Move EventHandlerManager to public API

[Abhinay Agarwal]

Hi,

Classes which extends Node have access to the protected method `setEventHandler`[1]. It makes it exceptional easy to register a user-defined onXXX event handler.

However, for custom EventTarget which do not extend Node, it becomes cumbersome as JavaFX expects us to create a whole new EventDispatcher to register custom event handlers/filters on these targets. JavaFX already has a number of implementation for EventDispatcher in the `com.sun` package. The most basic of which are BasicEventDispatcher and EventHandlerManager. The later seems to have all the necessary public methods to make it easier to create new EventTargets.

Unless there is a good reason which I am missing, JavaFX should provide a basic implementation of EventDispatcher to make it easier for developers to create custom EventTarget.

FYR, ControlsFX has 3 classes which implement EventTarget directly:

  1.

AutoCompletionBinding [2]


  2.

GridBase [3]

  3.

SpreadsheetCellBase [4]

Regards,
Abhinay

[1] https://github.com/openjdk/jfx/blob/master/modules/javafx.graphics/src/main/java/javafx/scene/Node.java#L8776
[2] https://github.com/controlsfx/controlsfx/blob/jfx-13/controlsfx/src/main/java/org/controlsfx/control/textfield/AutoCompletionBinding.java
[3] https://github.com/controlsfx/controlsfx/blob/jfx-13/controlsfx/src/main/java/org/controlsfx/control/spreadsheet/GridBase.java
[4] https://github.com/controlsfx/controlsfx/blob/jfx-13/controlsfx/src/main/java/org/controlsfx/control/spreadsheet/SpreadsheetCellBase.java