[Qt-qml] property "alias" on run-time

[Leonardo Cunha]

hi,

the switches example in qt-components/examples/gallery does exactly what you
want:

Item {
    Grid {
        anchors.fill: parent

        Switch {
            id: switch1
        }

        Label {
            text: "First switch is " + (switch1.enabled ? "ENABLED" :
"Disabled")
        }

        Switch {
            id: switch2
        }

        Label {
            text: "Second switch is " + (switch2.enabled ? "ENABLED" :
"Disabled")
        }

        Switch {
            id: bindSwitch

            Binding {
                target: switch1
                property: "enabled"
                value: switch2.enabled
                when: bindSwitch.enabled
            }

            Binding {
                target: switch2
                property: "enabled"
                value: switch1.enabled
                when: bindSwitch.enabled
            }
        }

        Label {
            text: "Bind the values of the two switches above"
        }
    }
}


br,
// leo

From: qt-qml-bounces at trolltech.com [mailto:qt-qml-bounces at trolltech.com] On
Behalf Of Jokela Pekka.E (Nokia-MS/Tampere)
Sent: Thursday, September 02, 2010 7:16 AM
To: qt-qml at trolltech.com
Subject: [Qt-qml] property "alias" on run-time

 
Hi,
 
I have a two properties
property var A
property var B
 
and I’d like to have them equal when condition C is met i.e. two way binding
i.e. as “property alias B: A”
 
So, when C is met:
-changing A changes B to be equal to A
-changing B changes A to be equal to B
 
When C is not met, the A and B can be changed independently without changing
each other.
 
I tried something like:
 
    states: [
        State {
            name: "C met"
            when: C == true
            PropertyChanges { A: B }
            PropertyChanges { B: A }
        }
    ]
 
But I think the latter one cancels the first one to avoid infinite loops.
Any pointers?