QML ListView hidden delegate item

Question

Is there any way to hide certain item in ListView?

import QtQuick 2.4
import QtQuick.Controls 1.3
import QtQuick.Window 2.2

ApplicationWindow {
    title: qsTr("Hello World")
    width: 640
    height: 480
    visible: true



    ListView {
        anchors.fill: parent

        model: ListModel {
            ListElement { color: "red"; visible: true}
            ListElement { color: "green"; visible: false}
            ListElement { color: "blue"; visible: true}
        }

        delegate: Rectangle {
            width: parent.width
            height: model.visible ? 30 : 0
            color: model.color
            visible: model.visible
            enabled: model.visible
        }
    }
}

Solution above would be good if only ListView could ignore invisible Items' height.

Setting height to 0 manually is bad for performance so I need a better solution. Could you help me?

Answer 1

I hope this will solve the problem. For a beginner like me, solving this question has helped in understanding qml a bit more.

import QtQuick 2.2
import QtQuick.Controls 1.1
import QtQuick.Window 2.0

ApplicationWindow {
    width: 640
    height: 480
    visible: true

ListView {
    id: displayListView
    anchors.fill: parent
    model: displayDelegateModel
}

ListModel {
    id: myModel
    ListElement { colo: "orange"; visible: true}
    ListElement { colo: "red"; visible: false}
    ListElement { colo: "white"; visible: true}
    ListElement { colo: "black"; visible: false}
    ListElement { colo: "green"; visible: true}
    ListElement { colo: "yellow"; visible: false}
}

VisualDataModel {
    id: displayDelegateModel

    delegate:  Rectangle {
        width: parent.width
        height: 30
        color: colo

        Text {
            text: colo
            anchors.centerIn: parent
            font.bold: true
            font.pixelSize: 20
        }
    }

    model: myModel

    groups: [
        VisualDataGroup {
            includeByDefault: false
            name: "visible"
        }
    ]

    filterOnGroup: "visible"

    Component.onCompleted: {
        var rowCount = myModel.count;
        items.remove(0,rowCount);
        for( var i = 0;i < rowCount;i++ ) {
            var entry = myModel.get(i);
            if(entry.visible == true) {
                items.insert(entry, "visible");
            }
        }
    }
}
}

Answer 2

import QtQuick 2.2
import QtQuick.Controls 1.1
import QtQuick.Window 2.0

ApplicationWindow {
    width: 640
    height: 480
    visible: true
    property var model_items:[
        {id: 0,  _color: "red"     , _visible: true},
        {id: 1,  _color: "blue"    , _visible: false},
        {id: 2,  _color: "yellow"  , _visible: true},
        {id: 3,  _color: "gray"    , _visible: true},
    ]
    ListView {
        id: displayListView
        anchors.fill: parent
        model: myModel
        delegate: Rectangle{
            id: rec
            width: 200
            height: 200
            color: _color
        }
    }
    function createModel(){
        myModel.clear()
        for(var i=0;i<model_items.legth; i++)
            if(model_items[i]._visible)
                myModel.append(model_items[i])
    }

    ListModel {
        id: myModel
    }

    Component.onCompleted: {
        createModel()
    }
}

Answer 3

You can use QSortFilterProxyModel to filter values:

m_filterModel->setSourceModel(m_model);