如何在 Vaadin 中将 Keylistener 添加到 ListSelect？

Question

I have a vaadin ListSelect component on which I would like to remove items if the key DEL is used.

All I found was the ShortcutListener but if I add the following listener, the DEL key does not work in the rest of my application (eg deleting text in a TextField ):

listSelect.addShortcutListener(new ShortcutListener("", KeyCode.DELETE, null) {
        private static final long serialVersionUID = 4703134138899283799L;

        @Override
        public void handleAction(Object sender, Object target) {
            // handle delete
        }
    });

How should I implement a listener for the DEL key?

EDIT: Tried to use a wrapper Panel as suggested in comments, but it still doesn't work. Here my current code:

listSelect = new ListSelect(null);
listSelect.setWidth(100, Unit.PERCENTAGE);
listSelect.setHeight(82, Unit.PIXELS);
listSelect.setMultiSelect(true);
listSelect.setNullSelectionAllowed(false);

listSelect.setDescription("Löschen mit der DEL Taste");
listSelect.addShortcutListener(new ShortcutListener("", KeyCode.DELETE, null) {
    private static final long serialVersionUID = 4703134138899283799L;

    @Override
    public void handleAction(Object sender, Object target) {
        // handle delete
    }
});
Panel wrapperPanel = new Panel(listSelect);
form.addComponent(wrapperPanel);

The form is a GridLayout , the parent of form is a Panel . This panel is part of a TabSheet . I'm using Vaadin Version 7.7.1.

Answer 1

Looking at the sources (currently line 110) , it seems that the action is delegated to the containing window...

 /** * Keeps track of the Actions added to this component; the actual * handling/notifying is delegated, usually to the containing window. */ private ConnectorActionManager actionManager;

... or parent container at least, because based on this question Select-all shortcut (Ctrl-A) in Vaadin Table? you can work around this issue. If you wrap the list select in a panel and add the short-cut listener to the panel instead, it works as expected:

public class MyListSelectComponent extends VerticalLayout {

    public MyListSelectComponent() {
        ListSelect list = new ListSelect("Press DEL to remove items");
        TextField input = new TextField("Focus this input and press DEL to delete some text");
        input.setValue("This is some very long text, or not...");

        for (int i = 0; i < 10; i++) {
            list.addItem(i);
        }

        Panel panel = new Panel(list);
        panel.addShortcutListener(new ShortcutListener("", ShortcutAction.KeyCode.DELETE, null) {
            @Override
            public void handleAction(Object sender, Object target) {
                if (list.getValue() != null) {
                    list.removeItem(list.getValue());
                }
            }
        });

        addComponent(panel);
        addComponent(input);
    }
}

Actual output: