How to stop textureview listener and display an image before closing app

Question

I have a simple xml layout as follow with just a TextureView inside a FrameLayout.

And the following main activity:

public class MainActivity   extends Activity 
implements TextureView.SurfaceTextureListener {
private static final String    TAG = "MainActivity";    

// Local references to layout components
private TextureView mTxvCameraPreview;

// Camera manager
private CameraManager mCameraManager;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Initialize layout and components
    setContentView(R.layout.activity_main);     
    mTxvCameraPreview = (TextureView)findViewById(R.id.txv_camera_preview);


    // Camera managing
    mCameraManager = new CameraManager(this);
    mTxvCameraPreview.setSurfaceTextureListener(this);
}

@Override
protected void onResume() {
    super.onResume();

    if (mTxvCameraPreview.isAvailable())
        mCameraManager.startPreview(mTxvCameraPreview.getSurfaceTexture());     
}

@Override
protected void onPause() {
    super.onPause();
    mCameraManager.stopPreview();
}


@Override
public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
    mCameraManager.startPreview(surface);       
}

@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
    mCameraManager.stopPreview();
    return true;
}

@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {} // Unused

@Override
public void onSurfaceTextureUpdated(SurfaceTexture surface) {} // Unused

}

For every frame I do some elaboration and it is OK. What I want is to add a button which stops the camera and display in the TextureView a file load from sdcard.

A pseudo-code of this can be something like this:

public void onButtonClicked(View view) {
    // stop the surface listener (it is needed?)
    File imgFile = new  File(“/sdcard/Images/elaboration_result.jpg”);
    Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());
    // show myBitmap on TextureView (if possible)
}

It is possible to do this without modifying the xml layout? Thanks in advance!

You should be able to disconnect the camera from the TextureView by stopping the camera preview, then just lock the Surface to get a Canvas and draw your bitmap. You probably can't go back -- once you connect a Canvas to a Surface it doesn't like to let go -- but if you're about to close the Activity anyway that won't matter. — fadden, Apr 10 '14 at 14:51
OK thanks, but how I can do this? Are somebody able to complete the pseudo-code I wrote? Thanks again! — user3318590, Apr 11 '14 at 05:41

score 3 · Accepted Answer · edited May 23 '17 at 12:15

You cannot set the content of a TextureView manually, I'm afraid. Your best bet is to make a new ImageView on top of your TextureView and set its image when you need to.

public void onButtonClicked(View view) {
    // if we don't need to keep previewing new frames, stop the preview
    mCameraManager.stopPreview();
    // now, show our ImageView (which should be in front of the TextureView)
    Bitmap myBitmap = BitmapFactory.decodeFile(file_path_here);
    myImageView.setImageBitmap(myBitmap);
    myImageView.setVisibility(View.VISIBLE);
}

score 1 · Answer 2 · edited Mar 25 '20 at 11:53

1

No need to create another Image. Just use

textureView.getBitmap(file.getAbsolutePath);

edited Mar 25 '20 at 11:53

mohammed wazeem

1,310
1
10
26

answered Mar 25 '20 at 07:06

Zerocool

29
2

How to stop textureview listener and display an image before closing app

2 Answers2