chrome/browser/ui/libgtk2ui/gtk2_event_loop.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/ui/libgtk2ui/gtk2_event_loop.h"
   6
   7 #include <gdk/gdk.h>
   8 #include <gdk/gdkx.h>
   9 #include <gtk/gtk.h>
  10 #include <X11/X.h>
  11
  12 #include "base/memory/singleton.h"
  13 #include "ui/gfx/x/x11_types.h"
  14
  15 namespace libgtk2ui {
  16
  17 // static
  18 Gtk2EventLoop* Gtk2EventLoop::GetInstance() {
  19   return Singleton<Gtk2EventLoop>::get();
  20 }
  21
  22 Gtk2EventLoop::Gtk2EventLoop() {
  23   gdk_event_handler_set(DispatchGdkEvent, NULL, NULL);
  24 }
  25
  26 Gtk2EventLoop::~Gtk2EventLoop() {
  27   gdk_event_handler_set(reinterpret_cast<GdkEventFunc>(gtk_main_do_event),
  28                         NULL, NULL);
  29 }
  30
  31 // static
  32 void Gtk2EventLoop::DispatchGdkEvent(GdkEvent* gdk_event, gpointer) {
  33   switch (gdk_event->type) {
  34     case GDK_KEY_PRESS:
  35     case GDK_KEY_RELEASE:
  36       ProcessGdkEventKey(gdk_event->key);
  37       break;
  38     default:
  39       break;  // Do nothing.
  40   }
  41
  42   gtk_main_do_event(gdk_event);
  43 }
  44
  45 // static
  46 void Gtk2EventLoop::ProcessGdkEventKey(const GdkEventKey& gdk_event_key) {
  47   // This function translates GdkEventKeys into XKeyEvents and puts them to
  48   // the X event queue.
  49   //
  50   // base::MessagePumpX11 is using the X11 event queue and all key events should
  51   // be processed there.  However, there are cases(*1) that GdkEventKeys are
  52   // created instead of XKeyEvents.  In these cases, we have to translate
  53   // GdkEventKeys to XKeyEvents and puts them to the X event queue so our main
  54   // event loop can handle those key events.
  55   //
  56   // (*1) At least ibus-gtk in async mode creates a copy of user's key event and
  57   // pushes it back to the GDK event queue.  In this case, there is no
  58   // corresponding key event in the X event queue.  So we have to handle this
  59   // case.  ibus-gtk is used through gtk-immodule to support IMEs.
  60
  61   XEvent x_event = {0};
  62   x_event.xkey.type =
  63       gdk_event_key.type == GDK_KEY_PRESS ? KeyPress : KeyRelease;
  64   x_event.xkey.send_event = gdk_event_key.send_event;
  65   x_event.xkey.display = gfx::GetXDisplay();
  66   x_event.xkey.window = GDK_WINDOW_XID(gdk_event_key.window);
  67   x_event.xkey.root = DefaultRootWindow(x_event.xkey.display);
  68   x_event.xkey.time = gdk_event_key.time;
  69   x_event.xkey.state = gdk_event_key.state;
  70   x_event.xkey.keycode = gdk_event_key.hardware_keycode;
  71   x_event.xkey.same_screen = true;
  72
  73   XPutBackEvent(x_event.xkey.display, &x_event);
  74 }
  75
  76 }  // namespace libgtk2ui