Add unittests for X11TopmostWindowFinder

ui/views/test/x11_property_change_waiter.cc

Index: ui/views/test/x11_property_change_waiter.cc
diff --git a/ui/views/test/x11_property_change_waiter.cc b/ui/views/test/x11_property_change_waiter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c6208e1484ce803cb38d7c1c218f15fcc7d4855e
--- /dev/null
+++ b/ui/views/test/x11_property_change_waiter.cc
@@ -0,0 +1,91 @@
+// 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;
+
+  // PropertyChangeWaiter (or one of its subclasses) may be constructed after
+  // the property change has occurred.
+  if (!ShouldKeepOnWaiting(NULL)) {
+    wait_ = false;
+    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 event != NULL;
+}
+
+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