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Illegal argument exception and thread issues on lockCanvas

asked 2018-08-30 23:22:15 -0500

bfialkoff gravatar image

updated 2018-08-31 00:38:43 -0500

I am attempting to take a picture, and in the onPictureTaken I atempt to make some layout changes and then pass the image data to a new activity. When making layout changes the app crashes with an illegal argument error that traces back to the CameraWorker thread running in JavaCameraView.

I know this is kind of long but I'm really stumped. I'd really appreciate any help.

The idea is like this: When the onPictureTaken is called i freeze the preview (to show the user the image he captured) and display an "ok" button and a "retry" button. However when I attempt to change the layout (i.e make the buttons visible) the app crashes wit the above error and the following stacktrace:

E/SurfaceHolder: Exception locking surface
                     at android.view.Surface.nativeLockCanvas(Native Method)
                     at android.view.Surface.lockCanvas(
                     at android.view.SurfaceView$4.internalLockCanvas(
                     at android.view.SurfaceView$4.lockCanvas(

The methods are in CameraBridgeViewBase and are called via a thread that is running in JavaCameraView which is why I think this is a thread issue. Unfortunately I dont know where to go from here.

My methods that cause the crash are here:

    public void onPictureTaken(byte[] data, Camera camera) {
        Log.i(TAG, "Saving a bitmap to file");
        Toast.makeText(context,"Not Starting New Activity. Look at me now error!",Toast.LENGTH_LONG).show();;
        //attempt to export all this to JavaCameraView, i have a feeling that there is a conflict with his thread....maybe that will help


    private void buttonManager(byte[] data) {
        //find buttons
        final byte[] img_data = data;
        final int width = this.getWidth();
        final int height = this.getHeight();


        okButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                Intent startImgProc = new Intent(context,ImageProcessing.class);
                ((Activity) context).finish();

        retryButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {

The call to deliverAndDrawFrame is from JavaCameraView here:

private class CameraWorker implements Runnable {

        public void run() {
            do {
                boolean hasFrame = false;
                synchronized (JavaCameraView.this) {
                    try {
                        while (!mCameraFrameReady && !mStopThread) {
                    } catch (InterruptedException e) {
                    if (mCameraFrameReady)
                        mChainIdx = 1 - mChainIdx;
                        mCameraFrameReady = false;
                        hasFrame = true;

                if (!mStopThread && hasFrame) {
                    if (!mFrameChain[1 - mChainIdx].empty())
                        deliverAndDrawFrame(mCameraFrame[1 - mChainIdx]);
            } while (!mStopThread);
            Log.d(TAG, "Finish processing thread");

and the method itself

protected void deliverAndDrawFrame(CvCameraViewFrame frame) {
    Mat modified;

    if (mListener != null) {
        modified = mListener.onCameraFrame(frame);
    } else {
        modified = frame.rgba();

    boolean bmpValid = true;
    if (modified != null) {
        try {
            Utils.matToBitmap(modified, mCacheBitmap);
        } catch(Exception e) {
            Log.e(TAG, "Mat type: " + modified);
            Log.e(TAG, "Bitmap type: " + mCacheBitmap.getWidth ...
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your SO link is useless here. if you're too lazy to give us the details HERE, probably noone will answer it.

berak gravatar imageberak ( 2018-08-31 00:02:57 -0500 )edit

There isn't a code format option here. I assumed that was the best alternative. Happy to provide details here. Coming right up.

bfialkoff gravatar imagebfialkoff ( 2018-08-31 00:21:45 -0500 )edit

"There isn't a code format option here." -- there is ! mark your code with mouse, and press crtl-k (or use the 10101 button)

berak gravatar imageberak ( 2018-08-31 00:23:25 -0500 )edit

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answered 2018-08-31 00:27:27 -0500

bfialkoff gravatar image

Oops I missed that,thanks.

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Asked: 2018-08-30 23:22:15 -0500

Seen: 549 times

Last updated: Aug 31 '18