CameraSource .setAutoFocusEnabled(true) returns: Camera auto focus is not supported on this device although device supports auto focus

Question

Below is my barcode scanner activity, everything works fine except for the setAutoFocusEnabled(true). It returns a message on runtime that says my device does not support au

Answer 1

So after two days of struggle I finally managed to "concoct" a fix. But Android development team should seriously look into why setAutoFocusEnabled(true) doesn't work on devices with Auto Focus.

Here is my fix, hope it saves someone else some time:

@Override
public boolean onTouchEvent(MotionEvent event) {
    if(event.getAction() == MotionEvent.ACTION_UP) {
        float x =  event.getX();
        float y = event.getY();
        float touchMajor = event.getTouchMajor();
        float touchMinor = event.getTouchMinor();

        Rect touchRect = new Rect((int)(x - touchMajor / 2), (int)(y - touchMinor / 2), (int)(x + touchMajor / 2), (int)(y + touchMinor / 2));

        this.submitFocusAreaRect(touchRect);
    }
    return super.onTouchEvent(event);
}

private void submitFocusAreaRect(final Rect touchRect) {
    Field[] declaredFields = CameraSource.class.getDeclaredFields();

    for (Field field : declaredFields) {
        if (field.getType() == Camera.class) {
            field.setAccessible(true);
            try {
                Camera camera = (Camera) field.get(cameraSource);
                if (camera != null) {
                    Camera.Parameters cameraParameters = camera.getParameters();

                    if(cameraParameters.getMaxNumFocusAreas() == 0) {
                        return;
                    }

                    Rect focusArea = new Rect();

                    focusArea.set(touchRect.left * 2000 / cameraView.getWidth() - 1000,
                            touchRect.top * 2000 / cameraView.getHeight() - 1000,
                            touchRect.right * 2000 / cameraView.getWidth() - 1000,
                            touchRect.bottom * 2000 / cameraView.getHeight() - 1000);

                    ArrayList<Camera.Area> focusAreas = new ArrayList<>();
                    focusAreas.add(new Camera.Area(focusArea, 1000));

                    cameraParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
                    cameraParameters.setFocusAreas(focusAreas);
                    camera.setParameters(cameraParameters);

                    camera.autoFocus(this);
                }
            } catch (IllegalAccessException | RuntimeException e) {
                e.getMessage();
            }

            break;
        }
    }

}

Now I can scan barcodes with the rear camera as well. Yay!