aura: Add an EasyResizeWindowTargeter.

Add EasyResizeWindowTargeter to allow easily resizing windows with mouse/touch
with the new event-dispatch code. This will eventually allow getting rid of
Window::SetHitTestBoundsOverrideOuter() once the new event-dispatch code is used
for all event types. This patch installs an EasyResizeWindowTargeter for the
shelf and status-area widgets. Subsequent CLs will install such targeters for the
toplevel windows too.

Collateral change includes adding some dependencies on wm_public (in DEPS and gyp).

BUG=318879
R=ben@chromium.org

Review URL: https://codereview.chromium.org/118553004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243177 0039d316-1c4b-4281-b951-d872f2087c98

10 files changed, 339 insertions, 15 deletions

diff --git a/ash/ash.gyp b/ash/ash.gyp
index 9362e16..59810a6 100644
--- a/ash/ash.gyp
+++ b/ash/ash.gyp
@@ -42,6 +42,7 @@
         '../ui/views/controls/webview/webview.gyp:webview',
         '../ui/views/views.gyp:views',
         '../ui/web_dialogs/web_dialogs.gyp:web_dialogs',
+        '../ui/wm/wm.gyp:wm_public',
         '../url/url.gyp:url_lib',
         'ash_strings.gyp:ash_strings',
         'ash_resources',
diff --git a/ash/shelf/shelf_layout_manager.h b/ash/shelf/shelf_layout_manager.h
index 06a1307..18d6ba4 100644
--- a/ash/shelf/shelf_layout_manager.h
+++ b/ash/shelf/shelf_layout_manager.h
@@ -315,6 +315,7 @@ class ASH_EXPORT ShelfLayoutManager :
       ShelfVisibilityState visibility_state) const;
 
   // Updates the hit test bounds override for shelf and status area.
+  // TODO(sad): Remove this (crbug.com/318879)
   void UpdateHitTestBounds();
 
   // Returns true if |window| is a descendant of the shelf.
@@ -336,6 +337,7 @@ class ASH_EXPORT ShelfLayoutManager :
       DockedWindowLayoutManagerObserver::Reason reason) OVERRIDE;
 
   // Generates insets for inward edge based on the current shelf alignment.
+  // TODO(sad): Remove this (crbug.com/318879)
   gfx::Insets GetInsetsForAlignment(int distance) const;
 
   // The RootWindow is cached so that we don't invoke Shell::GetInstance() from
diff --git a/ash/shelf/shelf_widget.cc b/ash/shelf/shelf_widget.cc
index 7628b64..e7bda3f 100644
--- a/ash/shelf/shelf_widget.cc
+++ b/ash/shelf/shelf_widget.cc
@@ -37,6 +37,7 @@
 #include "ui/views/accessible_pane_view.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_delegate.h"
+#include "ui/wm/public/easy_resize_window_targeter.h"
 
 namespace {
 // Size of black border at bottom (or side) of shelf.
@@ -233,6 +234,77 @@ void DimmerView::DimmerEventFilter::OnTouchEvent(ui::TouchEvent* event) {
   touch_inside_ = touch_inside;
 }
 
