start)))))
      (select-window window)
      (setq mouse-secondary-start (make-marker))
      (move-marker mouse-secondary-start (point))
      (move-overlay mouse-secondary-overlay (point) click-pt buf)
      (kill-ring-save (point) click-pt))

     ;; If the user clicked without moving point, delete the secondary
     ;; selection.  This also resets `mouse-secondary-click-count'.
     ((and (eq last-command 'mouse-secondary-save-then-kill)
	   (eq click-pt mouse-save-then-kill-posn)
	   (eq window (selected-window)))
      (mouse-save-then-kill-delete-region beg end)
      (delete-overlay mouse-secondary-overlay)
      (setq mouse-secondary-click-count 0)
      (setq mouse-save-then-kill-posn nil))

     ;; Otherwise, if there is a suitable secondary selection overlay,
     ;; adjust it by moving one end (whichever is closer) to CLICK-PT.
     ((and beg (eq buf (overlay-buffer mouse-secondary-overlay)))
      (let* ((range (mouse-start-end click-pt click-pt click-count)))
	(if (< (abs (- click-pt beg))
	       (abs (- click-pt end)))
	    (move-overlay mouse-secondary-overlay (car range) end)
	  (move-overlay mouse-secondary-overlay beg (nth 1 range))))
      (setq deactivate-mark nil)
      (if (eq last-command 'mouse-secondary-save-then-kill)
	  ;; If the front of the kill ring comes from an immediately
	  ;; previous use of this command, replace the entry.
	  (kill-new
	   (buffer-substring (overlay-start mouse-secondary-overlay)
			     (overlay-end mouse-secondary-overlay))
	   t)
	(let (deactivate-mark)
	  (copy-region-as-kill (overlay-start mouse-secondary-overlay)
			       (overlay-end mouse-secondary-overlay))))
      (setq mouse-save-then-kill-posn click-pt))

     ;; Otherwise, set the secondary selection overlay.
     (t
      (select-window window)
      (if mouse-secondary-start
	  ;; All we have is one end of a selection, so put the other
	  ;; end here.
	  (let ((start (+ 0 mouse-secondary-start)))
	    (kill-ring-save start click-pt)
	    (move-overlay mouse-secondary-overlay start click-pt)))
      (setq mouse-save-then-kill-posn click-pt))))

  ;; Finally, set the window system's secondary selection.
  (let (str)
    (and (overlay-buffer mouse-secondary-overlay)
	 (setq str (buffer-substring (overlay-start mouse-secondary-overlay)
				     (overlay-end mouse-secondary-overlay)))
	 (> (length str) 0)
	 (gui-set-selection 'SECONDARY str))))

(defun secondary-selection-exist-p ()
  "Return non-nil if the secondary selection exists in the current buffer."
  (memq mouse-secondary-overlay (overlays-in (point-min) (point-max))))

(defun secondary-selection-to-region ()
  "Set beginning and end of the region to those of the secondary selection.
This puts mark and point at the beginning and the end of the
secondary selection, respectively.  This works when the secondary
selection exists and the region does not exist in current buffer;
the secondary selection will be deleted afterward.
If the region is active, or the secondary selection doesn't exist,
this function does nothing."
  (when (and (not (region-active-p))
             (secondary-selection-exist-p))
    (let ((beg (overlay-start mouse-secondary-overlay))
          (end (overlay-end mouse-secondary-overlay)))
      (push-mark beg t t)
      (goto-char end))
    ;; Delete the secondary selection on current buffer.
    (delete-overlay mouse-secondary-overlay)))

(defun secondary-selection-from-region ()
  "Set beginning and end of the secondary selection to those of the region.
When there is no region, this function does nothing."
  (when (region-active-p) ; Create the secondary selection from the region.
    (delete-overlay mouse-secondary-overlay) ; Delete the secondary selection even on a different buffer.
    (move-overlay mouse-secondary-overlay (region-beginning) (region-end))))

\f
(defcustom mouse-buffer-menu-maxlen 20
  "Number of buffers in one pane (submenu) of the buffer menu.
If we have lots of buffers, divide them into groups of
`mouse-buffer-menu-maxlen' and make a pane (or submenu) for each one."
  :type 'integer)

(defcustom mouse-buffer-menu-mode-mult 4
  "Group the buffers by the major mode groups on \\[mouse-buffer-menu]?
This number which determines (in a hairy way) whether \\[mouse-buffer-menu]
will split the buffer menu by the major modes (see
`mouse-buffer-menu-mode-groups') or just by menu length.
Set to 1 (or even 0!) if you want to group by major mode always, and to
a large number if you prefer a mixed multitude.  The default is 4."
  :type 'integer
  :version "20.3")

