android: Use UIResource for overscroll glow

content/browser/android/system_ui_resource_manager_impl.cc

+// Copyright 2014 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 "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/location.h"
+#include "base/threading/worker_pool.h"
+#include "cc/resources/ui_resource_bitmap.h"
+#include "content/browser/android/system_ui_resource_manager_impl.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/base/android/system_ui_resource.h"
+#include "ui/base/android/ui_resource_client_android.h"
+#include "ui/base/android/ui_resource_provider.h"
+#include "ui/gfx/android/java_bitmap.h"
+
+namespace {
+
+class SystemUIResourceImpl : public ui::UIResourceClientAndroid,
+                             public ui::SystemUIResource {
+ public:
+  static scoped_ptr<SystemUIResourceImpl> Create(
+      const SkBitmap& bitmap,
+      ui::UIResourceProvider* provider) {
+    return make_scoped_ptr(new SystemUIResourceImpl(bitmap, provider));
+  }
+
+  virtual ~SystemUIResourceImpl() {
+    if (id_)
+      provider_->DeleteUIResource(id_);
+    id_ = 0;
+    if (client_)
+      client_->OnUIResourceIdChanged();
+  }
+
+  // cc::UIResourceClient implementation.
+  virtual cc::UIResourceBitmap GetBitmap(cc::UIResourceId uid,
+                                         bool resource_lost) OVERRIDE {
+    DCHECK(!bitmap_.empty());
+    return cc::UIResourceBitmap(bitmap_);
+  }
+
+  // ui::UIResourceClientAndroid implementation.
+  virtual void UIResourceIsInvalid() OVERRIDE {
+    id_ = 0;
+    if (client_)
+      client_->OnUIResourceIdChanged();
+  }
+
+  // ui::SystemUIResource implementation
+  virtual cc::UIResourceId id() OVERRIDE { return id_; }
+
+  virtual void Load() OVERRIDE {
+    if (id_)
+      return;
+
+    id_ = provider_->CreateUIResource(this);
+
+    if (client_)
+      client_->OnUIResourceIdChanged();
+  }
+
+  virtual void SetClient(ui::SystemUIResourceClient* client) OVERRIDE {
+    client_ = client;
+  }
+
+ private:
+  SystemUIResourceImpl(const SkBitmap& bitmap, ui::UIResourceProvider* provider)
+      : bitmap_(bitmap), id_(0), provider_(provider), client_(NULL) {
+    DCHECK(provider_);
+    Load();
+  }
+
+  SkBitmap bitmap_;
+  cc::UIResourceId id_;
+  ui::UIResourceProvider* provider_;
+  ui::SystemUIResourceClient* client_;
+
+  DISALLOW_COPY_AND_ASSIGN(SystemUIResourceImpl);
+};
+
+}  // namespace
+
+namespace content {
+
+SystemUIResourceManagerImpl::SystemUIResourceManagerImpl()
+    : ui::SystemUIResourceManager(), weak_factory_(this) {
+}
+
+void SystemUIResourceManagerImpl::BuildResource(
+    ui::SystemUIResource::Type type) {
+  if (GetData(type)->HasResource())
+    return;
+
+  // Instead of blocking the main thread, we post a task to load the bitmap.
+  SkBitmap* bitmap = new SkBitmap();
+  base::Closure load_bitmap =
+      base::Bind(&SystemUIResourceManagerImpl::LoadBitmap, type, bitmap);
+  base::Closure finished_load =
+      base::Bind(&SystemUIResourceManagerImpl::OnFinishedLoadBitmap,
+                 weak_factory_.GetWeakPtr(),
+                 type,
+                 base::Owned(bitmap));
+  base::WorkerPool::PostTaskAndReply(
+      FROM_HERE, load_bitmap, finished_load, true);
+}
+
+void SystemUIResourceManagerImpl::LoadBitmap(ui::SystemUIResource::Type type,
+                                             SkBitmap* bitmap_holder) {
+  SkBitmap bitmap;
+  switch (type) {
+    case ui::SystemUIResource::OVERSCROLL_EDGE:
+      bitmap = CreateSkBitmapFromAndroidResource(
+          "android:drawable/overscroll_edge", gfx::Size(128, 12));
+      break;
+    case ui::SystemUIResource::OVERSCROLL_GLOW:
+      bitmap = CreateSkBitmapFromAndroidResource(
+          "android:drawable/overscroll_glow", gfx::Size(128, 64));
+      break;
+  }
+  bitmap.setImmutable();
+  *bitmap_holder = bitmap;
+}
+
+void SystemUIResourceManagerImpl::OnFinishedLoadBitmap(
+    ui::SystemUIResource::Type type,
+    SkBitmap* bitmap_holder) {
+  scoped_ptr<SystemUIResourceImpl> resource =
+      SystemUIResourceImpl::Create(*bitmap_holder, GetUIResourceProvider());
+  GetData(type)->SetResource(resource.PassAs<ui::SystemUIResource>());
+}
+
+} // namespace content