+using ash::internal::ShelfLayoutManager;
+
+// ShelfWindowTargeter makes it easier to resize windows with the mouse when the
+// window-edge slightly overlaps with the shelf edge. The targeter also makes it
+// easier to drag the shelf out with touch while it is hidden.
+class ShelfWindowTargeter : public wm::EasyResizeWindowTargeter,
+                            public ash::ShelfLayoutManagerObserver {
+ public:
+  ShelfWindowTargeter(aura::Window* container,
+                      ShelfLayoutManager* shelf)
+      : wm::EasyResizeWindowTargeter(container, gfx::Insets(), gfx::Insets()),
+        shelf_(shelf) {
+    WillChangeVisibilityState(shelf_->visibility_state());
+    shelf_->AddObserver(this);
+  }
+
+  virtual ~ShelfWindowTargeter() {
+    // |shelf_| may have been destroyed by this time.
+    if (shelf_)
+      shelf_->RemoveObserver(this);
+  }
+
+ private:
+  gfx::Insets GetInsetsForAlignment(int distance,
+                                    ash::ShelfAlignment alignment) {
+    switch (alignment) {
+      case ash::SHELF_ALIGNMENT_BOTTOM:
+        return gfx::Insets(distance, 0, 0, 0);
+      case ash::SHELF_ALIGNMENT_LEFT:
+        return gfx::Insets(0, 0, 0, distance);
+      case ash::SHELF_ALIGNMENT_RIGHT:
+        return gfx::Insets(0, distance, 0, 0);
+      case ash::SHELF_ALIGNMENT_TOP:
+        return gfx::Insets(0, 0, distance, 0);
+    }
+    NOTREACHED();
+    return gfx::Insets();
+  }
+
+  // ash::ShelfLayoutManagerObserver:
+  virtual void WillDeleteShelf() OVERRIDE {
+    shelf_ = NULL;
+  }
+
+  virtual void WillChangeVisibilityState(
+      ash::ShelfVisibilityState new_state) OVERRIDE {
+    gfx::Insets mouse_insets;
+    gfx::Insets touch_insets;
+    if (new_state == ash::SHELF_VISIBLE) {
+      // Let clicks at the very top of the shelf through so windows can be
+      // resized with the bottom-right corner and bottom edge.
+      mouse_insets = GetInsetsForAlignment(
+          ShelfLayoutManager::kWorkspaceAreaVisibleInset,
+          shelf_->GetAlignment());
+    } else if (new_state == ash::SHELF_AUTO_HIDE) {
+      // Extend the touch hit target out a bit to allow users to drag shelf out
+      // while hidden.
+      touch_insets = GetInsetsForAlignment(
+          -ShelfLayoutManager::kWorkspaceAreaAutoHideInset,
+          shelf_->GetAlignment());
+    }
+
+    set_mouse_extend(mouse_insets);
+    set_touch_extend(touch_insets);
+  }
+
+  ShelfLayoutManager* shelf_;
+
+  DISALLOW_COPY_AND_ASSIGN(ShelfWindowTargeter);
+};
+
 }  // namespace
 
 namespace ash {
@@ -564,6 +636,11 @@ ShelfWidget::ShelfWidget(aura::Window* shelf_container,
   status_container->SetLayoutManager(
       new internal::StatusAreaLayoutManager(this));
 
+  shelf_container->set_event_targeter(scoped_ptr<ui::EventTargeter>(new
+      ShelfWindowTargeter(shelf_container, shelf_layout_manager_)));
+  status_container->set_event_targeter(scoped_ptr<ui::EventTargeter>(new
+      ShelfWindowTargeter(status_container, shelf_layout_manager_)));
+
   views::Widget::AddObserver(this);
 }
 
