How to change the height and width of surface view in Camera 2

Question

I am using camera 2. I want to customize the surface view height and width. I am using the following code.

<FrameLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@android:color/holo_blue_dark">
    <TextureView
        android:id="@+id/texture"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</FrameLayout>

Java Code:

protected void createCameraPreview() {
        try {
            SurfaceTexture texture = textureView.getSurfaceTexture();
            assert texture != null;
            texture.setDefaultBufferSize(imageDimension.getWidth(), imageDimension.getHeight());
            Surface surface = new Surface(texture);
            captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
            captureRequestBuilder.addTarget(surface);
            cameraDevice.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback(){
                @Override
                public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
                    //The camera is already closed
                    if (null == cameraDevice) {
                        return;
                    }
                    // When the session is ready, we start displaying the preview.
                    cameraCaptureSessions = cameraCaptureSession;
                    updatePreview();
                }
                @Override
                public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
                    Toast.makeText(MainActivity.this, "Configuration change", Toast.LENGTH_SHORT).show();
                }
            }, null);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

I want to show only 400dp of the surface view. But the whole height is shrinked and displaying in the surface view.

Expected OP:

But I am getting following OP:

How to show only 400dp of camera view in the surface view.

I tried the Soution. But I am not getting the expected result.

private void updateTextureMatrix(int width, int height) { // 200, 200
    int previewWidth =  getScreenWidth(); //720
    int previewHeight = getScreenHeight(); // 1280

    float ratioSurface = (float) width / height; // 1.0
    float ratioPreview = (float) previewWidth / previewHeight; // 0.5625

    float scaleX; float scaleY;

    if (ratioSurface > ratioPreview) { //(0.5625 > 1.0)
        scaleX = (float) height / previewHeight; // 0.15625
        scaleY = 1; 
    } else {
        scaleX = 1;
        scaleY = (float) width / previewWidth;
    }

    Matrix matrix = new Matrix();

    matrix.setScale(scaleX, scaleY); //(0.15625 , 1.0)
    textureView.setTransform(matrix);

    float scaledWidth = width * scaleX; // 31.25
    float scaledHeight = height * scaleY; // 200.0

    float dx = (width - scaledWidth) / 2; // 84.375
    float dy = (height - scaledHeight) / 2; // 0.00
    textureView.setTranslationX(dx);
    textureView.setTranslationY(dy);
}

I am getting the following result.

I gave 200 width and 200 height. But not getting expected result. And also camera view also getting stretched.

Answer 1

Finally come up with the following solution. Parent layout width and height is 400. And texture view height and with as screen height and screen width.

<FrameLayout
        android:id="@+id/parent_layout"
        android:layout_width="300dp"
        android:layout_height="300dp"
        android:background="@android:color/holo_blue_dark">
        <com.example.camerasample.AutoFitTextureView
            android:id="@+id/texture"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>
    </FrameLayout>

Java Code:

textureView.setLayoutParams(new FrameLayout.LayoutParams(getScreenWidth(),getScreenHeight()));

And finally crop the image after taking photo using the following code.

private byte[] cropImage(Bitmap bitmap, View textureView, View parentView) {

        int heightOriginal = textureView.getHeight();
        int widthOriginal = textureView.getWidth();
        int heightFrame = parentView.getHeight();
        int widthFrame = parentView.getWidth();
        int leftFrame = parentView.getLeft();
        int topFrame = parentView.getTop();
        int heightReal = bitmap.getHeight();
        int widthReal = bitmap.getWidth();
        int widthFinal = widthFrame * widthReal / widthOriginal;
        int heightFinal = heightFrame * heightReal / heightOriginal;
        int leftFinal = leftFrame * widthReal / widthOriginal;
        int topFinal = topFrame * heightReal / heightOriginal;
        Bitmap bitmapFinal = Bitmap.createBitmap(
                bitmap,
                leftFinal, topFinal, widthFinal, heightFinal
        );
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmapFinal.compress(
                Bitmap.CompressFormat.JPEG,
                100,
                stream
        );
        return stream.toByteArray();
    }