Initial support of large mouse cursor on Exosphere

components/exo/pointer.cc

Index: components/exo/pointer.cc
diff --git a/components/exo/pointer.cc b/components/exo/pointer.cc
index 6c0c6482e26e753e6a00c62e76cb684625c378c3..e8a440b71a0a9874398dbf2eb9d8b881b8c377a9 100644
--- a/components/exo/pointer.cc
+++ b/components/exo/pointer.cc
@@ -39,7 +39,13 @@ Pointer::Pointer(PointerDelegate* delegate)
       surface_(nullptr),
       focus_(nullptr),
       cursor_scale_(1.0f) {
-  ash::Shell::GetInstance()->AddPreTargetHandler(this);
+  ash::Shell* ash_shell = ash::Shell::GetInstance();

[reveman, 2016/06/15 17:48:30]

nit: not sure this temporary variable is needed but if you add it here then
please do the same in dtor for consistency

+  ash_shell->AddPreTargetHandler(this);
+
+  wm::CursorManager* cursor_manager = ash_shell->cursor_manager();
+  DCHECK(cursor_manager);
+  cursor_manager->AddObserver(this);
+  use_large_cursor_ = (cursor_manager->GetCursorSet() == ui::CURSOR_SET_LARGE);
 }
 
 Pointer::~Pointer() {
@@ -52,6 +58,9 @@ Pointer::~Pointer() {
   }
   if (widget_)
     widget_->CloseNow();
+
+  DCHECK(ash::Shell::GetInstance()->cursor_manager());
+  ash::Shell::GetInstance()->cursor_manager()->RemoveObserver(this);
   ash::Shell::GetInstance()->RemovePreTargetHandler(this);
 }
 
@@ -211,21 +220,7 @@ void Pointer::OnMouseEvent(ui::MouseEvent* event) {
       widget_->GetNativeWindow()->SetBounds(bounds);
     }
 
-    // Update cursor scale if the effective UI scale has changed since last
-    // mouse event.
-    display::Display display =
-        display::Screen::GetScreen()->GetDisplayNearestWindow(
-            widget_->GetNativeWindow());
-    float ui_scale = ash::Shell::GetInstance()
-                         ->display_manager()
-                         ->GetDisplayInfo(display.id())
-                         .GetEffectiveUIScale();
-    if (ui_scale != cursor_scale_) {
-      gfx::Transform transform;
-      transform.Scale(ui_scale, ui_scale);
-      widget_->GetNativeWindow()->SetTransform(transform);
-      cursor_scale_ = ui_scale;
-    }
+    ResetCursor();
   } else {
     if (widget_ && widget_->IsVisible())
       widget_->Hide();
@@ -236,6 +231,11 @@ void Pointer::OnScrollEvent(ui::ScrollEvent* event) {
   OnMouseEvent(event);
 }
 
+void Pointer::OnCursorSetChanged(ui::CursorSetType cursor_set) {
+  use_large_cursor_ = (cursor_set == ui::CURSOR_SET_LARGE);
+  ResetCursor();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // SurfaceDelegate overrides:
 
@@ -294,4 +294,29 @@ Surface* Pointer::GetEffectiveTargetForEvent(ui::Event* event) const {
   return delegate_->CanAcceptPointerEventsForSurface(target) ? target : nullptr;
 }
 
+void Pointer::ResetCursor() {
+  if (!focus_)
+    return;
+
+  // Update cursor scale if the effective UI scale has changed.
+  display::Display display =
+      display::Screen::GetScreen()->GetDisplayNearestWindow(
+          widget_->GetNativeWindow());
+  float ui_scale = ash::Shell::GetInstance()
+                       ->display_manager()
+                       ->GetDisplayInfo(display.id())
+                       .GetEffectiveUIScale();
+
+  // TODO(yoshiki): Use large cursor asset instead of scaling.

[reveman, 2016/06/15 17:48:30]

nit: Remove this TODO as we should still apply the scale after making the client
aware of it. If the client is aware of this scale, then it can provide a larger
resolution buffer and the result of this scale is not going to be blurred from
bi-linear filtering. This works exactly the same way as device scale factor for
non-cursor surfaces.

+  if (use_large_cursor_)
+    ui_scale *= 2;
+
+  if (ui_scale != cursor_scale_) {
+    gfx::Transform transform;
+    transform.Scale(ui_scale, ui_scale);
+    widget_->GetNativeWindow()->SetTransform(transform);
+    cursor_scale_ = ui_scale;
+  }
+}
+
 }  // namespace exo