onTouchEvent，如果用户将手指放在控件之外，则检测ACTION_MOVE

Question

I have my own toggle button with:

@Override
public boolean onTouchEvent(MotionEvent event) {

    super.onTouchEvent(event);

if (event.getAction() == MotionEvent.ACTION_MOVE) {

        if (event.getY() >= getHeight()) {
            if(isChecked()) {
                this.setChecked(true);
                this.performClick();
            }
        } else if (event.getY() <= 0) {
            if(!isChecked()) {
                this.setChecked(false);
                this.performClick();
            }
        }
    }
    return true;
}

I want detect if user holds his finger across my togglebutton and change it. But if user presses a finger on the outside of the control I can not detect onTouchEvent. What are the solutions?

Answer 1

You can register OnTouchListener for your view:

mOnTouchListener = new OnTouchListener() {
        @Override
        public boolean onTouch(View view, MotionEvent motionEvent) {
            final int action = motionEvent.getAction();
            boolean ret = false;

            switch (action) {
            case MotionEvent.ACTION_DOWN:
                ret = ...;
                break;
            case MotionEvent.ACTION_MOVE:
                ret = ...;
                break;
            case MotionEvent.ACTION_UP:
                ret = ...;
                break;
            }

            return ret;
        }
    };      

What returns by onTouch(View view, MotionEvent motionEvent) method defines that any other OnTouchListener() must audit this event or no.You can see this question .

Edit :
Create two OnTouchListener() classes and register each one to observe it's motion events.(one for your button and one for it's parent ).Return true in onTouch method of class witch audit your buttons motion events,so only this class audit button's motion events and not parents listener.