Add tinted static UI resource cache

ui/android/resources/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 "ui/android/resources/resource_manager_impl.h"
 
 #include <stddef.h>
 
 #include <utility>
 #include <vector>
 
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/resources/scoped_ui_resource.h"
 #include "jni/ResourceManager_jni.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkColorFilter.h"
 #include "ui/android/resources/ui_resource_provider.h"
 #include "ui/android/window_android.h"
 #include "ui/gfx/android/java_bitmap.h"
 #include "ui/gfx/geometry/rect.h"
 
 using base::android::JavaArrayOfIntArrayToIntVector;
 using base::android::JavaRef;
 
 namespace ui {
 
+namespace {
+// The maximum number of tinted variations of a single resource.
+// TODO(mdjones): Implement real caching logic; something similar to priority
+// that is used by the thumbnails.
+const int kMaxTintResourceCount = 4;
+}  // namespace
+
 // static
 ResourceManagerImpl* ResourceManagerImpl::FromJavaObject(jobject jobj) {
   return reinterpret_cast<ResourceManagerImpl*>(
       Java_ResourceManager_getNativePtr(base::android::AttachCurrentThread(),
                                         jobj));
 }
 
 ResourceManagerImpl::ResourceManagerImpl(gfx::NativeWindow native_window)
     : host_(nullptr) {
   JNIEnv* env = base::android::AttachCurrentThread();
@@ skipping 29 matching lines @@
 
   if (!resource || res_type == ANDROID_RESOURCE_TYPE_DYNAMIC ||
       res_type == ANDROID_RESOURCE_TYPE_DYNAMIC_BITMAP) {
     RequestResourceFromJava(res_type, res_id);
     resource = resources_[res_type].Lookup(res_id);
   }
 
   return resource;
 }
 
+ResourceManager::Resource* ResourceManagerImpl::GetStaticResourceWithTint(
+    int res_id,
+    int tint_color,
+    int default_color) {
+  int color = tint_color;
+  ResourceMap* resource_map = tinted_resources_.Lookup(color);
+
+  // If the cache is too large, use the default color for the resource.
+  if (!resource_map && tinted_resources_.size() >= kMaxTintResourceCount) {
+    color = default_color;
+    resource_map = tinted_resources_.Lookup(color);
+  }
+
+  if (!resource_map) {
+    resource_map = new ResourceMap();
+    tinted_resources_.AddWithID(resource_map, color);
+  }
+
+  Resource* tinted_resource = resource_map->Lookup(res_id);
+
+  // If the resource is already cached, use it.
+  if (tinted_resource)
+    return tinted_resource;
+
+  ResourceManager::Resource* base_image =
+      GetResource(ANDROID_RESOURCE_TYPE_STATIC, res_id);
+  if (!base_image)
+    return nullptr;
+
+  SkBitmap tinted_bitmap;
+  tinted_bitmap.allocPixels(SkImageInfo::MakeN32Premul(base_image->size.width(),
+      base_image->size.height()));
+
+  SkCanvas canvas(tinted_bitmap);
+  canvas.clear(SK_ColorTRANSPARENT);
+
+  // Build a color filter to use on the base resource. This filter multiplies
+  // the RGB components by the components of the new color but retains the
+  // alpha of the original image.
+  SkPaint color_filter;
+  SkScalar color_matrix[] = {
+      SkColorGetR(color) / 255.0f, 0, 0, 0, 0,
+      0, SkColorGetG(color) / 255.0f, 0, 0, 0,
+      0, 0, SkColorGetB(color) / 255.0f, 0, 0,
+      0, 0, 0, 1.0f, 0
+  };
+  color_filter.setColorFilter(
+      SkColorFilter::MakeMatrixFilterRowMajor255(color_matrix));
+
+  // Draw the resource and make it immutable.
+  base_image->ui_resource->GetBitmap(base_image->ui_resource->id(), false)
+      .DrawToCanvas(&canvas, &color_filter);
+  tinted_bitmap.setImmutable();
+
+  // Create a UI resource from the new bitmap.
+  tinted_resource = new Resource();
+  tinted_resource->size = gfx::Size(base_image->size);
+  tinted_resource->padding = gfx::Rect(base_image->padding);
+  tinted_resource->aperture = gfx::Rect(base_image->aperture);
+  tinted_resource->tint = color;
+  tinted_resource->ui_resource = cc::ScopedUIResource::Create(host_,
+      cc::UIResourceBitmap(tinted_bitmap));
+
+  resource_map->AddWithID(tinted_resource, res_id);
+
+  return tinted_resource;
+}
+
+void ResourceManagerImpl::ClearTintedResourceCache(JNIEnv* env,
+    const JavaRef<jobject>& jobj) {
+  tinted_resources_.Clear();
+}
+
 void ResourceManagerImpl::PreloadResource(AndroidResourceType res_type,
                                           int res_id) {
   DCHECK_GE(res_type, ANDROID_RESOURCE_TYPE_FIRST);
   DCHECK_LE(res_type, ANDROID_RESOURCE_TYPE_LAST);
 
   // Don't send out a query if the resource is already loaded.
   if (resources_[res_type].Lookup(res_id))
     return;
 
   PreloadResourceFromJava(res_type, res_id);
@@ skipping 160 matching lines @@
   TRACE_EVENT2("ui",
                "ResourceManagerImpl::RequestCrushedSpriteResourceFromJava",
                "bitmap_res_id", bitmap_res_id,
                "metadata_res_id", metadata_res_id);
   Java_ResourceManager_crushedSpriteResourceRequested(
       base::android::AttachCurrentThread(), java_obj_, bitmap_res_id,
       metadata_res_id, reloading);
 }
 
 }  // namespace ui