Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
554 views
in Technique[技术] by (71.8m points)

java - ComboBox SAME item selected action listener

A combo box will fire an event if a DIFFERENT value is selected. I want to be also be able to listen to the SAME item being selected (that is, valueProperty has no change). There seems to be no way to do this.

I tried extending the ComboBox and finding a way to listen for the little popup menu being closed, but I don't even have access to that! What can I do?

Here is what I was trying:

class ResponsiveComboBox<E> extends ComboBox<E> {

    public ResponsiveComboBox() {
        super();
        assert getContextMenu() != null; //Asssertion failed!
        this.getContextMenu().setOnHiding((WindowEvent event) -> {
            fireEvent(new ActionEvent());
        });
    }

}
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)
comboBox.showingProperty().addListener((obs, wasShowing, isShowing) -> {
    if (! isShowing) {
        System.out.println("Combo box popup hidden");
    }
});

This event handler might be triggered before the value is changed.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...