- Qt 5.5
- Qt Quick
- Qt Quick Particles Examples - System
- dynamiccomparison.qml Example File
- Qt 5.5.1 Reference Documentation

# dynamiccomparison.qml Example File

particles/system/content/dynamiccomparison.qml

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** You may use this file under the terms of the BSD license as follows:
    **
    ** "Redistribution and use in source and binary forms, with or without
    ** modification, are permitted provided that the following conditions are
    ** met:
    **   * Redistributions of source code must retain the above copyright
    **     notice, this list of conditions and the following disclaimer.
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    **     notice, this list of conditions and the following disclaimer in
    **     the documentation and/or other materials provided with the
    **     distribution.
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    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
    **
    **
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    ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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    import QtQuick 2.0
    import QtQuick.Particles 2.0

    Rectangle {
        id: root
        color: "black"
        width: 640
        height: 480
        ParticleSystem {
            id: sys
        }

        ImageParticle {
            system: sys
            source: "qrc:///particleresources/glowdot.png"
            color: "white"
            colorVariation: 1.0
            alpha: 0.1
            entryEffect: ImageParticle.None
        }

        Emitter {
            id: emitter
            system: sys
            width: parent.width/2
            velocity: PointDirection {y: 72; yVariation: 24}
            lifeSpan: 10000
            emitRate: 1000
            enabled: false
            size: 32
        }

        Item {
            id: fakeEmitter
            function burst(number) {
                while (number > 0) {
                    var item = fakeParticle.createObject(root);
                    item.lifeSpan = Math.random() * 5000 + 5000;
                    item.x = Math.random() * (root.width/2) + (root.width/2);
                    item.y = 0;
                    number--;
                }
            }

            Component {
                id: fakeParticle
                Image {
                    id: container
                    property int lifeSpan: 10000
                    width: 32
                    height: 32
                    source: "qrc:///particleresources/glowdot.png"
                    y: 0
                    PropertyAnimation on y {from: -16; to: root.height-16; duration: container.lifeSpan; running: true}
                    SequentialAnimation on opacity {
                        running: true
                        NumberAnimation { from:0; to: 1; duration: 500}
                        PauseAnimation { duration: container.lifeSpan - 1000}
                        NumberAnimation { from:1; to: 0; duration: 500}
                        ScriptAction { script: container.destroy(); }
                    }
                }
            }
        }

        //Hooked to a timer, but click for extra bursts that really stress performance
        Timer {
            interval: 10000
            triggeredOnStart: true
            repeat: true
            running: true
            onTriggered: {
                emitter.burst(1000);
                fakeEmitter.burst(1000);
            }
        }
        Text {
            anchors.left: parent.left
            anchors.bottom: parent.bottom
            text: "1000 particles"
            color: "white"
            MouseArea {
                anchors.fill: parent
                onClicked: emitter.burst(1000);
            }
        }
        Text {
            anchors.right: parent.right
            anchors.bottom: parent.bottom
            text: "1000 items"
            color: "white"
            MouseArea {
                anchors.fill: parent
                onClicked: fakeEmitter.burst(1000);
            }
        }
    }