[Contextual Search] Add support for crushed sprites and animate the search provider icon

chrome/browser/android/compositor/layer/crushed_sprite_layer.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 "chrome/browser/android/compositor/layer/crushed_sprite_layer.h"
+
+#include "cc/layers/layer.h"
+#include "cc/layers/ui_resource_layer.h"
+#include "content/public/browser/android/compositor.h"
+#include "ui/android/resources/crushed_sprite_resource.h"
+#include "ui/android/resources/resource_manager.h"
+#include "ui/gfx/canvas.h"
+#include "ui/gfx/skia_util.h"
+
+namespace chrome {
+namespace android {
+
+// static
+scoped_refptr<CrushedSpriteLayer> CrushedSpriteLayer::Create() {
+  return make_scoped_refptr(new CrushedSpriteLayer());
+}
+
+scoped_refptr<cc::Layer> CrushedSpriteLayer::layer() {
+  return layer_;
+}
+
+void CrushedSpriteLayer::DrawSpriteFrame(
+    ui::ResourceManager* resource_manager,
+    int bitmap_res_id,
+    int metadata_res_id,
+    float completion_percentage) {
+  DCHECK(completion_percentage >= 0.f && completion_percentage <= 1.f);
+
+  int sprite_frame = completion_percentage * (frame_count_ - 1);
+
+  if (frame_count_ == -1 || sprite_frame != previous_frame_) {
+    // Get resource and setup variables.
+    ui::CrushedSpriteResource* resource =
+        resource_manager->GetCrushedSpriteResource(
+            bitmap_res_id,
+            metadata_res_id);
+    if (frame_count_ == -1) {
+      frame_count_ = resource->GetFrameCount();
+      sprite_frame = completion_percentage * (frame_count_ - 1);
+    }
+
+    // Reset the previous_frame if the animation is being re-run.
+    if (previous_frame_ > sprite_frame) {
+      previous_frame_ = 0;
+    }
+
+    // Set up an SkCanvas backed by an SkBitmap to draw into.
+    SkBitmap bitmap;
+    bitmap.allocN32Pixels(resource->GetSpriteSize().width(),
+                           resource->GetSpriteSize().height());
+    skia::RefPtr<SkCanvas> canvas = skia::AdoptRef(new SkCanvas(bitmap));
+
+    // If this isn't the first or last frame, draw the previous frame(s).
+    // Note(twellington): This assumes that the last frame in the crushed sprite
+    // animation does not require any previous frames drawn before it. This code
+    // needs to be updated if crushed sprites are added for which this
+    // assumption does not hold.
+    if (sprite_frame != 0 && sprite_frame != resource->GetFrameCount() - 1) {
+      // Draw the previous frame.
+      canvas->drawBitmap(previous_frame_bitmap_, 0, 0, nullptr);
+
+      // Draw any skipped frames.
+      for (int i = previous_frame_ + 1; i < sprite_frame; ++i) {
+        DrawRectanglesForFrame(resource, i, canvas);
+      }
+    }
+
+    // Draw the current frame.
+    DrawRectanglesForFrame(resource, sprite_frame, canvas);
+
+    // Set the bitmap on layer_.
+    bitmap.setImmutable();
+    layer_->SetBitmap(bitmap);
+
+    // Evict the crushed sprite bitmap from memory if this is the last frame.
+    if (sprite_frame == frame_count_ - 1) {
+      resource->EvictBitmapFromMemory();
+    }
+
+    // Update previous_frame_* variables.
+    previous_frame_bitmap_ = bitmap;
+    previous_frame_ = sprite_frame;
+  }
+}
+
+void CrushedSpriteLayer::DrawRectanglesForFrame(
+    ui::CrushedSpriteResource* resource,
+    int frame,
+    skia::RefPtr<SkCanvas> canvas) {
+  ui::CrushedSpriteResource::FrameSrcDstRects src_dst_rects =
+       resource->GetRectanglesForFrame(frame);
+  for (const auto& rect : src_dst_rects) {
+    canvas->drawBitmapRect(resource->GetBitmap(),
+                           gfx::RectToSkRect(rect.first),
+                           gfx::RectToSkRect(rect.second),
+                           nullptr);
+  }
+}
+
+CrushedSpriteLayer::CrushedSpriteLayer()
+    : layer_(
+          cc::UIResourceLayer::Create(content::Compositor::LayerSettings())),
+      frame_count_(-1),
+      previous_frame_(-1) {
+  layer_->SetIsDrawable(true);
+}
+
+
+CrushedSpriteLayer::~CrushedSpriteLayer() {
+}
+
+}  // namespace android
+}  // namespace chrome