NS port horizontal scroll-bars

NS port horizontal scroll-bars

[Alan Third]

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I've been trying to complete the horizontal scroll-bars implementation
in the NS port and have run into a bit of a problem I can't work out.

They display correctly, and when you click on them they, I think, send
a correctly formatted emacs_event, but nothing happens. Vertical
scroll-bars work as expected.

Have I missed somewhere where I need to enable the horizontal
scroll-bar events or something? Any pointers would be appreciated.

I've attached a patch containing what I've done so far.
-- 
Alan Third

[-- Attachment #2: Horizontal scroll-bars patch --]
[-- Type: text/plain, Size: 10421 bytes --]

diff --git a/lisp/scroll-bar.el b/lisp/scroll-bar.el
index 5cfa2c4..01194f9 100644
--- a/lisp/scroll-bar.el
+++ b/lisp/scroll-bar.el
@@ -149,7 +149,8 @@ horizontal-scroll-bars-available-p
   (and (display-graphic-p)
        (boundp 'x-toolkit-scroll-bars)
        x-toolkit-scroll-bars
-       (not (eq (window-system) 'ns))))
+       ;; (not (eq (window-system) 'ns))
+       ))
 
 (define-minor-mode horizontal-scroll-bar-mode
   "Toggle horizontal scroll bars on all frames (Horizontal Scroll Bar mode).
diff --git a/src/nsterm.h b/src/nsterm.h
index 0aea9cc..93b19e4 100644
--- a/src/nsterm.h
+++ b/src/nsterm.h
@@ -72,7 +72,7 @@ typedef float EmacsCGFloat;
    Hint: keep the trailing whitespace -- the version control system
    will reject accidental commits. */
 
-/* #define NSTRACE_ENABLED 1          */
+#define NSTRACE_ENABLED 1
 
 
 /* When non-zero, trace output is enabled for all parts, except those
@@ -681,6 +681,8 @@ char const * nstrace_fullscreen_type_name (int);
 
    BOOL condemned;
 
+   BOOL horizontal;
+   
    /* optimize against excessive positioning calls generated by emacs */
    int em_position;
    int em_portion;
diff --git a/src/nsterm.m b/src/nsterm.m
index 34c5395..91af34f 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -4442,11 +4442,11 @@ ns_set_horizontal_scroll_bar (struct window *window,
   NSTRACE ("ns_set_horizontal_scroll_bar");
 
   /* Get dimensions.  */
-  window_box (window, ANY_AREA, 0, &window_x, &window_width, 0);
+  window_box (window, ANY_AREA, &window_x, 0, &window_width, 0);
   left = window_x;
   width = window_width;
   height = WINDOW_CONFIG_SCROLL_BAR_LINES (window) * FRAME_LINE_HEIGHT (f);
-  top = WINDOW_SCROLL_BAR_AREA_Y (window);
+  top = WINDOW_SCROLL_BAR_AREA_Y (window) - FRAME_LINE_HEIGHT (f);
 
   r = NSMakeRect (left, top, width, height);
   /* the parent view is flipped, so we need to flip y value */
@@ -4484,10 +4484,10 @@ ns_set_horizontal_scroll_bar (struct window *window,
       NSRect oldRect;
       bar = XNS_SCROLL_BAR (window->horizontal_scroll_bar);
       oldRect = [bar frame];
-      r.size.width = oldRect.size.width;
+      r.size.height = oldRect.size.height;
       if (FRAME_LIVE_P (f) && !NSEqualRects (oldRect, r))
         {
-          if (oldRect.origin.x != r.origin.x)
+          if (oldRect.origin.y != r.origin.y)
               ns_clear_frame_area (f, left, top, width, height);
           [bar setFrame: r];
           update_p = YES;
@@ -8110,12 +8110,21 @@ not_in_argv (NSString *arg)
   return r;
 }
 
-
 - initFrame: (NSRect )r window: (Lisp_Object)nwin
 {
   NSTRACE ("[EmacsScroller initFrame: window:]");
 
