❔ Pan and zoom control zooms into the top left once the content width exceeds the parent width (WPF)

protected override Size MeasureOverride(Size constraint) {
    Size size = new Size();
    if (this.InternalChild is UIElement child) {
        child.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
        Size desired = child.DesiredSize;
        size.Width = desired.Width * this.ZoomScale;
        size.Height = desired.Height * this.ZoomScale;
    }
    return size;
}
protected override Size ArrangeOverride(Size arrangeSize) {
    UIElement child = this.InternalChild;
    if (child != null) {
        Size desired = child.DesiredSize;
        double left = ((arrangeSize.Width - desired.Width) / 2) + this.HorizontalOffset;
        double top = ((arrangeSize.Height - desired.Height) / 2) + this.VerticalOffset;
        this.InternalTransform = new ScaleTransform(this.ZoomScale, this.ZoomScale, arrangeSize.Width / 2d, arrangeSize.Height / 2d);
        child.Arrange(new Rect(new Point(left, top), desired));
    }
    return arrangeSize;
}