Loading...

XML

Word

Printable

Details

Type: Bug
Resolution: Fixed
Priority: P1: Critical
Fix Version/s: 6.5.6, 6.5, 6.6.3, 6.7.0 RC, 6.8.0 FF
Affects Version/s: 6.4, 6.6.1
Component/s: QML: Declarative and Javascript Engine
Labels:
- Reported_by_support_standard

Platform/s:

Linux/X11
Commits:
98ecc9adb (dev), a262824c2 (6.7), ae9905b0c (6.6), 7cfd1ac42 (tqtc/lts-6.5)

Description

In case when we have initial binding to some "var" property with function and trying to change this binding using Binding QML type to another function restoring of original value will not happen after Binding was activated twice (same with arrays).

Please take a look at the video: simplescreenrecorder-2024-02-24_00.19.01.mkv

First row is function replaced by binding to another function. As you can see after change is done twice original value is never restored.
Second row is about array and there is the same issue.
Third row about array, but original value is not plain value, but a binding and everything works fine.
Fourth row about function, but value inside the Binding component is null instead of another function and in this case everything works as expected as well

Please see the example from the video:

import QtQuick
import QtQuick.Controls
Window {
    width: 640
    height: 800
    visible: true
    title: qsTr("Hello World")
    Item {
        id: root
        width: parent.width
        height: 200
        property var func: function() {
            console.log("func original");
        }
        property bool funcSwitcher: false
        Binding {
            root.func: function() {
                console.log("func imposter");
            }
            when: root.funcSwitcher
            restoreMode: Binding.RestoreBindingOrValue
        }
        Row {
            Button {
                text: "call func"
                onClicked: {
                    root.func();
                }
            }
            Button {
                text: "switch func isImposter: " + root.funcSwitcher
                onClicked: {
                    root.funcSwitcher = !root.funcSwitcher;
                }
            }
        }
    }
    Item {
        id: root2
        anchors.top: root.bottom
        width: parent.width
        height: 200
        property var func: [1, 2, 3]
        property bool funcSwitcher: false
        Binding {
            root2.func: [1, 2]
            when: root2.funcSwitcher
            restoreMode: Binding.RestoreBindingOrValue
        }
        Row {
            Button {
                text: "call func"
                onClicked: {
                    console.log(root2.func)
                }
            }
            Button {
                text: "switch func isImposter: " + root2.funcSwitcher
                onClicked: {
                    root2.funcSwitcher = !root2.funcSwitcher;
                }
            }
        }
    }
    Item {
        id: root3
        anchors.top: root2.bottom
        width: parent.width
        height: 200
        property var func: !root3.funcSwitcher ? [1, 2, 3] : []
        property bool funcSwitcher: false
        Binding {
            root3.func: [1, 2]
            when: root3.funcSwitcher
            restoreMode: Binding.RestoreBindingOrValue
        }
        Row {
            Button {
                text: "call func"
                onClicked: {
                    console.log(root3.func)
                }
            }
            Button {
                text: "switch func isImposter: " + root3.funcSwitcher
                onClicked: {
                    root3.funcSwitcher = !root3.funcSwitcher;
                }
            }
        }
    }
    Item {
        id: root4
        anchors.top: root3.bottom
        width: parent.width
        height: 200
        property var func: function() {
            console.log("func original");
        }
        property bool funcSwitcher: false
        Binding {
            root4.func: null
            when: root4.funcSwitcher
            restoreMode: Binding.RestoreBindingOrValue
        }
        Row {
            Button {
                text: "call func"
                onClicked: {
                    root4.func();
                }
            }
            Button {
                text: "switch func isImposter: " + root4.funcSwitcher
                onClicked: {
                    root4.funcSwitcher = !root4.funcSwitcher;
                }
            }
        }
    }
}