Change layout attached properties

Eligijus

Hello,
I want to change mBlueRect Layout.maximumHeight property in main.qml how can this be accomplished?

//main.qml
import QtQuick 2.6
import QtQuick.Window 2.2

Window {
    visible: true
    width: 640
    height: 480

    Test {
        anchors.fill: parent
        blueRect.Layout.maximumHeight: 100 //This doesn't work
    }
}

//Test.qml
import QtQuick 2.6
import QtQuick.Layouts 1.3

ColumnLayout {
    property alias blueRect: mBlueRect

    Rectangle {
        id: redRect
        Layout.fillHeight: true
        Layout.fillWidth: true
        color: "red"
    }
    Rectangle {
        id: mBlueRect
        Layout.fillHeight: true
        Layout.fillWidth: true
        Layout.maximumHeight: 20
        color: "blue"
    }
}

Eeli K

@Eligijus Try:

//main.qml
...
Test {
        anchors.fill: parent
        maxH: 100
    }
...
//Test.qml
...
ColumnLayout {
property int maxH: 20
...
Layout.maximumHeight: maxH

Eligijus

@Eeli-K Thanks. But why can't I write something like this?

property alias myMax: Layout.maximumHeight

Eeli K

@Eligijus I think attached properties just behave differently. They are available only for the object they are attached to and can't be aliased, either. We have to live with that.

Syntactically and semantically this "Layout" or "Layout.maximumHeight" isn't a property of the object which uses it. Therefore you can't refer to it like to object's own properties.