Stick windows to sides of workspaces

ash/wm/workspace/workspace_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/workspace/workspace_window_resizer.h"
 
 #include <algorithm>
 #include <cmath>
 #include <utility>
 #include <vector>
 
 #include "ash/ash_switches.h"
 #include "ash/display/display_controller.h"
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/coordinate_conversion.h"
 #include "ash/wm/default_window_resizer.h"
+#include "ash/wm/dock/dock_layout_manager.h"
+#include "ash/wm/dock/dock_window_resizer.h"
 #include "ash/wm/drag_window_resizer.h"
 #include "ash/wm/panels/panel_window_resizer.h"
 #include "ash/wm/property_util.h"
 #include "ash/wm/window_properties.h"
 #include "ash/wm/window_util.h"
 #include "ash/wm/workspace/phantom_window_controller.h"
 #include "ash/wm/workspace/snap_sizer.h"
 #include "base/command_line.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/window_types.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/compositor/layer.h"
 #include "ui/gfx/screen.h"
 #include "ui/gfx/transform.h"
 
 namespace ash {
 
 scoped_ptr<WindowResizer> CreateWindowResizer(aura::Window* window,
                                               const gfx::Point& point_in_parent,
                                               int window_component) {
   DCHECK(window);
   // No need to return a resizer when the window cannot get resized.
   if (!wm::CanResizeWindow(window) && window_component != HTCAPTION)
     return scoped_ptr<WindowResizer>();
 
+  // TODO(varkha): The chaining of window resizers causes some of the logic
+  // to be repeated and the logic flow difficult to control. With some windows
+  // classes using reparenting during drag operations it becomes challenging to
+  // implement proper transition from one resizer to another during or at the
+  // end of the drag. This also causes http://crbug.com/247085.
+  // It seems the only thing the panel or dock resizer needs to do is notify the
+  // layout manager when a docked window is being dragged. We should have a
+  // better way of doing this, perhaps by having a way of observing drags or
+  // having a generic drag window wrapper which informs a layout manager that a
+  // drag has started or stopped.
+  // It may be possible to refactor and eliminate chaining.
   WindowResizer* window_resizer = NULL;
   if (window->parent() &&
       window->parent()->id() == internal::kShellWindowId_WorkspaceContainer) {
     // Allow dragging maximized windows if it's not tracked by workspace. This
     // is set by tab dragging code.
     if (!wm::IsWindowNormal(window) &&
         (window_component != HTCAPTION || GetTrackedByWorkspace(window)))
       return scoped_ptr<WindowResizer>();
     window_resizer = internal::WorkspaceWindowResizer::Create(
         window,
         point_in_parent,
         window_component,
         std::vector<aura::Window*>());
   } else if (wm::IsWindowNormal(window)) {
     window_resizer = DefaultWindowResizer::Create(
         window, point_in_parent, window_component);
   }
   if (window_resizer) {
     window_resizer = internal::DragWindowResizer::Create(
         window_resizer, window, point_in_parent, window_component);
   }
+  if (window_resizer && IsWindowDocked(window)) {
+    window_resizer = DockWindowResizer::Create(
+        window_resizer, window, point_in_parent, window_component);
+  }
   if (window_resizer && window->type() == aura::client::WINDOW_TYPE_PANEL) {
     window_resizer = PanelWindowResizer::Create(
         window_resizer, window, point_in_parent, window_component);
   }
   return make_scoped_ptr<WindowResizer>(window_resizer);
 }
 
 namespace internal {
 
 namespace {
@@ skipping 283 matching lines @@
   if (bounds != window()->bounds())
     window()->SetBounds(bounds);
 }
 
 void WorkspaceWindowResizer::CompleteDrag(int event_flags) {
   wm::SetUserHasChangedWindowPositionOrSize(details_.window, true);
   snap_phantom_window_controller_.reset();
   if (!did_move_or_resize_ || details_.window_component != HTCAPTION)
     return;
 
-  // When the window is not in the normal show state, we do not snap thw window.
+  // When the window is not in the normal show state, we do not snap the window.
   // This happens when the user minimizes or maximizes the window by keyboard
   // shortcut while dragging it. If the window is the result of dragging a tab
   // out of a maximized window, it's already in the normal show state when this
   // is called, so it does not matter.
   if (wm::IsWindowNormal(window()) &&
       (window()->type() != aura::client::WINDOW_TYPE_PANEL ||
        !window()->GetProperty(kPanelAttachedKey)) &&
       (snap_type_ == SNAP_LEFT_EDGE || snap_type_ == SNAP_RIGHT_EDGE)) {
     if (!GetRestoreBoundsInScreen(window())) {
       gfx::Rect initial_bounds = ScreenAsh::ConvertRectToScreen(
@@ skipping 462 matching lines @@
   gfx::Rect area(ScreenAsh::GetDisplayBoundsInParent(window()));
   if (location.x() <= area.x())
     return SNAP_LEFT_EDGE;
   if (location.x() >= area.right() - 1)
     return SNAP_RIGHT_EDGE;
   return SNAP_NONE;
 }
 
 }  // namespace internal
 }  // namespace ash