[Android WebView] Implement the capture picture API.

android_webview/native/aw_contents.cc

Index: android_webview/native/aw_contents.cc
diff --git a/android_webview/native/aw_contents.cc b/android_webview/native/aw_contents.cc
index a44fb06c5c6945cbc8b05ac3e8faea6b47783fce..d638a4591972366d75d04ccafc7390e68e49b426 100644
--- a/android_webview/native/aw_contents.cc
+++ b/android_webview/native/aw_contents.cc
@@ -4,6 +4,7 @@
 
 #include "android_webview/native/aw_contents.h"
 
+#include <android/bitmap.h>
 #include <sys/system_properties.h>
 
 #include "android_webview/browser/aw_browser_main_parts.h"
@@ -37,11 +38,10 @@
 #include "content/public/common/ssl_status.h"
 #include "jni/AwContents_jni.h"
 #include "net/base/x509_certificate.h"
-#include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkDevice.h"
-#include "third_party/skia/include/core/SkPicture.h"
+#include "third_party/skia/include/core/SkGraphics.h"
 #include "ui/gfx/transform.h"
 #include "ui/gl/gl_bindings.h"
 
@@ -86,6 +86,7 @@ namespace android_webview {
 namespace {
 
 AwDrawSWFunctionTable* g_draw_sw_functions = NULL;
+bool g_is_skia_version_compatible = false;
 
 const void* kAwContentsUserDataKey = &kAwContentsUserDataKey;
 
@@ -121,6 +122,7 @@ AwContents::AwContents(JNIEnv* env,
       view_visible_(false),
       compositor_visible_(false),
       is_composite_pending_(false),
+      on_new_picture_mode_(kOnNewPictureDisabled),
       last_frame_context_(NULL) {
   RendererPictureMap::CreateInstance();
   android_webview::AwBrowserDependencyFactory* dependency_factory =
@@ -379,9 +381,11 @@ void AwContents::DrawGL(AwDrawGLInfo* draw_info) {
 }
 
 bool AwContents::DrawSW(JNIEnv* env, jobject obj, jobject java_canvas) {
-  skia::RefPtr<SkPicture> picture =
-      RendererPictureMap::GetInstance()->GetRendererPicture(
-          web_contents_->GetRoutingID());
+  // TODO(leandrogracia): once Ubercompositor is ready and we support software
+  // rendering mode, we should avoid this as much as we can, ideally always.
+  // This includes finding a proper replacement for onDraw calls in hardware
+  // mode with software canvases. http://crbug.com/170086.
+  skia::RefPtr<SkPicture> picture = GetLastCapturedPicture();
   if (!picture)
     return false;
 
@@ -462,6 +466,11 @@ void AwContents::Destroy(JNIEnv* env, jobject obj) {
 void SetAwDrawSWFunctionTable(JNIEnv* env, jclass, jint function_table) {
   g_draw_sw_functions =
       reinterpret_cast<AwDrawSWFunctionTable*>(function_table);
+  // TODO(leandrogracia): uncomment once the glue layer implements this method.
+  //g_is_skia_version_compatible =
+  //   g_draw_sw_functions->is_skia_version_compatible(&SkGraphics::GetVersion);
+  if (!g_is_skia_version_compatible)
+    LOG(WARNING) << "Skia native versions are not compatible.";
 }
 
 // static
@@ -696,7 +705,13 @@ void AwContents::Invalidate() {
   if (obj.is_null())
     return;
 
-  Java_AwContents_invalidate(env, obj.obj());
+  if (view_visible_)
+    Java_AwContents_invalidate(env, obj.obj());
+
+  // When not in invalidation-only mode onNewPicture will be triggered
+  // from the OnPictureUpdated callback.
+  if (on_new_picture_mode_ == kOnNewPictureInvalidationOnly)
+    Java_AwContents_onNewPicture(env, obj.obj(), NULL);
 }
 
 void AwContents::SetCompositorVisibility(bool visible) {
@@ -848,14 +863,123 @@ jint AwContents::ReleasePopupWebContents(JNIEnv* env, jobject obj) {
   return reinterpret_cast<jint>(pending_contents_.release());
 }
 
