[linux/aura] Supports IBus in async mode.

chrome/browser/ui/libgtk2ui/gtk2_event_loop.cc

+// Copyright 2014 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.
+
+#include "chrome/browser/ui/libgtk2ui/gtk2_event_loop.h"
+
+#include <gdk/gdk.h>
+#include <gdk/gdkx.h>
+#include <gtk/gtk.h>
+#include <X11/X.h>
+
+#include "base/memory/singleton.h"
+#include "base/message_loop/message_pump_x11.h"
+
+namespace libgtk2ui {
+
+// static
+Gtk2EventLoop* Gtk2EventLoop::GetInstance() {
+  return Singleton<Gtk2EventLoop>::get();
+}
+
+Gtk2EventLoop::Gtk2EventLoop() {
+  gdk_event_handler_set(GdkEventTrampoline, this, NULL);
+}
+
+Gtk2EventLoop::~Gtk2EventLoop() {
+  gdk_event_handler_set(reinterpret_cast<GdkEventFunc>(gtk_main_do_event),
+                        NULL, NULL);
+}
+
+// static
+void Gtk2EventLoop::GdkEventTrampoline(GdkEvent* event, gpointer data) {
+  Gtk2EventLoop* loop = reinterpret_cast<Gtk2EventLoop*>(data);
+  loop->DispatchGdkEvent(event);
+}
+
+void Gtk2EventLoop::DispatchGdkEvent(GdkEvent* gdk_event) {
+  switch (gdk_event->type) {
+    case GDK_KEY_PRESS:
+    case GDK_KEY_RELEASE:
+      ProcessGdkEventKey(gdk_event->key);
+      break;
+    default:
+      break;  // Do nothing.
+  }
+
+  gtk_main_do_event(gdk_event);
+}
+
+void Gtk2EventLoop::ProcessGdkEventKey(const GdkEventKey& gdk_event_key) {
+  // This function translates GdkEventKeys into XKeyEvents and puts them to
+  // the X event queue.
+  //
+  // base::MessagePumpX11 is using the X11 event queue and all key events should
+  // be processed there.  However, there are cases(*1) that GdkEventKeys are
+  // created instead of XKeyEvents.  In these cases, we have to translate
+  // GdkEventKeys to XKeyEvents and puts them to the X event queue so our main
+  // event loop can handle those key events.
+  //
+  // (*1) At least ibus-gtk in async mode creates a copy of user's key event and
+  // pushes it back to the GDK event queue.  In this case, there is no
+  // corresponding key event in the X event queue.  So we have to handle this
+  // case.  ibus-gtk is used through gtk-immodule to support IMEs.
+
+  XEvent x_event = {0};
+  x_event.xkey.type =
+      gdk_event_key.type == GDK_KEY_PRESS ? KeyPress : KeyRelease;
+  x_event.xkey.send_event = gdk_event_key.send_event;
+  x_event.xkey.display = base::MessagePumpX11::GetDefaultXDisplay();
+  x_event.xkey.window = GDK_WINDOW_XID(gdk_event_key.window);
+  x_event.xkey.root = DefaultRootWindow(x_event.xkey.display);
+  x_event.xkey.time = gdk_event_key.time;
+  x_event.xkey.state = gdk_event_key.state;
+  x_event.xkey.keycode = gdk_event_key.hardware_keycode;
+  x_event.xkey.same_screen = true;
+
+  XPutBackEvent(x_event.xkey.display, &x_event);
+}
+
+}  // namespace libgtk2ui