(defvar mouse-buffer-menu-mode-groups
  (mapcar (lambda (arg) (cons  (purecopy (car arg)) (purecopy (cdr arg))))
  '(("Info\\|Help\\|Apropos\\|Man" . "Help")
    ("\\bVM\\b\\|\\bMH\\b\\|Message\\|Mail\\|Group\\|Score\\|Summary\\|Article"
     . "Mail/News")
    ("\\<C\\>" . "C")
    ("ObjC" . "C")
    ("Text" . "Text")
    ("Outline" . "Text")
    ("\\(HT\\|SG\\|X\\|XHT\\)ML" . "SGML")
    ("log\\|diff\\|vc\\|cvs\\|Annotate" . "Version Control") ; "Change Management"?
    ("Threads\\|Memory\\|Disassembly\\|Breakpoints\\|Frames\\|Locals\\|Registers\\|Inferior I/O\\|Debugger"
     . "GDB")
    ("Lisp" . "Lisp")))
  "How to group various major modes together in \\[mouse-buffer-menu].
Each element has the form (REGEXP . GROUPNAME).
If the major mode's name string matches REGEXP, use GROUPNAME instead.")

(defun mouse-buffer-menu (event)
  "Pop up a menu of buffers for selection with the mouse.
This switches buffers in the window that you clicked on,
and selects that window."
  (interactive "e")
  (mouse-minibuffer-check event)
  (let ((buf (x-popup-menu event (mouse-buffer-menu-map)))
        (window (posn-window (event-start event))))
    (when buf
      (select-window
       (if (framep window) (frame-selected-window window)
         window))
      (switch-to-buffer buf))))

(defun mouse-buffer-menu-map ()
  ;; Make an alist of elements that look like (MENU-ITEM . BUFFER).
  (let ((buffers (buffer-list)) split-by-major-mode sum-of-squares)
    (dolist (buf buffers)
      ;; Divide all buffers into buckets for various major modes.
      ;; Each bucket looks like (MODE NAMESTRING BUFFERS...).
      (with-current-buffer buf
        (let* ((adjusted-major-mode major-mode) elt)
          (dolist (group mouse-buffer-menu-mode-groups)
            (when (string-match (car group) (format-mode-line mode-name))
              (setq adjusted-major-mode (cdr group))))
          (setq elt (assoc adjusted-major-mode split-by-major-mode))
          (unless elt
            (setq elt (list adjusted-major-mode
                            (if (stringp adjusted-major-mode)
                                adjusted-major-mode
                              (format-mode-line mode-name nil nil buf)))
                  split-by-major-mode (cons elt split-by-major-mode)))
          (or (memq buf (cdr (cdr elt)))
              (setcdr (cdr elt) (cons buf (cdr (cdr elt))))))))
    ;; Compute the sum of squares of sizes of the major-mode buckets.
    (let ((tail split-by-major-mode))
      (setq sum-of-squares 0)
      (while tail
	(setq sum-of-squares
	      (+ sum-of-squares
		 (let ((len (length (cdr (cdr (car tail)))))) (* len len))))
	(setq tail (cdr tail))))
    (if (< (* sum-of-squares mouse-buffer-menu-mode-mult)
	   (* (length buffers) (length buffers)))
	;; Subdividing by major modes really helps, so let's do it.
	(let (subdivided-menus (buffers-left (length buffers)))
	  ;; Sort the list to put the most popular major modes first.
	  (setq split-by-major-mode
		(sort split-by-major-mode
		      (function (lambda (elt1 elt2)
				  (> (length elt1) (length elt2))))))
	  ;; Make a separate submenu for each major mode
	  ;; that has more than one buffer,
	  ;; unless all the remaining buffers are less than 1/10 of them.
	  (while (and split-by-major-mode
		      (and (> (length (car split-by-major-mode)) 3)
			   (> (* buffers-left 10) (length buffers))))
	    (let ((this-mode-list (mouse-buffer-menu-alist
				   (cdr (cdr (car split-by-major-mode))))))
	      (and this-mode-list
		   (setq subdivided-menus
			 (cons (cons
				(nth 1 (car split-by-major-mode))
				this-mode-list)
			       subdivided-menus))))
	    (setq buffers-left
		  (- buffers-left (length (cdr (car split-by-major-mode)))))
	    (setq split-by-major-mode (cdr split-by-major-mode)))
	  ;; If any major modes are left over,
	  ;; make a single submenu for them.
	  (if split-by-major-mode
	      (let ((others-list
		     (mouse-buffer-menu-alist
		      ;; we don't need split-by-major-mode any more,
		      ;; so we can ditch it with nconc (mapcan).
		      (mapcan 'cddr split-by-major-mode))))
		(and others-list
		     (setq subdivided-menus
			   (cons (cons "Others" others-list)
				 subdivided-menus)))))
          (cons "Buffer Menu" (nreverse subdivided-menus)))
      (cons "Buffer Menu"
            (mouse-buffer-menu-split "Select Buffer"
                                     (mouse-buffer-menu-alist buffers))))))

