Merge pull request #6164 from MaxWhere/master

beginFrameSubscription bugfix and improvement

atom/browser/api/atom_api_web_contents.cc

@@ -1182,11 +1182,20 @@ void WebContents::SendInputEvent(v8::Isolate* isolate,
 }
 
 void WebContents::BeginFrameSubscription(
-    const FrameSubscriber::FrameCaptureCallback& callback) {
+  mate::Arguments* args) {
+  FrameSubscriber::FrameCaptureCallback callback;
+  bool only_dirty = false;
+
+  if (!args->GetNext(&callback)) {
+    args->GetNext(&only_dirty);
+    if (!args->GetNext(&callback))
+      args->ThrowTypeError("'callback' must be defined");
+  }
+
   const auto view = web_contents()->GetRenderWidgetHostView();
   if (view) {
     std::unique_ptr<FrameSubscriber> frame_subscriber(new FrameSubscriber(
-        isolate(), view, callback));
+        isolate(), view, callback, only_dirty));
     view->BeginFrameSubscription(std::move(frame_subscriber));
   }
 }

atom/browser/api/atom_api_web_contents.h

@@ -139,8 +139,7 @@ class WebContents : public mate::TrackableObject<WebContents>,
   void SendInputEvent(v8::Isolate* isolate, v8::Local<v8::Value> input_event);
 
   // Subscribe to the frame updates.
-  void BeginFrameSubscription(
-      const FrameSubscriber::FrameCaptureCallback& callback);
+  void BeginFrameSubscription(mate::Arguments* args);
   void EndFrameSubscription();
 
   // Methods for creating <webview>.

atom/browser/api/frame_subscriber.cc

@@ -6,6 +6,7 @@
 
 #include "base/bind.h"
 #include "atom/common/node_includes.h"
+#include "atom/common/native_mate_converters/gfx_converter.h"
 #include "content/public/browser/render_widget_host.h"
 
 namespace atom {
@@ -14,12 +15,14 @@ namespace api {
 
 FrameSubscriber::FrameSubscriber(v8::Isolate* isolate,
                                  content::RenderWidgetHostView* view,
-                                 const FrameCaptureCallback& callback)
-    : isolate_(isolate), view_(view), callback_(callback), weak_factory_(this) {
+                                 const FrameCaptureCallback& callback,
+                                 bool only_dirty)
+    : isolate_(isolate), view_(view), callback_(callback),
+      only_dirty_(only_dirty), weak_factory_(this) {
 }
 
 bool FrameSubscriber::ShouldCaptureFrame(
-    const gfx::Rect& damage_rect,
+    const gfx::Rect& dirty_rect,
     base::TimeTicks present_time,
     scoped_refptr<media::VideoFrame>* storage,
     DeliverFrameCallback* callback) {
@@ -27,21 +30,27 @@ bool FrameSubscriber::ShouldCaptureFrame(
   if (!view_ || !host)
     return false;
 
-  const auto size = view_->GetVisibleViewportSize();
+  if (dirty_rect.IsEmpty())
+    return false;
+
+  gfx::Rect rect = gfx::Rect(view_->GetVisibleViewportSize());
+  if (only_dirty_)
+    rect = dirty_rect;
 
   host->CopyFromBackingStore(
-      gfx::Rect(size),
-      size,
+      rect,
+      rect.size(),
       base::Bind(&FrameSubscriber::OnFrameDelivered,
-                 weak_factory_.GetWeakPtr(), callback_),
+                 weak_factory_.GetWeakPtr(), callback_, rect),
       kBGRA_8888_SkColorType);
 
   return false;
 }
 
 void FrameSubscriber::OnFrameDelivered(const FrameCaptureCallback& callback,
-  const SkBitmap& bitmap, content::ReadbackResponse response) {
-  if (bitmap.computeSize64() == 0)
+  const gfx::Rect& damage_rect, const SkBitmap& bitmap,
+  content::ReadbackResponse response) {
+  if (response != content::ReadbackResponse::READBACK_SUCCESS)
     return;
 
   v8::Locker locker(isolate_);
@@ -57,7 +66,10 @@ void FrameSubscriber::OnFrameDelivered(const FrameCaptureCallback& callback,
     reinterpret_cast<uint8_t*>(node::Buffer::Data(buffer.ToLocalChecked())),
     rgb_arr_size);
 
-  callback_.Run(buffer.ToLocalChecked());
+  v8::Local<v8::Value> damage =
+    mate::Converter<gfx::Rect>::ToV8(isolate_, damage_rect);
+
+  callback_.Run(buffer.ToLocalChecked(), damage);
 }
 
