Split Screen mode implementation

athena/wm/window_overview_mode.cc

 // 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 "athena/wm/window_overview_mode.h"
 
 #include <algorithm>
 #include <functional>
 #include <vector>
 
+#include "athena/wm/public/window_list_provider.h"
 #include "base/macros.h"
 #include "ui/aura/scoped_window_targeter.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/aura/window_property.h"
 #include "ui/aura/window_targeter.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/events/event_handler.h"
 #include "ui/gfx/transform.h"
 #include "ui/wm/core/shadow.h"
@@ skipping 17 matching lines @@
 }  // namespace
 
 DECLARE_WINDOW_PROPERTY_TYPE(WindowOverviewState*)
 DEFINE_OWNED_WINDOW_PROPERTY_KEY(WindowOverviewState,
                                  kWindowOverviewState,
                                  NULL)
 namespace athena {
 
 namespace {
 
-bool ShouldShowWindowInOverviewMode(aura::Window* window) {
-  return window->type() == ui::wm::WINDOW_TYPE_NORMAL;
-}
-
 // Sets the progress-state for the window in the overview mode.
 void SetWindowProgress(aura::Window* window, float progress) {
   WindowOverviewState* state = window->GetProperty(kWindowOverviewState);
   gfx::Transform transform =
       gfx::Tween::TransformValueBetween(progress, state->top, state->bottom);
   window->SetTransform(transform);
   state->progress = progress;
 }
 
 // Resets the overview-related state for |window|.
@@ skipping 27 matching lines @@
   }
 
   aura::Window* target_;
   DISALLOW_COPY_AND_ASSIGN(StaticWindowTargeter);
 };
 
 class WindowOverviewModeImpl : public WindowOverviewMode,
                                public ui::EventHandler {
  public:
   WindowOverviewModeImpl(aura::Window* container,
+                         const WindowListProvider* window_list_provider,
                          WindowOverviewModeDelegate* delegate)
       : container_(container),
+        window_list_provider_(window_list_provider),
         delegate_(delegate),
         scoped_targeter_(new aura::ScopedWindowTargeter(
             container,
             scoped_ptr<ui::EventTargeter>(
                 new StaticWindowTargeter(container)))) {
     container_->set_target_handler(this);
 
     // Prepare the desired transforms for all the windows, and set the initial
     // state on the windows.
     ComputeTerminalStatesForAllWindows();
     SetInitialWindowStates();
   }
 
   virtual ~WindowOverviewModeImpl() {
     container_->set_target_handler(container_->delegate());
-
-    const aura::Window::Windows& windows = container_->children();
-    for (aura::Window::Windows::const_iterator iter = windows.begin();
-         iter != windows.end();
-         ++iter) {
-      if ((*iter)->GetProperty(kWindowOverviewState))
-        RestoreWindowState(*iter);
-    }
+    aura::Window::Windows windows = window_list_provider_->GetWindowList();
+    if (windows.empty())
+      return;
+    std::for_each(windows.begin(), windows.end(), &RestoreWindowState);
   }
 
  private:
   // Computes the transforms for all windows in both the topmost and bottom-most
   // positions. The transforms are set in the |kWindowOverviewState| property of
   // the windows.
   void ComputeTerminalStatesForAllWindows() {
-    const aura::Window::Windows& windows = container_->children();
-    size_t window_count = std::count_if(windows.begin(), windows.end(),
-                                        ShouldShowWindowInOverviewMode);
-
+    aura::Window::Windows windows = window_list_provider_->GetWindowList();
+    size_t window_count = windows.size();
     size_t index = 0;
     const gfx::Size container_size = container_->bounds().size();
 
     const int kGapBetweenWindowsBottom = 10;
     const int kGapBetweenWindowsTop = 5;
     const float kMinScale = 0.6f;
     const float kMaxScale = 0.95f;
 
     for (aura::Window::Windows::const_reverse_iterator iter = windows.rbegin();
          iter != windows.rend();
-         ++iter) {
+         ++iter, ++index) {
       aura::Window* window = (*iter);
-      if (!ShouldShowWindowInOverviewMode(window))
-        continue;
 
       gfx::Transform top_transform;
       int top = (window_count - index - 1) * kGapBetweenWindowsTop;
       float x_translate = container_size.width() * (1 - kMinScale) / 2.;
       top_transform.Translate(x_translate, top);
       top_transform.Scale(kMinScale, kMinScale);
 
       gfx::Transform bottom_transform;
       int bottom = GetScrollableHeight() - (index * kGapBetweenWindowsBottom);
       x_translate = container_size.width() * (1 - kMaxScale) / 2.;
       bottom_transform.Translate(x_translate, bottom - window->bounds().y());
       bottom_transform.Scale(kMaxScale, kMaxScale);
 
       WindowOverviewState* state = new WindowOverviewState;
       state->top = top_transform;
       state->bottom = bottom_transform;
       state->progress = 0.f;
       state->shadow = CreateShadowForWindow(window);
       window->SetProperty(kWindowOverviewState, state);
-
-      index++;
     }
   }
 