(defun mouse-buffer-menu-alist (buffers)
  (let (tail
	(maxlen 0)
	head)
    (setq buffers
	  (sort buffers
		(function (lambda (elt1 elt2)
			    (string< (buffer-name elt1) (buffer-name elt2))))))
    (setq tail buffers)
    (while tail
      (or (eq ?\s (aref (buffer-name (car tail)) 0))
	  (setq maxlen
		(max maxlen
		     (length (buffer-name (car tail))))))
      (setq tail (cdr tail)))
    (setq tail buffers)
    (while tail
      (let ((elt (car tail)))
	(if (/= (aref (buffer-name elt) 0) ?\s)
	    (setq head
		  (cons
		   (cons
		    (format
		     (format "%%-%ds  %%s%%s  %%s" maxlen)
		     (buffer-name elt)
		     (if (buffer-modified-p elt) "*" " ")
		     (with-current-buffer elt
		       (if buffer-read-only "%" " "))
		     (or (buffer-file-name elt)
			 (with-current-buffer elt
			   (if list-buffers-directory
			       (expand-file-name
				list-buffers-directory)))
			 ""))
		    elt)
		   head))))
      (setq tail (cdr tail)))
    ;; Compensate for the reversal that the above loop does.
    (nreverse head)))

(defun mouse-buffer-menu-split (title alist)
  ;; If we have lots of buffers, divide them into groups of 20
  ;; and make a pane (or submenu) for each one.
  (if (> (length alist) (/ (* mouse-buffer-menu-maxlen 3) 2))
      (let ((alist alist) sublists next
	    (i 1))
	(while alist
	  ;; Pull off the next mouse-buffer-menu-maxlen buffers
	  ;; and make them the next element of sublist.
	  (setq next (nthcdr mouse-buffer-menu-maxlen alist))
	  (if next
	      (setcdr (nthcdr (1- mouse-buffer-menu-maxlen) alist)
		      nil))
	  (setq sublists (cons (cons (format "Buffers %d" i) alist)
			       sublists))
	  (setq i (1+ i))
	  (setq alist next))
	(nreverse sublists))
    ;; Few buffers--put them all in one pane.
    (list (cons title alist))))
\f
(define-obsolete-function-alias
  'mouse-choose-completion 'choose-completion "23.2")

;; Font selection.

(defun font-menu-add-default ()
  (let* ((default (frame-parameter nil 'font))
	 (font-alist x-fixed-font-alist)
	 (elt (or (assoc "Misc" font-alist) (nth 1 font-alist))))
    (if (assoc "Default" elt)
	(delete (assoc "Default" elt) elt))
    (setcdr elt
	    (cons (list "Default" default)
		  (cdr elt)))))

(defvar x-fixed-font-alist
  (list
   (purecopy "Font Menu")
   (cons
    (purecopy "Misc")
    (mapcar
     (lambda (arg) (cons  (purecopy (car arg)) (purecopy (cdr arg))))
     ;; For these, we specify the pixel height and width.
    '(("fixed" "fixed")
     ("6x10" "-misc-fixed-medium-r-normal--10-*-*-*-c-60-iso8859-1" "6x10")
     ("6x12"
      "-misc-fixed-medium-r-semicondensed--12-*-*-*-c-60-iso8859-1" "6x12")
     ("6x13"
      "-misc-fixed-medium-r-semicondensed--13-*-*-*-c-60-iso8859-1" "6x13")
     ("7x13" "-misc-fixed-medium-r-normal--13-*-*-*-c-70-iso8859-1" "7x13")
     ("7x14" "-misc-fixed-medium-r-normal--14-*-*-*-c-70-iso8859-1" "7x14")
     ("8x13" "-misc-fixed-medium-r-normal--13-*-*-*-c-80-iso8859-1" "8x13")
     ("9x15" "-misc-fixed-medium-r-normal--15-*-*-*-c-90-iso8859-1" "9x15")
     ("10x20" "-misc-fixed-medium-r-normal--20-*-*-*-c-100-iso8859-1" "10x20")
     ("11x18" "-misc-fixed-medium-r-normal--18-*-*-*-c-110-iso8859-1" "11x18")
     ("12x24" "-misc-fixed-medium-r-normal--24-*-*-*-c-120-iso8859-1" "12x24")
     ("")
     ("clean 5x8"
      "-schumacher-clean-medium-r-normal--8-*-*-*-c-50-iso8859-1")
     ("clean 6x8"
      "-schumacher-clean-medium-r-normal--8-*-*-*-c-60-iso8859-1")
     ("clean 8x8"
      "-schumacher-clean-medium-r-normal--8-*-*-*-c-80-iso8859-1")
     ("clean 8x10"
      "-schumacher-clean-medium-r-normal--10-*-*-*-c-80-iso8859-1")
     ("clean 8x14"
      "-schumacher-clean-medium-r-normal--14-*-*-*-c-80-iso8859-1")
     ("clean 8x16"
      "-schumacher-clean-medium-r-normal--16-*-*-*-c-80-iso8859-1")
     ("")
     ("sony 8x16" "-sony-fixed-medium-r-normal--16-*-*-*-c-80-iso8859-1")
     ;; We don't seem to have these; who knows what they are.
     ;; ("fg-18" "fg-18")
     ;; ("fg-25" "fg-25")
     ("lucidasanstypewriter-12" "-b&h-lucidatypewriter-medium-r-normal-sans-*-120-*-*-*-*-iso8859-1")
     ("lucidasanstypewriter-bold-14" "-b&h-lucidatypewriter-bold-r-normal-sans-*-140-*-*-*-*-iso8859-1")
     ("lucidasanstypewriter-bold-24"
      "-b&h-lucidatypewriter-bold-r-normal-sans-*-240-*-*-*-*-iso8859-1")
     ;; ("lucidatypewriter-bold-r-24" "-b&h-lucidatypewriter-bold-r-normal-sans-24-240-75-75-m-140-iso8859-1")
     ;; ("fixed-medium-20" "-misc-fixed-medium-*-*-*-20-*-*-*-*-*-*-*")
     )))

