Customizing Qt Quick Controls 2

Qt Quick Controls 2 consist of a hierarchy (tree) of items. In order to provide a custom look and feel, the default QML implementation of each item can be replaced with a custom one.

Customizing a Control

Sometimes you'll want to create a "one-off" look for a specific part of your UI, and use a complete style everywhere else. Perhaps you're happy with the style you're using, but there's a certain button that has some special significance.

The first way to create this button is to simply define it in-place, wherever it is needed. For example, perhaps you're not satisfied with the default style's Button having square corners. To make them rounded, you can override the background item and set the radius property of Rectangle:

import QtQuick 2.6
import QtQuick.Controls 2.1

ApplicationWindow {
    width: 400
    height: 400
    visible: true

    Button {
        id: button
        text: "A Special Button"
        background: Rectangle {
            implicitWidth: 100
            implicitHeight: 40
            color: button.down ? "#d6d6d6" : "#f6f6f6"
            border.color: "#26282a"
            border.width: 1
            radius: 4
        }
    }
}

The second way to create the button is good if you plan to use your rounded button in several places. It involves moving the code into its own QML file within your project.

For this approach, we'll copy the background code from the default style's Button.qml. This file can be found in the following path in your Qt installation:

$QTDIR/qml/QtQuick/Controls.2/Button.qml

After doing that, we'll simply add the following line:

radius: 4

To avoid confusion with the controls in the module itself, we'll call the file MyButton.qml. To use the control in your application, refer to it by its filename:

import QtQuick.Controls 2.1

ApplicationWindow {
    MyButton {
        text: qsTr("A Special Button")
    }
}

The third way to create the button is a bit more structured, both in terms of where the file sits in the file system and how it is used in QML. First, copy an existing file as you did above, but this time, put it into a subfolder in your project named (for example) controls. To use the control, first import the folder into a namespace:

import QtQuick.Controls 2.1
import "controls" as MyControls

ApplicationWindow {
    MyControls.Button {
        text: qsTr("A Special Button")
    }
}

As you now have the MyControls namespace, you can name the controls after their actual counterparts in the Qt Quick Controls 2 module. You can repeat this process for any control that you wish to add.

An added benefit of these three methods is that it's not necessary to implement the template from scratch.

Creating a Custom Style

There are several ways to go about creating your own styles. Below, we'll explain the various approaches.

Definition of a Style

In Qt Quick Controls 2, a style is essentially an interchangeable set of QML files within a single directory. There are three requirements for a style to be usable:

• At least one QML file whose name matches a control (for example, Button.qml) must exist.
• Each QML file must contain the relevant type from the QtQuick.Templates import as the root item. For example, Button.qml must contain a Button template as its root item.

  If we instead used the corresponding type from the QtQuick.Controls import as we did in the previous section, it would not work: the control we were defining would try to derive from itself.

• The files must be in a directory in the filesystem or in the resource system.

  For example, these are all valid paths to a style:

  • ./myapp -style /home/absolute/path/to/my/style
  • ./myapp -style :/mystyle
  • ./myapp -style relative/path/to/my/style
  • ./myapp -style MyStyle

  The third and fourth paths will be looked up within the QML engine's import path list. This is the same as what happens when you pass Material as the style, for example.

By default, the styling system uses the Default style as a fallback for controls that aren't implemented. To customize or extend any other built-in style, it is possible to specify a different fallback style using QQuickStyle.

What this means is that you can implement as many controls as you like for your custom style, and place them almost anywhere. It also allows users to create their own styles for your application.

Previewing Custom Styles in Qt Quick Designer

Using the approach above, it is possible to preview a custom style in Qt Quick Designer. In order to do so, ensure that the project has a qtquickcontrols2.conf file, and that the following entry exists:

[Controls]
Style=MyStyle

For more information, take a look at the Flat Style example.

Style-specific C++ Extensions

Sometimes you may need to use C++ to extend your custom style. There are two ways to expose such types to QML:

• If the style that uses the type is the only style used by an application, it's enough to register it with the QML engine via qmlRegisterType():

  qmlRegisterType<ACoolCppItem>("MyApp", 1, 0, "ACoolItem");

  See Using C++ Data From QML for more information about this.

