Apply rounded corners to the Picture-in-Picture window.

stayed upon resizing the window.

Bug: b/112668689
Bug: 841886
Test: Created a PIP window and it had rounded corners. Rounded corners
Change-Id: Ie57223d8c5a2701a0013eee0bce2cf5333d2c304
Reviewed-on: https://chromium-review.googlesource.com/1219426
Commit-Queue: Eliot Courtney <edcourtney@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594962}

ash/wm/base_state.cc

@@ -39,6 +39,7 @@ void BaseState::OnWMEvent(WindowState* window_state, const WMEvent* event) {
 
   if (event->IsBoundsEvent()) {
     HandleBoundsEvents(window_state, event);
+    window_state->UpdatePipRoundedCorners();
     return;
   }
   DCHECK(event->IsTransitionEvent());

ash/wm/window_state.cc

@@ -32,6 +32,7 @@
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/display/display.h"
 #include "ui/display/screen.h"
+#include "ui/views/painter.h"
 #include "ui/wm/core/coordinate_conversion.h"
 #include "ui/wm/core/ime_util_chromeos.h"
 #include "ui/wm/core/window_util.h"
@@ -40,6 +41,9 @@ namespace ash {
 namespace wm {
 namespace {
 
+// TODO(edcourtney): Move this to a PIP specific file, once it's created.
+const int kPipRoundedCornerRadius = 8;
+
 bool IsTabletModeEnabled() {
   return Shell::Get()
       ->tablet_mode_controller()
@@ -660,6 +664,28 @@ void WindowState::SetBoundsDirectCrossFade(const gfx::Rect& new_bounds,
   CrossFadeAnimation(window_, std::move(old_layer_owner), animation_type);
 }
 
+void WindowState::UpdatePipRoundedCorners() {
+  auto* layer = window()->layer();
+  if (!IsPip()) {
+    if (layer)
+      layer->SetMaskLayer(nullptr);
+    pip_mask_.reset();
+    return;
+  }
+
+  gfx::Rect bounds = window()->bounds();
+  if (layer && (!pip_mask_ || pip_mask_->layer()->size() != bounds.size())) {
+    layer->SetMaskLayer(nullptr);
+    pip_mask_ = views::Painter::CreatePaintedLayer(
+        views::Painter::CreateSolidRoundRectPainter(SK_ColorBLACK,
+                                                    kPipRoundedCornerRadius));
+    pip_mask_->layer()->SetBounds(bounds);
+    pip_mask_->layer()->SetFillsBoundsOpaquely(false);
+    layer->SetFillsBoundsOpaquely(false);
+    layer->SetMaskLayer(pip_mask_->layer());
+  }
+}
+
 WindowState* GetActiveWindowState() {
   aura::Window* active = GetActiveWindow();
   return active ? GetWindowState(active) : nullptr;

ash/wm/window_state.h

@@ -17,6 +17,7 @@
 #include "base/optional.h"
 #include "ui/aura/window_observer.h"
 #include "ui/base/ui_base_types.h"
+#include "ui/compositor/layer_owner.h"
 #include "ui/gfx/animation/tween.h"
 
 namespace gfx {
@@ -399,6 +400,10 @@ class ASH_EXPORT WindowState : public aura::WindowObserver {
       const gfx::Rect& bounds,
       gfx::Tween::Type animation_type = gfx::Tween::EASE_OUT);
 
+  // Updates rounded corners for PIP window states. Removes rounded corners
+  // for non-PIP window states.
+  void UpdatePipRoundedCorners();
+
   // aura::WindowObserver:
   void OnWindowPropertyChanged(aura::Window* window,
                                const void* key,
@@ -422,6 +427,9 @@ class ASH_EXPORT WindowState : public aura::WindowObserver {
   bool cached_always_on_top_;
   bool allow_set_bounds_direct_ = false;
 
+  // Mask layer for PIP windows.
+  std::unique_ptr<ui::LayerOwner> pip_mask_ = nullptr;
+
   // A property to save the ratio between snapped window width and display
   // workarea width. It is used to update snapped window width on
   // AdjustSnappedBounds() when handling workspace events.