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javafxfocusselectiontreetable

JavaFX / TreeTableView: Relationship between Selection and Focus

I need some clarification on the relationship between Focus and Selection in javafx.scene.control.TreeTableView.

In my code I have defined:

ttvMainTree.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);

Assumption 1: I was assuming, that the focused item is always the last item with left-click. Also I was assuming that the a left-click always moves the selection. So that in SelectionMode.SINGLE the focused item and the selected item are always identical.

This seemed to be correct in 90% of all situations. Anyhow after some random left-clickes my code produced such a picture:

enter image description here

Kindly confirm:

  • The item with the blue background is the selected item
  • The item with the blue border ist the focused item

Here the focused item can be changed with left-click, the selected item seems to be not influenced by left-click.

My apologies for not providing an SSCCE. At the moment I don't know how to shorten my code and reproduce this behavior.

Therefore a general question:

  • What is wrong with assumption 1?
Solution

  • In my humble opinion, i don't think there is a difference on the behavior of the two, it is rather a relationship as you said, when you select a Node, this one request the focus. The focus can be controlled with the "focusTraversable" :

    focusTraversable : Specifies whether this Node should be a part of focus traversal cycle. When this property is true focus can be moved to this Node and from this Node using regular focus traversal keys.

    For your case I think maybe it's because you have chosen a TreeTableView that is both child and parent Child 2 !