Android Move ImageView

Question

I searched the web for a simple solution to freely move an ImageView. I finally found some code that produces the perfect result:

public class MainActivity extends Activity implements View.OnTouchListener {

    private int _xDelta;
    private int _yDelta;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ImageView j = (ImageView)findViewById(R.id.j);

        j.setOnTouchListener(this);

    }

    public boolean onTouch(View view, MotionEvent event) {
        final int X = (int) event.getRawX();
        final int Y = (int) event.getRawY();
        ImageView j = (ImageView)findViewById(R.id.j);
        switch (event.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:
                RelativeLayout.LayoutParams lParams = (RelativeLayout.LayoutParams) view.getLayoutParams();
                _xDelta = (int) (X - j.getTranslationX());
                _yDelta = (int) (Y - j.getTranslationY());
                break;
            case MotionEvent.ACTION_UP:
                break;
            case MotionEvent.ACTION_POINTER_DOWN:
                break;
            case MotionEvent.ACTION_POINTER_UP:
                break;
            case MotionEvent.ACTION_MOVE:
                RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) view.getLayoutParams();

                j.setTranslationX(X - _xDelta);
                j.setTranslationY(Y - _yDelta);
                break;
        }

        return true;
    }}

Since I don't really know how my code works, I wanted to see if there were better solutions.

user_14641018 · Answer

it's work

public class MainActivity extends AppCompatActivity {
ImageView imageView;
float xDown = 0;
float yDown = 0;

@SuppressLint("ClickableViewAccessibility")
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    imageView = findViewById(R.id.subview);
    imageView.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            switch (event.getActionMasked()) {
                case MotionEvent.ACTION_DOWN:
                    xDown = event.getX();
                    yDown = event.getY();
                    break;
                case MotionEvent.ACTION_MOVE:
                    float moveX,moveY;
                    moveX = event.getX();
                    moveY = event.getY();

                    float distanceX = moveX -xDown;
                    float distanceY  = moveY -yDown;
                    imageView.setX(imageView.getX()+distanceX);
                    imageView.setY(imageView.getY()+distanceY);
                    break;
            }
            return true;
        }
    });
}

}

Android Move ImageView

5 Answers