   (cons
    (purecopy "Courier")
    (mapcar
     (lambda (arg) (cons  (purecopy (car arg)) (purecopy (cdr arg))))
     ;; For these, we specify the point height.
     '(("8" "-adobe-courier-medium-r-normal--*-80-*-*-m-*-iso8859-1")
     ("10" "-adobe-courier-medium-r-normal--*-100-*-*-m-*-iso8859-1")
     ("12" "-adobe-courier-medium-r-normal--*-120-*-*-m-*-iso8859-1")
     ("14" "-adobe-courier-medium-r-normal--*-140-*-*-m-*-iso8859-1")
     ("18" "-adobe-courier-medium-r-normal--*-180-*-*-m-*-iso8859-1")
     ("24" "-adobe-courier-medium-r-normal--*-240-*-*-m-*-iso8859-1")
     ("8 bold" "-adobe-courier-bold-r-normal--*-80-*-*-m-*-iso8859-1")
     ("10 bold" "-adobe-courier-bold-r-normal--*-100-*-*-m-*-iso8859-1")
     ("12 bold" "-adobe-courier-bold-r-normal--*-120-*-*-m-*-iso8859-1")
     ("14 bold" "-adobe-courier-bold-r-normal--*-140-*-*-m-*-iso8859-1")
     ("18 bold" "-adobe-courier-bold-r-normal--*-180-*-*-m-*-iso8859-1")
     ("24 bold" "-adobe-courier-bold-r-normal--*-240-*-*-m-*-iso8859-1")
     ("8 slant" "-adobe-courier-medium-o-normal--*-80-*-*-m-*-iso8859-1")
     ("10 slant" "-adobe-courier-medium-o-normal--*-100-*-*-m-*-iso8859-1")
     ("12 slant" "-adobe-courier-medium-o-normal--*-120-*-*-m-*-iso8859-1")
     ("14 slant" "-adobe-courier-medium-o-normal--*-140-*-*-m-*-iso8859-1")
     ("18 slant" "-adobe-courier-medium-o-normal--*-180-*-*-m-*-iso8859-1")
     ("24 slant" "-adobe-courier-medium-o-normal--*-240-*-*-m-*-iso8859-1")
     ("8 bold slant" "-adobe-courier-bold-o-normal--*-80-*-*-m-*-iso8859-1")
     ("10 bold slant" "-adobe-courier-bold-o-normal--*-100-*-*-m-*-iso8859-1")
     ("12 bold slant" "-adobe-courier-bold-o-normal--*-120-*-*-m-*-iso8859-1")
     ("14 bold slant" "-adobe-courier-bold-o-normal--*-140-*-*-m-*-iso8859-1")
     ("18 bold slant" "-adobe-courier-bold-o-normal--*-180-*-*-m-*-iso8859-1")
     ("24 bold slant" "-adobe-courier-bold-o-normal--*-240-*-*-m-*-iso8859-1")
    ))))
  "X fonts suitable for use in Emacs.")

(declare-function generate-fontset-menu "fontset" ())

(defun mouse-select-font ()
  "Prompt for a font name, using `x-popup-menu', and return it."
  (interactive)
  (unless (display-multi-font-p)
    (error "Cannot change fonts on this display"))
  (car
   (x-popup-menu
    (if (listp last-nonmenu-event)
	last-nonmenu-event
      (list '(0 0) (selected-window)))
    (append x-fixed-font-alist
	    (list (generate-fontset-menu))))))

(declare-function text-scale-mode "face-remap")

(defun mouse-set-font (&rest fonts)
  "Set the default font for the selected frame.
The argument FONTS is a list of font names; the first valid font
in this list is used.

