Stick windows to sides of workspaces

ash/wm/panels/panel_window_resizer.cc

 // Copyright (c) 2012 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 "ash/wm/panels/panel_window_resizer.h"
 
 #include "ash/display/display_controller.h"
 #include "ash/launcher/launcher.h"
 #include "ash/root_window_controller.h"
 #include "ash/screen_ash.h"
@@ skipping 39 matching lines @@
 PanelWindowResizer::Create(WindowResizer* next_window_resizer,
                            aura::Window* window,
                            const gfx::Point& location,
                            int window_component) {
   Details details(window, location, window_component);
   return details.is_resizable ?
       new PanelWindowResizer(next_window_resizer, details) : NULL;
 }
 
 void PanelWindowResizer::Drag(const gfx::Point& location, int event_flags) {
+  last_mouse_location_ = location;
+  wm::ConvertPointToScreen(GetTarget()->parent(), &last_mouse_location_);
   bool destroyed = false;
   if (!did_move_or_resize_) {
     did_move_or_resize_ = true;
     StartedDragging();
   }
   gfx::Point location_in_screen = location;
   wm::ConvertPointToScreen(GetTarget()->parent(), &location_in_screen);
 
   // Check if the destination has changed displays.
   gfx::Screen* screen = Shell::GetScreen();
@@ skipping 57 matching lines @@
 PanelWindowResizer::PanelWindowResizer(WindowResizer* next_window_resizer,
                                        const Details& details)
     : details_(details),
       next_window_resizer_(next_window_resizer),
       panel_container_(NULL),
       did_move_or_resize_(false),
       was_attached_(GetTarget()->GetProperty(internal::kPanelAttachedKey)),
       should_attach_(was_attached_),
       destroyed_(NULL) {
   DCHECK(details_.is_resizable);
+  root_window_ = details.window->GetRootWindow();
   panel_container_ = Shell::GetContainer(
       details.window->GetRootWindow(),
       internal::kShellWindowId_PanelContainer);
 }
 
 bool PanelWindowResizer::AttachToLauncher(const gfx::Rect& bounds,
                                           gfx::Point* offset) {
   bool should_attach = false;
   if (panel_container_) {
     internal::PanelLayoutManager* panel_layout_manager =
@@ skipping 34 matching lines @@
     }
   }
   return should_attach;
 }
 
 void PanelWindowResizer::StartedDragging() {
   // Tell the panel layout manager that we are dragging this panel before
   // attaching it so that it does not get repositioned.
   if (panel_container_)
     GetPanelLayoutManager(panel_container_)->StartDragging(GetTarget());
-  if (!was_attached_) {
+  if (!was_attached_ && !IsWindowDocked(GetTarget())) {

[flackr, 2013/06/11 17:59:31]

Don't we want dragged panels to show in front of other panels even if they were
dragged from the dock?

[varkha, 2013/06/12 04:52:13]

Eliminating window property made this redundant I think so this file is only
changed to fix the bug with moving panels near screen edge.

     // Attach the panel while dragging placing it in front of other panels.
     GetTarget()->SetProperty(internal::kContinueDragAfterReparent, true);
     GetTarget()->SetProperty(internal::kPanelAttachedKey, true);
     GetTarget()->SetDefaultParentByRootWindow(
         GetTarget()->GetRootWindow(),
         GetTarget()->GetBoundsInScreen());
   }
 }
 
 void PanelWindowResizer::FinishDragging() {
   if (!did_move_or_resize_)
     return;
   if (GetTarget()->GetProperty(internal::kPanelAttachedKey) !=
       should_attach_) {
     GetTarget()->SetProperty(internal::kPanelAttachedKey, should_attach_);
-    GetTarget()->SetDefaultParentByRootWindow(
-        GetTarget()->GetRootWindow(),
-        GetTarget()->GetBoundsInScreen());
+    gfx::Rect near_last_mouse_location(last_mouse_location_, gfx::Size());
+    GetTarget()->SetDefaultParentByRootWindow(root_window_,

[flackr, 2013/06/11 17:59:31]

This is using the root window from the start of the drag but this would change
when dragging to another display.

[varkha, 2013/06/12 04:52:13]

We end up using a root pointed by the |near_last_mouse_location| and not really
using the first argument. StackingController::GetDefaultParent() is ignoring the
|context| argument and calling wm::GetRootWindowMatching(gfx::Rect&) to get the
root. I will change the argument here and in DockedWindowResizer (and that
removes the need for root_window_ members) because it is a bit confusing and add
a comment but this will not change the behavior. Can you take a look at the code
in
https://code.google.com/p/chromium/codesearch#chromium/src/ash/wm/stacking_co...
and see if it is doing the right thing ignoring the |context| argument?

+                                              near_last_mouse_location);
   }
   if (panel_container_)
     GetPanelLayoutManager(panel_container_)->FinishDragging();
 }
 
 void PanelWindowResizer::UpdateLauncherPosition() {
   if (panel_container_) {
     GetPanelLayoutManager(panel_container_)->launcher()->
         UpdateIconPositionForWindow(GetTarget());
   }
 }
 
 }  // namespace aura