Implement Tap to Focus in Camera2 API

Question

i want to implement tap to focus feature in my custom camera. This is the basic code provided by Google https://github.com/googlesamples/android-Camera2Basic

Here\'s

Answer 1

 public void handleFocus(MotionEvent event) {
    int pointerId = event.getPointerId(0);
    int pointerIndex = event.findPointerIndex(pointerId);
    // Get the pointer's current position
    float x = event.getX(pointerIndex);
    float y = event.getY(pointerIndex);

    Rect touchRect = new Rect(
            (int) (x - 100),
            (int) (y - 100),
            (int) (x + 100),
            (int) (y + 100) );


    if (mCameraId == null) return;
    CameraManager cm = (CameraManager)this.getSystemService(Context.CAMERA_SERVICE);
    CameraCharacteristics cc = null;
    try {
        cc = cm.getCameraCharacteristics(mCameraId);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }


    MeteringRectangle focusArea = new MeteringRectangle(touchRect,MeteringRectangle.METERING_WEIGHT_DONT_CARE);
    mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_TRIGGER, CameraMetadata.CONTROL_AF_TRIGGER_CANCEL);
    try {
        mCaptureSession.capture(mPreviewRequestBuilder.build(), mCaptureCallback,
                mBackgroundHandler);
        // After this, the camera will go back to the normal state of preview.
        mState = STATE_PREVIEW;
    } catch (CameraAccessException e){
        // log
    }

    /* if (isMeteringAreaAESupported(cc)) {
     *//*mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_REGIONS,
                new MeteringRectangle[]{focusArea});*//*
    }
    if (isMeteringAreaAFSupported(cc)) {
        *//*mPreviewRequestBuilder
                .set(CaptureRequest.CONTROL_AF_REGIONS, new MeteringRectangle[]{focusArea});
        mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,
                CaptureRequest.CONTROL_AF_MODE_AUTO);*//*
    }*/
    mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_REGIONS,
            new MeteringRectangle[]{focusArea});
    mPreviewRequestBuilder
            .set(CaptureRequest.CONTROL_AF_REGIONS, new MeteringRectangle[]{focusArea});
    mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,
            CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
    mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_TRIGGER,
            CameraMetadata.CONTROL_AF_TRIGGER_START);
    mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER,
            CameraMetadata.CONTROL_AE_PRECAPTURE_TRIGGER_START);
    try {
        mCaptureSession.setRepeatingRequest(mPreviewRequestBuilder.build(), mCaptureCallback,
                mBackgroundHandler);
        /* mManualFocusEngaged = true;*/
    } catch (CameraAccessException e) {
        // error handling
    }
}

call on touch event method in averide on touch