-  r.size.width = [EmacsScroller scrollerWidth];
+  if (r.size.width > r.size.height)
+    {
+      horizontal = YES;
+      r.size.height = [EmacsScroller scrollerWidth];
+    }
+  else
+    {
+      horizontal = NO;
+      r.size.width = [EmacsScroller scrollerWidth];
+    }
+
   [super initWithFrame: r/*NSMakeRect (0, 0, 0, 0)*/];
   [self setContinuous: YES];
   [self setEnabled: YES];
@@ -8131,7 +8140,10 @@ not_in_argv (NSString *arg)
 
   window = XWINDOW (nwin);
   condemned = NO;
-  pixel_height = NSHeight (r);
+  if (horizontal)
+    pixel_height = NSWidth (r);
+  else
+    pixel_height = NSHeight (r);
   if (pixel_height == 0) pixel_height = 1;
   min_portion = 20 / pixel_height;
 
@@ -8162,7 +8174,10 @@ not_in_argv (NSString *arg)
   NSTRACE ("[EmacsScroller setFrame:]");
 
 /*  block_input (); */
-  pixel_height = NSHeight (newRect);
+  if (newRect.size.width > newRect.size.height)
+    pixel_height = NSWidth (newRect);
+  else
+    pixel_height = NSHeight (newRect);
   if (pixel_height == 0) pixel_height = 1;
   min_portion = 20 / pixel_height;
   [super setFrame: newRect];
@@ -8174,7 +8189,12 @@ not_in_argv (NSString *arg)
 {
   NSTRACE ("[EmacsScroller dealloc]");
   if (window)
-    wset_vertical_scroll_bar (window, Qnil);
+    {
+      if (horizontal)
+        wset_horizontal_scroll_bar (window, Qnil);
+      else
+        wset_vertical_scroll_bar (window, Qnil);
+    }
   window = 0;
   [super dealloc];
 }
@@ -8289,10 +8309,15 @@ not_in_argv (NSString *arg)
   XSETWINDOW (win, window);
   emacs_event->frame_or_window = win;
   emacs_event->timestamp = EV_TIMESTAMP (e);
-  emacs_event->kind = SCROLL_BAR_CLICK_EVENT;
-  emacs_event->arg = Qnil;
-  XSETINT (emacs_event->x, loc * pixel_height);
+  if (horizontal)
+    emacs_event->kind = HORIZONTAL_SCROLL_BAR_CLICK_EVENT;
+  else
+    emacs_event->kind = SCROLL_BAR_CLICK_EVENT;
+  XSETINT (emacs_event->x, loc);
   XSETINT (emacs_event->y, pixel_height-20);
+  emacs_event->arg = Qnil;
+
+  printf("x: %d, y: %d\n", emacs_event->x, emacs_event->y);
 
   if (q_event_ptr)
     {
@@ -8355,13 +8380,13 @@ not_in_argv (NSString *arg)
   switch (part)
     {
     case NSScrollerDecrementPage:
-        last_hit_part = scroll_bar_above_handle; inc = -1.0; break;
+        last_hit_part = scroll_bar_above_handle; break;
     case NSScrollerIncrementPage:
-        last_hit_part = scroll_bar_below_handle; inc = 1.0; break;
+        last_hit_part = scroll_bar_below_handle; break;
     case NSScrollerDecrementLine:
-      last_hit_part = scroll_bar_up_arrow; inc = -0.1; break;
+      last_hit_part = scroll_bar_up_arrow; break;
     case NSScrollerIncrementLine:
-      last_hit_part = scroll_bar_down_arrow; inc = 0.1; break;
+      last_hit_part = scroll_bar_down_arrow; break;
     case NSScrollerKnob:
       last_hit_part = scroll_bar_handle; break;
     case NSScrollerKnobSlot:  /* GNUstep-only */
@@ -8372,36 +8397,34 @@ not_in_argv (NSString *arg)
       return;
     }
 
-  if (inc != 0.0)
-    {
-      pos = 0;      /* ignored */
-
-      /* set a timer to repeat, as we can't let superclass do this modally */
-      scroll_repeat_entry
-	= [[NSTimer scheduledTimerWithTimeInterval: SCROLL_BAR_FIRST_DELAY
-                                            target: self
-                                          selector: @selector (repeatScroll:)
-                                          userInfo: 0
-                                           repeats: YES]
-	    retain];
-    }
-  else
+  if (part == NSScrollerKnob || part == NSScrollerKnobSlot)
     {
       /* handle, or on GNUstep possibly slot */
       NSEvent *fake_event;
-
+      int length;
+      
       /* compute float loc in slot and mouse offset on knob */
       sr = [self convertRect: [self rectForPart: NSScrollerKnobSlot]
                       toView: nil];
-      loc = NSHeight (sr) - ([e locationInWindow].y - NSMinY (sr));
+      if (horizontal)
+        {
+          length = NSWidth (sr);
+          loc = ([e locationInWindow].x - NSMinX (sr));
+        }
+      else
+        {
+          length = NSHeight (sr);
+          loc = length - ([e locationInWindow].y - NSMinY (sr));
+        }
+      
       if (loc <= 0.0)
         {
           loc = 0.0;
           edge = -1;
         }
-      else if (loc >= NSHeight (sr))
+      else if (loc >= length)
         {
-          loc = NSHeight (sr);
+          loc = length;
           edge = 1;
         }
 