• If the style that uses the type is one of many styles used by an application, it may be better to only register it when necessary. This is the point at which it would make sense to implement your own QML plugin.

  Using a plugin as part of your style is not that much different from using a set of QML files. The only difference is that the plugin and its qmldir file must be present in the same directory as the QML files.

Attached properties

It is common for a style to have certain properties or attributes that apply to all controls. Attached properties are a great way of extending an item in QML without having to modify any existing C++ belonging to that item. For example, both the Material and Universal styles have an attached theme property that controls whether an item and its children will be rendered in a light or dark theme.

As an example, let's add an attached property that controls elevation. Our style will illustrate the elevation with a drop shadow; the higher the elevation, the larger the shadow.

The first step is to create a new Qt Quick Controls 2 application in Qt Creator. After that, we add a C++ type that stores the elevation. Since the type will be used for every control supported by our style, and because we may wish to add other attached properties later on, we'll call it MyStyle. Here is MyStyle.h:

#ifndef MYSTYLE_H
#define MYSTYLE_H

#include <QObject>
#include <QtQml>

class MyStyle : public QObject
{
    Q_OBJECT
    Q_PROPERTY(int elevation READ elevation WRITE setElevation NOTIFY elevationChanged)

public:
    explicit MyStyle(QObject *parent = nullptr);

    static MyStyle *qmlAttachedProperties(QObject *object);

    int elevation() const;
    void setElevation(int elevation);

signals:
    void elevationChanged();

private:
    int m_elevation;
};

QML_DECLARE_TYPEINFO(MyStyle, QML_HAS_ATTACHED_PROPERTIES)

#endif // MYSTYLE_H

MyStyle.cpp:

#include "mystyle.h"

MyStyle::MyStyle(QObject *parent) :
    QObject(parent),
    m_elevation(0)
{
}

MyStyle *MyStyle::qmlAttachedProperties(QObject *object)
{
    return new MyStyle(object);
}

int MyStyle::elevation() const
{
    return m_elevation;
}

void MyStyle::setElevation(int elevation)
{
    if (elevation == m_elevation)
        return;

    m_elevation = elevation;
    emit elevationChanged();
}

The MyStyle type is special in the sense that it shouldn't be instantiated, but rather used for its attached properties. For that reason, we register it in the following manner in main.cpp:

#include <QGuiApplication>
#include <QQmlApplicationEngine>

#include "mystyle.h"

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QGuiApplication app(argc, argv);

    qmlRegisterUncreatableType<MyStyle>("MyStyle", 1, 0, "MyStyle", "MyStyle is an attached property");

    QQmlApplicationEngine engine;
    engine.load(QUrl(QLatin1String("qrc:/main.qml")));

    return app.exec();
}

We then copy Button.qml from the Default style in $QTDIR/qml/QtQuick/Controls.2/ into a new myproject folder in our project directory. Add the newly copied Button.qml to qml.qrc, which is the resource file that contains our QML files.

Next, we add a drop shadow to the background delegate of the Button:

// ...
import QtGraphicalEffects 1.0
import MyStyle 1.0
// ...

background: Rectangle {
    // ...

    layer.enabled: control.enabled && control.MyStyle.elevation > 0
    layer.effect: DropShadow {
        verticalOffset: 1
        color: control.visualFocus ? "#330066ff" : "#aaaaaa"
        samples: control.MyStyle.elevation
        spread: 0.5
    }
}

Note that we:

• Don't bother using the drop shadow when the elevation is 0
• Change the shadow's color depending on whether or not the button has focus
• Make the size of the shadow depend on the elevation

To try out the attached property, we create a Row with two Buttons in main.qml:

import QtQuick 2.6
import QtQuick.Controls 2.1

import MyStyle 1.0

ApplicationWindow {
    id: window
    width: 400
    height: 400
    visible: true

    Row {
        spacing: 20
        anchors.centerIn: parent

        Button {
            text: "Button 1"
        }
        Button {
            text: "Button 2"
            MyStyle.elevation: 10
        }
    }
}

One button has no elevation, and the other has an elevation of 10.

