Toolbar is a root layer for the UI compositor

chrome/browser/android/compositor/scene_layer/toolbar_scene_layer.cc

+// Copyright 2016 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/scene_layer/toolbar_scene_layer.h"
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_array.h"
+#include "cc/layers/solid_color_layer.h"
+#include "chrome/browser/android/compositor/layer/toolbar_layer.h"
+#include "content/public/browser/android/compositor.h"
+#include "content/public/browser/android/content_view_core.h"
+#include "jni/ToolbarSceneLayer_jni.h"
+#include "ui/android/resources/resource_manager_impl.h"
+#include "ui/gfx/android/java_bitmap.h"
+
+namespace chrome {
+namespace android {
+
+ToolbarSceneLayer::ToolbarSceneLayer(JNIEnv* env, jobject jobj)
+    : SceneLayer(env, jobj),
+      should_show_background_(false),
+      background_color_(SK_ColorWHITE),
+      content_container_(cc::Layer::Create()) {
+  layer()->AddChild(content_container_);
+  layer()->SetIsDrawable(true);
+}
+
+ToolbarSceneLayer::~ToolbarSceneLayer() {
+}
+
+void ToolbarSceneLayer::UpdateToolbarLayer(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& object,
+    const JavaParamRef<jobject>& jresource_manager,
+    jint toolbar_resource_id,
+    jint toolbar_background_color,
+    jint url_bar_resource_id,
+    jfloat url_bar_alpha,
+    jfloat top_offset,
+    bool visible,
+    bool show_shadow) {
+  // If the toolbar layer has not been created yet, create it.
+  if (!toolbar_layer_) {
+    ui::ResourceManager* resource_manager =
+        ui::ResourceManagerImpl::FromJavaObject(jresource_manager);
+    toolbar_layer_ = ToolbarLayer::Create(resource_manager);
+    toolbar_layer_->layer()->SetHideLayerAndSubtree(true);
+    layer_->AddChild(toolbar_layer_->layer());
+  }
+
+  toolbar_layer_->layer()->SetHideLayerAndSubtree(!visible);
+  if (visible) {
+    toolbar_layer_->layer()->SetPosition(gfx::PointF(0, top_offset));
+    // If we're at rest, hide the shadow.  The Android view should be drawing.
+    bool clip_shadow = top_offset >= 0.f && !show_shadow;
+    toolbar_layer_->PushResource(toolbar_resource_id, toolbar_background_color,
+                                 false, SK_ColorWHITE, url_bar_resource_id,
+                                 url_bar_alpha, false, clip_shadow);
+  }
+}
+
+void ToolbarSceneLayer::UpdateProgressBar(JNIEnv* env,
+                                       const JavaParamRef<jobject>& object,
+                                       jint progress_bar_x,
+                                       jint progress_bar_y,
+                                       jint progress_bar_width,
+                                       jint progress_bar_height,
+                                       jint progress_bar_color,
+                                       jint progress_bar_background_x,
+                                       jint progress_bar_background_y,
+                                       jint progress_bar_background_width,
+                                       jint progress_bar_background_height,
+                                       jint progress_bar_background_color) {
+  if (!toolbar_layer_) return;
+  toolbar_layer_->UpdateProgressBar(progress_bar_x,
+                                    progress_bar_y,
+                                    progress_bar_width,
+                                    progress_bar_height,
+                                    progress_bar_color,
+                                    progress_bar_background_x,
+                                    progress_bar_background_y,
+                                    progress_bar_background_width,
+                                    progress_bar_background_height,
+                                    progress_bar_background_color);
+}
+
+void ToolbarSceneLayer::SetContentTree(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& jobj,
+    const JavaParamRef<jobject>& jcontent_tree) {
+  SceneLayer* content_tree = FromJavaObject(env, jcontent_tree);
+  if (!content_tree || !content_tree->layer()) return;
+
+  if (!content_tree->layer()->parent()
+      || (content_tree->layer()->parent()->id() != content_container_->id())) {
+    // Clear out all the children of the container when the content changes.
+    // This indicates that the layout has switched.
+    content_container_->RemoveAllChildren();
+    content_container_->AddChild(content_tree->layer());
+  }
+
+  // Propagate the background color up from the content layer.
+  should_show_background_ = content_tree->ShouldShowBackground();
+  background_color_ = content_tree->GetBackgroundColor();
+}
+
+SkColor ToolbarSceneLayer::GetBackgroundColor() {
+  return background_color_;
+}
+
+bool ToolbarSceneLayer::ShouldShowBackground() {
+  return should_show_background_;
+}
+
+static jlong Init(JNIEnv* env, const JavaParamRef<jobject>& jobj) {
+  // This will automatically bind to the Java object and pass ownership there.
+  ToolbarSceneLayer* toolbar_scene_layer =
+      new ToolbarSceneLayer(env, jobj);
+  return reinterpret_cast<intptr_t>(toolbar_scene_layer);
+}
+
+bool RegisterToolbarSceneLayer(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+}  // namespace android
+}  // namespace chrome