When called interactively, pop up a menu and allow the user to
choose a font."
  (interactive
   (progn (unless (display-multi-font-p)
	    (error "Cannot change fonts on this display"))
	  (x-popup-menu
	   (if (listp last-nonmenu-event)
	       last-nonmenu-event
	     (list '(0 0) (selected-window)))
	   ;; Append list of fontsets currently defined.
	   (append x-fixed-font-alist (list (generate-fontset-menu))))))
  (if fonts
      (let (font)
	(while fonts
	  (condition-case nil
	      (progn
		(set-frame-font (car fonts))
		(setq font (car fonts))
		(setq fonts nil))
	    (error
	     (setq fonts (cdr fonts)))))
	(if (null font)
	    (error "Font not found")))))

(defvar mouse-appearance-menu-map nil)
(declare-function x-select-font "xfns.c" (&optional frame ignored)) ; USE_GTK
(declare-function buffer-face-mode-invoke "face-remap"
                  (face arg &optional interactive))
(declare-function font-face-attributes "font.c" (font &optional frame))
(defvar w32-use-w32-font-dialog)
(defvar w32-fixed-font-alist)

(defun mouse-appearance-menu (event)
  "Show a menu for changing the default face in the current buffer."
  (interactive "@e")
  (require 'face-remap)
  (when (display-multi-font-p)
    (with-selected-window (car (event-start event))
      (if mouse-appearance-menu-map
	  nil ; regenerate new fonts
	;; Initialize mouse-appearance-menu-map
	(setq mouse-appearance-menu-map
	      (make-sparse-keymap "Change Default Buffer Face"))
	(define-key mouse-appearance-menu-map [face-remap-reset-base]
	  '(menu-item "Reset to Default" face-remap-reset-base))
	(define-key mouse-appearance-menu-map [text-scale-decrease]
	  '(menu-item "Decrease Buffer Text Size" text-scale-decrease))
	(define-key mouse-appearance-menu-map [text-scale-increase]
	  '(menu-item "Increase Buffer Text Size" text-scale-increase))
	;; Font selector
	(if (and (functionp 'x-select-font)
		 (or (not (boundp 'w32-use-w32-font-dialog))
		     w32-use-w32-font-dialog))
	    (define-key mouse-appearance-menu-map [x-select-font]
	      '(menu-item "Change Buffer Font..." x-select-font))
	  ;; If the select-font is unavailable, construct a menu.
	  (let ((font-submenu (make-sparse-keymap "Change Text Font"))
		(font-alist (cdr (append
				  (if (eq system-type 'windows-nt)
				      w32-fixed-font-alist
				    x-fixed-font-alist)
				  (list (generate-fontset-menu))))))
	    (dolist (family font-alist)
	      (let* ((submenu-name (car family))
		     (submenu-map (make-sparse-keymap submenu-name)))
		(dolist (font (cdr family))
		  (let ((font-name (car font))
			font-symbol)
		    (if (string= font-name "")
			(define-key submenu-map [space]
			  '("--"))
		      (setq font-symbol (intern (cadr font)))
		      (define-key submenu-map (vector font-symbol)
			(list 'menu-item (car font) font-symbol)))))
		(define-key font-submenu (vector (intern submenu-name))
		  (list 'menu-item submenu-name submenu-map))))
	    (define-key mouse-appearance-menu-map [font-submenu]
	      (list 'menu-item "Change Text Font" font-submenu)))))
      (let ((choice (x-popup-menu event mouse-appearance-menu-map)))
	(setq choice (nth (1- (length choice)) choice))
	(cond ((eq choice 'text-scale-increase)
	       (text-scale-increase 1))
	      ((eq choice 'text-scale-decrease)
	       (text-scale-increase -1))
	      ((eq choice 'face-remap-reset-base)
	       (text-scale-mode 0)
	       (buffer-face-mode 0))
	      (choice
	       ;; Either choice == 'x-select-font, or choice is a
	       ;; symbol whose name is a font.
	       (let ((font (if (eq choice 'x-select-font)
			       (x-select-font)
			     (symbol-name choice))))
		 (buffer-face-mode-invoke
		  (if (fontp font 'font-spec)
		      (list :font font)
		    (font-face-attributes font))
		  t (called-interactively-p 'interactive)))))))))

\f
;; Drag and drop support.
(defcustom mouse-drag-and-drop-region nil
  "If non-nil, dragging the mouse drags the region, if it exists.
If the value is a modifier, such as `control' or `shift' or
`meta', then if that modifier key is pressed when dropping the
region, text is copied instead of being cut."
  :type `(choice
          (const :tag "Disable dragging the region" nil)
          ,@(mapcar
             (lambda (modifier)
               `(const :tag ,(format "Enable, but copy with the %s modifier"
                                     modifier)
                       modifier))
             '(alt super hyper shift control meta))
          (other :tag "Enable dragging the region" t))
  :version "26.1")

(defcustom mouse-drag-and-drop-region-cut-when-buffers-differ nil
  "If non-nil, cut text also when source and destination buffers differ.
If this option is nil, `mouse-drag-and-drop-region' will leave
the text in the source buffer alone when dropping it in a
different buffer.  If this is non-nil, it will cut the text just
as it does when dropping text in the source buffer."
  :type 'boolean
  :version "26.1")

(defcustom mouse-drag-and-drop-region-show-tooltip 256
  "If non-nil, text is shown by a tooltip in a graphic display.
If this option is nil, `mouse-drag-and-drop-region' does not show
tooltips.  If this is t, it shows the entire text dragged in a
tooltip.  If this is an integer (as with the default value of
256), it will show that many characters of the dragged text in
a tooltip."
  :type 'integer
  :version "26.1")

