How to prevent closing of AutoCompleteCombobox popupmenu on SPACE key press in JavaFX

Question

I have created a AutoCompleteCombobox in JavaFX with the help of code mentioned on https://github.com/jesuino/javafx-combox-autocomplete/blob/master/src/main/java/org/fxapps

Answer 1

As a complement, this also works in java 8, you just have to import the internal Skin class:

import com.sun.javafx.scene.control.skin.ComboBoxListViewSkin;

Answer 2

I have been trying to create a AutoCompleteCombobox as well and was wondering why the popup gets closed every time you enter space, until I got your hint that the actual bug is in the ComboBoxListViewSkin class.

You just need to replace the skin of the ComboBox with a new one, which has an EventFilter.

ComboBoxListViewSkin<T> comboBoxListViewSkin = new ComboBoxListViewSkin<T>(comboBox);
comboBoxListViewSkin.getPopupContent().addEventFilter(KeyEvent.ANY, (event) -> {
    if( event.getCode() == KeyCode.SPACE ) {
        event.consume();
    }
});
comboBox.setSkin(comboBoxListViewSkin);

I only tested this solution with Oracle Java 10 on Ubuntu, but it should work on other platforms as well.