DevTools: [Android] implement RenderWidgetHostViewAndroid::CopyFromCompositingSurface

content/browser/android/content_view_core_impl.cc

Index: content/browser/android/content_view_core_impl.cc
diff --git a/content/browser/android/content_view_core_impl.cc b/content/browser/android/content_view_core_impl.cc
index 80fe628dd022781a85a0bd56fe22b32d2d270490..aed58a3d19598a5da0741563dc05243f83aadd2d 100644
--- a/content/browser/android/content_view_core_impl.cc
+++ b/content/browser/android/content_view_core_impl.cc
@@ -61,6 +61,8 @@ using base::android::ConvertJavaStringToUTF16;
 using base::android::ConvertJavaStringToUTF8;
 using base::android::ConvertUTF16ToJavaString;
 using base::android::ConvertUTF8ToJavaString;
+using base::android::HasException;
+using base::android::JavaByteArrayToByteVector;
 using base::android::ScopedJavaGlobalRef;
 using base::android::ScopedJavaLocalRef;
 using WebKit::WebGestureEvent;
@@ -707,6 +709,42 @@ void ContentViewCoreImpl::SetNeedsAnimate() {
   Java_ContentViewCore_setNeedsAnimate(env, obj.obj());
 }
 
+bool ContentViewCoreImpl::GrabSnapshot(const std::string& format,
+                                       int quality,
+                                       double scale,
+                                       std::vector<uint8>* data) {
+  gfx::Size size = gfx::ToFlooredSize(gfx::ScaleSize(GetViewportSizePix(),
+                                                     scale));

[Sami, 2013/08/05 16:56:15]

Check that no dimension of |size| is zero here.

+  SkBitmap bitmap;

[Sami, 2013/08/05 16:56:15]

To avoid the extra allocation and copy on line 735, let's flip this around so
that we allocate the java bitmap from the beginning and point
PopulateBitmapWithContents directly into it. Something like this:

    jobject bitmapObject = <call into java to create a bitmap of the right size>
    gfx::JavaBitmap javaBitmap(bitmapObject);
    SkBitmap bitmap;
    bitmap.setConfig(SkBitmap::kARGB_8888_Config, size.width(), size.height());
    bitmap.setPixels(javaBitmap.pixels());
    // call PopulateBitmapWithContents as below

Make sure you destroy |javaBitmap| before try compressing the Java bitmap.

+  bitmap.setConfig(SkBitmap::kARGB_8888_Config, size.width(), size.height());
+  bitmap.allocPixels();
+  SkAutoLockPixels lock(bitmap);
+
+  RenderWidgetHostViewAndroid* view = GetRenderWidgetHostViewAndroid();
+  if (!view->PopulateBitmapWithContents(size, &bitmap))

[no sievers, 2013/08/05 21:46:44]

We'd like to deprecate this API and make all readbacks asynchronous. Essentially
you invoke the readback and you'd eventually get a callback that passes you an
SkBitmap.

I think crbug.com/252037 tracks that for GrabWindow/ViewSnapshot().

+    return false;
+
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
+  if (obj.is_null())
+    return false;
+
+  ScopedJavaLocalRef<jstring> jstring_format =
+      ConvertUTF8ToJavaString(env, format);
+  ScopedJavaLocalRef<jobject> java_bitmap =
+      gfx::ConvertToJavaBitmap(&bitmap);
+  DCHECK(!java_bitmap.is_null());
+
+  ScopedJavaLocalRef<jbyteArray> data_ref =
+      Java_ContentViewCore_compressBitmap(env, obj.obj(), java_bitmap.obj(),
+                                          jstring_format.obj(), quality);
+  if (HasException(env) || data_ref.is_null())
+    return false;
+
+  JavaByteArrayToByteVector(env, data_ref.obj(), data);
+  return true;
+}
+
 ui::ViewAndroid* ContentViewCoreImpl::GetViewAndroid() const {
   // view_android_ should never be null for Chrome.
   DCHECK(view_android_);