Fading to transparent gradient

[Cyna]

Hi, I'm trying to create a dynamic item which edges are fading to transparent same like here https://www.getpaint.net/doc/latest/GradientTool.html (linear gradient example)
I've tried with opacityMask and LinearGradient but in LinearGradient I had to use specific color. At that example https://stackoverflow.com/a/48472948 it looks good as background is white, but in my case background doesnt have solid color.
Do you have any ideas how that can be done?

[Jacob.zhang]

I think you want the result like this:

import QtQuick 2.9
import QtQuick.Window 2.3
import QtGraphicalEffects 1.0

Window {
    visible: true
    width: 500
    height: 500
    title: qsTr("Hello World")

    Image {
        source: "back.jpg"
    }

    Image {
        id: image
        anchors.centerIn: parent
        source: "image.jpg"
        visible: false
    }

    LinearGradient {
        id: mask
        anchors.fill: image
        start: Qt.point(0, 0)
        end: Qt.point(image.width, 0)
        gradient: Gradient {
            GradientStop { position: 0.2; color: "transparent" }
            GradientStop { position: 0.5; color: "white" }
            GradientStop { position: 0.8; color: "transparent" }
        }
        visible: false
    }

    OpacityMask {
        anchors.fill: image
        source: image
        maskSource: mask
    }
}

[Cyna]

@Jacob.zhang That works, so visiblity do the trick. Thanks.