Howto set property for delegate

Asperamanca

I'm a Qt (C++) vet, but new to QML. I'm displaying a simple model in a TableView. Some of my columns use custom delegates, and I'd like to set some properties on them:

Delegate:

    Component
    {
        id: buttonDelegate
        Item
        {
            anchors.fill: parent
            Button
            {
                id: actionButton
                anchors.centerIn: parent
                width: parent.width * 0.9
                height: parent.height - 2
            }
        }
    }

Use of delegate:

        TableViewColumn
        {
            id: startButtonColumn
            title: "someTitle"
            movable: false
            resizable: false
            width: tableView.width * 0.15
            delegate: buttonDelegate
            // I would like to set the text to the delegate
        }

As per the comment, I'd like to set the text for the button within the delegate from the TableViewColumn, because I use the same delegate for multiple columns (and the button needs different texts).
Preferably, I'd like to set the text as a top-level property of the delegate, something like:

buttonDelegate
{
    buttonText: "SomeText"
}

I have found a couple of posts on similar topics (e.g. on stackoverflow), but frankly, without the necessary background, I don't understand them, and they don't simply work for me through copy-paste.

J.Hilk

hi, @Asperamanca

I haven't jet touch a TableView myself, but I try to explain the principles, as I understand them, on a very simply ListView

lets asume an array/List of strings as your model:

ListView{
    model: ["Item1", "Item2", "Item3"]
}

and a custom delegate that as a text-property you want to set to the correlating item: You can access the current model-item via modelData

ListView{
    model: ["Item1", "Item2", "Item3"]

    delegate: FancyViewItem{
         text:modelData
   }
}

A bit more complex example:
Lets asume you create a QList<QObjects> in a cpp BackEnd and you want to create a Listview based on that List. Also let's asume QObject is a QObject derived class with the Q_PROPERTYs filePath, fileName and createdAt

ListView{
    model: cppBackEnd.fileModel//fileModel == Q_PROPERTY(QVariant fileModel READ .... WRITE.... NOTIFY....)

    delegate: FancyViewItem{
         textPath: modelData.filePath
         textFileName: modelData.fileName 
         timeStamp: modelData.createdAt
   }
}

Asperamanca

@J.Hilk said in Howto set property for delegate:

FancyViewItem

Thanks for your reply.
Could I re-use FancyViewItem in multiple columns? I want to avoid defining a lengthy delegate multiple times, with 90 % identical definition, and only one or two properties that differ by column.

J.Hilk

@Asperamanca said in Howto set property for delegate:

Could I re-use FancyViewItem in multiple columns? I want to avoid defining a lengthy delegate multiple times, with 90 % identical definition, and only one or two properties that differ by column.

sure, thats what I usually do.

I create an "external" .qml file with the name FancyViewItem

//FancyViewItem.qml
import QtQuick 2.9

Item{
     property text: "This is a text property"
     .....
}

as long as your qml file is in the same directory as the main file you can simply write

FancyViewItem{

}

to create a new "instance" of that item

if its in a different directory, you'll have to import that directory

import "qrc:/qml/FancyViewItemDir"

make sure you use a Capital letter in the beginning of your *.qml file!!!!

Asperamanca

Thanks again.
Does the filename have to match the item name? Because that runs counter to the naming conventions I follow. Or is there a way I define the the name 'FancyViewItem' somewhere within the file, and still import and use it?

J.Hilk

@Asperamanca said in Howto set property for delegate:

Thanks again.
Does the filename have to match the item name? Because that runs counter to the naming conventions I follow. Or is there a way I define the the name 'FancyViewItem' somewhere within the file, and still import and use it?

Ok, here's where my knowledge ends x)

But, as far as I know:

Filename = Itemname (-.qml)

and

you would have to copy&past the definition everytime if you do it inside a single file.

Asperamanca

So I solved the initial problem:

Delegate in separate file lpad_buttondelegate.qml:

Item
{
    anchors.fill: parent
    Button
    {
        id: actionButton
        anchors.centerIn: parent
        width: parent.width * 0.9
        text: buttonText
    }
}

Use of delegate:

        TableViewColumn
        {
            id: startButtonColumn
            title: "SomeTitle"
            movable: false
            resizable: false
            width: tableView.width * 0.15
            delegate: Loader
            {
                property string buttonText: "Start"
                source: "lpad_buttondelegate.qml"
            }
        }

New problems abound...but not in this thread.

J.Hilk

@Asperamanca
great, keep on coding! and good luck ;-)

Because I noticed increased reminders about this, don't forget to set the topic to solved :)