Supports Gtk keyboard themes....

chrome/browser/renderer_host/gtk_key_bindings_handler.h

+// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_RENDERER_HOST_GTK_KEY_BINDINGS_HANDLER_H_
+#define CHROME_BROWSER_RENDERER_HOST_GTK_KEY_BINDINGS_HANDLER_H_
+
+#include <gtk/gtk.h>
+
+#include <string>
+
+#include "chrome/common/edit_command.h"
+#include "chrome/common/owned_widget_gtk.h"
+
+class NativeWebKeyboardEvent;
+
+// This class is a convenience class for handling editor key bindings defined
+// in gtk keyboard theme.
+// In gtk, only GtkEntry and GtkTextView support customizing editor key bindings
+// through keyboard theme. And in gtk keyboard theme definition file, each key
+// binding must be bound to a specific class or object. So existing keyboard
+// themes only define editor key bindings exactly for GtkEntry and GtkTextView.
+// Then, the only way for us to intercept editor key bindings defined in
+// keyboard theme, is to create a GtkEntry or GtkTextView object and call
+// gtk_bindings_activate_event() against it for the key events. If a key event
+// matches a predefined key binding, corresponding signal will be emitted.
+// GtkTextView is used here because it supports more key bindings than GtkEntry,
+// but in order to minimize the side effect of using a GtkTextView object, a new
+// class derived from GtkTextView is used, which overrides all signals related
+// to key bindings, to make sure GtkTextView won't receive them.
+//
+// See third_party/WebKit/WebCore/editing/EditorCommand.cpp for detailed
+// definition of webkit edit commands.
+// See webkit/glue/editor_client_impl.cc for key bindings predefined in our
+// webkit glue.
+class GtkKeyBindingsHandler {
+ public:
+  explicit GtkKeyBindingsHandler(GtkWidget* parent_widget);
+  ~GtkKeyBindingsHandler();
+
+  // Key bindings handler will be disabled when IME is disabled by webkit.
+  void set_enabled(bool enabled) {
+    enabled_ = enabled;
+  }
+
+  // Matches a key event against predefined gtk key bindings, false will be
+  // returned if the key event doesn't correspond to a predefined key binding.
+  // Edit commands matched with |wke| will be stored in |edit_commands|.
+  bool Match(const NativeWebKeyboardEvent& wke, EditCommands* edit_commands);
+
+ private:
+  // Object structure of Handler class, which is derived from GtkTextView.
+  struct Handler {
+    GtkTextView parent_object;
+    GtkKeyBindingsHandler *owner;
+  };
+
+  // Class structure of Handler class.
+  struct HandlerClass {
+    GtkTextViewClass parent_class;
+  };
+
+  // Creates a new instance of Handler class.
+  GtkWidget* CreateNewHandler();
+
+  // Adds an edit command to the key event.
+  void EditCommandMatched(const std::string& name, const std::string& value);
+
+  // Initializes Handler structure.
+  static void HandlerInit(Handler *self);
+
+  // Initializes HandlerClass structure.
+  static void HandlerClassInit(HandlerClass *klass);
+
+  // Registeres Handler class to GObject type system and return its type id.
+  static GType HandlerGetType();
+
+  // Gets the GtkKeyBindingsHandler object which owns the Handler object.
+  static GtkKeyBindingsHandler* GetHandlerOwner(GtkTextView* text_view);
+
+  // Handler of "backspace" signal.
+  static void BackSpace(GtkTextView* text_view);
+
+  // Handler of "copy-clipboard" signal.
+  static void CopyClipboard(GtkTextView* text_view);
+
+  // Handler of "cut-clipboard" signal.
+  static void CutClipboard(GtkTextView* text_view);
+
+  // Handler of "delete-from-cursor" signal.
+  static void DeleteFromCursor(GtkTextView* text_view, GtkDeleteType type,
+                               gint count);
+
+  // Handler of "insert-at-cursor" signal.
+  static void InsertAtCursor(GtkTextView* text_view, const gchar* str);
+
+  // Handler of "move-cursor" signal.
+  static void MoveCursor(GtkTextView* text_view, GtkMovementStep step,
+                         gint count, gboolean extend_selection);
+
+  // Handler of "move-viewport" signal.
+  static void MoveViewport(GtkTextView* text_view, GtkScrollStep step,
+                           gint count);
+
+  // Handler of "paste-clipboard" signal.
+  static void PasteClipboard(GtkTextView* text_view);
+
+  // Handler of "select-all" signal.
+  static void SelectAll(GtkTextView* text_view, gboolean select);
+
+  // Handler of "set-anchor" signal.
+  static void SetAnchor(GtkTextView* text_view);
+
+  // Handler of "toggle-cursor-visible" signal.
+  static void ToggleCursorVisible(GtkTextView* text_view);
+
+  // Handler of "toggle-overwrite" signal.
+  static void ToggleOverwrite(GtkTextView* text_view);
+
+  OwnedWidgetGtk handler_;
+
+  // Buffer to store the match results.
+  EditCommands edit_commands_;
+
+  // Indicates if key bindings handler is enabled or not.
+  // It'll only be enabled if IME is enabled by webkit.
+  bool enabled_;
+};
+
+#endif  // CHROME_BROWSER_RENDERER_HOST_GTK_KEY_BINDINGS_HANDLER_H_