diff --git a/ash/shelf/shelf_widget_unittest.cc b/ash/shelf/shelf_widget_unittest.cc
index 9f36556..50fce9d 100644
--- a/ash/shelf/shelf_widget_unittest.cc
+++ b/ash/shelf/shelf_widget_unittest.cc
@@ -16,6 +16,7 @@
 #include "ash/test/shelf_view_test_api.h"
 #include "ash/wm/window_util.h"
 #include "ui/aura/root_window.h"
+#include "ui/events/event_utils.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/screen.h"
 #include "ui/views/corewm/corewm_switches.h"
@@ -189,6 +190,120 @@ TEST_F(ShelfWidgetTest, ShelfInitiallySizedAfterLogin) {
             shelf_widget->GetContentsView()->width() -
                 test::ShelfTestAPI(shelf).shelf_view()->width());
 }
-#endif
+#endif  // defined(OS_CHROMEOS)
+
+// Tests that the shelf lets mouse-events close to the edge fall through to the
+// window underneath.
+TEST_F(ShelfWidgetTest, ShelfEdgeOverlappingWindowHitTestMouse) {
+  ShelfWidget* shelf_widget = GetShelfWidget();
+  gfx::Rect shelf_bounds = shelf_widget->GetWindowBoundsInScreen();
+  EXPECT_TRUE(!shelf_bounds.IsEmpty());
+  internal::ShelfLayoutManager* shelf_layout_manager =
+      shelf_widget->shelf_layout_manager();
+  ASSERT_TRUE(shelf_layout_manager);
+  EXPECT_EQ(SHELF_VISIBLE, shelf_layout_manager->visibility_state());
+
+  // Create a Widget which overlaps with the shelf in the top edge.
+  const int kOverlapSize = 15;
+  const int kWindowHeight = 200;
+  views::Widget* widget = new views::Widget;
+  views::Widget::InitParams params(views::Widget::InitParams::TYPE_WINDOW);
+  params.bounds = gfx::Rect(0, shelf_bounds.y() - kWindowHeight + kOverlapSize,
+                            200, kWindowHeight);
+  params.context = CurrentContext();
+  // Widget is now owned by the parent window.
+  widget->Init(params);
+  widget->Show();
+  gfx::Rect widget_bounds = widget->GetWindowBoundsInScreen();
+  EXPECT_TRUE(widget_bounds.Intersects(shelf_bounds));
+
+
+  ui::EventTarget* root = widget->GetNativeWindow()->GetRootWindow();
+  ui::EventTargeter* targeter = root->GetEventTargeter();
+  {
+    // Create a mouse-event targetting the top of the shelf widget. The
+    // window-targeter should find |widget| as the target (instead of the
+    // shelf).
+    gfx::Point event_location(20, shelf_bounds.y() + 1);
+    ui::MouseEvent mouse(ui::ET_MOUSE_MOVED, event_location, event_location,
+                         ui::EF_NONE, ui::EF_NONE);
+    ui::EventTarget* target = targeter->FindTargetForEvent(root, &mouse);
+    EXPECT_EQ(widget->GetNativeWindow(), target);
+  }
+
+  // Now auto-hide (hidden) the shelf.
+  shelf_layout_manager->SetAutoHideBehavior(SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS);
+  shelf_layout_manager->LayoutShelf();
+  EXPECT_EQ(SHELF_AUTO_HIDE, shelf_layout_manager->visibility_state());
+  EXPECT_EQ(SHELF_AUTO_HIDE_HIDDEN, shelf_layout_manager->auto_hide_state());
+  shelf_bounds = shelf_widget->GetWindowBoundsInScreen();
+  EXPECT_TRUE(!shelf_bounds.IsEmpty());
+
+  // Move |widget| so it still overlaps the shelf.
+  widget->SetBounds(gfx::Rect(0, shelf_bounds.y() - kWindowHeight +
+                              kOverlapSize, 200, kWindowHeight));
+  widget_bounds = widget->GetWindowBoundsInScreen();
+  EXPECT_TRUE(widget_bounds.Intersects(shelf_bounds));
+  {
+    // Create a mouse-event targetting the top of the shelf widget. This time,
+    // window-target should find the shelf as the target.
+    gfx::Point event_location(20, shelf_bounds.y() + 1);
+    ui::MouseEvent mouse(ui::ET_MOUSE_MOVED, event_location, event_location,
+                         ui::EF_NONE, ui::EF_NONE);
+    ui::EventTarget* target = targeter->FindTargetForEvent(root, &mouse);
+    EXPECT_EQ(shelf_widget->GetNativeWindow(), target);
+  }
+}
+
+// Tests that the shelf has a slightly larger hit-region for touch-events when
+// it's in the auto-hidden state.
+TEST_F(ShelfWidgetTest, HiddenShelfHitTestTouch) {
+  ShelfWidget* shelf_widget = GetShelfWidget();
+  gfx::Rect shelf_bounds = shelf_widget->GetWindowBoundsInScreen();
+  EXPECT_TRUE(!shelf_bounds.IsEmpty());
+  internal::ShelfLayoutManager* shelf_layout_manager =
+      shelf_widget->shelf_layout_manager();
+  ASSERT_TRUE(shelf_layout_manager);
+  EXPECT_EQ(SHELF_VISIBLE, shelf_layout_manager->visibility_state());
+
+  // Create a widget to make sure that the shelf does auto-hide.
+  views::Widget* widget = new views::Widget;
+  views::Widget::InitParams params(views::Widget::InitParams::TYPE_WINDOW);
+  params.bounds = gfx::Rect(0, 0, 200, 200);
+  params.context = CurrentContext();
+  // Widget is now owned by the parent window.
+  widget->Init(params);
+  widget->Show();
+
+  ui::EventTarget* root = shelf_widget->GetNativeWindow()->GetRootWindow();
+  ui::EventTargeter* targeter = root->GetEventTargeter();
+  // Touch just over the shelf. Since the shelf is visible, the window-targeter
+  // should not find the shelf as the target.
+  {
+    gfx::Point event_location(20, shelf_bounds.y() - 1);
+    ui::TouchEvent touch(ui::ET_TOUCH_PRESSED, event_location, 0,
+                         ui::EventTimeForNow());
+    EXPECT_NE(shelf_widget->GetNativeWindow(),
+              targeter->FindTargetForEvent(root, &touch));
+  }
+
+  // Now auto-hide (hidden) the shelf.
+  shelf_layout_manager->SetAutoHideBehavior(SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS);
+  shelf_layout_manager->LayoutShelf();
+  EXPECT_EQ(SHELF_AUTO_HIDE, shelf_layout_manager->visibility_state());
+  EXPECT_EQ(SHELF_AUTO_HIDE_HIDDEN, shelf_layout_manager->auto_hide_state());
+  shelf_bounds = shelf_widget->GetWindowBoundsInScreen();
+  EXPECT_TRUE(!shelf_bounds.IsEmpty());
+
+  // Touch just over the shelf again. This time, the targeter should find the
+  // shelf as the target.
+  {
+    gfx::Point event_location(20, shelf_bounds.y() - 1);
+    ui::TouchEvent touch(ui::ET_TOUCH_PRESSED, event_location, 0,
+                         ui::EventTimeForNow());
+    EXPECT_EQ(shelf_widget->GetNativeWindow(),
+              targeter->FindTargetForEvent(root, &touch));
+  }
+}
 