With that in place, we can run our example. To tell the application to use our new style, we pass -style :/mystyle as an application argument, but there are many ways to specify the style to use.

The end result:

Note that the import MyStyle 1.0 statement is only necessary because we are using the attached property belonging to MyStyle. Both buttons will use our custom style, even if we were to remove the import.

Customization Reference

The following snippets present examples where the default style's controls have been customized using the same approach as the Customizing a Control section. The code can be used as a starting point to implement a custom look and feel.

Customizing ApplicationWindow

ApplicationWindow consists of one visual item: background. It is also possible to customize the modal and modeless items.

import QtQuick 2.7
import QtQuick.Controls 2.0

ApplicationWindow {
    visible: true

    background: Rectangle {
        gradient: Gradient {
            GradientStop { position: 0; color: "#ffffff" }
            GradientStop { position: 1; color: "#c1bbf9" }
        }
    }

    overlay.modal: Rectangle {
        color: "#8f28282a"
    }

    overlay.modeless: Rectangle {
        color: "#2f28282a"
    }
}

Customizing BusyIndicator

BusyIndicator consists of two visual items: background and contentItem.

import QtQuick 2.6
import QtQuick.Controls 2.1

BusyIndicator {
    id: control

    contentItem: Item {
        implicitWidth: 64
        implicitHeight: 64

        Item {
            id: item
            x: parent.width / 2 - 32
            y: parent.height / 2 - 32
            width: 64
            height: 64
            opacity: control.running ? 1 : 0

            Behavior on opacity {
                OpacityAnimator {
                    duration: 250
                }
            }

            RotationAnimator {
                target: item
                running: control.visible && control.running
                from: 0
                to: 360
                loops: Animation.Infinite
                duration: 1250
            }

            Repeater {
                id: repeater
                model: 6

                Rectangle {
                    x: item.width / 2 - width / 2
                    y: item.height / 2 - height / 2
                    implicitWidth: 10
                    implicitHeight: 10
                    radius: 5
                    color: "#21be2b"
                    transform: [
                        Translate {
                            y: -Math.min(item.width, item.height) * 0.5 + 5
                        },
                        Rotation {
                            angle: index / repeater.count * 360
                            origin.x: 5
                            origin.y: 5
                        }
                    ]
                }
            }
        }
    }
}

Customizing Button

Button consists of two visual items: background and content item.

import QtQuick 2.6
import QtQuick.Controls 2.1

Button {
    id: control
    text: qsTr("Button")

    contentItem: Text {
        text: control.text
        font: control.font
        opacity: enabled ? 1.0 : 0.3
        color: control.down ? "#17a81a" : "#21be2b"
        horizontalAlignment: Text.AlignHCenter
        verticalAlignment: Text.AlignVCenter
        elide: Text.ElideRight
    }

    background: Rectangle {
        implicitWidth: 100
        implicitHeight: 40
        opacity: enabled ? 1 : 0.3
        border.color: control.down ? "#17a81a" : "#21be2b"
        border.width: 1
        radius: 2
    }
}

Customizing CheckBox

CheckBox consists of three visual items: background, contentItem and indicator.

import QtQuick 2.6
import QtQuick.Controls 2.1

CheckBox {
    id: control
    text: qsTr("CheckBox")
    checked: true

    indicator: Rectangle {
        implicitWidth: 26
        implicitHeight: 26
        x: control.leftPadding
        y: parent.height / 2 - height / 2
        radius: 3
        border.color: control.down ? "#17a81a" : "#21be2b"

        Rectangle {
            width: 14
            height: 14
            x: 6
            y: 6
            radius: 2
            color: control.down ? "#17a81a" : "#21be2b"
            visible: control.checked
        }
    }

    contentItem: Text {
        text: control.text
        font: control.font
        opacity: enabled ? 1.0 : 0.3
        color: control.down ? "#17a81a" : "#21be2b"
        verticalAlignment: Text.AlignVCenter
        leftPadding: control.indicator.width + control.spacing
    }
}

Customizing CheckDelegate

CheckDelegate consists of three visual items: background, contentItem and indicator.

