Adding proper dragging behavior for L/R maximized windows.

ash/wm/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/window_resizer.h"
 
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
+#include "ash/wm/property_util.h"
+#include "ash/wm/window_util.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/base/hit_test.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/gfx/screen.h"
 
 namespace ash {
@@ skipping 86 matching lines @@
       position_change_direction(0),
       size_change_direction(0),
       is_resizable(false) {
 }
 
 WindowResizer::Details::Details(aura::Window* window,
                                 const gfx::Point& location,
                                 int window_component)
   : window(window),
     initial_bounds(window->bounds()),
+    restore_bounds(gfx::Rect()),
     initial_location_in_parent(location),
     initial_opacity(window->layer()->opacity()),
     window_component(window_component),
     bounds_change(GetBoundsChangeForWindowComponent(window_component)),
     position_change_direction(
         GetPositionChangeDirectionForWindowComponent(window_component)),
     size_change_direction(
         GetSizeChangeDirectionForWindowComponent(window_component)),
     is_resizable(bounds_change != kBoundsChangeDirection_None) {
+  if (wm::IsWindowNormal(window) &&
+      GetRestoreBoundsInScreen(window) &&
+      window_component == HTCAPTION)
+    restore_bounds = *GetRestoreBoundsInScreen(window);
 }
 
 WindowResizer::Details::~Details() {
 }
 
 WindowResizer::WindowResizer() {
 }
 
 WindowResizer::~WindowResizer() {
 }
@@ skipping 34 matching lines @@
 
   int delta_x = location.x() - details.initial_location_in_parent.x();
   int delta_y = location.y() - details.initial_location_in_parent.y();
 
   // The minimize size constraint may limit how much we change the window
   // position.  For example, dragging the left edge to the right should stop
   // repositioning the window when the minimize size is reached.
   gfx::Size size = GetSizeForDrag(details, &delta_x, &delta_y);
   gfx::Point origin = GetOriginForDrag(details, delta_x, delta_y);
 
+  // When we might want to reposition a window which is also restored to its
+  // previous size, to keep the cursor within the dragged window.
+  if (!details.restore_bounds.IsEmpty() &&
+      details.bounds_change & kBoundsChange_Repositions) {
+    // However - it is not desirable to change the origin if the window would
+    // be still hit by the cursor.
+    if (details.initial_location_in_parent.x() >
+            details.initial_bounds.x() + details.restore_bounds.width())
+      origin.set_x(location.x() - details.restore_bounds.width() / 2);
+  }
+
   gfx::Rect new_bounds(origin, size);
   // Update bottom edge to stay in the work area when we are resizing
   // by dragging the bottome edge or corners.
   if (details.window_component == HTBOTTOM ||
       details.window_component == HTBOTTOMRIGHT ||
       details.window_component == HTBOTTOMLEFT) {
     gfx::Rect work_area =
         ScreenAsh::GetDisplayWorkAreaBoundsInParent(details.window);
     if (new_bounds.bottom() > work_area.bottom())
       new_bounds.Inset(0, 0, 0,
@@ skipping 34 matching lines @@
 
 // static
 gfx::Size WindowResizer::GetSizeForDrag(const Details& details,
                                         int* delta_x,
                                         int* delta_y) {
   gfx::Size size = details.initial_bounds.size();
   if (details.bounds_change & kBoundsChange_Resizes) {
     gfx::Size min_size = details.window->delegate()->GetMinimumSize();
     size.SetSize(GetWidthForDrag(details, min_size.width(), delta_x),
                  GetHeightForDrag(details, min_size.height(), delta_y));
+  } else if (!details.restore_bounds.IsEmpty()) {
+    size = details.restore_bounds.size();
   }
   return size;
 }
 
 // static
 int WindowResizer::GetWidthForDrag(const Details& details,
                                    int min_width,
                                    int* delta_x) {
   int width = details.initial_bounds.width();
   if (details.size_change_direction & kBoundsChangeDirection_Horizontal) {
@@ skipping 41 matching lines @@
         gfx::Screen::GetDisplayNearestWindow(details.window).bounds().height();
     if (height > max_height) {
       height = max_height;
       *delta_y = -y_multiplier * (details.initial_bounds.height() - max_height);
     }
   }
   return height;
 }
 
 }  // namespace aura