LayoutUpdateHandler

Control *pButton = Button::create().text("Check out my layout!");

LayoutUpdateHandler::create(pButton)
    .onLayoutFrameChanged(this, SLOT(handleLayoutFrameUpdated(QRectF)));

// pButton owns the created handler so there is no need to keep a reference to it,
// and it will be deleted when the button is deleted.

Container {
    layout: AbsoluteLayout {}

    // The position and size of this container is bound to
    // the position and size of the button.
    Container {
        preferredWidth: handler.layoutFrame.width + 20
        preferredHeight: handler.layoutFrame.height + 20
        layoutProperties: AbsoluteLayoutProperties {
            positionX: handler.layoutFrame.x - 10
            positionY: handler.layoutFrame.y - 10
        }
        background: Color.Blue
    }
    Button {
        text: "I'm being followed!"
        layoutProperties: AbsoluteLayoutProperties {
            id: props
        }
        onClicked: {
            props.positionX += 10;
            props.positionY += 10;
        }
        attachedObjects: [
            // This handler is tracking the layout frame of the button.
            LayoutUpdateHandler {
                id: handler
                onLayoutFrameChanged: {
                    // Individual layout frame values can be
                    // retrieved from the signal parameter
                    console.log("Layout Frame: [" +
                                layoutFrame.x + ", " + layoutFrame.y +
                                layoutFrame.width + ", " + 
                                layoutFrame.height + "]");
                }
            }
        ]
    }
}