Why is android:transcriptMode="normal" not working properly?

Question

I've been doing a lot of fiddling with an issue I've been having. What happens is each time an item gets added to my listview (adapter) I expect it to auto-scroll if I'm at the last item (which it will do to an extent); HOWEVER, if 3 or more items get added at once, it will not auto-scroll.

Here is the XML of that listview:

    <ListView android:id="@android:id/list"
    android:layout_width="fill_parent" 
    android:layout_height="0dip"
    android:layout_weight="1"
    android:transcriptMode="normal"/>

I tried a workaround using a snippet I found here.

My code is as follows:

public void addChat(final String text, final String username) {
    this.runOnUiThread(new Runnable() {
        public void run() {
            globals.chatAdapter.add(DateFormat.format("hh:mmaa", Calendar.getInstance()).toString(), username, text);

            globals.chatAdapter.notifyDataSetChanged();

            int lastP = getListView().getLastVisiblePosition();
            int count = globals.chatAdapter.getCount() - 1;

            if (lastP == globals.chatAdapter.oldP || lastP == -1) {
                getListView().setSelection(count);
            }

            globals.chatAdapter.oldP = count;
        }
    });
}

The problem with this is when a bunch of items come in at once, getListView().getLastVisiblePosition() will not update right away causing a setSelection() to never get called, and thus no auto-scroll.

Any suggestions?

Answer 1

As a workaround, I modified the scroll listener...a little crude, but it gets the job done.

OLD CODE - NEW CODE FOUND AFTER EDIT BELOW

    this.getListView().setOnScrollListener(new OnScrollListener() {
        public void onScroll(AbsListView view, int first, int visible, int total) {
            if (visible == 0 || visible < total && (first + visible == total) || (getListView().getTranscriptMode() == 2) && (first + visible == total)) {
                if (getListView().getTranscriptMode() != 2)
                    getListView().setTranscriptMode(2);
            } else {
                if (getListView().getTranscriptMode() != 0)
                    getListView().setTranscriptMode(0);
            }
        }

        public void onScrollStateChanged(AbsListView view, int scrollState) {}
    });

EDIT 6/6/11:

I went ahead and modified it again as I found a UI bug in my own implementation (The initial snap to the bottom wouldn't hold after I removed my alwaysScroll xml setting). I'll leave the old code above, but here's what I'm using now:

        getListView().setOnScrollListener(new OnScrollListener() {
            public void onScroll(AbsListView view, int first, int visible, int total) {
                    if (visible == 0 || visible == total || (first + visible == total) {
                        if (getListView().getTranscriptMode() != AbsListView.TRANSCRIPT_MODE_ALWAYS_SCROLL)
                            getListView().setTranscriptMode(AbsListView.TRANSCRIPT_MODE_ALWAYS_SCROLL);
                    } else {
                        if (getListView().getTranscriptMode() != AbsListView.TRANSCRIPT_MODE_DISABLED)
                            getListView().setTranscriptMode(AbsListView.TRANSCRIPT_MODE_DISABLED);
                    }
            }

            public void onScrollStateChanged(AbsListView view, int scrollState) {}
        });