ListView scroll with different cell sizes

Question

Hello,
my application changes the size of (some) cells in a listview.
Now in my case the scrolling of the listview becomes a problem. Because a larger cell is passed much faster than smaller cells - so the scrolling speed is not constant anymore.
But I need the scrolling to stay contant. Is that possible?
I hope this explanation was understandable ...
thanks!!!

Answer 1

Thanks for your answer!
Unfortunately I don't really understand your solution...
But let me show you my problem a little more precisely:
When you try the following code a listview will appear. Double clicking an item will expand the item's size. Now try to drag the scroll bar and you will see what i mean (the expanded item is passed very fast). Unlike that when clicking the arrows of the scrollbar, the behaviour is as I want it.
So does your solution fix that?
thanks!!!!
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.scene.layout.Stack;
import javafx.scene.control.Label;
import javafx.scene.control.ListCell;
import javafx.scene.control.ListView;
class ExpandablePane extends Stack {
    var expanded = false;
    var expanding = false;
    var prefHeight:Number;
    var h:Number on replace {
        if (expanding) requestLayout();
    public function toggle() {
        if (not expanding) {
            if (expanded) {
                contract();
            } else {
                expand();
    function expand():Void {
        expanding = true;
        h = prefHeight = height; // store off the old height
        Timeline {
            keyFrames: KeyFrame {
                time: 250ms
                values: [
                    h => 200,
                    expanding => false,
                    expanded => true
        }.play();
    function contract():Void {
        expanding = true;
        Timeline {
            keyFrames: KeyFrame {
                time: 250ms
                values: [
                    h => prefHeight,
                    expanding => false,
                    expanded => false
        }.play();
    override function getPrefHeight(width) {
        if (expanded or expanding) {
            return h;
        } else {
            return super.getPrefHeight(width);
ListView {
    items: for(i in [1..20]){
        ListCell {
            var ep:ExpandablePane;
            node: ep = ExpandablePane {
                content: Label {
                    text: "{i}"
            onMouseClicked: function(e) {
                if (e.clickCount == 2) {
                    ep.toggle();
}