Only support left/right maximizing at 50% width when the --ash-enable-alternate-caption-button

ash/accelerators/accelerator_controller.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/accelerators/accelerator_controller.h"
 
 #include <algorithm>
 #include <cmath>
 #include <iostream>
 #include <string>
@@ skipping 818 matching lines @@
     case WINDOW_SNAP_RIGHT: {
       aura::Window* window = wm::GetActiveWindow();
       // Disable window docking shortcut key for full screen window due to
       // http://crbug.com/135487.
       if (!window ||
           window->type() != aura::client::WINDOW_TYPE_NORMAL ||
           wm::IsWindowFullscreen(window)) {
         break;
       }
 
-      internal::SnapSizer::SnapWindow(window,
-          action == WINDOW_SNAP_LEFT ? internal::SnapSizer::LEFT_EDGE :
-                                       internal::SnapSizer::RIGHT_EDGE);
+      using internal::SnapSizer;

[varkha, 2013/08/30 17:13:25]

Is there a reason that
ScopedLayerAnimationSettings::SetPreemptionStrategy(ui::LayerAnimator::REPLACE_QUEUED_ANIMATIONS);
is not used here? Would it belong inside the SnapWindow()?

[pkotwicz, 2013/08/30 21:10:57]

Good catch!
You are right that we probably should be animating snapping left and right. We
do not animate when snapping left and right as a result of FrameMaximizeButton
and we probably should.
I need to figure out whether we want to animate as a result of side maximizing
via WorkspaceWindowResizer
In terms of AcceleratorController, we do not animate for WINDOW_POSITION_CENTER
(via Alt+Shift+"=") So for better or for worse we are consistent there.

(For the sake of fun, there is a completely unrelated partial maximize mode that
you can enter by double clicking the borders of a window which is also not
animated)

+      SnapSizer::Edge edge = (action == WINDOW_SNAP_LEFT) ?
+          SnapSizer::LEFT_EDGE : SnapSizer::RIGHT_EDGE;
+      if (SnapSizer::CanSnapWindow(window, edge))
+        SnapSizer::SnapWindow(window, edge, SnapSizer::STEP_YES);
       return true;
     }
     case WINDOW_MINIMIZE: {
       aura::Window* window = wm::GetActiveWindow();
       // Attempt to restore the window that would be cycled through next from
       // the launcher when there is no active window.
       if (!window)
         return HandleCycleWindowMRU(WindowCycleController::FORWARD, false);
       // Disable the shortcut for minimizing full screen window due to
       // crbug.com/131709, which is a crashing issue related to minimizing
@@ skipping 145 matching lines @@
     keyboard_brightness_control_delegate) {
   keyboard_brightness_control_delegate_ =
       keyboard_brightness_control_delegate.Pass();
 }
 
 bool AcceleratorController::CanHandleAccelerators() const {
   return true;
 }
 
 }  // namespace ash