 }  // namespace ash
diff --git a/ui/aura/window_targeter.cc b/ui/aura/window_targeter.cc
index 586392b..5ed0e3f 100644
--- a/ui/aura/window_targeter.cc
+++ b/ui/aura/window_targeter.cc
@@ -17,6 +17,29 @@ namespace aura {
 WindowTargeter::WindowTargeter() {}
 WindowTargeter::~WindowTargeter() {}
 
+bool WindowTargeter::WindowCanAcceptEvent(aura::Window* window,
+                                          const ui::LocatedEvent& event) const {
+  if (!window->IsVisible())
+    return false;
+  if (window->ignore_events())
+    return false;
+  client::EventClient* client = client::GetEventClient(window->GetRootWindow());
+  if (client && !client->CanProcessEventsWithinSubtree(window))
+    return false;
+
+  Window* parent = window->parent();
+  if (parent && parent->delegate_ && !parent->delegate_->
+      ShouldDescendIntoChildForEventHandling(window, event.location())) {
+    return false;
+  }
+  return true;
+}
+
+bool WindowTargeter::EventLocationInsideBounds(
+    aura::Window* window, const ui::LocatedEvent& event) const {
+  return window->bounds().Contains(event.location());
+}
+
 ui::EventTarget* WindowTargeter::FindTargetForEvent(ui::EventTarget* root,
                                                     ui::Event* event) {
   if (event->IsKeyEvent()) {
@@ -42,20 +65,10 @@ bool WindowTargeter::SubtreeShouldBeExploredForEvent(
     ui::EventTarget* root,
     const ui::LocatedEvent& event) {
   Window* window = static_cast<Window*>(root);
-  if (!window->IsVisible())
-    return false;
-  if (window->ignore_events())
-    return false;
-  client::EventClient* client = client::GetEventClient(window->GetRootWindow());
-  if (client && !client->CanProcessEventsWithinSubtree(window))
+  if (!WindowCanAcceptEvent(window, event))
     return false;
 
-  Window* parent = window->parent();
-  if (parent && parent->delegate_ && !parent->delegate_->
-      ShouldDescendIntoChildForEventHandling(window, event.location())) {
-    return false;
-  }
-  return window->bounds().Contains(event.location());
+  return EventLocationInsideBounds(window, event);
 }
 
 ui::EventTarget* WindowTargeter::FindTargetForLocatedEvent(
diff --git a/ui/aura/window_targeter.h b/ui/aura/window_targeter.h
index 4457f77..6244102 100644
--- a/ui/aura/window_targeter.h
+++ b/ui/aura/window_targeter.h
@@ -2,18 +2,28 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "ui/aura/aura_export.h"
 #include "ui/events/event_targeter.h"
 
 namespace aura {
 
 class Window;
 
-class WindowTargeter : public ui::EventTargeter {
+class AURA_EXPORT WindowTargeter : public ui::EventTargeter {
  public:
   WindowTargeter();
   virtual ~WindowTargeter();
 
