ui/views/test/x11_property_change_waiter.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 "ui/views/test/x11_property_change_waiter.h"

#include <X11/Xlib.h>

#include "base/run_loop.h"
#include "ui/events/platform/platform_event_source.h"
#include "ui/events/platform/scoped_event_dispatcher.h"
#include "ui/gfx/x/x11_atom_cache.h"

namespace views {

X11PropertyChangeWaiter::X11PropertyChangeWaiter(XID window,
                                                 const char* property)
    : x_window_(window),
      property_(property),
      wait_(true),
      old_event_mask_(0) {
  Display* display = gfx::GetXDisplay();

  // Ensure that we are listening to PropertyNotify events for |window|. This
  // is not the case for windows which were not created by
  // DesktopWindowTreeHostX11.
  XWindowAttributes attributes;
  XGetWindowAttributes(display, x_window_, &attributes);
  old_event_mask_ = attributes.your_event_mask;
  XSelectInput(display, x_window_, old_event_mask_ | PropertyChangeMask);

  const char* kAtomsToCache[] = { property, NULL };
  atom_cache_.reset(new ui::X11AtomCache(display, kAtomsToCache));

  // Override the dispatcher so that we get events before
  // DesktopWindowTreeHostX11 does. We must do this because
  // DesktopWindowTreeHostX11 stops propagation.
  dispatcher_ = ui::PlatformEventSource::GetInstance()->
      OverrideDispatcher(this).Pass();
}

X11PropertyChangeWaiter::~X11PropertyChangeWaiter() {
  XSelectInput(gfx::GetXDisplay(), x_window_, old_event_mask_);
}

void X11PropertyChangeWaiter::Wait() {
  if (!wait_)
    return;

  base::RunLoop run_loop;
  quit_closure_ = run_loop.QuitClosure();
  run_loop.Run();

  dispatcher_.reset();
}

bool X11PropertyChangeWaiter::ShouldKeepOnWaiting(
    const ui::PlatformEvent& event) {
  // Stop waiting once we get a property change.
  return true;
}

bool X11PropertyChangeWaiter::CanDispatchEvent(const ui::PlatformEvent& event) {
  NOTREACHED();
  return true;
}

uint32_t X11PropertyChangeWaiter::DispatchEvent(
    const ui::PlatformEvent& event) {
  if (!wait_ ||
      event->type != PropertyNotify ||
      event->xproperty.window != x_window_ ||
      event->xproperty.atom != atom_cache_->GetAtom(property_) ||
      ShouldKeepOnWaiting(event)) {
    return ui::POST_DISPATCH_PERFORM_DEFAULT;
  }

  wait_ = false;
  if (!quit_closure_.is_null())
    quit_closure_.Run();
  return ui::POST_DISPATCH_PERFORM_DEFAULT;
}

}  // namespace views