Stick windows to sides of workspaces

ash/wm/dock/dock_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/dock/dock_window_resizer.h"
+
+#include "ash/display/display_controller.h"
+#include "ash/launcher/launcher.h"
+#include "ash/root_window_controller.h"
+#include "ash/screen_ash.h"
+#include "ash/shelf/shelf_types.h"
+#include "ash/shelf/shelf_widget.h"
+#include "ash/shell.h"
+#include "ash/shell_window_ids.h"
+#include "ash/wm/coordinate_conversion.h"
+#include "ash/wm/dock/dock_layout_manager.h"
+#include "ash/wm/property_util.h"
+#include "ash/wm/window_properties.h"
+#include "ui/aura/client/aura_constants.h"
+#include "ui/aura/env.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/gfx/screen.h"
+#include "ui/views/widget/widget.h"
+
+namespace ash {
+
+namespace {
+
+internal::DockLayoutManager* GetDockLayoutManager(
+    aura::Window* dock_container) {
+  DCHECK(dock_container->id() == internal::kShellWindowId_DockContainer);
+  return static_cast<internal::DockLayoutManager*>(
+      dock_container->layout_manager());
+}
+
+}  // namespace
+
+DockWindowResizer::~DockWindowResizer() {
+}
+
+// static
+DockWindowResizer*
+DockWindowResizer::Create(WindowResizer* next_window_resizer,
+                          aura::Window* window,
+                          const gfx::Point& location,
+                          int window_component) {
+  Details details(window, location, window_component);
+  return details.is_resizable ?
+      new DockWindowResizer(next_window_resizer, details) : NULL;
+}
+
+void DockWindowResizer::Drag(const gfx::Point& location, int event_flags) {
+  if (!did_move_or_resize_) {
+    did_move_or_resize_ = true;
+    StartedDragging();
+  }
+  next_window_resizer_->Drag(location, event_flags);
+}
+
+void DockWindowResizer::CompleteDrag(int event_flags) {
+  // The root window can change when dragging into a different screen.
+  next_window_resizer_->CompleteDrag(event_flags);
+  FinishDragging();
+}
+
+void DockWindowResizer::RevertDrag() {
+  next_window_resizer_->RevertDrag();
+  FinishDragging();
+}
+
+aura::Window* DockWindowResizer::GetTarget() {
+  return next_window_resizer_->GetTarget();
+}
+
+DockWindowResizer::DockWindowResizer(WindowResizer* next_window_resizer,
+                                     const Details& details)
+    : details_(details),
+      next_window_resizer_(next_window_resizer),
+      dock_container_(NULL),
+      did_move_or_resize_(false) {
+  DCHECK(details_.is_resizable);
+  dock_container_ = Shell::GetContainer(details.window->GetRootWindow(),
+                                        internal::kShellWindowId_DockContainer);

[flackr, 2013/06/04 19:58:10]

Since the dock container is never directly used, just the dock container's
layout manager, just save the dock_layout_manager_ instead. You can inline
GetDockLayoutManager here since it will only be needed in the one place :-).

[varkha, 2013/06/07 19:01:28]

Done.

+}
+
+void DockWindowResizer::StartedDragging() {
+  // Tell the dock layout manager that we are dragging this window.
+  if (dock_container_)
+    GetDockLayoutManager(dock_container_)->StartDragging(GetTarget());
+}
+
+void DockWindowResizer::FinishDragging() {
+  if (!did_move_or_resize_)
+    return;
+  if (dock_container_)
+    GetDockLayoutManager(dock_container_)->FinishDragging();
+}
+
+}  // namespace aura