Draggable peeking/fullscreen launcher with transparent background.

ui/app_list/views/app_list_view.cc

Index: ui/app_list/views/app_list_view.cc
diff --git a/ui/app_list/views/app_list_view.cc b/ui/app_list/views/app_list_view.cc
index 08ff586e0718196f00aa7d3b2ef2b0615af3deba..336db5a248a327f400eaf0c55ef115d7ae3e407a 100644
--- a/ui/app_list/views/app_list_view.cc
+++ b/ui/app_list/views/app_list_view.cc
@@ -56,6 +56,20 @@ namespace {
 // The margin from the edge to the speech UI.
 const int kSpeechUIMargin = 12;
 
+// The height/width of the shelf.
+const int kShelfSize = 48;

[xiyuan, 2017/05/26 18:27:31]

const -> constexpr for all

[newcomer, 2017/05/26 23:20:22]

Done.

+
+// The height of the peeking launcher.
+const int kPeekingLauncherHeight = 320;
+// The fraction of launcher height that the launcher must be released at in
+// order to transition to the next state.
+const int kLauncherThresholdDenominator = 3;
+// The velocity the launcher must be dragged in order to transition to the next
+// state, measured in DIPs/event.
+const int kLauncherDragVelocityThreshold = 25;
+
+const float kLauncherOpacity = 0.8;

[vadimt, 2017/05/26 17:58:55]

Comment!!!!!

[newcomer, 2017/05/26 23:20:21]

Done.

+
 // The vertical position for the appearing animation of the speech UI.
 const float kSpeechUIAppearingPosition = 12;
 
@@ -175,14 +189,22 @@ AppListView::AppListView(AppListViewDelegate* delegate)
       search_box_focus_host_(nullptr),
       search_box_widget_(nullptr),
       search_box_view_(nullptr),
+      display_observer_(this),
       overlay_view_(nullptr),
       animation_observer_(new HideViewAnimationObserver()) {
   CHECK(delegate);
 
   delegate_->GetSpeechUI()->AddObserver(this);
+
+  if (features::IsFullscreenAppListEnabled())
+    display_observer_.Add(display::Screen::GetScreen());
 }
 
 AppListView::~AppListView() {
+  // Remove this instance from the DisplayManager's list of observers.
+  if (features::IsFullscreenAppListEnabled())
+    display_observer_.Remove(display::Screen::GetScreen());

[xiyuan, 2017/05/26 18:27:31]

nit: Get rid of this since ScopedObsever would do this automatically.

[newcomer, 2017/05/26 23:20:22]

Done.

+
   delegate_->GetSpeechUI()->RemoveObserver(this);
   animation_observer_.reset();
   // Remove child views first to ensure no remaining dependencies on delegate_.
@@ -203,8 +225,10 @@ void AppListView::Initialize(gfx::NativeView parent, int initial_apps_page) {
 
   InitChildWidgets();
   AddChildView(overlay_view_);
+
   if (delegate_)
     delegate_->ViewInitialized();
+
   UMA_HISTOGRAM_TIMES("Apps.AppListCreationTime",
                       base::Time::Now() - start_time);
 }
@@ -237,10 +261,18 @@ void AppListView::CloseAppList() {
 
 void AppListView::UpdateBounds() {
   // if the AppListView is a bubble
-  if (!features::IsFullscreenAppListEnabled())
+  if (!launcher_background_shield_)
     SizeToContents();
 }
 
+void AppListView::UpdateDimensions() {
+  display_work_area_bounds_ = display::Screen::GetScreen()
+                                  ->GetDisplayNearestView(parent_window())
+                                  .work_area();
+  default_peeking_launcher_y_ =
+      display_work_area_bounds_.height() + kShelfSize - kPeekingLauncherHeight;
+}
+
 void AppListView::SetAppListOverlayVisible(bool visible) {
   DCHECK(overlay_view_);
 
@@ -330,7 +362,16 @@ void AppListView::InitContents(gfx::NativeView parent, int initial_apps_page) {
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "440224, 441028 AppListView::InitContents"));
 
