text: // Copyright (c) 2012 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 CONTENT_BROWSER_RENDERER_HOST_GTK_KEY_BINDINGS_HANDLER_H_
  #define CONTENT_BROWSER_RENDERER_HOST_GTK_KEY_BINDINGS_HANDLER_H_
  
  #include <gtk/gtk.h>
  
  #include <string>
  
  #include "content/common/edit_command.h"
  #include "content/common/content_export.h"
  #include "ui/base/gtk/owned_widget_gtk.h"
  
  namespace content {
  struct 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/Source/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 CONTENT_EXPORT GtkKeyBindingsHandler {
   public:
    explicit GtkKeyBindingsHandler(GtkWidget* parent_widget);
    ~GtkKeyBindingsHandler();
  
    // 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 content::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);
  
    // Handler of "show-help" signal.
    static gboolean ShowHelp(GtkWidget* widget, GtkWidgetHelpType arg1);
  
    // Handler of "move-focus" signal.
    static void MoveFocus(GtkWidget* widget, GtkDirectionType arg1);
  
    ui::OwnedWidgetGtk handler_;
  
    // Buffer to store the match results.
    EditCommands edit_commands_;
  };
  
  #endif  // CONTENT_BROWSER_RENDERER_HOST_GTK_KEY_BINDINGS_HANDLER_H_
  