ListView Item Manual Positioning Animations QML

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Manual ListView Item Positioning

Introduction

Let's say for instance instead of wanting a plain ListView with its items laid out horizontally and linearly, you instead want a list to respond so that when one item is selected, that item animates towards a different position (lower y value). This item is singled out and when a different item is selected, they swap places. This was useful for my case of KDE's login manager theme, where the items were user face images.

Implementation

Here we create a ListView, a simple array just as filler for what your model will actually be, a delegate with an image and text item, and then we manually set the y and x position of them.

QML Code

<br />import QtQuick 1.0

Item {<br /> width: 600<br /> height: 600<br /> property int itemWidth: 50

ListView {<br /> id: view<br /> model: new Array(1,2,3,4,5,6,7,8)<br /> delegate: item<br /> anchors {<br /> top: parent.top;<br /> topMargin: 10;<br /> horizontalCenter:<br /> parent.horizontalCenter;<br /> bottom:<br /> parent.bottom;<br /> }<br /> width: model.length * itemWidth + (model.length - 1) * spacing<br /> spacing: 2<br /> orientation: Qt.Horizontal<br /> snapMode: ListView.SnapOneItem<br /> highlightRangeMode: ListView.ApplyRange<br /> interactive: false<br /> Component.onCompleted: currentIndex = <s>1;<br /> }

<br /> Component {<br /> id: item
<br /> Rectangle {<br /> width: itemWidth<br /> height: 50<br /> color: &quot;red&amp;quot;<br /> x: {<br /> if (ListView.isCurrentItem) {<br /> if (view.flickingHorizontally) {<br /> (view.width/2)</s> (width/2)<br /> } else {<br /> (view.width/2)-(width/2)<br /> }<br /> } else {<br /> if ( view.currentIndex==<s>1) {<br /> index * (width + view.spacing)<br /> } else {<br /> if ( index &lt; view.currentIndex) {<br /> index * (width + view.spacing) + (width/2)<br /> } else {<br /> index * (width + view.spacing)</s> (width/2)<br /> }<br /> }<br /> }<br /> }<br /> y: ListView.isCurrentItem ? 200 : 0<br /> Behavior on x { SpringAnimation { spring: 4; damping: 0.4 } }<br /> Behavior on y { SpringAnimation { spring: 4; damping: 0.4 } }

Text {<br /> text: model.index<br /> }

MouseArea {<br /> anchors.fill: parent<br /> onClicked: {<br /> if (!ListView.isCurrentItem)<br /> view.currentIndex = index;<br /> else<br /> view.currentIndex = –1;<br /> }<br /> }<br /> }<br /> }<br />}<br />