If you want your CustomNode to be 90 pixels high, you need to specify that in the node constraints when you add it to MigLayout.
1
2Stage {
3 title: "Mig Docking Test"
4 scene: XScene {
5 width: 400
6 height: 400
7 fill: Color.LEMONCHIFFON
8 content: XVBox{
9 content:
10 MigLayout {
11 constraints: "fill"
12 content: [
13 migNode( MyCustomNode{}, "north, h 90!"),
14 migNode( createLabel( Color.GOLDENROD, "Center" ), "center, grow" ),
15 ]
16 }
17 }
18 }
19}
This still won't cause your CustomNode to fill the area, though. CustomNodes are not Resizable.
Dean