[ash-md] Makes sure that minimized windows can be activated in overview

When windows are minimized before entering overview mode, they are
replaced with a widget that has mirrored layers. Opacity of the original
window needs to be then set to 1 in order to make it visible
(in WindowMirrorView::InitLayerOwner()).
Upon exiting overview the original window's opacity is restored.
This logic breaks if a window is selected - the opacity need not be
restored (to zero).
Make it so that the opacity is set to 1 upon exit if a window is
selected.

BUG=677177

Review-Url: https://codereview.chromium.org/2637403013
Cr-Commit-Position: refs/heads/master@{#445524}

ash/common/wm/overview/scoped_transform_overview_window.cc

@@ -446,15 +446,21 @@ WmWindow* ScopedTransformOverviewWindow::GetOverviewWindow() const {
   return window_;
 }
 
+void ScopedTransformOverviewWindow::EnsureVisible() {
+  original_opacity_ = 1.f;
+}
+
 void ScopedTransformOverviewWindow::OnGestureEvent(ui::GestureEvent* event) {
   if (event->type() == ui::ET_GESTURE_TAP) {
+    EnsureVisible();
     window_->Show();
     window_->Activate();
   }
 }
 
 void ScopedTransformOverviewWindow::OnMouseEvent(ui::MouseEvent* event) {
   if (event->type() == ui::ET_MOUSE_PRESSED && event->IsOnlyLeftMouseButton()) {
+    EnsureVisible();
     window_->Show();
     window_->Activate();
   }

ash/common/wm/overview/scoped_transform_overview_window.h

@@ -141,6 +141,9 @@ class ASH_EXPORT ScopedTransformOverviewWindow : public ui::EventHandler {
   // For minmiezd window, this will be a window that hosts mirrored layers.
   WmWindow* GetOverviewWindow() const;
 
+  // Ensures that a window is visible by setting its opacity to 1.
+  void EnsureVisible();
+
   // Returns the window created for minimized window, or nullptr
   // if it does not exit.
   WmWindow* GetOverviewWindowForMinimizedState() const;

ash/common/wm/overview/window_selector.cc

@@ -407,7 +407,8 @@ void WindowSelector::OnGridEmpty(WindowGrid* grid) {
     CancelSelection();
 }
 
-void WindowSelector::SelectWindow(WmWindow* window) {
+void WindowSelector::SelectWindow(WindowSelectorItem* item) {
+  WmWindow* window = item->GetWindow();
   std::vector<WmWindow*> window_list =
       WmShell::Get()->mru_window_tracker()->BuildMruWindowList();
   if (!window_list.empty()) {
@@ -425,7 +426,7 @@ void WindowSelector::SelectWindow(WmWindow* window) {
                                1 + it - window_list.begin());
     }
   }
-
+  item->EnsureVisible();
   window->GetWindowState()->Activate();
 }
 
@@ -481,8 +482,7 @@ bool WindowSelector::HandleKeyEvent(views::Textfield* sender,
                                   (num_key_presses_ * 100) / num_items_, 1, 300,
                                   30);
       WmShell::Get()->RecordUserMetricsAction(UMA_WINDOW_OVERVIEW_ENTER_KEY);
-      SelectWindow(
-          grid_list_[selected_grid_index_]->SelectedWindow()->GetWindow());
+      SelectWindow(grid_list_[selected_grid_index_]->SelectedWindow());
       break;
     default:
       // Not a key we are interested in, allow the textfield to handle it.

ash/common/wm/overview/window_selector.h

@@ -61,8 +61,8 @@ class ASH_EXPORT WindowSelector : public display::DisplayObserver,
   // Called when the last window selector item from a grid is deleted.
   void OnGridEmpty(WindowGrid* grid);
 
-  // Activates |window|.
-  void SelectWindow(WmWindow* window);
+  // Activates |item's| window.
+  void SelectWindow(WindowSelectorItem* item);
 
   // Called when |window| is about to get closed.
   void WindowClosing(WindowSelectorItem* window);

ash/common/wm/overview/window_selector_item.cc

@@ -442,6 +442,10 @@ void WindowSelectorItem::RestoreWindow() {
       OverviewAnimationType::OVERVIEW_ANIMATION_LAY_OUT_SELECTOR_ITEMS);
 }
 
+void WindowSelectorItem::EnsureVisible() {
+  transform_window_.EnsureVisible();
+}
+
 void WindowSelectorItem::Shutdown() {
   if (transform_window_.GetTopInset()) {
     // Activating a window (even when it is the window that was active before
@@ -555,7 +559,7 @@ void WindowSelectorItem::ButtonPressed(views::Button* sender,
     return;
   }
   CHECK(sender == caption_container_view_->listener_button());
-  window_selector_->SelectWindow(transform_window_.window());
+  window_selector_->SelectWindow(this);
 }
 
 void WindowSelectorItem::OnWindowDestroying(WmWindow* window) {

ash/common/wm/overview/window_selector_item.h

@@ -66,6 +66,9 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
   // Restores and animates the managed window to its non overview mode state.
   void RestoreWindow();
 
+  // Ensures that a possibly minimized window becomes visible after restore.
+  void EnsureVisible();
+
   // Restores stacking of window captions above the windows, then fades out.
   void Shutdown();
 

ash/wm/overview/window_selector_unittest.cc

@@ -469,12 +469,14 @@ TEST_F(WindowSelectorTest, ActivateMinimized) {
   wm::WMEvent minimize_event(wm::WM_EVENT_MINIMIZE);
   window_state->OnWMEvent(&minimize_event);
   EXPECT_FALSE(window->IsVisible());
+  EXPECT_EQ(0.f, window->layer()->GetTargetOpacity());
   EXPECT_EQ(wm::WINDOW_STATE_TYPE_MINIMIZED,
             wm::GetWindowState(window.get())->GetStateType());
 
   ToggleOverview();
 
   EXPECT_FALSE(window->IsVisible());
+  EXPECT_EQ(0.f, window->layer()->GetTargetOpacity());
   EXPECT_EQ(wm::WINDOW_STATE_TYPE_MINIMIZED,
             wm::GetWindowState(window.get())->GetStateType());
   aura::Window* window_for_minimized_window =
@@ -490,6 +492,7 @@ TEST_F(WindowSelectorTest, ActivateMinimized) {
   EXPECT_FALSE(IsSelecting());
 
   EXPECT_TRUE(window->IsVisible());
+  EXPECT_EQ(1.f, window->layer()->GetTargetOpacity());
   EXPECT_EQ(wm::WINDOW_STATE_TYPE_NORMAL,
             wm::GetWindowState(window.get())->GetStateType());
 }