Avoids updating dock alignment when drag is cancelled

ash/wm/dock/docked_window_layout_manager.cc

Index: ash/wm/dock/docked_window_layout_manager.cc
diff --git a/ash/wm/dock/docked_window_layout_manager.cc b/ash/wm/dock/docked_window_layout_manager.cc
index fcbecfc00f4255e730db781b11349fae71853c1f..c8433539119cbd95dba43feec7cfb477023e0596 100644
--- a/ash/wm/dock/docked_window_layout_manager.cc
+++ b/ash/wm/dock/docked_window_layout_manager.cc
@@ -458,6 +458,16 @@ 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_);
@@ -507,6 +517,15 @@ void DockedWindowLayoutManager::FinishDragging(DockedAction action,
   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_) {
@@ -985,25 +1004,9 @@ void DockedWindowLayoutManager::UpdateDockedWidth(int 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;
 }