@@ -8411,17 +8434,16 @@ not_in_argv (NSString *arg)
         {
           kr = [self convertRect: [self rectForPart: NSScrollerKnob]
                           toView: nil];
-          kloc = NSHeight (kr) - ([e locationInWindow].y - NSMinY (kr));
+          if (horizontal)
+            kloc = ([e locationInWindow].x - NSMinX (kr));
+          else
+            kloc = NSHeight (kr) - ([e locationInWindow].y - NSMinY (kr));
         }
       last_mouse_offset = kloc;
 
-      /* if knob, tell emacs a location offset by knob pos
-         (to indicate top of handle) */
-      if (part == NSScrollerKnob)
-          pos = (loc - last_mouse_offset) / NSHeight (sr);
-      else
-        /* else this is a slot click on GNUstep: go straight there */
-        pos = loc / NSHeight (sr);
+      if (part != NSScrollerKnob)
+        /* this is a slot click on GNUstep: go straight there */
+        pos = loc / length;
 
       /* send a fake mouse-up to super to preempt modal -trackKnob: mode */
       fake_event = [NSEvent mouseEventWithType: NSLeftMouseUp
@@ -8435,6 +8457,19 @@ not_in_argv (NSString *arg)
                                       pressure: [e pressure]];
       [super mouseUp: fake_event];
     }
+  else
+    {
+      pos = 0;      /* ignored */
+
+      /* set a timer to repeat, as we can't let superclass do this modally */
+      scroll_repeat_entry
+	= [[NSTimer scheduledTimerWithTimeInterval: SCROLL_BAR_FIRST_DELAY
+                                            target: self
+                                          selector: @selector (repeatScroll:)
+                                          userInfo: 0
+                                           repeats: YES]
+	    retain];
+    }
 
   if (part != NSScrollerKnob)
     [self sendScrollEventAtLoc: pos fromEvent: e];
@@ -8446,23 +8481,34 @@ not_in_argv (NSString *arg)
 {
     NSRect sr;
     double loc, pos;
-
+    int length;
+    
     NSTRACE ("[EmacsScroller mouseDragged:]");
 
       sr = [self convertRect: [self rectForPart: NSScrollerKnobSlot]
                       toView: nil];
-      loc = NSHeight (sr) - ([e locationInWindow].y - NSMinY (sr));
+
+      if (horizontal)
+        {
+          length = NSWidth (sr);
+          loc = ([e locationInWindow].x - NSMinX (sr));
+        }
+      else
+        {
+          length = NSHeight (sr);
+          loc = length - ([e locationInWindow].y - NSMinY (sr));
+        }
 
       if (loc <= 0.0)
         {
           loc = 0.0;
         }
-      else if (loc >= NSHeight (sr) + last_mouse_offset)
+      else if (loc >= length + last_mouse_offset)
         {
-          loc = NSHeight (sr) + last_mouse_offset;
+          loc = length + last_mouse_offset;
         }
 
-      pos = (loc - last_mouse_offset) / NSHeight (sr);
+      pos = (loc - last_mouse_offset);
       [self sendScrollEventAtLoc: pos fromEvent: e];
 }
 
diff --git a/src/window.h b/src/window.h
index 0cfff88..a1c4aaa 100644
--- a/src/window.h
+++ b/src/window.h
@@ -786,7 +786,7 @@ wset_next_buffers (struct window *w, Lisp_Object val)
    || WINDOW_HAS_VERTICAL_SCROLL_BAR_ON_RIGHT (W))
 
 #if (defined (HAVE_WINDOW_SYSTEM)					\
-     && ((defined (USE_TOOLKIT_SCROLL_BARS) && !defined (HAVE_NS))	\
+     && ((defined (USE_TOOLKIT_SCROLL_BARS))	\
 	 || defined (HAVE_NTGUI)))
 # define USE_HORIZONTAL_SCROLL_BARS true
 #else

Re: NS port horizontal scroll-bars

[Anders Lindgren]

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Hi!

