Gtk3 ui: Add libgtk3ui as a separate build component

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 "ui/events/platform/x11/x11_event_source.h"
-#include "ui/gfx/x/x11_types.h"
-
-namespace libgtk2ui {
-
-// static
-Gtk2EventLoop* Gtk2EventLoop::GetInstance() {
-  return base::Singleton<Gtk2EventLoop>::get();
-}
-
-Gtk2EventLoop::Gtk2EventLoop() {
-  gdk_event_handler_set(DispatchGdkEvent, NULL, NULL);
-}
-
-Gtk2EventLoop::~Gtk2EventLoop() {
-  gdk_event_handler_set(reinterpret_cast<GdkEventFunc>(gtk_main_do_event),
-                        NULL, NULL);
-}
-
-// static
-void Gtk2EventLoop::DispatchGdkEvent(GdkEvent* gdk_event, gpointer) {
-  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);
-}
-
-// static
-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 = gfx::GetXDisplay();
-  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;
-
-  // We want to process the gtk2 event; mapped to an X11 event immediately
-  // otherwise if we put it back on the queue we may get items out of order.
-  if (ui::X11EventSource* x11_source = ui::X11EventSource::GetInstance())
-    x11_source->DispatchXEventNow(&x_event);
-  else
-    XPutBackEvent(x_event.xkey.display, &x_event);
-}
-
-}  // namespace libgtk2ui