QML - Combobox

[FlyingFish]

Is it possible to construct a combo box using QML? Thank you! :)

[Diph]

Use Text input and ListView. When user types, show filtered ListView.

[andre]

If you are afraid what will happen if the list falls outside of the QML area, then perhaps "this post":http://labs.qt.nokia.com/2011/08/26/toplevel-windows-and-menus-with-qt-quick/ is of interest to you.

[jech]

I'm trying to create a combobox myself. It is somehow working, the biggest problem was to cover items which are bellow the combobox when it gets expanded.

Check this out:

Main.qml
@import QtQuick 1.0

Rectangle {

id: main
width: 200
height: 300
anchors.fill: parent
color: "#343434"


ListModel {
    id: model

    ListElement {
        value: 1
    }

    ListElement {
        value: 2
    }

    ListElement {
        value: 3
    }

    ListElement {
        value: 4
    }

    ListElement {
        value: 5
    }
}

Rectangle {
    id: comboBoxContainer            
    anchors.top: parent.top
    anchors.left: parent.left
    anchors.leftMargin: parent.width/4
    anchors.topMargin: parent.height/6
    width: parent.width/2
    height: parent.height/6
    color: "#343434"
    z: 1

    ComboBox {
        id: comboBox            
        anchors.top: parent.top
        anchors.left: parent.left
        width: main.width/2
        height: main.height/6
        initialText: "1"
        maxHeight: main.height/2
        listModel: model

        onExpanded: {
            comboBoxContainer.height = main.height/3*2
        }    

        onClosed: {
            comboBoxContainer.height = main.height/6
        }    
    }        
}

Text {
    id: gamePriceText
    anchors.bottom: parent.bottom
    anchors.left: parent.left
    anchors.leftMargin: parent.width/4
    anchors.bottomMargin: parent.height/6
    width: parent.width/2
    height: parent.height/6        
    color: "#fff"
    text: "Some text"
    font.pixelSize: 20
    font.bold: true      
}

}@

ComboBox.qml
@import QtQuick 1.0

FocusScope {
id: comboBox

property string initialText
property int maxHeight
property int selectedItem: 0
property variant listModel
signal expanded
signal closed

ComboBoxButton {
    id: comboBoxButton
    width: parent.width
    height: parent.height
    source: "images/down.png"
    borderColor: "#fff"
    radius: 10
    margin: 5
    borderWidth: 2
    text: initialText
    textSize: parent.height-20
    
    onClicked: {
        if (listView.height == 0) {
            listView.height = Math.min(maxHeight, listModel.count*comboBoxButton.height)
            comboBox.expanded()}
        else {
            listView.height = 0
            comboBox.closed()}                
    }
}

Component {
    id: comboBoxDelegate

    Rectangle {
        id: delegateRectangle
        width: comboBoxButton.width
        height: comboBoxButton.height
        color: "#00000000"
        radius: comboBoxButton.radius
        border.width: comboBoxButton.borderWidth
        border.color: comboBoxButton.borderColor

        Item {
            anchors.left: parent.left
            width: parent.width-parent.height-2*comboBoxButton.margin
            anchors.top: parent.top
            anchors.bottom: parent.bottom
            // anchors.leftMargin: comboBoxButton.margin*2
            
            Text {
                //color: "#fff"
                color: index == listView.currentIndex ? "#ffff00" : "#ffffff"
                anchors.centerIn: parent
                font.pixelSize: comboBoxButton.height-20
                text: value
                font.bold: true
            }
        }
        
        MouseArea {
            anchors.fill: parent
            
            onClicked: {
                listView.height = 0
                listView.currentIndex = index
                comboBox.selectedItem = index
                comboBoxButton.text = value
                comboBox.closed()
            }
        }
    }
}

ListView {
    // visible: false
    id: listView
    anchors.top: comboBoxButton.bottom
    anchors.left: comboBoxButton.left
    width: parent.width
    //height: Math.min(maxHeight, listModel.count*comboBoxButton.height)
    height: 0
    clip: true
    model: listModel
    delegate: comboBoxDelegate
    currentIndex: selectedItem

    Behavior on height {
    
        NumberAnimation {
            id: animateHeight
            property: "height"
            //from: 0.99
            //to: 1.0
            //loops: Animation.Infinite
            duration: 200
            easing {type: Easing.Linear}
        }
    }            
}    

}@

[jech]

And the last component:

ComboBoxButton.qml
@import QtQuick 1.0

FocusScope {
id: container
signal clicked
property string source
property string text
property string color: "#ffffff"
property int textSize: 12
property string borderColor: "#00000000"
property int borderWidth: 0
property int radius: 0
property int margin: 0

Rectangle {
    id: buttonRectangle
    anchors.fill: parent
    color: "#00000000"
    radius: container.radius
    border.width: container.borderWidth
    border.color: container.borderColor

    Image {
        id: image
        smooth: true
        fillMode: Image.PreserveAspectFit
        anchors.right: parent.right
        anchors.top: parent.top
        height: parent.height-2*container.margin
        width: parent.height
        anchors.topMargin: container.margin
        anchors.bottomMargin: container.margin
        anchors.leftMargin: container.margin
        anchors.rightMargin: container.margin
        source: container.source 
    }

    Item {
        anchors.left: parent.left
        anchors.right: image.left
        anchors.top: parent.top
        anchors.bottom: parent.bottom
        anchors.leftMargin: container.margin*2
        
        Text {
            color: container.color
            anchors.centerIn: parent
            font.pixelSize: container.textSize
            text: container.text+" "
            font.bold: true
        }
    }

    MouseArea {
        id: mouseArea;
        anchors.fill: parent
        onClicked: {
            buttonRectangle.state = "pressed"
            stateTimer.start()            
            container.clicked()
        }
    }

    states: State {
        name: "pressed"
        PropertyChanges { target: image; scale: 0.7 }
    }

    Timer {
        id: stateTimer
        interval: 200;
        repeat: false
        onTriggered: buttonRectangle.state = 'State0'
    }

    transitions: Transition {
        NumberAnimation { properties: "scale"; duration: 200; easing.type: Easing.InOutQuad }
    }
}

}
@

Put an image file with arrow down to "images/down.png".

[srikanth_trulyit]

How about using "selectionlistitem":http://doc.qt.nokia.com/qt-components-symbian-1.0/qml-selectionlistitem.html with "selection dialog.":http://doc.qt.nokia.com/qt-components-symbian-1.0/qml-selectiondialog.html.

!http://doc.qt.nokia.com/qt-components-symbian-1.0/images//selectionlistitem.png(Looks like this)!

[riaank]

@Andre
Could you elaborate more please. I do not quite understand how the "toplevel window" article will help with for example a listview expanding outside the QML area.

[andre]

Well, basically, the dropdown of a combobox is like a menu or a list view that is layered on top of other windows. Just like menu's and other top level widgets, it may fall outside of the original area of the application. Without the ability to show top level windows, this is a problem. It would be good idea to make sure that a combo box used the top level window facilities (in the same way menus do) to show the list on.

[FlyingFish]

Thank you all for your help :D. I now have a working combo box, but I have a follow-up question regarding the listelement values. How do I use them in an if statement?

e.g. if (listelementvalue == "something")

Thanks again! :)