I think you simply haven't mapped the horizontal events to anything.
ns-win.el contains the following:

(global-set-key [vertical-scroll-bar down-mouse-1]
'ns-handle-scroll-bar-event)
(global-unset-key [vertical-scroll-bar mouse-1])
(global-unset-key [vertical-scroll-bar drag-mouse-1])

If I do the same with `horizontal-scroll-bar' I can drag it around, and
Emacs react to it. (Unfortunately, it then scroll the window vertically
rather than horizontally, but that just a technicality :)

Also, if you evaluate (read-key-sequence "Click on something: ") and either
click on the empty space next to the scroll bar or drag it, it will return
events with the type `horizontal-scroll-bar'.

Thanks for starting to work on the NS port!

    -- Anders


On Sun, Apr 24, 2016 at 6:01 PM, Alan Third <alan@idiocy.org> wrote:

> I've been trying to complete the horizontal scroll-bars implementation
> in the NS port and have run into a bit of a problem I can't work out.
>
> They display correctly, and when you click on them they, I think, send
> a correctly formatted emacs_event, but nothing happens. Vertical
> scroll-bars work as expected.
>
> Have I missed somewhere where I need to enable the horizontal
> scroll-bar events or something? Any pointers would be appreciated.
>
> I've attached a patch containing what I've done so far.
> --
> Alan Third
>

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Re: NS port horizontal scroll-bars

[Alan Third]

On Sun, Apr 24, 2016 at 07:28:58PM +0200, Anders Lindgren wrote:
> I think you simply haven't mapped the horizontal events to anything.
> ns-win.el contains the following:
> 
> (global-set-key [vertical-scroll-bar down-mouse-1]
> 'ns-handle-scroll-bar-event)
> (global-unset-key [vertical-scroll-bar mouse-1])
> (global-unset-key [vertical-scroll-bar drag-mouse-1])

Yup, that's it exactly!

Now I just need to work out how to turn the values I get into columns
that I can scroll the screen to.

Is there a function that returns the width of the longest visible
line, or the width of the buffer with truncated lines? I can't find
anything like that.
-- 
Alan Third

Re: NS port horizontal scroll-bars

[Anders Lindgren]

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Hi!


> Yup, that's it exactly!
>

Great!


> Now I just need to work out how to turn the values I get into columns
> that I can scroll the screen to.
>
> Is there a function that returns the width of the longest visible
> line, or the width of the buffer with truncated lines? I can't find
> anything like that.
>

I don't know of any such function either. However, I noticed that the
scroll bar change length depending on the content of the window. So,
presumably, you get all relevant information when
`ns_set_horizontal_scroll_bar' is called.

    -- Anders

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Re: NS port horizontal scroll-bars

[martin rudalics]

 > Is there a function that returns the width of the longest visible
 > line,

You can use ‘window-text-pixel-size’ for this but I don't understand
what you need it for.  The basic slider size and position calculations
are done in set_horizontal_scroll_bar in xdisp.c and that function calls
the set_horizontal_scroll_bar_hook corresponding to your platform which
should be ns_set_horizontal_scroll_bar.  The latter probably needs some
tweaking as for the other platforms.

 > or the width of the buffer with truncated lines? I can't find
 > anything like that.

Many thanks for working on this, martin

Re: NS port horizontal scroll-bars

[Alan Third]

On 26 April 2016 at 07:35, martin rudalics <rudalics@gmx.at> wrote:
>> Is there a function that returns the width of the longest visible
>> line,
>
> You can use ‘window-text-pixel-size’ for this but I don't understand
> what you need it for.  The basic slider size and position calculations
> are done in set_horizontal_scroll_bar in xdisp.c and that function calls
> the set_horizontal_scroll_bar_hook corresponding to your platform which
> should be ns_set_horizontal_scroll_bar.  The latter probably needs some
> tweaking as for the other platforms.

(I've not got the code in front of me right now, so this may be a little
vague. I hope you can understand it.)

It's actually the other end of the process that I'm struggling with. I
write pixel values for dragging the scroll-bar into an emacs_event
struct (location of mouse in scroll-bar and total length of scroll-bar),
and when that data pops back out in scroll-bar.el it doesn't seem to be
any use to the standard scroll-bar functions.

