Add xwidget-webkit-edit-mode to make using the WebKit browser easier

* doc/emacs/misc.texi: Document changes.
* etc/NEWS: Document recent changes.
* lisp/xwidget.el (xwidget-webkit-pass-command-event): New variable.
* lisp/xwidget.el (xwidget-perform-lispy-event): New function
declaration.
* lisp/xwidget.el (xwidget-webkit-edit-mode): New minor mode.

doc/emacs/misc.texi

@@ -2953,6 +2953,14 @@ one-key commands for scrolling the widget, changing its size, and
 reloading it.  Type @w{@kbd{C-h b}} in that buffer to see the key
 bindings.
 
+@findex xwidget-webkit-edit-mode
+@cindex xwidget-webkit-edit-mode
+  By default, typing a self-inserting character inside an xwidget
+webkit buffer will do nothing, or trigger some special action.  To
+make those characters and other common editing keys insert themselves
+when pressed, you can enable @code{xwidget-webkit-edit-mode}, which
+redefines them to be passed through to the WebKit xwidget.
+
 @node Browse-URL
 @subsection  Following URLs
 @cindex World Wide Web

etc/NEWS

@@ -495,6 +495,13 @@ the buffer will take you to that directory.
 This is a convenience function to extract the field data from
 'exif-parse-file' and 'exif-parse-buffer'.
 
+** Xwidgets
+
+*** New minor mode `xwidget-webkit-edit-mode'.
+When this mode is enabled, self-inserting characters and other common
+web browser shotcut keys are redefined to send themselves to the
+WebKit widget.
+
 
 * New Modes and Packages in Emacs 29.1
 
@@ -719,6 +726,14 @@ an exact match, then the lowercased '[menu-bar foo\ bar]' and finally
 '[menu-bar foo-bar]'.  This further improves backwards-compatibility
 when converting menus to use 'easy-menu-define'.
 
++++
+** New function `xwidget-perform-lispy-event'.
+This function allows you to send events to xwidgets.  Usually, some
+equivalent of the event will be sent, but there is no guarantee of
+what the widget will actually receive.
+
+On GTK+, only key and function key events are implemented.
+
 
 * Changes in Emacs 29.1 on Non-Free Operating Systems
 

lisp/xwidget.el

@@ -124,6 +124,14 @@ in `split-window-right' with a new xwidget webkit session."
     (with-selected-window (split-window-right)
       (xwidget-webkit-new-session url))))
 
+(declare-function xwidget-perform-lispy-event "xwidget.c")
+
+(defun xwidget-webkit-pass-command-event ()
+  "Pass `last-command-event' to the current buffer's WebKit widget."
+  (interactive)
+  (xwidget-perform-lispy-event (xwidget-webkit-current-session)
+                               last-command-event))
+
 ;;todo.
 ;; - check that the webkit support is compiled in
 (defvar xwidget-webkit-mode-map
@@ -684,6 +692,44 @@ You can retrieve the value with `xwidget-get'."
   (set-xwidget-plist xwidget
                      (plist-put (xwidget-plist xwidget) propname value)))
 
+(defvar xwidget-webkit-edit-mode-map (make-keymap))
+
+(define-key xwidget-webkit-edit-mode-map [backspace] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [tab] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [left] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [right] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [up] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [down] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [return] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [C-left] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [C-right] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [C-up] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [C-down] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [C-return] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [S-left] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [S-right] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [S-up] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [S-down] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [S-return] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [M-left] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [M-right] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [M-up] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [M-down] 'xwidget-webkit-pass-command-event)
+(define-key xwidget-webkit-edit-mode-map [M-return] 'xwidget-webkit-pass-command-event)
+
+(define-minor-mode xwidget-webkit-edit-mode
+  "Minor mode for editing the content of WebKit buffers.
+
+This defines most self-inserting characters and some common
+keyboard shortcuts to `xwidget-webkit-pass-command-event', which
+will pass the key events corresponding to these characters to the
+WebKit widget."
+  :keymap xwidget-webkit-edit-mode-map)
+
+(substitute-key-definition 'self-insert-command
+                           'xwidget-webkit-pass-command-event
+                           xwidget-webkit-edit-mode-map
+                           global-map)
 
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