FocusScope

export component Example inherits Window {
    width: 100px;
    height: 100px;
    forward-focus: my-key-handler;
    my-key-handler := FocusScope {
        key-pressed(event) => {
            debug(event.text);
            if (event.modifiers.control) {
                debug("control was pressed during this event");
            }
            if (event.text == Key.Escape) {
                debug("Esc key was pressed")
            }
            accept
        }
    }
}

The FocusScope exposes callbacks to intercept key events. Note that FocusScope will only invoke them when it has-focus.

The KeyEvent has a text property, which is a character of the key entered. When a non-printable key is pressed, the character will be either a control character, or it will be mapped to a private unicode character. The mapping of these non-printable, special characters is available in the Key namespace

Properties

has-focus

bool (out) default: false

Is true when the element has keyboard focus.

enabled

bool default: true

When true, the FocusScope will make itself the focused element when clicked. Set this to false if you don’t want the click-to-focus behavior. Similarly, a disabled FocusScope does not accept the focus via tab focus traversal. A parent FocusScope will still receive key events from child FocusScopes that were rejected, even if enabled is set to false.

Functions

focus()

Call this function to transfer keyboard focus to this FocusScope, to receive future KeyEvents.

clear-focus()

Call this function to remove keyboard focus from this FocusScope if it currently has the focus. See also .

Callbacks

key-pressed(KeyEvent) -> EventResult

Invoked when a key is pressed, the argument is a KeyEvent struct. The returned EventResult indicates whether to accept or ignore the event. Ignored events are forwarded to the parent element.

key-released(KeyEvent) -> EventResult

Invoked when a key is released, the argument is a KeyEvent struct. The returned EventResult indicates whether to accept or ignore the event. Ignored events are forwarded to the parent element.

focus-changed-event()

Invoked when the focus on the FocusScope has changed.