How to keep an image inside the screen limits while using pinch zoom and drag gestures?

Question

I\'m building an app that uses the pinch zoom and drag. The problem is that for now I can drag the picture out of it bounds. I wanted to know how can I use drag and make sure th

Answer 1

public boolean onTouch(View v, MotionEvent event) {
        int action = event.getAction();

        DisplayMetrics displaymetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
        int sH = displaymetrics.heightPixels;
        int sW = displaymetrics.widthPixels;
        float dx, dy, newX, newY;

        switch (action) {
            case MotionEvent.ACTION_DOWN:
                dx = event.getRawX() - v.getX();
                dy = event.getRawY() - v.getY();
                break;

            case MotionEvent.ACTION_MOVE:
                newX = event.getRawX() - dx;
                newY = event.getRawY() - dy;

                if ((newX <= 0 || newX >= sW-v.getWidth()) || (newY <= 0 || newY >= sH-v.getHeight()))
                    break;

                v.setX(newX);
                v.setY(newY);
                break;   

            default:
                break;
        }

        return true;
    }