import QtQuick 2.6
import QtQuick.Controls 2.1

CheckDelegate {
    id: control
    text: qsTr("CheckDelegate")
    checked: true

    contentItem: Text {
        rightPadding: control.indicator.width + control.spacing
        text: control.text
        font: control.font
        opacity: enabled ? 1.0 : 0.3
        color: control.down ? "#17a81a" : "#21be2b"
        elide: Text.ElideRight
        verticalAlignment: Text.AlignVCenter
    }

    indicator: Rectangle {
        implicitWidth: 26
        implicitHeight: 26
        x: control.width - width - control.rightPadding
        y: control.topPadding + control.availableHeight / 2 - height / 2
        radius: 3
        color: "transparent"
        border.color: control.down ? "#17a81a" : "#21be2b"

        Rectangle {
            width: 14
            height: 14
            x: 6
            y: 6
            radius: 2
            color: control.down ? "#17a81a" : "#21be2b"
            visible: control.checked
        }
    }

    background: Rectangle {
        implicitWidth: 100
        implicitHeight: 40
        visible: control.down || control.highlighted
        color: control.down ? "#bdbebf" : "#eeeeee"
    }
}

Customizing ComboBox

ComboBox consists of background, content item, popup, indicator, and delegate.

import QtQuick 2.6
import QtQuick.Controls 2.1

ComboBox {
    id: control
    model: ["First", "Second", "Third"]

    delegate: ItemDelegate {
        width: control.width
        contentItem: Text {
            text: modelData
            color: "#21be2b"
            font: control.font
            elide: Text.ElideRight
            verticalAlignment: Text.AlignVCenter
        }
        highlighted: control.highlightedIndex === index
    }

    indicator: Canvas {
        id: canvas
        x: control.width - width - control.rightPadding
        y: control.topPadding + (control.availableHeight - height) / 2
        width: 12
        height: 8
        contextType: "2d"

        Connections {
            target: control
            onPressedChanged: canvas.requestPaint()
        }

        onPaint: {
            context.reset();
            context.moveTo(0, 0);
            context.lineTo(width, 0);
            context.lineTo(width / 2, height);
            context.closePath();
            context.fillStyle = control.pressed ? "#17a81a" : "#21be2b";
            context.fill();
        }
    }

    contentItem: Text {
        leftPadding: 0
        rightPadding: control.indicator.width + control.spacing

        text: control.displayText
        font: control.font
        color: control.pressed ? "#17a81a" : "#21be2b"
        verticalAlignment: Text.AlignVCenter
        elide: Text.ElideRight
    }

    background: Rectangle {
        implicitWidth: 120
        implicitHeight: 40
        border.color: control.pressed ? "#17a81a" : "#21be2b"
        border.width: control.visualFocus ? 2 : 1
        radius: 2
    }

    popup: Popup {
        y: control.height - 1
        width: control.width
        implicitHeight: contentItem.implicitHeight
        padding: 1

        contentItem: ListView {
            clip: true
            implicitHeight: contentHeight
            model: control.popup.visible ? control.delegateModel : null
            currentIndex: control.highlightedIndex

            ScrollIndicator.vertical: ScrollIndicator { }
        }

        background: Rectangle {
            border.color: "#21be2b"
            radius: 2
        }
    }
}

Customizing DelayButton

DelayButton consists of two visual items: background and content item.

import QtQuick 2.6
import QtQuick.Controls 2.2

DelayButton {
    id: control
    checked: true
    text: qsTr("Delay\nButton")

    contentItem: Text {
        text: control.text
        font: control.font
        opacity: enabled ? 1.0 : 0.3
        color: "white"
        horizontalAlignment: Text.AlignHCenter
        verticalAlignment: Text.AlignVCenter
        elide: Text.ElideRight
    }

    background: Rectangle {
        implicitWidth: 100
        implicitHeight: 100
        opacity: enabled ? 1 : 0.3
        color: control.down ? "#17a81a" : "#21be2b"
        radius: size / 2

        readonly property real size: Math.min(control.width, control.height)
        width: size
        height: size
        anchors.centerIn: parent