-  app_list_main_view_ = new AppListMainView(delegate_);
+  if (features::IsFullscreenAppListEnabled()) {
+    // The shield view that colors the background of the launcher and makes it
+    // transparent.
+    launcher_background_shield_ = new views::View;
+    launcher_background_shield_->SetPaintToLayer(ui::LAYER_SOLID_COLOR);
+    launcher_background_shield_->layer()->SetColor(SK_ColorBLACK);
+    launcher_background_shield_->layer()->SetOpacity(kLauncherOpacity);
+    AddChildView(launcher_background_shield_);
+  }
+  app_list_main_view_ = new AppListMainView(delegate_, this);
   AddChildView(app_list_main_view_);
   app_list_main_view_->SetPaintToLayer();
   app_list_main_view_->layer()->SetFillsBoundsOpaquely(false);
@@ -338,6 +379,7 @@ void AppListView::InitContents(gfx::NativeView parent, int initial_apps_page) {
   // This will be added to the |search_box_widget_| after the app list widget is
   // initialized.
   search_box_view_ = new SearchBoxView(app_list_main_view_, delegate_);
+  search_box_view_->SetAppListView(this);
   search_box_view_->SetPaintToLayer();
   search_box_view_->layer()->SetFillsBoundsOpaquely(false);
   search_box_view_->layer()->SetMasksToBounds(true);
@@ -404,21 +446,34 @@ void AppListView::InitChildWidgets() {
 
 void AppListView::InitializeFullscreen(gfx::NativeView parent,
                                        int initial_apps_page) {
-  views::Widget* widget = new views::Widget;
+  UpdateDimensions();
+
+  gfx::Rect app_list_overlay_view_bounds(
+      display_work_area_bounds_.x(), default_peeking_launcher_y_,
+      display_work_area_bounds_.width(),
+      display_work_area_bounds_.height() + kShelfSize);
+
+  fullscreen_widget_ = new views::Widget;
   views::Widget::InitParams app_list_overlay_view_params(
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
 
+  app_list_overlay_view_params.name = "AppList";
   app_list_overlay_view_params.parent = parent;
   app_list_overlay_view_params.delegate = this;
   app_list_overlay_view_params.opacity =
       views::Widget::InitParams::TRANSLUCENT_WINDOW;
-  app_list_overlay_view_params.bounds =
-      display::Screen::GetScreen()->
-      GetDisplayNearestView(parent).work_area();
-  widget->Init(app_list_overlay_view_params);
-  widget->GetLayer()->SetBackgroundBlur(10);
+  app_list_overlay_view_params.bounds = app_list_overlay_view_bounds;
+  app_list_overlay_view_params.layer_type = ui::LAYER_SOLID_COLOR;
+  fullscreen_widget_->Init(app_list_overlay_view_params);
 
+  fullscreen_widget_bounds_ = fullscreen_widget_->GetWindowBoundsInScreen();
   overlay_view_ = new AppListOverlayView(0 /* no corners */);
+
+  // Launcher + shelf height, used in HandleDrag.
+  launcher_threshold_ =
+      (default_peeking_launcher_y_ + fullscreen_widget_bounds_.height() -
+       fullscreen_widget_bounds_.y()) /
+      kLauncherThresholdDenominator;
 }
 
 void AppListView::InitializeBubble(gfx::NativeView parent,
@@ -428,7 +483,7 @@ void AppListView::InitializeBubble(gfx::NativeView parent,
   set_shadow(views::BubbleBorder::NO_ASSETS);
 
   // This creates the app list widget. (Before this, child widgets cannot be
-  // created.)
+  // created.
   views::BubbleDialogDelegateView::CreateBubble(this);
 
   SetBubbleArrow(views::BubbleBorder::FLOAT);
@@ -443,6 +498,89 @@ void AppListView::InitializeBubble(gfx::NativeView parent,
   overlay_view_->SetBoundsRect(GetContentsBounds());
 }
 
+void AppListView::HandleDrag(gfx::Point location, ui::EventType type) {

[xiyuan, 2017/05/26 18:27:31]

nit: Break this into StartDrag, UpdateDrag and EndDrag. We can keep HandleDrag
to call them from the switch statement.

[newcomer, 2017/05/26 23:20:21]

Done.

