Question

In android, how do i get the scroll position of the listview?

I know that I can retrieve the scroll position of a uniform populated listview with the following code:

int scrollY = -this.getChildAt(0).getTop() + this.getFirstVisiblePosition()* this.getChildAt(0).getHeight();

the code assumes all heights of children(item) in the listview to be equal(this.getChildAt(0).getHeight())

Now, if i populate my listview with not equally sized items, how do i get the proper scroll position?

My listview looks something like this:

This is why I need the scroll position:

private Canvas drawIndicator(Canvas canvas) {

    int scrollY = getCurrentScrollPosition();



    paint.setColor(Color.GRAY);
    paint.setAlpha(100);
    canvas.drawRect(getLeft(), indicatorPosition[0] - scrollY, getRight(), indicatorPosition[1]
            - scrollY, paint);

     //Log.d(VIEW_LOG_TAG, "drawIndicator:" + (indicatorPosition[1] -
     //scrollY));

    paint.setColor(Color.parseColor("#47B3EA"));
    canvas.drawRect(getLeft(), indicatorPosition[1] - scrollY - (indicatorHeight / 2),
            getRight(), indicatorPosition[1] - scrollY + indicatorHeight, paint);

    return canvas;
}

i need to draw a indicator that follows the scroll of the listview

i would invoke it like

@Override
protected void onDraw(Canvas canvas) {
    canvas.save();
    canvas = drawIndicator(canvas);
    super.onDraw(canvas);
    canvas.restore();
}

Answer 1

Assuming that you know the size of All your items type:

int currentY = 0;
        for (int i = 0; i < listView.getFirstVisiblePosition(); i++) {

            int type = listView.getAdapter().getItemViewType(i);
            currentY += getHightForViewType(type);
        }

        int scrollY = -listView.getChildAt(0).getTop() + currentY;

and using your adapter:

 private int getHightForViewType(int itemViewType) {

        int hightItem;
        switch (itemViewType) {
            case 0:
                hightItem = 100;
                break;

            default:
                hightItem = 60;
                break;
        }
        return hightItem;

    }