(defcustom mouse-drag-and-drop-region-show-cursor t
  "If non-nil, move point with mouse cursor during dragging.
If this is nil, `mouse-drag-and-drop-region' leaves point alone.
Otherwise, it will move point together with the mouse cursor and,
in addition, temporarily highlight the original region with the
`mouse-drag-and-drop-region' face."
  :type 'boolean
  :version "26.1")

(defface mouse-drag-and-drop-region '((t :inherit region))
  "Face to highlight original text during dragging.
This face is used by `mouse-drag-and-drop-region' to temporarily
highlight the original region when
`mouse-drag-and-drop-region-show-cursor' is non-nil."
  :version "26.1")

(defun mouse-drag-and-drop-region (event)
  "Move text in the region to point where mouse is dragged to.
The transportation of text is also referred as `drag and drop'.
When text is dragged over to a different buffer, or if a
modifier key was pressed when dropping, and the value of the
variable `mouse-drag-and-drop-region' is that modifier, the text
is copied instead of being cut."
  (interactive "e")
  (let* ((mouse-button (event-basic-type last-input-event))
         (mouse-drag-and-drop-region-show-tooltip
          (when (and mouse-drag-and-drop-region-show-tooltip
                     (display-multi-frame-p)
                     (require 'tooltip))
            mouse-drag-and-drop-region-show-tooltip))
         (start (region-beginning))
         (end (region-end))
         (point (point))
         (buffer (current-buffer))
         (window (selected-window))
         (text-from-read-only buffer-read-only)
         (mouse-drag-and-drop-overlay (make-overlay start end))
         point-to-paste
         point-to-paste-read-only
         window-to-paste
         buffer-to-paste
         cursor-in-text-area
         no-modifier-on-drop
         drag-but-negligible
         clicked
         value-selection    ; This remains nil when event was "click".
         text-tooltip
         states
         window-exempt)

    ;; STATES stores for each window on this frame its start and point
    ;; positions so we can restore them on all windows but for the one
    ;; where the drop occurs.  For inter-frame drags we'll have to do
    ;; this for all windows on all visible frames.  In addition we save
    ;; also the cursor type for the window's buffer so we can restore it
    ;; in case we modified it.
    ;; https://lists.gnu.org/archive/html/emacs-devel/2017-12/msg00090.html
    (walk-window-tree
     (lambda (window)
       (setq states
             (cons
              (list
               window
               (copy-marker (window-start window))
               (copy-marker (window-point window))
               (with-current-buffer (window-buffer window)
                 cursor-type))
              states))))

    (ignore-errors
      (track-mouse
        ;; When event was "click" instead of "drag", skip loop.
        (while (progn
                 (setq event (read-key))      ; read-event or read-key
                 (or (mouse-movement-p event)
                     ;; Handle `mouse-autoselect-window'.
                     (eq (car-safe event) 'select-window)))
          ;; Obtain the dragged text in region.  When the loop was
          ;; skipped, value-selection remains nil.
          (unless value-selection
            (setq value-selection (buffer-substring start end))
            (when mouse-drag-and-drop-region-show-tooltip
              (let ((text-size mouse-drag-and-drop-region-show-tooltip))
                (setq text-tooltip
                      (if (and (integerp text-size)
                               (> (length value-selection) text-size))
                          (concat
                           (substring value-selection 0 (/ text-size 2))
                           "\n...\n"
                           (substring value-selection (- (/ text-size 2)) -1))
                        value-selection))))

            ;; Check if selected text is read-only.
            (setq text-from-read-only (or text-from-read-only
                                          (get-text-property start 'read-only)
                                          (not (equal
                                                (next-single-char-property-change
                                                 start 'read-only nil end)
                                                end)))))
          (setq window-to-paste (posn-window (event-end event)))
          (setq point-to-paste (posn-point (event-end event)))
          ;; Set nil when target buffer is minibuffer.
          (setq buffer-to-paste (let (buf)
                                  (when (windowp window-to-paste)
                                    (setq buf (window-buffer window-to-paste))
                                    (when (not (minibufferp buf))
                                      buf))))
          (setq cursor-in-text-area (and window-to-paste
                                         point-to-paste
                                         buffer-to-paste))

          (when cursor-in-text-area
            ;; Check if point under mouse is read-only.
            (save-window-excursion
              (select-window window-to-paste)
              (setq point-to-paste-read-only
                    (or buffer-read-only
                        (get-text-property point-to-paste 'read-only))))

            ;; Check if "drag but negligible".  Operation "drag but
            ;; negligible" is defined as drag-and-drop the text to
            ;; the original region.  When modifier is pressed, the
            ;; text will be inserted to inside of the original
            ;; region.
            (setq drag-but-negligible
                  (and (eq (overlay-buffer mouse-drag-and-drop-overlay)
                           buffer-to-paste)
                       (<= (overlay-start mouse-drag-and-drop-overlay)
                          point-to-paste)
                       (<= point-to-paste
                          (overlay-end mouse-drag-and-drop-overlay)))))

          ;; Show a tooltip.
          (if mouse-drag-and-drop-region-show-tooltip
              (tooltip-show text-tooltip)
            (tooltip-hide))

