IssueTracker

Hi Ed, Thank you so much for these suggestions. I've been reviewing them and merging them in. Hopefully it should be live. I've included a thank you note too in the article.

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 776f4998f2996afd88ffd87e90580d7edf671743
Author: Scott Nien <scottnien@google.com>
Date:   Tue May 12 14:20:09 2020

    Change getSurfaceProvider to onSurfaceRequested and add waitForNextFrame in PreviewImplementation
   
    (1) PreviewImplementatin#getSurfaceProvider() is changed to
        onSurfaceRequested(). Besides a SurfaceRequest parameter, a
        listener can also be set to be notified when the surface is no
        longer in use or the SurfaceRequest is cancelled before a
        surfaced is provided.
   
        The listener can be used in PreviewView as a signal that the
        SurfaceRequest and the camera is no longer associated with the PreviewView and we can do some
        cleaning.
   
    (2) Add waitForNextFrame() in PreviewViewImplementation.
        It returns a ListenbleFuture for PreviewView to be wait for the next frame being ready.
   
    Bug: 154652477
    Test: TextureViewImplementationTest, SurfaceViewImplementationTest
    Change-Id: If054210b08cb8ddde6f8107f7bf18b3faeeade1a

M       camera/camera-view/build.gradle
M       camera/camera-view/src/androidTest/java/androidx/camera/view/PreviewViewTest.java
A       camera/camera-view/src/androidTest/java/androidx/camera/view/SurfaceViewImplementationTest.kt
M       camera/camera-view/src/androidTest/java/androidx/camera/view/TextureViewImplementationTest.java
M       camera/camera-view/src/main/java/androidx/camera/view/PreviewView.java
M       camera/camera-view/src/main/java/androidx/camera/view/PreviewViewImplementation.java
M       camera/camera-view/src/main/java/androidx/camera/view/SurfaceViewImplementation.java
M       camera/camera-view/src/main/java/androidx/camera/view/TextureViewImplementation.java

https://android-review.googlesource.com/1309276

Project: platform/frameworks/support
Branch: androidx-master-dev

commit ac3f0116e47f63c570465b7bf33d7482fb8fdb46
Author: Scott Nien <scottnien@google.com>
Date:   Fri May 01 01:25:40 2020

    Add getPreviewStreamState to PreviewView
   
    (1) Attach Camera instead of CameraInfo in SurfaceRequest because
    we need to know the state of Camera.
   
    (2) addOberver to camera.getCameraState() when onSurfaceRequested,
        removeObserver when OnSurfaceNotInUseListener is called .
   
    (3) When camera is opening/opened, start the flow to wait for
        session capture result event and the next frame event to
        change the STREAMSTATE
   
    (4) When camera is closing/closed/releasing,  change back to
        IDLE and stop the flow.
   
    Preview StreamState has 2 states
    IDLE:  preview not visible
    STREAMING:  preview is visible and streaming
          (onCaptureCompleted and then frame updated.)
   
    Relnote: "Add `PreviewView#getPreviewStreamState` API which
       allows apps to observe if preview is streaming or not. When
       the PreviewView is in TEXTURE_VIEW mode, the STREAMING state
       also guarantees the preview image is visible."
    Bug: 154652477
    Test: PreviewViewStreamStateTest
    Change-Id: Ic0906d25aa89b3b1a9abb02ca42e15f676b1c72f

M       camera/camera-core/src/androidTest/java/androidx/camera/core/SurfaceRequestTest.java
M       camera/camera-core/src/main/java/androidx/camera/core/Preview.java
M       camera/camera-core/src/main/java/androidx/camera/core/SurfaceRequest.java
A       camera/camera-view/src/androidTest/java/androidx/camera/view/PreviewViewStreamStateTest.kt
M       camera/camera-view/src/androidTest/java/androidx/camera/view/PreviewViewTest.java
M       camera/camera-view/src/androidTest/java/androidx/camera/view/SurfaceViewImplementationTest.kt
M       camera/camera-view/src/androidTest/java/androidx/camera/view/TextureViewImplementationTest.java
A       camera/camera-view/src/main/java/androidx/camera/view/PreviewStreamStateObserver.java
M       camera/camera-view/src/main/java/androidx/camera/view/PreviewView.java
M       camera/camera-view/src/test/java/androidx/camera/view/PreviewViewTest.java

https://android-review.googlesource.com/1299378

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 921f54f9bd1c6f2d787a1d9290ff7e45fbefbfec
Author: Xi Zhang <xizh@google.com>
Date:   Wed May 20 14:38:42 2020

    Bugfix: do not notify the same IDLE state.
   
    Have one place to post the stream state so the same state won't get posted twice.
   
    Bug: 154652477
    Test: manual test and ./gradlew bOS
    Change-Id: Ia170cc5813fb23812a336314efd2dcaa340743a7

M       camera/camera-view/src/main/java/androidx/camera/view/PreviewStreamStateObserver.java
M       camera/camera-view/src/main/java/androidx/camera/view/PreviewView.java

https://android-review.googlesource.com/1315449

It showing, marked as fixed.

When can we expect this fix be available for us to consume?
Also please let us know interface changes as well.

Regards,
Venkatesh.



On Fri, May 22, 2020 at 12:54 AM <buganizer-system@google.com> wrote:

Hi Venkatesh,

The new API will be in beta04/alpha-11 release scheduled at May 27th. (Pacific time).
You will need to update the core/camera2/lifecycle to beta04,  and camera-view to alpha-11.

It is just a new API in PreviewView which returns a LiveData of StreamStates.
StreamState.IDLE --> PreviewView is not showing preview yet.
StreamState.STREAMING -->. Preview is streaming and visible(guaranteed only in TEXTURE_VIEW mode only).

To use it , you can add observer to it like the following:

previewView.getPreviewStreamState().observe( lifecycleOwner,  
           streamState -> {
                  if (streamState == IDLE) {
                          // Show the overlay to hide the preview.
                  } else if (streamState == STREAMING) {
                       // hide the overlay to show the preview,
                 }
           }
);

please note you have to setPreferredImplementation to TEXTURE_VIEW to ensure that preview is visible when in STREAMING state.
(there could be a minor latency for preview to be visible  in SURFACE_VIEW mode).

Scott

Super!!

Thanks a lot Scott!!!

Regards,
Venkatesh.