+  switch (type) {
+    case ui::ET_GESTURE_SCROLL_BEGIN:
+    case ui::ET_MOUSE_PRESSED: {
+      // Drag start, grab the initial_drag_separation_ to maintain the relative
+      // position of the top of the widget and the mouse/gesture.
+      initial_drag_separation_ = location.y();
+      fullscreen_widget_bounds_ = fullscreen_widget_->GetWindowBoundsInScreen();
+      break;
+    }
+    case ui::ET_GESTURE_SCROLL_UPDATE:
+    case ui::ET_MOUSE_DRAGGED: {
+      // Drag update, update the bounds of the widget while maintaining the
+      // relative position of the top of the widget and the mouse/gesture.
+      // Block drags north of 0 and recalculate the initial_drag_separation_.
+      int new_y_position = location.y() - initial_drag_separation_ +

[vadimt, 2017/05/26 17:58:55]

Nit: this can be const.

[newcomer, 2017/05/26 23:20:22]

Done.

+                           fullscreen_widget_bounds_.y();
+      if (new_y_position < 0) {
+        fullscreen_widget_bounds_.set_y(0);
+        initial_drag_separation_ = location.y();
+      } else {
+        fullscreen_widget_bounds_.set_y(new_y_position);
+      }
+      fullscreen_widget_->SetBounds(fullscreen_widget_bounds_);
+      break;
+    }
+
+    case ui::ET_GESTURE_END:
+    case ui::ET_MOUSE_RELEASED: {
+      // Drag completion, either snap to fullscreen or close the App List based
+      // on where the drag ended. If fling velocity was over the threshold, snap
+      // to the next state in the direction of the fling.
+      int new_y_position = location.y() - initial_drag_separation_ +
+                           fullscreen_widget_bounds_.y();
+      if (std::abs(last_fling_velocity_) > kLauncherDragVelocityThreshold) {
+        // If the user releases drag with velocity over the threshold, snap to
+        // the next state, ignoring the drag release position.
+        if (is_fullscreen_launcher_) {
+          if (last_fling_velocity_ > 0) {
+            ToPeeking();
+          }
+        } else {
+          if (last_fling_velocity_ > 0) {
+            CloseAppList();
+          } else if (last_fling_velocity_ < 0) {
+            ToFullscreen();
+          }
+        }
+        last_fling_velocity_ = 0;
+      } else {
+        // The drag release velocity was too low, so use the release point.
+        int launcher_snap_y =
+            is_fullscreen_launcher_ ? 0 : default_peeking_launcher_y_;
+        // If the user releases +/- 1/3 of launcher_threshold_ , snap to the
+        // next state.
+        if (std::abs(launcher_snap_y - new_y_position) <
+            (launcher_threshold_)) {
+          // If the drag released to the state above.
+          if (is_fullscreen_launcher_) {
+            ToFullscreen();
+          } else {
+            ToPeeking();
+          }
+        } else if ((launcher_snap_y + (launcher_threshold_)) < new_y_position) {
+          // If the user released to the state below.
+          if (is_fullscreen_launcher_) {
+            ToPeeking();
+          } else {
+            CloseAppList();
+          }
+        } else {
+          // if the user released to the state above, go to the state above.
+          ToFullscreen();
+        }
+      }
+      break;
+    }
+    default:
+      NOTREACHED();
+      break;
+  }
+}
+
 void AppListView::OnBeforeBubbleWidgetInit(views::Widget::InitParams* params,
                                            views::Widget* widget) const {
   if (!params->native_widget) {
@@ -476,6 +614,42 @@ void AppListView::GetWidgetHitTestMask(gfx::Path* mask) const {
   mask->addRect(gfx::RectToSkRect(GetBubbleFrameView()->GetContentsBounds()));
 }
 
+void AppListView::OnMouseEvent(ui::MouseEvent* event) {
+  if (!launcher_background_shield_)
+    return;
+
+  switch (event->type()) {
+    case ui::ET_MOUSE_PRESSED:
+    case ui::ET_MOUSE_DRAGGED:
+    case ui::ET_MOUSE_RELEASED:
+      HandleDrag(event->location(), event->type());
+      event->SetHandled();
+      break;
+    default:
+      break;
+  }
+}
+
+void AppListView::OnGestureEvent(ui::GestureEvent* event) {
+  if (!launcher_background_shield_)
+    return;
+
+  switch (event->type()) {
+    case ui::ET_GESTURE_SCROLL_UPDATE:
+      last_fling_velocity_ = event->details().velocity_y();
+      HandleDrag(event->location(), event->type());
+      event->SetHandled();
+      break;
+    case ui::ET_GESTURE_SCROLL_BEGIN:
+    case ui::ET_GESTURE_END:
+      HandleDrag(event->location(), event->type());
+      event->SetHandled();
+      break;
+    default:
+      break;
+  }
+}
+
 bool AppListView::AcceleratorPressed(const ui::Accelerator& accelerator) {
   DCHECK_EQ(ui::VKEY_ESCAPE, accelerator.key_code());
 