  protected:
+  bool WindowCanAcceptEvent(aura::Window* window,
+                            const ui::LocatedEvent& event) const;
+
+  // Returns whether the location of the event is in an actionable region of the
+  // window. Note that the location etc. of |event| is in the |window|'s
+  // parent's coordinate system.
+  virtual bool EventLocationInsideBounds(aura::Window* window,
+                                         const ui::LocatedEvent& event) const;
+
   // ui::EventTargeter:
   virtual ui::EventTarget* FindTargetForEvent(ui::EventTarget* root,
                                               ui::Event* event) OVERRIDE;
diff --git a/ui/wm/DEPS b/ui/wm/DEPS
new file mode 100644
index 0000000..98fe186
--- /dev/null
+++ b/ui/wm/DEPS
@@ -0,0 +1,4 @@
+include_rules = [
+  "+ui/aura",
+  "+ui/gfx",
+]
diff --git a/ui/wm/core/easy_resize_window_targeter.cc b/ui/wm/core/easy_resize_window_targeter.cc
new file mode 100644
index 0000000..f3a2b0a
--- /dev/null
+++ b/ui/wm/core/easy_resize_window_targeter.cc
@@ -0,0 +1,48 @@
+// Copyright 2014 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 "ui/wm/public/easy_resize_window_targeter.h"
+
+#include "ui/aura/window.h"
+#include "ui/gfx/geometry/insets_f.h"
+#include "ui/gfx/geometry/rect.h"
+
+namespace wm {
+
+EasyResizeWindowTargeter::EasyResizeWindowTargeter(
+    aura::Window* container,
+    const gfx::Insets& mouse_extend,
+    const gfx::Insets& touch_extend)
+    : container_(container),
+      mouse_extend_(mouse_extend),
+      touch_extend_(touch_extend) {
+}
+
+EasyResizeWindowTargeter::~EasyResizeWindowTargeter() {
+}
+
+bool EasyResizeWindowTargeter::EventLocationInsideBounds(
+    aura::Window* window,
+    const ui::LocatedEvent& event) const {
+  // Use the extended bounds only for immediate child windows of |container_|.
+  // Use the default targetter otherwise.
+  if (window->parent() == container_ && (!window->transient_parent() ||
+      window->transient_parent() == container_)) {
+    gfx::RectF bounds(window->bounds());
+    gfx::Transform transform = window->layer()->transform();
+    transform.TransformRect(&bounds);
+    if (event.IsTouchEvent() || event.IsGestureEvent()) {
+      bounds.Inset(touch_extend_);
+    } else {
+      bounds.Inset(mouse_extend_);
+    }
+
+    // Note that |event|'s location is in the |container_|'s coordinate system,
+    // as is |bounds|.
+    return bounds.Contains(event.location());
+  }
+  return WindowTargeter::EventLocationInsideBounds(window, event);
+}
+
+}  // namespace wm
diff --git a/ui/wm/public/easy_resize_window_targeter.h b/ui/wm/public/easy_resize_window_targeter.h
new file mode 100644
index 0000000..c4c7137
--- /dev/null
+++ b/ui/wm/public/easy_resize_window_targeter.h
@@ -0,0 +1,48 @@
+// Copyright 2014 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.
+
+#ifndef UI_WM_PUBLIC_EASY_RESIZE_WINDOW_TARGETER_H_
+#define UI_WM_PUBLIC_EASY_RESIZE_WINDOW_TARGETER_H_
+
+#include "ui/aura/window_targeter.h"
+#include "ui/gfx/geometry/insets.h"
+
+namespace wm {
+
+// An EventTargeter for a container window that uses a slightly larger
+// hit-target region for easier resize.
+class EasyResizeWindowTargeter : public aura::WindowTargeter {
+ public:
+  // |container| window is the owner of this targeter.
+  EasyResizeWindowTargeter(aura::Window* container,
+                           const gfx::Insets& mouse_extend,
+                           const gfx::Insets& touch_extend);
+
+  virtual ~EasyResizeWindowTargeter();
+
+ protected:
+  void set_mouse_extend(const gfx::Insets& mouse_extend) {
+    mouse_extend_ = mouse_extend;
+  }
+
+  void set_touch_extend(const gfx::Insets& touch_extend) {
+    touch_extend_ = touch_extend;
+  }
+
+  // aura::WindowTargeter:
+  virtual bool EventLocationInsideBounds(
+      aura::Window* window,
+      const ui::LocatedEvent& event) const OVERRIDE;
+
+ private:
+  aura::Window* container_;
+  gfx::Insets mouse_extend_;
+  gfx::Insets touch_extend_;
+
+  DISALLOW_COPY_AND_ASSIGN(EasyResizeWindowTargeter);
+};
+
+}  // namespace wm
+
+#endif  // UI_WM_PUBLIC_EASY_RESIZE_WINDOW_TARGETER_H_
diff --git a/ui/wm/wm.gyp b/ui/wm/wm.gyp
index 5063551..725d9ea 100644
--- a/ui/wm/wm.gyp
+++ b/ui/wm/wm.gyp
@@ -10,7 +10,14 @@
     {
       'target_name': 'wm_public',
       'type': 'static_library',
+      'dependencies': [
+        '../../skia/skia.gyp:skia',
+        '../aura/aura.gyp:aura',
+        '../gfx/gfx.gyp:gfx_geometry',
+      ],
       'sources': [
+        'core/easy_resize_window_targeter.cc',
+        'public/easy_resize_window_targeter.h',
         'public/window_types.h',
       ],
     },
@@ -20,7 +27,6 @@
       'dependencies': [
         '../../skia/skia.gyp:skia',
         '../aura/aura.gyp:aura',
-        '../views/views.gyp:views',
       ],
       'sources': [
         'test/wm_test_helper.cc',