 }  // namespace api

atom/browser/api/frame_subscriber.h

@@ -20,11 +20,13 @@ namespace api {
 
 class FrameSubscriber : public content::RenderWidgetHostViewFrameSubscriber {
  public:
-  using FrameCaptureCallback = base::Callback<void(v8::Local<v8::Value>)>;
+  using FrameCaptureCallback =
+    base::Callback<void(v8::Local<v8::Value>, v8::Local<v8::Value>)>;
 
   FrameSubscriber(v8::Isolate* isolate,
                   content::RenderWidgetHostView* view,
-                  const FrameCaptureCallback& callback);
+                  const FrameCaptureCallback& callback,
+                  bool only_dirty);
 
   bool ShouldCaptureFrame(const gfx::Rect& damage_rect,
                           base::TimeTicks present_time,
@@ -33,11 +35,13 @@ class FrameSubscriber : public content::RenderWidgetHostViewFrameSubscriber {
 
  private:
   void OnFrameDelivered(const FrameCaptureCallback& callback,
-    const SkBitmap& bitmap, content::ReadbackResponse response);
+    const gfx::Rect& damage_rect, const SkBitmap& bitmap,
+    content::ReadbackResponse response);
 
   v8::Isolate* isolate_;
   content::RenderWidgetHostView* view_;
   FrameCaptureCallback callback_;
+  bool only_dirty_;
 
   base::WeakPtrFactory<FrameSubscriber> weak_factory_;
 

docs/api/web-contents.md

@@ -919,12 +919,14 @@ For the `mouseWheel` event, the `event` object also have following properties:
 * `hasPreciseScrollingDeltas` Boolean
 * `canScroll` Boolean
 
-### `webContents.beginFrameSubscription(callback)`
+### `webContents.beginFrameSubscription([onlyDirty ,]callback)`
 
+* `onlyDirty` Boolean
 * `callback` Function
 
 Begin subscribing for presentation events and captured frames, the `callback`
-will be called with `callback(frameBuffer)` when there is a presentation event.
+will be called with `callback(frameBuffer, dirtyRect)` when there is a
+presentation event.
 
 The `frameBuffer` is a `Buffer` that contains raw pixel data. On most machines,
 the pixel data is effectively stored in 32bit BGRA format, but the actual
@@ -932,6 +934,11 @@ representation depends on the endianness of the processor (most modern
 processors are little-endian, on machines with big-endian processors the data
 is in 32bit ARGB format).
 
+The `dirtyRect` is an object with `x, y, width, height` properties that
+describes which part of the page was repainted. If `onlyDirty` is set to
+`true`, `frameBuffer` will only contain the repainted area. `onlyDirty`
+defaults to `false`.
+
 ### `webContents.endFrameSubscription()`
 
 End subscribing for frame presentation events.

spec/api-browser-window-spec.js

@@ -603,21 +603,42 @@ describe('browser-window module', function () {
   })
 
   describe('beginFrameSubscription method', function () {
-    this.timeout(20000)
+    it('subscribes to frame updates', function (done) {
+      this.timeout(20000)
 
-    it('subscribes frame updates', function (done) {
-      let called = false
-      w.loadURL('file://' + fixtures + '/api/blank.html')
-      w.webContents.beginFrameSubscription(function (data) {
-        // This callback might be called twice.
-        if (called) return
-        called = true
-
-        assert.notEqual(data.length, 0)
-        w.webContents.endFrameSubscription()
-        done()
+      w.loadURL('file://' + fixtures + '/api/frame-subscriber.html')
+      w.webContents.on('dom-ready', function () {
+        w.webContents.beginFrameSubscription(function (data) {
+          assert.notEqual(data.length, 0)
+          w.webContents.endFrameSubscription()
+          done()
+        })
       })
     })
+
+    it('subscribes to frame updates (only dirty rectangle)', function (done) {
+      this.timeout(20000)
+
+      w.loadURL('file://' + fixtures + '/api/frame-subscriber.html')
+      w.webContents.on('dom-ready', function () {
+        w.webContents.beginFrameSubscription(true, function (data) {
+          assert.notEqual(data.length, 0)
+          w.webContents.endFrameSubscription()
+          done()
+        })
+      })
+    })
+
+    it('throws error when subscriber is not well defined', function (done) {
+      this.timeout(20000)
+
+      w.loadURL('file://' + fixtures + '/api/frame-subscriber.html')
+      try{
+        w.webContents.beginFrameSubscription(true, true)
+      } catch(e) {
+        done()
+      }
+    })
   })
 
   describe('savePage method', function () {

spec/fixtures/api/frame-subscriber.html

@@ -0,0 +1,11 @@
+<html>
+<body>
+  <div style="width: 10px; height: 10px;" id="dirty"></div>
+</body>
+<script type="text/javascript" charset="utf-8">
+  setInterval(function(){
+    document.getElementById('dirty').style.backgroundColor =
+      '#'+(Math.random()*0xFFFFFF<<0).toString(16)
+  }, 100)
+</script>
+</html>