GridView, how to position the view at startup?

[Mesrine]

Hello everyone,

I do not know how to set the position of the view when the Gridview becomes visible.

As an example, the following code.qml:

import QtQuick.Layouts
import QtQuick.Controls
import QtQuick
import QtQml


ColumnLayout
{
    RowLayout
    {
        Layout.fillWidth: true
        SpinBox {
            id:spin
            value: 0
            from:0
            to:yearSelector.count-1
            onValueModified:
            {
                yearSelector.positionViewAtIndex(spin.value, GridView.Beginning)
            }
        }
    }

    GridView {
        id:yearSelector
        Layout.fillHeight: true
        Layout.fillWidth: true
        model:     ListModel {

            ListElement {year:0}
            ListElement {year:1}
            ListElement {year:2}
            ListElement {year:3}
            ListElement {year:4}
            ListElement {year:5}
            ListElement {year:6}
            ListElement {year:7}
            ListElement {year:8}
            ListElement {year:9}
            ListElement {year:10}
            ListElement {year:11}
            ListElement {year:12}
            ListElement {year:13}
            ListElement {year:14}
            ListElement {year:15}
            ListElement {year:16}
            ListElement {year:17}
            ListElement {year:18}
            ListElement {year:19}

        }
        cellWidth:yearSelector.width*0.3333
        cellHeight:yearSelector.height*0.5
        //currentIndex :15
        Component.onCompleted: yearSelector.positionViewAtIndex(15, GridView.Beginning)

        delegate:Button {
            text:year
        }


    }

}

shows a GridView with 20 Buttons. The grid view has 3 columns and 7 rows and shows 2 rows at a time.

I was thinking that setting currentIndex :15 will show in the view the button with text= 15 at startup, but this does not work.
Also, when calling Component.onCompleted: yearSelector.positionViewAtIndex(15, GridView.Beginning)
does not show the button with text =15 at startup.

If I change the spinBox value to 15 the GridView shows the button with text =15.

I am testing the type like

~/Qt/6.7.0/gcc_64/bin/qml code.qml

Is this a bug in GridView or i am doing something wrong?
Many thanks for your time.

[jeremy_k]

With a few minor changes to give the window a reasonable size and to some sort of rendering issue, the view starts with index 15 in the upper left corner on my macOS, Qt 6.5.3 installation. This may be a recently introduced bug.

Does the GridView.count property reflect the expected value?

[Mesrine]

@jeremy_k

if I do

Component.onCompleted:
        {
            console.log(yearSelector.count);
            yearSelector.positionViewAtIndex(15, GridView.Beginning)

        }

It prints 20 as expected;
Also, I tried with ~/Qt/6.5.3/gcc_64/bin/qml code.qml and got the same results, what did you change?

[jeremy_k]

import QtQuick.Layouts
import QtQuick.Controls
import QtQuick

ColumnLayout
{
    width: 300
    height: 600
    SpinBox {
        from:0
        to:yearSelector.count-1
        onValueModified: yearSelector.positionViewAtIndex(value, GridView.Beginning)
    }

    GridView {
        id:yearSelector
        Layout.fillHeight: true
        Layout.fillWidth: true
        model: 20
        cellWidth: width / 3
        cellHeight: height / 2
        Component.onCompleted: yearSelector.positionViewAtIndex(15, GridView.Beginning)

        delegate: Text { text: index }
    }
}

My setup (hardware, OS, applications, etc) seems to be particularly sensitive to contrast changes, leading to unreadable highlights and text in some applications. I don't think that the changes mentioned above are altering the behavior, but it's worth trying.