Detecting when scrollView has scrolled

I implemented a solution based on Jourbac comment.

Regards

import android.content.Context; import android.os.Handler; import android.os.Message; import android.util.AttributeSet; import android.util.Log; import android.widget.ScrollView; public class MyScrollView extends ScrollView { private static final int WHAT = 1; class MyHandler extends Handler { @Override public void handleMessage(Message msg) { super.handleMessage(msg); if(!hasMessages(WHAT)) { Log.i("TestScroll", "Last msg!. Position from " + msg.arg1 + " to " + msg.arg2); } } } private Handler mHandler = new MyHandler(); public MyScrollView(Context context) { super(context); } public MyScrollView(Context context, AttributeSet attrs) { super(context, attrs); } public MyScrollView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); } @Override protected void onScrollChanged(int l, int t, int oldl, int oldt) { super.onScrollChanged(l, t, oldl, oldt); final Message msg = Message.obtain(); msg.arg1 = oldt; msg.arg2 = t; msg.what = WHAT; mHandler.sendMessageDelayed(msg, 500); } } 

I would approach this by creating a child class of ScrollView, say MyScrollView, and using that instead of ScrollView.

That way you can override the methods of ScrollView which are invoked when scrolling; and add a callback of someform in them (not forgetting to call the corresponding method in super)

I can't really tell you which of ScrollView's methods will be invoked when; I assume one of them is called each time a scoll happens, but which one... maybe simply scrollTo().

I suppose it would be a very interesting and learning experience to override them all and just log when they're called. I might want to do that myself, if I do, I'll be sure to come back with a more useful answer, assuming noone else does during that time.