From ae73e4478a3fd7de2fc279122dc61e02ea66b217 Mon Sep 17 00:00:00 2001
From: Po Lu <luangruo@yahoo.com>
Date: Wed, 10 Nov 2021 21:01:40 +0800
Subject: [PATCH] Add `xwidget-webkit-load-html'

* doc/lispref/display.texi (Xwidgets): Document new function.
* etc/NEWS: Announce new function.
* src/xwidget.c (Fxwidget_webkit_load_html): New function.
(syms_of_xwidget): Define new subr.
---
 doc/lispref/display.texi |  9 +++++++++
 etc/NEWS                 |  7 +++++++
 src/xwidget.c            | 41 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 57 insertions(+)

diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index b6bd14f887..b7d12269ae 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -6943,6 +6943,15 @@ Xwidgets
 signals an error.
 @end defun
 
+@defun xwidget-webkit-load-html xwidget text &optional base-uri
+Load @var{text}, a string, into @var{xwidget}, which should be a
+WebKit xwidget.  Any HTML markup in @var{text} will be processed
+by @var{xwidget} while rendering the text.
+
+Optional argument @var{base-uri}, which should be a string, specifies
+the absolute location of the web resources referenced by @var{text},
+to be used for resolving relative links in @var{text}.
+
 @node Buttons
 @section Buttons
 @cindex buttons in buffers
diff --git a/etc/NEWS b/etc/NEWS
index 3cad0995ac..bc693b3205 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -796,6 +796,13 @@ what the widget will actually receive.
 
 On GTK+, only key and function key events are implemented.
 
++++
+*** New function 'xwidget-webkit-load-html'.
+This function is used to load HTML text into WebKit xwidgets
+directly, in contrast to creating a temporary file to hold the
+markup, and passing the URI of the file as an argument to
+'xwidget-webkit-goto-uri'.
+
 +++
 *** New functions for performing searches on WebKit xwidgets.
 Some new functions, such as 'xwidget-webkit-search', have been added
diff --git a/src/xwidget.c b/src/xwidget.c
index 2ae635092d..fc05f4f570 100644
--- a/src/xwidget.c
+++ b/src/xwidget.c
@@ -2278,6 +2278,44 @@ DEFUN ("xwidget-webkit-finish-search", Fxwidget_webkit_finish_search,
   return Qnil;
 }
 
+#ifdef USE_GTK
+DEFUN ("xwidget-webkit-load-html", Fxwidget_webkit_load_html,
+       Sxwidget_webkit_load_html, 2, 3, 0,
+       doc: /* Make XWIDGET's WebKit widget render TEXT.
+XWIDGET should be a WebKit xwidget, that will receive TEXT.  TEXT
+should be a string that will be displayed by XWIDGET as HTML markup.
+BASE_URI should be a string containing a URI that is used to locate
+resources with relative URLs, and if not specified, defaults
+to "about:blank".  */)
+  (Lisp_Object xwidget, Lisp_Object text, Lisp_Object base_uri)
+{
+  struct xwidget *xw;
+  WebKitWebView *webview;
+  char *data, *uri;
+
+  CHECK_XWIDGET (xwidget);
+  CHECK_STRING (text);
+  if (NILP (base_uri))
+    base_uri = build_string ("about:blank");
+  else
+    CHECK_STRING (base_uri);
+
+  base_uri = ENCODE_UTF_8 (base_uri);
+  text = ENCODE_UTF_8 (text);
+  xw = XXWIDGET (xwidget);
+
+  data = SSDATA (text);
+  uri = SSDATA (base_uri);
+  webview = WEBKIT_WEB_VIEW (xw->widget_osr);
+
+  block_input ();
+  webkit_web_view_load_html (webview, data, uri);
+  unblock_input ();
+
+  return Qnil;
+}
+#endif
+
 void
 syms_of_xwidget (void)
 {
@@ -2316,6 +2354,9 @@ syms_of_xwidget (void)
   defsubr (&Sxwidget_webkit_next_result);
   defsubr (&Sxwidget_webkit_previous_result);
   defsubr (&Sset_xwidget_buffer);
+#ifdef USE_GTK
+  defsubr (&Sxwidget_webkit_load_html);
+#endif
 
   DEFSYM (QCxwidget, ":xwidget");
   DEFSYM (QCtitle, ":title");
-- 
2.31.1