Stick windows to sides of workspaces

ash/wm/dock/dock_window_resizer.cc

Index: ash/wm/dock/dock_window_resizer.cc
diff --git a/ash/wm/dock/dock_window_resizer.cc b/ash/wm/dock/dock_window_resizer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..46a9561231ba6bb3e5e9715a53cc4572000db2c8
--- /dev/null
+++ b/ash/wm/dock/dock_window_resizer.cc
@@ -0,0 +1,121 @@
+// 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 "ash/wm/workspace_controller.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 {
+
+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) {
+  last_mouse_location_ = location;
+  wm::ConvertPointToScreen(GetTarget()->parent(), &last_mouse_location_);
+  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_layout_(NULL),
+      was_docked_(false),
+      did_move_or_resize_(false) {
+  DCHECK(details_.is_resizable);
+  root_window_ = details.window->GetRootWindow();
+  aura::Window* dock_container = Shell::GetContainer(
+      details.window->GetRootWindow(),
+      internal::kShellWindowId_DockContainer);
+  DCHECK(dock_container->id() == internal::kShellWindowId_DockContainer);
+  dock_layout_ = static_cast<internal::DockLayoutManager*>(
+      dock_container->layout_manager());
+}
+
+void DockWindowResizer::StartedDragging() {
+  // Tell the dock layout manager that we are dragging this window.
+  was_docked_ = IsWindowDocked(GetTarget());
+  dock_layout_->StartDragging(GetTarget());
+}
+
+void DockWindowResizer::FinishDragging() {
+  if (!did_move_or_resize_)
+    return;
+
+  aura::Window* window = GetTarget();
+  if (was_docked_ &&
+      !IsWindowDocked(window) &&
+      window->parent()->id() == internal::kShellWindowId_DockContainer) {
+    // Reparent the window back to workspace.
+    // We need to be careful to give SetDefaultParentByRootWindow location in
+    // the right root window (matching the logic in DragWindowResizer) based on
+    // which root window a mouse pointer is in. We want to undock into the right
+    // screen near the edge of a multiscreen setup (based on where the mouse is)
+    gfx::Rect near_last_mouse_location(last_mouse_location_, gfx::Size());
+    // Reparenting will cause Relayout and possible dock shrinking.
+    window->SetDefaultParentByRootWindow(root_window_,
+                                         near_last_mouse_location);
+    // A maximized workspace may be active so we may need to switch
+    // to a parent workspace of the window being dragged out.
+    internal::WorkspaceController* workspace_controller =
+        GetRootWindowController(
+            window->GetRootWindow())->workspace_controller();
+    workspace_controller->SetActiveWorkspaceByWindow(window);

[Jun Mukai, 2013/06/10 20:40:57]

This SetActiveworkspaceByWindow may not be necessary after my CL, since
maximized window doesn't have its own workspace.  Still fullscreen/immersive
windows have, but I heard that this dock doesn't appear with those windows.

[varkha, 2013/06/10 21:09:47]

Thanks, It will probably be unnecessary once your CL lands (I will remove it
then). For now it prevents assertion when a docked window is undocked and a
maximized window exists.

+  }
+  dock_layout_->FinishDragging();
+}
+
+}  // namespace aura