Add always-on-top property to app windows

chrome/browser/ui/gtk/apps/native_app_window_gtk.cc

 // Copyright 2013 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/gtk/apps/native_app_window_gtk.h"
 
 #include <gdk/gdkx.h>
 #include <vector>
 
 #include "base/message_loop/message_pump_gtk.h"
@@ skipping 30 matching lines @@
 } // namespace
 
 NativeAppWindowGtk::NativeAppWindowGtk(ShellWindow* shell_window,
                                        const ShellWindow::CreateParams& params)
     : shell_window_(shell_window),
       window_(NULL),
       state_(GDK_WINDOW_STATE_WITHDRAWN),
       is_active_(false),
       content_thinks_its_fullscreen_(false),
       frameless_(params.frame == ShellWindow::FRAME_NONE),
+      always_on_top_(params.always_on_top),
       frame_cursor_(NULL),
       atom_cache_(base::MessagePumpGtk::GetDefaultXDisplay(), kAtomsToCache),
       is_x_event_listened_(false) {
   Observe(web_contents());
 
   window_ = GTK_WINDOW(gtk_window_new(GTK_WINDOW_TOPLEVEL));
 
   gfx::NativeView native_view =
       web_contents()->GetView()->GetNativeView();
   gtk_container_add(GTK_CONTAINER(window_), native_view);
@@ skipping 23 matching lines @@
   // get our first configure-event
   bounds_ = restored_bounds_ = params.bounds;
   gint x, y;
   gtk_window_get_position(window_, &x, &y);
   bounds_.set_origin(gfx::Point(x, y));
 
   // Hide titlebar when {frame: 'none'} specified on ShellWindow.
   if (frameless_)
     gtk_window_set_decorated(window_, false);
 
+  if (always_on_top_)
+    gtk_window_set_keep_above(window_, TRUE);
+
   int min_width = params.minimum_size.width();
   int min_height = params.minimum_size.height();
   int max_width = params.maximum_size.width();
   int max_height = params.maximum_size.height();
   GdkGeometry hints;
   int hints_mask = 0;
   if (min_width || min_height) {
     hints.min_height = min_height;
     hints.min_width = min_width;
     hints_mask |= GDK_HINT_MIN_SIZE;
@@ skipping 228 matching lines @@
   }
 
   return GDK_FILTER_CONTINUE;
 }
 
 void NativeAppWindowGtk::FlashFrame(bool flash) {
   gtk_window_set_urgency_hint(window_, flash);
 }
 
 bool NativeAppWindowGtk::IsAlwaysOnTop() const {
-  return false;
+  return always_on_top_;
 }
 
 void NativeAppWindowGtk::RenderViewHostChanged(
     content::RenderViewHost* old_host,
     content::RenderViewHost* new_host) {
   web_contents()->GetView()->Focus();
 }
 
 gfx::Insets NativeAppWindowGtk::GetFrameInsets() const {
   if (frameless_)
@@ skipping 21 matching lines @@
       rect_with_decorations.width - current_width - left_inset);
 }
 
 bool NativeAppWindowGtk::IsVisible() const {
   return gtk_widget_get_visible(GTK_WIDGET(window_));
 }
 
 void NativeAppWindowGtk::HideWithApp() {}
 void NativeAppWindowGtk::ShowWithApp() {}
 
+void NativeAppWindowGtk::SetAlwaysOnTop(bool always_on_top) {
+  if (always_on_top_ != always_on_top) {
+    // gdk_window_get_state() does not give us the correct value for the
+    // GDK_WINDOW_STATE_ABOVE bit. Cache the current state.
+    always_on_top_ = always_on_top;
+    gtk_window_set_keep_above(window_, always_on_top_ ? TRUE : FALSE);
+    shell_window_->OnNativeWindowChanged();
+  }
+}
+
 gfx::NativeView NativeAppWindowGtk::GetHostView() const {
   NOTIMPLEMENTED();
   return NULL;
 }
 
 gfx::Point NativeAppWindowGtk::GetDialogPosition(const gfx::Size& size) {
   gint current_width = 0;
   gint current_height = 0;
   gtk_window_get_size(window_, &current_width, &current_height);
   return gfx::Point(current_width / 2 - size.width() / 2,
@@ skipping 250 matching lines @@
 }
 
 void NativeAppWindowGtk::UpdateDraggableRegions(
     const std::vector<extensions::DraggableRegion>& regions) {
   // Draggable region is not supported for non-frameless window.
   if (!frameless_)
     return;
 
   draggable_region_.reset(ShellWindow::RawDraggableRegionsToSkRegion(regions));
 }