In my app I have a ListView backed by ArrayAdapter. In it I'm
detecting events in OnScrollListener#onScroll method to find end of
the list. I noticed that on the phone (MyTouch) both track-ball and
gesture/touch scrolling will trigger the event twice. On the emulator
I get the same behavior with a scrolling wheel and click-and-drug
scrolling. However in emulator if I use down-arrow button to scroll
the event is fired only once.

Here's the code:

    this.view.setOnScrollListener(new OnScrollListener() {
        @Override
        public void onScroll(final AbsListView view, final int first,
                                    final int visible, final int
total) {
            // detect if last item is visible
            if (visible < total && (first + visible == total)) {
                Log.d("OnScrollListener - end of list", "fvi: " +
                   first + ", vic: " + visible + ", tic: " + total);
                // this line gets called twice
                onLastListItemDisplayed(total, visible);
            }
        }
    }

How do I suppress or handle this behavior? I need just a single event
and trying not to revert to silly hacks such as boolean field.

As far as I can tell - both events have identical stacktrace

    Thread [<3> main] (Suspended (breakpoint at line 116 in
SearchResultsView$4))
     SearchResultsView$4.onScroll(AbsListView, int, int, int) line:
116
     ListView(AbsListView).invokeOnItemScrollListener() line: 655
     ListView.arrowScrollImpl(int) line: 2256
     ListView.arrowScroll(int) line: 2172
     ListView.commonKey(int, int, KeyEvent) line: 1977
     ListView.onKeyMultiple(int, int, KeyEvent) line: 1929
     KeyEvent.dispatch(KeyEvent$Callback) line: 899
     ListView(View).dispatchKeyEvent(KeyEvent) line: 3647
     ListView(ViewGroup).dispatchKeyEvent(KeyEvent) line: 744
     ListView.dispatchKeyEvent(KeyEvent) line: 1909
     FrameLayout(ViewGroup).dispatchKeyEvent(KeyEvent) line: 746
     LinearLayout(ViewGroup).dispatchKeyEvent(KeyEvent) line: 746
     PhoneWindow$DecorView(ViewGroup).dispatchKeyEvent(KeyEvent) line:
746
     PhoneWindow$DecorView.superDispatchKeyEvent(KeyEvent) line: 1708
     PhoneWindow.superDispatchKeyEvent(KeyEvent) line: 1197
     SearchResultsView(Activity).dispatchKeyEvent(KeyEvent) line:
1967
     PhoneWindow$DecorView.dispatchKeyEvent(KeyEvent) line: 1684
     ViewRoot.deliverKeyEventToViewHierarchy(KeyEvent, boolean) line:
2329
     ViewRoot.handleFinishedEvent(int, boolean) line: 2299
     ViewRoot.handleMessage(Message) line: 1621
     ViewRoot(Handler).dispatchMessage(Message) line: 99
     Looper.loop() line: 123
     ActivityThread.main(String[]) line: 4203
     Method.invokeNative(Object, Object[], Class, Class[], Class, int,
boolean) line: not available [native method]
     Method.invoke(Object, Object...) line: 521
     ZygoteInit$MethodAndArgsCaller.run() line: 791
     ZygoteInit.main(String[]) line: 549
     NativeStart.main(String[]) line: not available [native method]
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