Create User Interfaces - JavaFX: Developing Rich Internet Applications - page 114

The boundsInParent reflects the Group's coordinate system and also reflects
the translateX and translateY transform from the Rectangle node. Notice
the dimensions are still 84 by 70 but the minX and minY and maxX and maxY val-
ues have changed to reflect the translateX and translateY transformation.
The boundsInScene reflects the Group's rotation, and now the bounding area is
a square that encloses the rotated rectangle. This reflects the Group's rotation.

Table 5.1 summarizes the differences between these four bounds.

Ta b l e 5 . 1 Bounds

Coordinate
Space Bounds Contribution

boundsInLocal Untransformed local coordinates, including shape

stroke, clip, and effect

Node

BoundsInLocal plus transforms[] sequence

Node

layoutBounds

LayoutBounds plus translateX / translateY ,
scaleX / scaleY , rotate

Parent

boundsInParent

boundsInScene BoundsInParent plus accumulated transforms of all

ancestor nodes

Scene

To position a node, you need to use the Nodes layoutBounds to determine its
basic size. If you need to incorporate transformations into this calculation, you
should use the transforms[] sequence rather than the standalone transform
instance variables, translateX/Y , scaleX/Y , and rotate . Listing 5.18 provides
an example to center a node in a scene.

Listing 5.18 Centering a Node in a Scene

var rect:Rectangle;
Stage {
var scene:Scene;
width: 200
height: 200
scene: scene = Scene {
content: rect = Rectangle {
translateX: bind (scene.width -
rect.layoutBounds.width)/2.0 -
rect.layoutBounds.minX