I am attempting to custom-made a scroll bar. How to "Move" control?

[WileyNg]

I have a Drawable, which has Content = someControl

I am trying to implement a scrollbar

protected override void OnMouseWheel(MouseEventArgs e)
        {
            base.OnMouseWheel(e);
        }

How can I move the whole Content of the Drawable up and down using Mousewheel? without redrawing everything?

[WileyNg]

        protected override void OnLoad(EventArgs e)
        {
            _layout = new PixelLayout() { };
            _layout.Add(_control, 0, _currentHeight);
            Content = _layout;
        }

        protected override void OnMouseWheel(MouseEventArgs e)
        {
            base.OnMouseWheel(e);
            _currentHeight += (int)e.Delta.Height;
            _layout.Move(_control, new Point(0, _currentHeight));
        }

Not sure if this is the best method. but it feels smooth.

[rafntor]

This may help get started ; https://github.com/rafntor/Eto.Containers/blob/master/Eto.Containers/DragZoomImageView.cs
Another approach may be to just let a 'Scrollable' contain your 'Drawable' and get scroll-support that way?

[WileyNg]

Recording.80.mp4

I made it with PixelLayout. Feels smooth and it helps me to do other things as well such as Tooltip.

But I downloaded rafntor's example. It opens my eyes about how IMatrix can be used.
will definitely try that out next.!

[WileyNg]

#2329 (comment)
Do you guys mind reviewing some of my approach on creating a expandable UI?

I am also not sure what means by "double-buffering" and how to enable it.

[rafntor]

Looks great! Would be nice to have that Expander-class published as a nuget

[WileyNg]

Looks great! Would be nice to have that Expander-class published as a nuget

#2329 (comment)
I posted the code there in the link above.

But like you see in the video, the animated expander is still very choppy, when there are so many controls in the panel.
Any idea how can I optimize it?