+ScopedJavaLocalRef<jobject> AwContents::CapturePicture(JNIEnv* env,
+                                                       jobject obj) {
+  skia::RefPtr<SkPicture> picture = GetLastCapturedPicture();
+  if (!picture || !g_draw_sw_functions)
+    return ScopedJavaLocalRef<jobject>();
+
+  if (g_is_skia_version_compatible)
+    return ScopedJavaLocalRef<jobject>(env,
+        g_draw_sw_functions->create_picture(env, picture->clone()));
+
+  // If Skia versions are not compatible, workaround it by rasterizing the
+  // picture into a bitmap and drawing it into a new Java picture.
+  return ScopedJavaLocalRef<jobject>(
+      Java_AwContents_rasterizeIntoPicture(env, obj,
+          reinterpret_cast<jint>(picture.get()),
+          picture->width(), picture->height()));
+}
+
+// static
+jboolean RasterizePicture(JNIEnv* env,
+                          jclass clazz,
+                          jobject jbitmap,
+                          jint native_picture) {
+  DCHECK(jbitmap);
+  DCHECK(native_picture);
+
+  AndroidBitmapInfo bitmap_info;
+  if (AndroidBitmap_getInfo(env, jbitmap, &bitmap_info) < 0) {
+    LOG(WARNING) << "Error getting java bitmap info.";
+    return false;
+  }
+
+  void* pixels = NULL;
+  if (AndroidBitmap_lockPixels(env, jbitmap, &pixels) < 0) {
+    LOG(WARNING) << "Error locking java bitmap pixels.";
+    return false;
+  }
+
+  {
+    SkBitmap bitmap;
+    bitmap.setConfig(SkBitmap::kARGB_8888_Config,
+                     bitmap_info.width,
+                     bitmap_info.height,
+                     bitmap_info.stride);
+    bitmap.setPixels(pixels);
+
+    SkDevice device(bitmap);
+    SkCanvas canvas(&device);
+    SkPicture* picture = reinterpret_cast<SkPicture*>(native_picture);
+    picture->draw(&canvas);
+  }
+
+  if (AndroidBitmap_unlockPixels(env, jbitmap) < 0) {
+    LOG(WARNING) << "Error unlocking java bitmap pixels.";
+    return false;
+  }
+
+  return true;
+}
+
+void AwContents::EnableOnNewPicture(JNIEnv* env,
+                                    jobject obj,
+                                    jboolean enabled,
+                                    jboolean invalidation_only) {
+  if (enabled) {
+    on_new_picture_mode_ = invalidation_only ? kOnNewPictureInvalidationOnly :
+        kOnNewPictureEnabled;
+  } else {
+    on_new_picture_mode_ = kOnNewPictureDisabled;
+  }
+
+  // If onNewPicture is triggered only on invalidation do not capture
+  // pictures on every new frame.
+  if (on_new_picture_mode_ == kOnNewPictureInvalidationOnly)
+    enabled = false;
+
+  // TODO(leandrogracia): uncomment when sw rendering uses Ubercompositor.
+  // Until then we need the callback enabled for SW mode invalidation.
+  // render_view_host_ext_->EnableCapturePictureCallback(enabled);
+}
+
 void AwContents::OnPictureUpdated(int process_id, int render_view_id) {
   CHECK_EQ(web_contents_->GetRenderProcessHost()->GetID(), process_id);
   if (render_view_id != web_contents_->GetRoutingID())
     return;
 
+  // TODO(leandrogracia): this can be made unconditional once software rendering
+  // uses Ubercompositor. Until then this path is required for SW invalidations.
+  if (on_new_picture_mode_ == kOnNewPictureEnabled) {
+    JNIEnv* env = AttachCurrentThread();
+    ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
+    if (!obj.is_null()) {
+      ScopedJavaLocalRef<jobject> picture = CapturePicture(env, obj.obj());
+      Java_AwContents_onNewPicture(env, obj.obj(), picture.obj());
+    }
+  }
+
   // TODO(leandrogracia): delete when sw rendering uses Ubercompositor.
   // Invalidation should be provided by the compositor only.
   Invalidate();
 }
 
+skia::RefPtr<SkPicture> AwContents::GetLastCapturedPicture() {
+  // Use the latest available picture if the listener callback is enabled.
+  skia::RefPtr<SkPicture> picture;
+  if (on_new_picture_mode_ == kOnNewPictureEnabled)
+    picture = RendererPictureMap::GetInstance()->GetRendererPicture(
+        web_contents_->GetRoutingID());
+
+  // If not available or not in listener mode get it synchronously.
+  if (!picture) {
+    render_view_host_ext_->CapturePictureSync();
+    picture = RendererPictureMap::GetInstance()->GetRendererPicture(
+        web_contents_->GetRoutingID());
+  }
+
+  return picture;
+}
+
 }  // namespace android_webview