          ;; Show cursor and highlight the original region.
          (when mouse-drag-and-drop-region-show-cursor
            ;; Modify cursor even when point is out of frame.
            (setq cursor-type (cond
                               ((not cursor-in-text-area)
                                nil)
                               ((or point-to-paste-read-only
                                    drag-but-negligible)
                                'hollow)
                               (t
                                'bar)))
            (when cursor-in-text-area
              (overlay-put mouse-drag-and-drop-overlay
                           'face 'mouse-drag-and-drop-region)
              (deactivate-mark)     ; Maintain region in other window.
              (mouse-set-point event)))))

      ;; Hide a tooltip.
      (when mouse-drag-and-drop-region-show-tooltip (tooltip-hide))

      ;; Check if modifier was pressed on drop.
      (setq no-modifier-on-drop
            (not (member mouse-drag-and-drop-region (event-modifiers event))))

      ;; Check if event was "click".
      (setq clicked (not value-selection))

      ;; Restore status on drag to outside of text-area or non-mouse input.
      (when (or (not cursor-in-text-area)
                (not (equal (event-basic-type event) mouse-button)))
        (setq drag-but-negligible t
              no-modifier-on-drop t))

      ;; Do not modify any buffers when event is "click",
      ;; "drag but negligible", or "drag to read-only".
      (let* ((mouse-drag-and-drop-region-cut-when-buffers-differ
              (if no-modifier-on-drop
                  mouse-drag-and-drop-region-cut-when-buffers-differ
                (not mouse-drag-and-drop-region-cut-when-buffers-differ)))
             (wanna-paste-to-same-buffer (equal buffer-to-paste buffer))
             (wanna-cut-on-same-buffer (and wanna-paste-to-same-buffer
                                            no-modifier-on-drop))
             (wanna-cut-on-other-buffer
              (and (not wanna-paste-to-same-buffer)
                   mouse-drag-and-drop-region-cut-when-buffers-differ))
             (cannot-paste (or point-to-paste-read-only
                               (when (or wanna-cut-on-same-buffer
                                         wanna-cut-on-other-buffer)
                                 text-from-read-only))))

        (cond
         ;; Move point within region.
         (clicked
          (deactivate-mark)
          (mouse-set-point event))
         ;; Undo operation. Set back the original text as region.
         ((or (and drag-but-negligible
                   no-modifier-on-drop)
              cannot-paste)
          ;; Inform user either source or destination buffer cannot be modified.
          (when (and (not drag-but-negligible)
                     cannot-paste)
            (message "Buffer is read-only"))

          ;; Select source window back and restore region.
          ;; (set-window-point window point)
          (select-window window)
          (goto-char point)
          (setq deactivate-mark nil)
          (activate-mark))
         ;; Modify buffers.
         (t
          ;; * DESTINATION BUFFER::
          ;; Insert the text to destination buffer under mouse.
          (select-window window-to-paste)
          (setq window-exempt window-to-paste)
          (goto-char point-to-paste)
          (push-mark)
          (insert value-selection)
          ;; On success, set the text as region on destination buffer.
          (when (not (equal (mark) (point)))
            (setq deactivate-mark nil)
            (activate-mark))

          ;; * SOURCE BUFFER::
          ;; Set back the original text as region or delete the original
          ;; text, on source buffer.
          (if wanna-paste-to-same-buffer
              ;; When source buffer and destination buffer are the same,
              ;; remove the original text.
              (when no-modifier-on-drop
                (let (deactivate-mark)
                  (delete-region (overlay-start mouse-drag-and-drop-overlay)
                                 (overlay-end mouse-drag-and-drop-overlay))))
            ;; When source buffer and destination buffer are different,
            ;; keep (set back the original text as region) or remove the
            ;; original text.
            (select-window window) ; Select window with source buffer.
            (goto-char point) ; Move point to the original text on source buffer.

            (if mouse-drag-and-drop-region-cut-when-buffers-differ
                ;; Remove the dragged text from source buffer like
                ;; operation `cut'.
                (delete-region (overlay-start mouse-drag-and-drop-overlay)
                               (overlay-end mouse-drag-and-drop-overlay))
              ;; Set back the dragged text as region on source buffer
              ;; like operation `copy'.
              (activate-mark))
            (select-window window-to-paste))))))

    ;; Clean up.
    (delete-overlay mouse-drag-and-drop-overlay)

    ;; Restore old states but for the window where the drop
    ;; occurred. Restore cursor types for all windows.
    (dolist (state states)
      (let ((window (car state)))
        (when (and window-exempt
                   (not (eq window window-exempt)))
          (set-window-start window (nth 1 state) 'noforce)
          (set-marker (nth 1 state) nil)
          ;; If window is selected, the following automatically sets
          ;; point for that window's buffer.
          (set-window-point window (nth 2 state))
          (set-marker (nth 2 state) nil))
        (with-current-buffer (window-buffer window)
          (setq cursor-type (nth 3 state)))))))
\f

;;; Bindings for mouse commands.

