Avoids updating dock alignment when drag is cancelled

ash/wm/dock/docked_window_layout_manager.cc

 // Copyright (c) 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 "ash/wm/dock/docked_window_layout_manager.h"
 
 #include "ash/ash_switches.h"
 #include "ash/screen_ash.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_constants.h"
@@ skipping 440 matching lines @@
 
 void DockedWindowLayoutManager::RemoveObserver(
     DockedWindowLayoutManagerObserver* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
 void DockedWindowLayoutManager::StartDragging(aura::Window* window) {
   DCHECK(!dragged_window_);
   dragged_window_ = window;
   DCHECK(!IsPopupOrTransient(window));
+
+  // If there are no other docked windows clear alignment when a docked window
+  // is moved.
+  if (dragged_window_->parent() == dock_container_ &&
+      !IsAnyWindowDocked() &&
+      wm::GetWindowState(dragged_window_)->drag_details() &&
+      !(wm::GetWindowState(dragged_window_)->drag_details()->bounds_change &
+          WindowResizer::kBoundsChange_Resizes)) {
+    alignment_ = DOCKED_ALIGNMENT_NONE;
+  }
   // Start observing a window unless it is docked container's child in which
   // case it is already observed.
   wm::WindowState* dragged_state = wm::GetWindowState(dragged_window_);
   if (dragged_window_->parent() != dock_container_) {
     dragged_window_->AddObserver(this);
     dragged_state->AddObserver(this);
   }
   is_dragged_from_dock_ = window->parent() == dock_container_;
   DCHECK(!is_dragged_window_docked_);
 
@@ skipping 29 matching lines @@
   is_dragged_from_dock_ = false;
 }
 
 void DockedWindowLayoutManager::FinishDragging(DockedAction action,
                                                DockedActionSource source) {
   DCHECK(dragged_window_);
   DCHECK(!IsPopupOrTransient(dragged_window_));
   if (is_dragged_window_docked_)
     OnDraggedWindowUndocked();
   DCHECK (!is_dragged_window_docked_);
+
+  // If this is the first window getting docked by moving it - update alignment.
+  if (dragged_window_->parent() == dock_container_ &&
+      !IsAnyWindowDocked() &&
+      wm::GetWindowState(dragged_window_)->drag_details() &&
+      !(wm::GetWindowState(dragged_window_)->drag_details()->bounds_change &
+          WindowResizer::kBoundsChange_Resizes)) {

[pkotwicz, 2014/01/16 21:43:27]

I wonder whether it is possible to have a new function
DockedWindowLayoutManager::GetClosestAlignment(aura::Window* window) which
returns DOCKED_ALIGNMENT_LEFT or DOCKED_ALIGNMENT_RIGHT based on which edge is
closer. I think we should be able to use
DockedWindowLayoutManager::GetClosestAlignment() everywhere that
DockedWindowLayoutManager::GetAlignmentOfWindow() is used with the exception of
WorkspaceWindowResizer::SetDraggedWindowDocked().
I think that doing this will allow you to remove the check for
DragDetails::bounds_change

Nit: You can move the if statement above MaybeMinimizeChildrenExcept()

[varkha, 2014/01/16 23:34:14]

I will try to use the "closest to edge" logic when I am dealing with the
"TODO(oshima|varkha)" in OnWindowAddedToLayout (soon). I have simplified the
logic here to match what we have in OnWindowAddedToLayout - you are right
checking alignment_ is enough here - no need for IsAnyWindowDocked or checking
if this is a resize drag since we would keep alignment in StartDragging for
resizing drags and not clear it.

+    alignment_ = GetAlignmentOfWindow(dragged_window_);
+  }
   // Stop observing a window unless it is docked container's child in which
   // case it needs to keep being observed after the drag completes.
   if (dragged_window_->parent() != dock_container_) {
     dragged_window_->RemoveObserver(this);
     wm::GetWindowState(dragged_window_)->RemoveObserver(this);
     if (last_active_window_ == dragged_window_)
       last_active_window_ = NULL;
 
     views::corewm::SetWindowShowAnimationDuration(dragged_window_,
                                                   base::TimeDelta());
@@ skipping 458 matching lines @@
 void DockedWindowLayoutManager::UpdateDockedWidth(int width) {
   if (docked_width_ == width)
     return;
   docked_width_ = width;
   UMA_HISTOGRAM_COUNTS_10000("Ash.Dock.Width", docked_width_);
 }
 
 void DockedWindowLayoutManager::OnDraggedWindowDocked(aura::Window* window) {
   DCHECK(!is_dragged_window_docked_);
   is_dragged_window_docked_ = true;
-
-  // If there are no other docked windows update alignment when the window is
-  // moved.
-  if (!IsAnyWindowDocked() &&
-      wm::GetWindowState(dragged_window_)->drag_details() &&
-      !(wm::GetWindowState(dragged_window_)->drag_details()->bounds_change &
-          WindowResizer::kBoundsChange_Resizes)) {
-    alignment_ = DOCKED_ALIGNMENT_NONE;
-  }
 }
 
 void DockedWindowLayoutManager::OnDraggedWindowUndocked() {
-  // If this is the first window getting docked by moving it - update alignment.
-  if (!IsAnyWindowDocked() &&
-      wm::GetWindowState(dragged_window_)->drag_details() &&
-      !(wm::GetWindowState(dragged_window_)->drag_details()->bounds_change &
-          WindowResizer::kBoundsChange_Resizes)) {
-    alignment_ = GetAlignmentOfWindow(dragged_window_);
-  }
   DCHECK (is_dragged_window_docked_);
   is_dragged_window_docked_ = false;
 }
 
 bool DockedWindowLayoutManager::IsAnyWindowDocked() {
   return CalculateAlignment() != DOCKED_ALIGNMENT_NONE;
 }
 
 void DockedWindowLayoutManager::Relayout() {
   if (in_layout_)
@@ skipping 288 matching lines @@
 void DockedWindowLayoutManager::OnKeyboardBoundsChanging(
     const gfx::Rect& keyboard_bounds) {
   // This bounds change will have caused a change to the Shelf which does not
   // propagate automatically to this class, so manually recalculate bounds.
   Relayout();
   UpdateDockBounds(DockedWindowLayoutManagerObserver::KEYBOARD_BOUNDS_CHANGING);
 }
 
 }  // namespace internal
 }  // namespace ash