/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim:set ts=2 sw=2 sts=2 et cindent: */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #ifndef CAPTURETASK_H #define CAPTURETASK_H #include "MediaStreamGraph.h" #include "MediaStreamListener.h" #include "PrincipalChangeObserver.h" #include "MediaStreamVideoSink.h" namespace mozilla { namespace dom { class Blob; class ImageCapture; class MediaStreamTrack; } // namespace dom /** * CaptureTask retrieves image from MediaStream and encodes the image to jpeg in * ImageEncoder. The whole procedures start at AttachTrack(), it will add this * class into MediaStream and retrieves an image in MediaStreamGraph thread. * Once the image is retrieved, it will be sent to ImageEncoder and the encoded * blob will be sent out via encoder callback in main thread. * * CaptureTask holds a reference of ImageCapture to ensure ImageCapture won't be * released during the period of the capturing process described above. */ class CaptureTask : public MediaStreamVideoSink, public dom::PrincipalChangeObserver<dom::MediaStreamTrack> { public: class MediaStreamEventListener; // MediaStreamVideoSink methods. void SetCurrentFrames(const VideoSegment& aSegment) override; void ClearFrames() override {} // PrincipalChangeObserver<MediaStreamTrack> method. void PrincipalChanged(dom::MediaStreamTrack* aMediaStreamTrack) override; // CaptureTask methods. // It is called when aBlob is ready to post back to script in company with // aRv == NS_OK. If aRv is not NS_OK, it will post an error event to script. // // Note: // this function should be called on main thread. nsresult TaskComplete(already_AddRefed<dom::Blob> aBlob, nsresult aRv); // Add listeners into MediaStreamTrack and PrincipalChangeObserver. // It should be on main thread only. void AttachTrack(); // Remove listeners from MediaStreamTrack and PrincipalChangeObserver. // It should be on main thread only. void DetachTrack(); // CaptureTask should be created on main thread. explicit CaptureTask(dom::ImageCapture* aImageCapture); protected: virtual ~CaptureTask() {} // Post a runnable on main thread to end this task and call TaskComplete to post // error event to script. It is called off-main-thread. void PostTrackEndEvent(); // The ImageCapture associates with this task. This reference count should not // change in this class unless it clears this reference after a blob or error // event to script. RefPtr<dom::ImageCapture> mImageCapture; RefPtr<MediaStreamEventListener> mEventListener; // True when an image is retrieved from MediaStreamGraph or MediaStreamGraph // sends a track finish, end, or removed event. bool mImageGrabbedOrTrackEnd; // True after MediaStreamTrack principal changes while waiting for a photo // to finish and we should raise a security error. bool mPrincipalChanged; }; } // namespace mozilla #endif // CAPTURETASK_H