QML Opacity Inheritance

Question

In QML, how can I prevent a child element from inheriting the opacity from its parent? I want to set different opacity values for the parent and it's child element.

Answer 1

I think, one way would be to use semi transparent colors as described here instead of opacity.

e.g. using quad color code like #800000FF for semi transparent blue.

Answer 2

Actually, setting layer.enabled: true for the parent element does the thing for me. The whole element is rendered to the buffer, and opacity is applied to the resulting buffer (to the whole layer at once).

See http://doc.qt.io/qt-5/qml-qtquick-item.html#layer.enabled-prop

Example code:

Rectangle {
    width: 400
    height: 200
    opacity: 0.5
    layer.enabled: true
    Rectangle {
            width: parent.width
            height: parent.height
            color: 'red'
    }
    Rectangle {
            width: parent.width / 2
            height: parent.height
            color: 'blue'
    }
}

That is a solution, but make sure that you know what you are doing when enabling layering.

Another possible solution would be using a shadereffect.

Thanks to peppe on #qt@freenode.