        Canvas {
            id: canvas
            anchors.fill: parent

            Connections {
                target: control
                onProgressChanged: canvas.requestPaint()
            }

            onPaint: {
                var ctx = getContext("2d")
                ctx.clearRect(0, 0, width, height)
                ctx.strokeStyle = "white"
                ctx.lineWidth = parent.size / 20
                ctx.beginPath()
                var startAngle = Math.PI / 5 * 3
                var endAngle = startAngle + control.progress * Math.PI / 5 * 9
                ctx.arc(width / 2, height / 2, width / 2 - ctx.lineWidth / 2 - 2, startAngle, endAngle)
                ctx.stroke()
            }
        }
    }
}

Customizing Dial

Dial consists of two visual items: background and handle.

import QtQuick 2.6
import QtQuick.Controls 2.1

Dial {
    id: control
    background: Rectangle {
        x: control.width / 2 - width / 2
        y: control.height / 2 - height / 2
        width: Math.max(64, Math.min(control.width, control.height))
        height: width
        color: "transparent"
        radius: width / 2
        border.color: control.pressed ? "#17a81a" : "#21be2b"
        opacity: control.enabled ? 1 : 0.3
    }

    handle: Rectangle {
        id: handleItem
        x: control.background.x + control.background.width / 2 - width / 2
        y: control.background.y + control.background.height / 2 - height / 2
        width: 16
        height: 16
        color: control.pressed ? "#17a81a" : "#21be2b"
        radius: 8
        antialiasing: true
        opacity: control.enabled ? 1 : 0.3
        transform: [
            Translate {
                y: -Math.min(control.background.width, control.background.height) * 0.4 + handleItem.height / 2
            },
            Rotation {
                angle: control.angle
                origin.x: handleItem.width / 2
                origin.y: handleItem.height / 2
            }
        ]
    }
}

Customizing Drawer

Drawer can have a visual background item.

background: Rectangle {
    Rectangle {
        x: parent.width - 1
        width: 1
        height: parent.height
        color: "#21be2b"
    }
}

Customizing Frame

Frame consists of one visual item: background.

import QtQuick 2.6
import QtQuick.Controls 2.1

Frame {
    background: Rectangle {
        color: "transparent"
        border.color: "#21be2b"
        radius: 2
    }

    Label {
        text: qsTr("Content goes here!")
    }
}

Customizing GroupBox

GroupBox consists of two visual items: background and label.

import QtQuick 2.6
import QtQuick.Controls 2.1

GroupBox {
    id: control
    title: qsTr("GroupBox")

    background: Rectangle {
        y: control.topPadding - control.bottomPadding
        width: parent.width
        height: parent.height - control.topPadding + control.bottomPadding
        color: "transparent"
        border.color: "#21be2b"
        radius: 2
    }

    label: Label {
        x: control.leftPadding
        width: control.availableWidth
        text: control.title
        color: "#21be2b"
        elide: Text.ElideRight
    }

    Label {
        text: qsTr("Content goes here!")
    }
}

Customizing ItemDelegate

ItemDelegate consists of two visual items: background and content item.

import QtQuick 2.6
import QtQuick.Controls 2.1

ItemDelegate {
    id: control
    text: qsTr("ItemDelegate")

    contentItem: Text {
        rightPadding: control.spacing
        text: control.text
        font: control.font
        color: control.enabled ? (control.down ? "#17a81a" : "#21be2b") : "#bdbebf"
        elide: Text.ElideRight
        verticalAlignment: Text.AlignVCenter
    }

    background: Rectangle {
        implicitWidth: 100
        implicitHeight: 40
        opacity: enabled ? 1 : 0.3
        color: control.down ? "#dddedf" : "#eeeeee"

        Rectangle {
            width: parent.width
            height: 1
            color: control.down ? "#17a81a" : "#21be2b"
            anchors.bottom: parent.bottom
        }
    }
}

Customizing Label

Label can have a visual background item.

import QtQuick 2.6
import QtQuick.Controls 2.1

Label {
    text: qsTr("Label")
    color: "#21be2b"
}

Customizing Menu

• Menu consists of a visual background item.
• MenuItem consists of four visual items: background, content item, indicator, and arrow.
• MenuSeparator consists of a visual background and content item.

