Initial support of large mouse cursor on Exosphere

components/exo/pointer.cc

 // Copyright 2015 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 "components/exo/pointer.h"
 
 #include "ash/common/shell_window_ids.h"
 #include "ash/display/display_info.h"
 #include "ash/display/display_manager.h"
 #include "ash/shell.h"
@@ skipping 21 matching lines @@
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // Pointer, public:
 
 Pointer::Pointer(PointerDelegate* delegate)
     : delegate_(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() {
   delegate_->OnPointerDestroying(this);
   if (surface_)
     surface_->RemoveSurfaceObserver(this);
   if (focus_) {
     focus_->RemoveSurfaceObserver(this);
     focus_->UnregisterCursorProvider(this);
   }
   if (widget_)
     widget_->CloseNow();
+
+  DCHECK(ash::Shell::GetInstance()->cursor_manager());
+  ash::Shell::GetInstance()->cursor_manager()->RemoveObserver(this);
   ash::Shell::GetInstance()->RemovePreTargetHandler(this);
 }
 
 void Pointer::SetCursor(Surface* surface, const gfx::Point& hotspot) {
   // Early out if the pointer doesn't have a surface in focus.
   if (!focus_)
     return;
 
   // If surface is different than the current pointer surface then remove the
   // current surface and add the new surface.
@@ skipping 139 matching lines @@
       CreatePointerWidget();
 
     // Update cursor location if mouse event caused it to change.
     gfx::Point mouse_location = aura::Env::GetInstance()->last_mouse_location();
     if (mouse_location != widget_->GetNativeWindow()->bounds().origin()) {
       gfx::Rect bounds = widget_->GetNativeWindow()->bounds();
       bounds.set_origin(mouse_location);
       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();
   }
 }
 
 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:
 
 void Pointer::OnSurfaceCommit() {
   surface_->CheckIfSurfaceHierarchyNeedsCommitToNewSurfaces();
   surface_->CommitSurfaceHierarchy();
   surface_->window()->SetBounds(
       gfx::Rect(gfx::Point() - hotspot_.OffsetFromOrigin(),
                 surface_->window()->layer()->size()));
 }
@@ skipping 38 matching lines @@
 
 Surface* Pointer::GetEffectiveTargetForEvent(ui::Event* event) const {
   Surface* target =
       Surface::AsSurface(static_cast<aura::Window*>(event->target()));
   if (!target)
     return nullptr;
 
   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