@@ -491,6 +665,23 @@ bool AppListView::AcceleratorPressed(const ui::Accelerator& accelerator) {
 }
 
 void AppListView::Layout() {
+  // If the fullscreen feature has been enabled.
+  if (launcher_background_shield_) {
+    UpdateDimensions();

[xiyuan, 2017/05/26 18:27:31]

Why this is needed? Shouldn't UpdateDimensions() only be called when
display/workarea changes? Think this and ToFullscreen() calls etc belongs to
OnDisplayMetricsChanged.

Resizing hosting widget from inside Layout is not good since widget resizing
might trigger Layout again.

[newcomer, 2017/05/26 23:20:21]

You're correct. Thanks for pointing that out.

+
+    gfx::Rect recomputed_fullscreen_widget_bounds(
+        display_work_area_bounds_.x(), default_peeking_launcher_y_,
+        display_work_area_bounds_.width(),
+        display_work_area_bounds_.height() + kShelfSize);
+
+    fullscreen_widget_bounds_ = recomputed_fullscreen_widget_bounds;

[xiyuan, 2017/05/26 18:27:31]

|fullscreen_widget_bounds_| is used to track the bounds for dragging. Why we
need to update it here?

[newcomer, 2017/05/26 23:20:21]

The bounds need to be updated when the screen rotates. This should live in
OnDisplayMetricsChanged. 

+
+    if (is_fullscreen_launcher_) {
+      ToFullscreen();
+    } else {
+      ToPeeking();
+    }
+  }
   const gfx::Rect contents_bounds = GetContentsBounds();
 
   // Make sure to layout |app_list_main_view_| and |speech_view_| at the center
@@ -511,6 +702,11 @@ void AppListView::Layout() {
     speech_bounds.Inset(-speech_view_->GetInsets());
     speech_view_->SetBoundsRect(speech_bounds);
   }
+  // If the fullscreen feature has been enabled.
+  if (launcher_background_shield_) {
+    app_list_main_view_->contents_view()->Layout();
+    launcher_background_shield_->SetBoundsRect(contents_bounds);
+  }
 }
 
 void AppListView::SchedulePaintInRect(const gfx::Rect& rect) {
@@ -519,6 +715,27 @@ void AppListView::SchedulePaintInRect(const gfx::Rect& rect) {
     GetBubbleFrameView()->SchedulePaint();
 }
 
+void AppListView::ToFullscreen() {
+  fullscreen_widget_bounds_.set_y(0);
+  fullscreen_widget_->SetBounds(fullscreen_widget_bounds_);
+  is_fullscreen_launcher_ = true;
+  launcher_threshold_ = (fullscreen_widget_bounds_.height() + kShelfSize) /
+                        kLauncherThresholdDenominator;
+}
+
+void AppListView::ToPeeking() {
+  fullscreen_widget_bounds_.set_y(default_peeking_launcher_y_);
+  fullscreen_widget_->SetBounds(fullscreen_widget_bounds_);
+  is_fullscreen_launcher_ = false;
+  launcher_threshold_ = (fullscreen_widget_bounds_.height() + kShelfSize -
+                         kPeekingLauncherHeight) /
+                        kLauncherThresholdDenominator;
+}
+
+bool AppListView::IsFullscreen() const {
+  return is_fullscreen_launcher_;
+}
+
 void AppListView::OnWidgetDestroying(views::Widget* widget) {
   BubbleDialogDelegateView::OnWidgetDestroying(widget);
   if (delegate_ && widget == GetWidget())
@@ -603,4 +820,9 @@ void AppListView::OnSpeechRecognitionStateChanged(
   }
 }
 
+void AppListView::OnDisplayMetricsChanged(const display::Display& display,
+                                          uint32_t changed_metrics) {
+  Layout();
+}
+
 }  // namespace app_list