MediaStream Image Capture (2): Platform::ImageCaptureFrameGrabber and grabFrame()

third_party/WebKit/Source/modules/imagecapture/ImageCapture.cpp

Index: third_party/WebKit/Source/modules/imagecapture/ImageCapture.cpp
diff --git a/third_party/WebKit/Source/modules/imagecapture/ImageCapture.cpp b/third_party/WebKit/Source/modules/imagecapture/ImageCapture.cpp
index b900c515a35b7254993b5b328094b64835464a21..a819ee0b95e3fbcf59542f8f6ffc8e72487bd578 100644
--- a/third_party/WebKit/Source/modules/imagecapture/ImageCapture.cpp
+++ b/third_party/WebKit/Source/modules/imagecapture/ImageCapture.cpp
@@ -4,12 +4,17 @@
 
 #include "modules/imagecapture/ImageCapture.h"
 
+#include "bindings/core/v8/CallbackPromiseAdapter.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMException.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/frame/ImageBitmap.h"
 #include "modules/EventTargetModules.h"
 #include "modules/mediastream/MediaStreamTrack.h"
+#include "platform/graphics/StaticBitmapImage.h"

[emircan, 2016/04/26 19:19:31]

Extra?

[mcasas, 2016/04/27 00:51:29]

Done.

 #include "public/platform/Platform.h"
+#include "public/platform/WebImageCaptureFrameGrabber.h"
+#include "public/platform/WebMediaStreamTrack.h"
 
 namespace blink {
 
@@ -60,7 +65,19 @@ ScriptPromise ImageCapture::grabFrame(ScriptState* scriptState, ExceptionState&
         return promise;
     }
 
-    resolver->reject(DOMException::create(NotSupportedError, "Not implemented yet"));
+    // Create |m_frameGrabber| the first time.
+    if (!m_frameGrabber)
+        m_frameGrabber = adoptPtr(Platform::current()->createImageCaptureFrameGrabber());
+
+    if (!m_frameGrabber) {

[emircan, 2016/04/26 19:19:31]

Can you move this inside the if on l.69? I dont think we need to double check
each time?

[mcasas, 2016/04/27 00:51:29]

This a get-or-create snippet, right? The first 
time around we create |m_frameGrabber|, but
still we need to check that it has been created
properly right? I guess I could move it back 
inside the first if(!) then create, but it'll need
to be there. Alternatives?

+        resolver->reject(DOMException::create(UnknownError, "Couldn't create platform resources"));
+        return promise;
+    }
+
+    // The platform does not know about MediaStreamTrack, so we wrap it up.
+    WebMediaStreamTrack track(m_streamTrack->component());
+    m_frameGrabber->grabFrame(&track, new CallbackPromiseAdapter<ImageBitmap, void>(resolver));
+
     return promise;
 }