A DESCRIPTION OF THE REQUEST :
It seems rather odd that the timeline and animation interfaces are completely lacking any styling support. This means they are only customizable programmatically and not by end users. A recent example I have is creating a timeline to animate the border of a Rectangle instance and not having any way of setting the properties from a style sheet. In this case it would be nice to be able to set the duration, target, and source values among other properties from a style sheet.

JUSTIFICATION :
Customizing animations is a fundamental part of application styling. The Qt framework's Qt Quick platform makes animation properties an integral part of the application styling.
http://doc.qt.io/qt-5/qtquick-statesanimations-animations.html

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I would expect to be able to style Transitions and Animations from style sheets.
ACTUAL -
There is no support for styling transitions and animations using style sheets.

---------- BEGIN SOURCE ----------
Rectangle rectangle = new Rectangle();
// this is used to animate the dotted border of a rectangle
strokeTimeline = new Timeline();
strokeTimeline.setCycleCount(Timeline.INDEFINITE);
// 12 is the cumulative offset of the stroke dash array in the style sheet
KeyValue kv = new KeyValue(rectangle.strokeDashOffsetProperty(), 12);
KeyFrame kf = new KeyFrame(Duration.millis(500), kv);
strokeTimeline.getKeyFrames().add(kf);
strokeTimeline.play();
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
The only current work around is to extend the transitions manually and add the CSSMetaData which is rather cumbersome and not very flexible. It also produces a large amount of boiler plate code.