QML Binding Loop when childrenrect is used.

Nitheesh

Hello,
I have a simple application as below :

import QtQuick 2.6
import QtQuick.Window 2.2

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("App1")

    Item {
        id: panel
        anchors.verticalCenter: parent.verticalCenter
        anchors.verticalCenterOffset: 1
        visible: true
        width: childrenRect.width + 11

        Image {
            id: divider
            visible: true
            anchors.horizontalCenter: parent.horizontalCenter
            anchors.verticalCenter: parent.verticalCenter
            source:"/../Desktop/51x51_button_activepressed.png"
        }
    }
}

Problem is i am seeing qml warning "qrc:/main.qml:10:5: QML Item: Binding loop detected for property "width"" on running this piece of code.

If the horizontal and vertical centers are removed form the image, then the code runs without any error.

But there are certain use cases in my actual applications where i wish to retain the horizontal and vertical positioners.

Please help me in understanding binding loop warning upon using "childrenrect.width".

Thanks in advance.

Laszlo LG

The Image calculates its horizontal center from the parent's horizontal center which I guess is calculated from its width but that comes from the child's width so there is a loop.

This is just a wild guess so I hope others will clarify this and let us know where the source codes of the relevant QML definitions are.

dheerendra

Use width: divider.width + 11.

childrenRect looks comes with four parameters including x, y.

J.Hilk

@Nitheesh

Image has also a sourceSize property. you could use that, to get the Image's width

Nitheesh

@dheerendra Thanks a lot!.. Worked alright for me..

Nitheesh

@Laszlo-LG thank you for the explanation