CODEWITHSUNDEEP
javaandroidviewgroup
Dishonered
Dishonered

Reputation: 8841

Prevent parent from getting touch events only for certain views?

I have a ScrollView and linear layout inside it. Inside the linear layout i have multiple views. One of the multiple views (DrawView lets say)is used to draw stuff so i have to override onTouchEvent of that method and draw things. Currently when i drag or move on the DrawView, the ScrollView also handles the touch leading the entire view moving. What i want is that when i touch the DrawView , the scroll view should not move . I went through some of these answers here

How to vary between child and parent view group touch events

but i did not find anything that i can add in DrawView which will prevent the ScrollView from moving up and down. Note that DrawView does not extend ViewGroup so i don't have access to requestDisallowInterceptTouchEvent

Upvotes: 4

Views: 2552

Answers (3)

Dishonered
Dishonered

Reputation: 8841

So i ended up doing this in my DrawView in the onTouchEvent method

getParent().requestDisallowInterceptTouchEvent(true); , it worked!

Upvotes: 1

Hong Duan
Hong Duan

Reputation: 4294

You can get the ScrollView from your DrawView's onTouchEvent:

ScrollView scrollView = (ScrollView) getParent();

then you can call requestDisallowInterceptTouchEvent on scrollView to prevent it from scrolling when you touch the DrawView.

scrollView.requestDisallowInterceptTouchEvent(true);

Upvotes: 6

Pankaj Kumar
Pankaj Kumar

Reputation: 82958

You can prevent scroll of ScrollView whenever your DrawView gets touch event. To do That you need to create a custom ScrollView calls like below [Original Code Snippet]

public class MyScrollView extends ScrollView {
    private boolean enableScrolling = true;
    public MyScrollView(Context context) {
        super(context);
    }

    public MyScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {

        if (scrollingEnabled()) {
            return super.onInterceptTouchEvent(ev);
        } else {
            return false;
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        if (scrollingEnabled()) {
            return super.onTouchEvent(ev);
        } else {
            return false;
        }
    }

    private boolean scrollingEnabled(){
        return enableScrolling;
    }

    public void setScrolling(boolean enableScrolling) {
        this.enableScrolling = enableScrolling;
    }
}

And you can call scrollView.setScrolling(true/false) as per your requirement.

Upvotes: 2

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