67     PropertyChanges provides a state change that modifies the properties of an item.

    68     PropertyChanges is used to define the property values or bindings in a 

    68 

    69     \l State. This enables an item's property values to be changed when it

    69     Here is a property change that modifies the text and color of a \l Text element

    70     \l {QML States}{changes between states}.

    70     when it is clicked:

    71 

    72     To create a PropertyChanges object, specify the \l target item whose 

    73     properties are to be modified, and define the new property values or

    74     bindings. For example:

    72     \qml

    76     \snippet doc/src/snippets/declarative/propertychanges.qml import 

    73     Text {

    77     \codeline

    74         id: myText

    78     \snippet doc/src/snippets/declarative/propertychanges.qml 0

    75         width: 100; height: 100

    79 

    76         text: "Hello"

    80     When the mouse is pressed, the \l Rectangle changes to the \e resized

    77         color: "blue"

    81     state. In this state, the PropertyChanges object sets the rectangle's 

    78 

    82     color to blue and the \c height value to that of \c container.height.

    79         states: State {

    83 

    80             name: "myState"

    84     Note this automatically binds \c rect.height to \c container.height 

    81 

    85     in the \e resized state. If a property binding should not be

    82             PropertyChanges {

    86     established, and the height should just be set to the value of

    83                 target: myText

    87     \c container.height at the time of the state change, set the \l explicit

    84                 text: "Goodbye"

    85                 color: "red"

    86             }

    87         }

    88 

    89         MouseArea { anchors.fill: parent; onClicked: myText.state = 'myState' }

    90     }

    91     \endqml

    92 

    93     By default, PropertyChanges will establish new bindings where appropriate.

    94     For example, the following creates a new binding for myItem's \c height property.

    95 

    96     \qml

    97     PropertyChanges {

    98         target: myItem

    99         height: parent.height

   100     }

   101     \endqml

   102 

   103     If you don't want a binding to be established (and instead just want to assign

   104     the value of the binding at the time the state is entered),

   105     you should set the PropertyChange's \l{PropertyChanges::explicit}{explicit}

   107     

    89    

   108     State-specific script for signal handlers can also be specified:

    90     A PropertyChanges object can also override the default signal handler

    91     for an object to implement a signal handler specific to the new state:

   117     You can reset a property in a state change by assigning \c undefined. In the following

   100     \note PropertyChanges can be used to change anchor margins, but not other anchor

   118     example we reset \c theText's width when we enter state1. This will give the text its

   101     values; use AnchorChanges for this instead. Similarly, to change an \l Item's

   119     natural width (which is the whole string on one line).

   102     \l {Item::}{parent} value, use ParentChanges instead.

   120 

   103 

   121     \qml

   104 

   122     import Qt 4.7

   105     \section2 Resetting property values

   123 

   106 

   124     Rectangle {

   107     The \c undefined value can be used to reset the property value for a state.

   125         width: 640

   108     In the following example, when \c theText changes to the \e widerText

   126         height: 480

   109     state, its \c width property is reset, giving the text its natural width

   127         Text {

   110     and displaying the whole string on a single line.

   128             id: theText

   111 

   129             width: 50

   112     \snippet doc/src/snippets/declarative/propertychanges.qml reset

   130             wrapMode: Text.WordWrap

   113 

   131             text: "a text string that is longer than 50 pixels"

   114 

   132         }

   115     \section2 Immediate property changes in transitions

   133 

   116 

   134         states: State {

   117     When \l Transitions are used to animate state changes, they animate 

   135             name: "state1"

   118     properties from their values in the current state to those defined in the

   136             PropertyChanges {

   119     new state (as defined by PropertyChanges objects). However, 

   137                 target: theText

   120     it is sometimes desirable to set a property value \e immediately during a 

   138                 width: undefined

   121     \l Transition, without animation; in these cases, the PropertyAction 

   139             }

   122     element can be used to force an immediate property change.

   140         }

   123 

   141     }

   124     See the PropertyAction documentation for more details.

   142     \endqml

   143 

   144     Anchor margins should be changed with PropertyChanges, but other anchor changes or changes to

   145     an Item's parent should be done using the associated change elements

   146     (ParentChange and AnchorChanges, respectively).

   399     

   371 

   400     Whether or not the previous values should be restored when

   372     This property holds whether the previous values should be restored when

   401     leaving the state. By default, restoreEntryValues is true.

   373     leaving the state. 

   402 

   374 

   403     By setting restoreEntryValues to false, you can create a temporary state

   375     The default value is \c true. Setting this value to \c false creates a

   404     that has permanent effects on property values.

   376     temporary state that has permanent effects on property values.