Hi,
I am trying to use a nice scrollbar, where you can swipe the content as well as moving the scrollbar.
This causes a binding loop. I am testing something based on this code :
http://stackoverflow.com/questions/17833103/how-to-create-scrollbar-in-qtquick-2-0
I always get a binding loop error for this part of the code :
Binding {
target: handle;
property: "y";
value: (flickable.contentY * clicker.drag.maximumY / (flickable.contentHeight - flickable.height));
when: (!clicker.drag.active);
}
Binding {
target: flickable;
property: "contentY";
value: (handle.y * (flickable.contentHeight - flickable.height) / clicker.drag.maximumY);
when: (clicker.drag.active || clicker.pressed);
}
it gives me :
file:///….MaScrollBar.qml:37:5: QML Binding: Binding loop detected for property “value”
So I tried to find a way out, make it more obvious to QML that both bindings are mutually exclusive,
but this doesnt work :
Binding {
id: bind1
target: flickable;
property: "contentY";
value: (handle.y * (flickable.contentHeight - flickable.height) / clicker.drag.maximumY);
when: (clicker.drag.active || clicker.pressed);
}
Binding {
id: bind2
target: handle;
property: "y";
value: (flickable.contentY * clicker.drag.maximumY / (flickable.contentHeight - flickable.height));
when: !bind1.when
}
this gives :
QML Binding: Binding loop detected for property “value”
QQmlExpression: Expression file:…./MaScrollBar.qml:42:15 depends on non-NOTIFYable properties:
QQmlBind::when
Would you know a solution to avoid this binding conflict for the scrollbar ?
So when you drag the scrollbar handle, the content needs to move. When you drag the content, scrollbar handle should move.
These situations are mutually exclusive, but qml doesn’t see it.
Maybe there’s a better scrollbar solution, working in a different way ?
↧