   // Sets the initial position for the windows for the overview mode.
   void SetInitialWindowStates() {
+    aura::Window::Windows windows = window_list_provider_->GetWindowList();
+    size_t window_count = windows.size();
     // The initial overview state of the topmost three windows.
     const float kInitialProgress[] = { 0.5f, 0.05f, 0.01f };
-    size_t index = 0;
-    const aura::Window::Windows& windows = container_->children();
-    for (aura::Window::Windows::const_reverse_iterator iter = windows.rbegin();
-         iter != windows.rend();
-         ++iter) {
-      aura::Window* window = (*iter);
-      if (!window->GetProperty(kWindowOverviewState))
-        continue;
-
+    for (size_t i = 0; i < window_count; ++i) {
       float progress = 0.f;
-      if (index < arraysize(kInitialProgress))
-        progress = kInitialProgress[index];
+      aura::Window* window = windows[window_count - 1 - i];
+      if (i < arraysize(kInitialProgress))
+        progress = kInitialProgress[i];
 
       scoped_refptr<ui::LayerAnimator> animator =
           window->layer()->GetAnimator();
 
       // Unset any in-progress animation.
       {
         ui::ScopedLayerAnimationSettings settings(animator);
         settings.SetPreemptionStrategy(
             ui::LayerAnimator::IMMEDIATELY_SET_NEW_TARGET);
         window->Show();
         window->SetTransform(gfx::Transform());
       }
       // Setup the animation.
       {
         ui::ScopedLayerAnimationSettings settings(animator);
         settings.SetPreemptionStrategy(
             ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
         settings.SetTransitionDuration(base::TimeDelta::FromMilliseconds(250));
         SetWindowProgress(window, progress);
       }
-      index++;
     }
   }
 
   scoped_ptr<wm::Shadow> CreateShadowForWindow(aura::Window* window) {
     scoped_ptr<wm::Shadow> shadow(new wm::Shadow());
     shadow->Init(wm::Shadow::STYLE_ACTIVE);
-    shadow->SetContentBounds(gfx::Rect(window->bounds().size()));
+    shadow->SetContentBounds(gfx::Rect(container_->bounds().size()));
     shadow->layer()->SetVisible(true);
     window->layer()->Add(shadow->layer());
     return shadow.Pass();
   }
 
   aura::Window* SelectWindowAt(ui::LocatedEvent* event) {
     CHECK_EQ(container_, event->target());
     // Find the old targeter to find the target of the event.
     ui::EventTarget* window = container_;
     ui::EventTargeter* targeter = scoped_targeter_->old_targeter();
     while (!targeter && window->GetParentTarget()) {
       window = window->GetParentTarget();
       targeter = window->GetEventTargeter();
     }
     if (!targeter)
       return NULL;
     aura::Window* target = static_cast<aura::Window*>(
         targeter->FindTargetForLocatedEvent(container_, event));
     while (target && target->parent() != container_)
       target = target->parent();
     return target;
   }
 
   // Scroll the window list by |delta_y| amount. |delta_y| is negative when
   // scrolling up; and positive when scrolling down.
   void DoScroll(float delta_y) {
     const float kEpsilon = 1e-3f;
     float delta_y_p = std::abs(delta_y) / GetScrollableHeight();
-    const aura::Window::Windows& windows = container_->children();
+    aura::Window::Windows windows = window_list_provider_->GetWindowList();
     if (delta_y < 0) {
       // Scroll up. Start with the top-most (i.e. behind-most in terms of
       // z-index) window, and try to scroll them up.
       for (aura::Window::Windows::const_iterator iter = windows.begin();
            delta_y_p > kEpsilon && iter != windows.end();
            ++iter) {
         aura::Window* window = (*iter);
         WindowOverviewState* state = window->GetProperty(kWindowOverviewState);
-        if (!state)
-          continue;
         if (state->progress > kEpsilon) {
           // It is possible to scroll |window| up. Scroll it up, and update
           // |delta_y_p| for the next window.
           float apply = delta_y_p * state->progress;
           SetWindowProgress(window, std::max(0.f, state->progress - apply * 3));
           delta_y_p -= apply;
         }
       }
     } else {
       // Scroll down. Start with the bottom-most (i.e. front-most in terms of
       // z-index) window, and try to scroll them down.
-      for (aura::Window::Windows::const_reverse_iterator iter =
-               windows.rbegin();
+      aura::Window::Windows::const_reverse_iterator iter;
+      for (iter = windows.rbegin();
            delta_y_p > kEpsilon && iter != windows.rend();
            ++iter) {
         aura::Window* window = (*iter);
         WindowOverviewState* state = window->GetProperty(kWindowOverviewState);
-        if (!state)
-          continue;
         if (1.f - state->progress > kEpsilon) {
           // It is possible to scroll |window| down. Scroll it down, and update
           // |delta_y_p| for the next window.
           SetWindowProgress(window, std::min(1.f, state->progress + delta_y_p));
           delta_y_p /= 2.f;
         }
       }
     }
   }
 
@@ skipping 26 matching lines @@
       if (select) {
         gesture->SetHandled();
         delegate_->OnSelectWindow(select);
       }
     } else if (gesture->type() == ui::ET_GESTURE_SCROLL_UPDATE) {
       DoScroll(gesture->details().scroll_y());
     }
   }
 
   aura::Window* container_;
+  // Provider of the stack of windows to show in the overview mode. Not owned.
+  const WindowListProvider* window_list_provider_;
   WindowOverviewModeDelegate* delegate_;
   scoped_ptr<aura::ScopedWindowTargeter> scoped_targeter_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowOverviewModeImpl);
 };
 
 }  // namespace
 
 // static
 scoped_ptr<WindowOverviewMode> WindowOverviewMode::Create(
     aura::Window* container,
+    const WindowListProvider* window_list_provider,
     WindowOverviewModeDelegate* delegate) {
   return scoped_ptr<WindowOverviewMode>(
-      new WindowOverviewModeImpl(container, delegate));
+      new WindowOverviewModeImpl(container, window_list_provider, delegate));
 }
 
 }  // namespace athena