Behavior QML Type

A Behavior defines the default animation to be applied whenever a particular property value changes.

For example, the following Behavior defines a NumberAnimation to be run whenever the Rectangle's width value changes. When the MouseArea is clicked, the width is changed, triggering the behavior's animation:

import QtQuick 2.0

Rectangle {
    id: rect
    width: 100; height: 100
    color: "red"

    Behavior on width {
        NumberAnimation { duration: 1000 }
    }

    MouseArea {
        anchors.fill: parent
        onClicked: rect.width = 50
    }
}

Note that a property cannot have more than one assigned Behavior. To provide multiple animations within a Behavior, use ParallelAnimation or SequentialAnimation.

If a state change has a Transition that matches the same property as a Behavior, the Transition animation overrides the Behavior for that state change. For general advice on using Behaviors to animate state changes, see Using Qt Quick Behaviors with States.

See Also▲

animation : Animation▲

enabled : bool▲

[since QtQuick 2.13] targetValue : Variant▲