When I set VerticalContentAlignment to Bottom and AllowMove to true i can move ChildWindow maximum to half of parent. I think this is issue witch calculate offsets and for testing this concept I change the calculate offset in ProcessMove method in clone repository from
When I set VerticalContentAlignment to Bottom and AllowMove to true i can move ChildWindow maximum to half of parent. I think this is issue witch calculate offsets and for testing this concept I change the calculate offset in ProcessMove method in clone repository from
var widthOffset = width / 2 - this.partWindow.RenderSize.Width / 2;
var heightOffset = height / 2 - this.partWindow.RenderSize.Height / 2;
to
var offset = VisualTreeHelper.GetOffset(this.partWindow);
var widthOffset = offset.X;
var heightOffset = offset.Y;
After these changes issue with moving will disappear. I don't know if this is a the best way to fix this issue.