For example, with a buffer where the longest line is 300 columns, it's
returning values between 0 and 556. As far as I can tell the standard
functions are expecting column numbers.

I think, from reading the comments in the emacs_event struct definition,
that I'm presenting the correct information, so I don't know why it
doesn't work.

The vertical scroll-bars in the NS port have their own functions defined
in ns-win.el, rather than using the functions in scroll-bar.el. I think
this is, at least in part, to enable clicking directional arrows in
older versions of OS X (and GNUSTEP), but it's doing something different
with dragging too.

-- 
Alan Third

Re: NS port horizontal scroll-bars

[YAMAMOTO Mitsuharu]

>>>>> On Tue, 26 Apr 2016 10:51:57 +0100, Alan Third <alan@idiocy.org> said:

> It's actually the other end of the process that I'm struggling
> with. I write pixel values for dragging the scroll-bar into an
> emacs_event struct (location of mouse in scroll-bar and total length
> of scroll-bar), and when that data pops back out in scroll-bar.el it
> doesn't seem to be any use to the standard scroll-bar functions.

Ah, that reminds me of something.  You can see how the Mac port
handles that (in the `work' branch based on Emacs 25.0.93 pretest).

https://bitbucket.org/mituharu/emacs-mac/src/472fe59bac472a9076cbb6e86e0ea92908f7b78d/src/macappkit.m?at=work&fileviewer=file-view-default#macappkit.m-6002

  6690	      if (bar->horizontal && whole > 0)
  6691		{
  6692		  /* The default horizontal scroll bar drag handler assumes
  6693		     previously-set `whole' value to be preserved and doesn't
  6694		     want overscrolling.  */
  6695		  int position = lround (whole * minEdge / maximum);
  6696	
  6697		  if (position > whole - portion)
  6698		    position = whole - portion;
  6699		  XSETINT (inputEvent.x, position);
  6700		  XSETINT (inputEvent.y, whole);
  6701		}
  6702	      else
  6703		{
  6704		  XSETINT (inputEvent.x, minEdge);
  6705		  XSETINT (inputEvent.y, maximum);
  6706		}
  6707	    }

> The vertical scroll-bars in the NS port have their own functions
> defined in ns-win.el, rather than using the functions in
> scroll-bar.el. I think this is, at least in part, to enable clicking
> directional arrows in older versions of OS X (and GNUSTEP), but it's
> doing something different with dragging too.

The Mac port (and its predecessors) has been using the standard
toolkit scroll bar handler in scroll-bar.el as it is, and there has
been no problem even in the old OS X versions having the directional
arrows.

				     YAMAMOTO Mitsuharu
				mituharu@math.s.chiba-u.ac.jp

Re: NS port horizontal scroll-bars

[Alan Third]

On Tue, Apr 26, 2016 at 08:27:35PM +0900, YAMAMOTO Mitsuharu wrote:
> >>>>> On Tue, 26 Apr 2016 10:51:57 +0100, Alan Third <alan@idiocy.org> said:
> 
> > It's actually the other end of the process that I'm struggling
> > with. I write pixel values for dragging the scroll-bar into an
> > emacs_event struct (location of mouse in scroll-bar and total length
> > of scroll-bar), and when that data pops back out in scroll-bar.el it
> > doesn't seem to be any use to the standard scroll-bar functions.
> 
> Ah, that reminds me of something.  You can see how the Mac port
> handles that (in the `work' branch based on Emacs 25.0.93 pretest).
> 
<snip code>

That's cracked it! Thanks! I've now got the horizontal scroll bar
working with the standard handler.

> The Mac port (and its predecessors) has been using the standard
> toolkit scroll bar handler in scroll-bar.el as it is, and there has
> been no problem even in the old OS X versions having the directional
> arrows.

I'm none-the-wiser as to why the NS port is using a custom handler
then. I've discovered that it's got a bug where scrolling an
unselected window also scrolls the selected window if they're
displaying the same buffer.

I'm feeling inclined towards trying to get rid of the custom handler
altogether.
-- 
Alan Third

Re: NS port horizontal scroll-bars

[Angelo Graziosi]

> Alan Third
> Implement horizontal scroll bars on NS
> * lisp/scroll-bar.el (horizontal-scroll-bars-available-p): Remove NS
> check.
> [...]

It seems that they work just fine!

Many thanks,
  Angelo.