(global-set-key [down-mouse-1]	'mouse-drag-region)
(global-set-key [mouse-1]	'mouse-set-point)
(global-set-key [drag-mouse-1]	'mouse-set-region)

(defun mouse--strip-first-event (_prompt)
  (substring (this-single-command-raw-keys) 1))

(define-key function-key-map [left-fringe mouse-1] 'mouse--strip-first-event)
(define-key function-key-map [right-fringe mouse-1] 'mouse--strip-first-event)

(global-set-key [mouse-2]	'mouse-yank-primary)
;; Allow yanking also when the corresponding cursor is "in the fringe".
(define-key function-key-map [right-fringe mouse-2] 'mouse--strip-first-event)
(define-key function-key-map [left-fringe mouse-2] 'mouse--strip-first-event)
(global-set-key [mouse-3]	'mouse-save-then-kill)
(define-key function-key-map [right-fringe mouse-3] 'mouse--strip-first-event)
(define-key function-key-map [left-fringe mouse-3] 'mouse--strip-first-event)

;; By binding these to down-going events, we let the user use the up-going
;; event to make the selection, saving a click.
(global-set-key [C-down-mouse-1] 'mouse-buffer-menu)
(if (not (eq system-type 'ms-dos))
    (global-set-key [S-down-mouse-1] 'mouse-appearance-menu))
;; C-down-mouse-2 is bound in facemenu.el.
(global-set-key [C-down-mouse-3]
  `(menu-item ,(purecopy "Menu Bar") ignore
    :filter (lambda (_)
              (if (zerop (or (frame-parameter nil 'menu-bar-lines) 0))
                  (mouse-menu-bar-map)
                (mouse-menu-major-mode-map)))))

;; Binding mouse-1 to mouse-select-window when on mode-, header-, or
;; vertical-line prevents Emacs from signaling an error when the mouse
;; button is released after dragging these lines, on non-toolkit
;; versions.
(global-set-key [header-line down-mouse-1] 'mouse-drag-header-line)
(global-set-key [header-line mouse-1] 'mouse-select-window)
;; (global-set-key [mode-line drag-mouse-1] 'mouse-select-window)
(global-set-key [mode-line down-mouse-1] 'mouse-drag-mode-line)
(global-set-key [mode-line mouse-1] 'mouse-select-window)
(global-set-key [mode-line mouse-2] 'mouse-delete-other-windows)
(global-set-key [mode-line mouse-3] 'mouse-delete-window)
(global-set-key [mode-line C-mouse-2] 'mouse-split-window-horizontally)
(global-set-key [vertical-scroll-bar C-mouse-2] 'mouse-split-window-vertically)
(global-set-key [horizontal-scroll-bar C-mouse-2] 'mouse-split-window-horizontally)
(global-set-key [vertical-line down-mouse-1] 'mouse-drag-vertical-line)
(global-set-key [vertical-line mouse-1] 'mouse-select-window)
(global-set-key [vertical-line C-mouse-2] 'mouse-split-window-vertically)
(global-set-key [right-divider down-mouse-1] 'mouse-drag-vertical-line)
(global-set-key [right-divider mouse-1] 'ignore)
(global-set-key [right-divider C-mouse-2] 'mouse-split-window-vertically)
(global-set-key [bottom-divider down-mouse-1] 'mouse-drag-mode-line)
(global-set-key [bottom-divider mouse-1] 'ignore)
(global-set-key [bottom-divider C-mouse-2] 'mouse-split-window-horizontally)
(global-set-key [left-edge down-mouse-1] 'mouse-drag-left-edge)
(global-set-key [left-edge mouse-1] 'ignore)
(global-set-key [top-left-corner down-mouse-1] 'mouse-drag-top-left-corner)
(global-set-key [top-left-corner mouse-1] 'ignore)
(global-set-key [top-edge down-mouse-1] 'mouse-drag-top-edge)
(global-set-key [top-edge mouse-1] 'ignore)
(global-set-key [top-right-corner down-mouse-1] 'mouse-drag-top-right-corner)
(global-set-key [top-right-corner mouse-1] 'ignore)
(global-set-key [right-edge down-mouse-1] 'mouse-drag-right-edge)
(global-set-key [right-edge mouse-1] 'ignore)
(global-set-key [bottom-right-corner down-mouse-1] 'mouse-drag-bottom-right-corner)
(global-set-key [bottom-right-corner mouse-1] 'ignore)
(global-set-key [bottom-edge down-mouse-1] 'mouse-drag-bottom-edge)
(global-set-key [bottom-edge mouse-1] 'ignore)
(global-set-key [bottom-left-corner down-mouse-1] 'mouse-drag-bottom-left-corner)
(global-set-key [bottom-left-corner mouse-1] 'ignore)

(provide 'mouse)

;;; mouse.el ends here

debug log:

solving cb63ca51c5 ...
found cb63ca51c5 in https://git.savannah.gnu.org/cgit/emacs.git

(*) Git path names are given by the tree(s) the blob belongs to.
    Blobs themselves have no identifier aside from the hash of its contents.^

Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).