QML State Element

Detailed Description

A state is a set of batched changes from the default configuration.

All items have a default state that defines the default configuration of objects and property values. New states can be defined by adding State items to the states property to allow items to switch between different configurations. These configurations can, for example, be used to apply different sets of property values or execute different scripts.

The following example displays a single Rectangle. In the default state, the rectangle is colored black. In the "clicked" state, a PropertyChanges element changes the rectangle's color to red. Clicking within the MouseArea toggles the rectangle's state between the default state and the "clicked" state, thus toggling the color of the rectangle between black and red.

 import QtQuick 1.0

 Rectangle {
     id: myRect
     width: 100; height: 100
     color: "black"

     MouseArea {
         id: mouseArea
         anchors.fill: parent
         onClicked: myRect.state == 'clicked' ? myRect.state = "" : myRect.state = 'clicked';
     }

     states: [
         State {
             name: "clicked"
             PropertyChanges { target: myRect; color: "red" }
         }
     ]
 }

Notice the default state is referred to using an empty string ("").

States are commonly used together with Transitions to provide animations when state changes occur.

Note: Setting the state of an object from within another state of the same object is not allowed.

See also states example, States, Transitions, and QtDeclarative.

Property Documentation

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

     MouseArea { id: mouseArea; anchors.fill: parent }

     states: State {
         name: "hidden"; when: mouseArea.pressed
         PropertyChanges { target: myRect; opacity: 0 }
     }
 }

 Item {
     states: [
         State { name: "state1"; when: sharedCondition },
         State { name: "state2"; when: sharedCondition }
     ]
     // ...
 }