Unable to assign [undefined] to QQuickItem*

Rohith

Hello,

There is small implementation in my code where i am trying to assign a property var to ShaderEffectSource Item, posting the code for better understanding

Screen.qml

Flickable {
        anchors.fill: parent
        contentHeight: flickItem.height
        clip: true
        flickableDirection: Flickable.VerticalFlick
        boundsBehavior: Flickable.StopAtBounds

        Item {
            id: flickItem
            ListView {
                id: list

                delegate: Item {
                       //Some Implementation is there here 
                        ShaderEffectSource {
                            id: option
                            anchors.left: parent.left
                            anchors.top: parent.top
                            anchors.bottom: parent.bottom
                            width: parent.width/2
                            sourceItem: PageRegister.get(index) //getting warning at this line Unable to assign [undefined] to QQuickItem*
                        }

                        Connections {
                            target: PageImageRegistry
                            onItemInserted: {
                                if (itemIndex === index) {
                                    option.sourceItem = PageRegister.get(index)
                                }
                            }
                        } 
                   }
              }
        }
}

PageRegister.qml

pragma Singleton
import QtQuick 2.9

QtObject {

    property var store: new Object
    property string key: "key"

    function get(index) {
        var str = key + index
        return store[str]
    }

    function insert(item, index) {
        var str = key + index
        store[str] = item
        itemInserted(index)
    }
    signal itemInserted(int itemIndex)
}

Can some one please help to resolve the error.

Thanks in advance !!

Regard's,
Rohith.G

J.Hilk

@Rohith said in Unable to assign [undefined] to QQuickItem*:

what is

PageImageRegistry

?

Rohith

Hi @J-Hilk,
Apologies, it should be PageRegister i have corrected the same.

J.Hilk

@Rohith

I thought as much, never the less, you still need an instance of PageRegister and refer to it via the id you give it. It won't work with just the class name :D

Rohith

Hi @J-Hilk
The PageRegister contains a pragma of Singleton, if possible can you please post a sample code. I started to work on qml newly.

Thanks in advance !!

J.Hilk

@Rohith said in Unable to assign [undefined] to QQuickItem*:

The PageRegister contains a pragma of Singleton

oh, didn't see that
didn't know it existed and omg, can't say I like the existence of it either.

are you sure this:

function get(index) {
        var str = key + index
        return store[str]
    }

does what you think it does ?

Rohith

Hi @J-Hilk ,

I hope it does because i am not seeing the warning all the time, and what i understood from the code snippet they are trying to got an object with the selected index value.

Reddy_12

Hi @J-Hilk ,

Can I know how we can get this warning resolved as we cannot create an instance of pageRegister due to pragma of singleton .

May I know if there is any other way to achieve the same.

Thanks in Advance.