- Qt 5.3
- Qt Quick
- QML Types
- Behavior QML Type
- Qt 5.3.2 Reference Documentation

# Behavior QML Type

Defines a default animation for a property change More...

Import Statement: | `import QtQuick 2.3`

- List of all members, including inherited members

## Properties

- animation : Animation
- enabled : bool

## Detailed Description

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 and Transitions in Qt Quick, Behavior example, and Qt QML.

## Property Documentation

default animation : Animation

This property holds the animation to run when the behavior is triggered.

enabled : bool

This property holds whether the behavior will be triggered when the tracked property changes value.

By default a Behavior is enabled.