Hook the mouse down event and stop it propagating further down the scenegraph

entity.mouseDown(function (event, control) {
    // Mouse down with button
    console.log('Mouse down button: ' + event.button);

    // Stop the event propagating further down the scenegraph
    control.stopPropagation();

    // You can ALSO stop propagation without the control object
    // reference via the global reference:
    ige.input.stopPropagation();
});