IntegratedTestBench/app/QtGraphicalEffects/private/DropShadowBase.qml

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** This file is part of the Qt Graphical Effects module.
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import QtQuick 2.12
import QtQuick.Window 2.12
import QtGraphicalEffects.private 1.12
import QtGraphicalEffects 1.12

Item {
    id: root

    property variant source
    property real radius: Math.floor(samples / 2)
    property int samples: 9
    property color color: "black"
    property real horizontalOffset: 0
    property real verticalOffset: 0
    property real spread: 0.0
    property bool cached: false
    property bool transparentBorder: true

    GaussianBlur {
        id: blur
        width: parent.width
        height: parent.height
        x: Math.round(horizontalOffset)
        y: Math.round(verticalOffset)
        source: root.source
        radius: root.radius * Screen.devicePixelRatio
        samples: root.samples * Screen.devicePixelRatio
        _thickness: root.spread
        transparentBorder: root.transparentBorder


        _color: root.color;
        _alphaOnly: true
        // ignoreDevicePixelRatio: root.ignoreDevicePixelRatio

        ShaderEffect {
            x: blur._outputRect.x - parent.x
            y: blur._outputRect.y - parent.y
            width: transparentBorder ? blur._outputRect.width : blur.width
            height: transparentBorder ? blur._outputRect.height : blur.height
            property variant source: blur._output;
        }

    }

    ShaderEffectSource {
        id: cacheItem
        x: -blur._kernelRadius + horizontalOffset
        y: -blur._kernelRadius + verticalOffset
        width: blur.width + 2 * blur._kernelRadius
        height: blur.height + 2 * blur._kernelRadius
        visible: root.cached
        smooth: true
        sourceRect: Qt.rect(-blur._kernelRadius, -blur._kernelRadius, width, height);
        sourceItem: blur
        hideSource: visible
    }


}