ListView, PositionViewAtBeginning()

JF002

Hi!

I have a listview. When I click on an item, I clear the model and add new items in the model (from c++).
This works fine, and the listview is updated properly.

The only problem is that the position of the listview is not changed when the model is updated. For example, if I scroll down to the end of the list, click on the last item, then, the list would be updated with new items, but I would still see the last item.
I would like to set the position to the beginning of the list when an item is clicked, but I don't know how to do that...

I tried to call positionViewAtBeginning() and to set currentIndex to 0 with no luck. Any help?

Thanks!

p3c0

Hi,

As per the docs
bq. Note: methods should only be called after the Component has completed. To position the view at startup, this method should be called by Component.onCompleted, viz :
@
Component.onCompleted: positionViewAtBeginning()
@

So are you calling it in the above mentioned way ?

JF002

Yes, I tried to add this line, but it seems that Component.onCompleted is called only once, when the component is created at launch time.

But when I remove/add data from the model, the list is updated accordingly, but onComleted is not called.

So, how to change the position of the list after the component has been created?

p3c0

Hi,

Depending upon your use case i created a small code, it positions the item to the top after clearing the list.
May be this would be useful

@

import QtQuick 2.0

Rectangle {
width: 320; height: 240

ListModel {
    id: model
    ListElement {
        name: "PrePopulated"
        number: "32423434"
    }
    ListElement {
        name: "PrePopulated"
        number: "23423232"
    }
    ListElement {
        name: "PrePopulated"
        number: "23323234"
    }
}

Component {
    id: delegate
    Item {
        width: 320; height: 40
        Column {
            Text { text: '<b>Name:</b> ' + name }
            Text { text: '<b>Number:</b> ' + number }
        }

        MouseArea {
            anchors.fill: parent
            onClicked: {
                //If clicked on last item in list, clear the list and populate the new items
                if(index===view.count-1)
                {
                    console.log(index);
                    addItem();
                }
            }
        }
    }
}

ListView {
    id: view
    anchors.fill: parent
    model: model
    delegate: delegate
    highlight: Rectangle { color: "lightsteelblue"; radius: 5 }
    focus: true
}

//Click to add Items to listview
Text {
    id: add
    text: "Add Item"
    anchors.bottom: parent.bottom
    MouseArea {
        anchors.fill: parent
        onClicked: {
            model.append({name: "ButtonClick", number: Math.floor((Math.random()*10000)+1).toString()} );
            view.positionViewAtEnd();
        }
    }
}

function addItem()
{
    model.clear();
    for(var i=0; i<10; i++)
    {
        var data = {'name': "ItemClicked " + i.toString(), 'number': Math.floor((Math.random()*10000)+1).toString() };
        model.append(data);
        view.positionViewAtBeginning();
    }
}

}

@