concept translation in category java

This is an excerpt from Manning's book JavaFX in Action. Login to get full access to this book.

Without the negative y axis translation the rectangle would hang off the radial line like a flag on a flagpole. We want the rectangle to straddle the radial, and that’s what the translation achieves.

In versions of JavaFX prior to 1.2 the layout variables didn’t exist, and the translate variables were used to position nodes. But 1.2 introduced the controls API, and with it more sophisticated layout management. The designers of JavaFX realized they needed to separate a node’s layout position from any movement it might subsequently make as part of an animation; thus the concept of separate layout and translation coordinates was born. So, the location of a node is determined by its layout coordinates (its home within its parent), combined with its translation coordinates (where an animation has since moved it), combined with its own local coordinates after transformations have been applied.