import QtQuick 2.10
import QtQuick.Controls 2.3

Menu {
    id: menu

    Action { text: qsTr("Tool Bar"); checkable: true }
    Action { text: qsTr("Side Bar"); checkable: true; checked: true }
    Action { text: qsTr("Status Bar"); checkable: true; checked: true }

    MenuSeparator {
        contentItem: Rectangle {
            implicitWidth: 200
            implicitHeight: 1
            color: "#21be2b"
        }
    }

    Menu {
        title: qsTr("Advanced")
        // ...
    }

    topPadding: 2
    bottomPadding: 2

    delegate: MenuItem {
        id: menuItem
        implicitWidth: 200
        implicitHeight: 40

        arrow: Canvas {
            x: parent.width - width
            implicitWidth: 40
            implicitHeight: 40
            visible: menuItem.subMenu
            onPaint: {
                var ctx = getContext("2d")
                ctx.fillStyle = menuItem.highlighted ? "#ffffff" : "#21be2b"
                ctx.moveTo(15, 15)
                ctx.lineTo(width - 15, height / 2)
                ctx.lineTo(15, height - 15)
                ctx.closePath()
                ctx.fill()
            }
        }

        indicator: Item {
            implicitWidth: 40
            implicitHeight: 40
            Rectangle {
                width: 26
                height: 26
                anchors.centerIn: parent
                visible: menuItem.checkable
                border.color: "#21be2b"
                radius: 3
                Rectangle {
                    width: 14
                    height: 14
                    anchors.centerIn: parent
                    visible: menuItem.checked
                    color: "#21be2b"
                    radius: 2
                }
            }
        }

        contentItem: Text {
            leftPadding: menuItem.indicator.width
            rightPadding: menuItem.arrow.width
            text: menuItem.text
            font: menuItem.font
            opacity: enabled ? 1.0 : 0.3
            color: menuItem.highlighted ? "#ffffff" : "#21be2b"
            horizontalAlignment: Text.AlignLeft
            verticalAlignment: Text.AlignVCenter
            elide: Text.ElideRight
        }

        background: Rectangle {
            implicitWidth: 200
            implicitHeight: 40
            opacity: enabled ? 1 : 0.3
            color: menuItem.highlighted ? "#21be2b" : "transparent"
        }
    }

    background: Rectangle {
        implicitWidth: 200
        implicitHeight: 40
        color: "#ffffff"
        border.color: "#21be2b"
        radius: 2
    }
}

Customizing MenuBar

MenuBar can have a visual background item, and MenuBarItem consists of two visual items: background and content item.

import QtQuick 2.10
import QtQuick.Controls 2.3

MenuBar {
    id: menuBar

    Menu { title: qsTr("File") }
    Menu { title: qsTr("Edit") }
    Menu { title: qsTr("View") }
    Menu { title: qsTr("Help") }

    delegate: MenuBarItem {
        id: menuBarItem

        contentItem: Text {
            text: menuBarItem.text
            font: menuBarItem.font
            opacity: enabled ? 1.0 : 0.3
            color: menuBarItem.highlighted ? "#ffffff" : "#21be2b"
            horizontalAlignment: Text.AlignLeft
            verticalAlignment: Text.AlignVCenter
            elide: Text.ElideRight
        }

        background: Rectangle {
            implicitWidth: 40
            implicitHeight: 40
            opacity: enabled ? 1 : 0.3
            color: menuBarItem.highlighted ? "#21be2b" : "transparent"
        }
    }

    background: Rectangle {
        implicitWidth: 40
        implicitHeight: 40
        color: "#ffffff"

        Rectangle {
            color: "#21be2b"
            width: parent.width
            height: 1
            anchors.bottom: parent.bottom
        }
    }
}

Customizing PageIndicator

PageIndicator consists of a background, content item, and delegate.

import QtQuick 2.6
import QtQuick.Controls 2.1

PageIndicator {
    id: control
    count: 5
    currentIndex: 2

    delegate: Rectangle {
        implicitWidth: 8
        implicitHeight: 8

        radius: width / 2
        color: "#21be2b"

        opacity: index === control.currentIndex ? 0.95 : pressed ? 0.7 : 0.45

        Behavior on opacity {
            OpacityAnimator {
                duration: 100
            }
        }
    }
}

Customizing Pane

Pane consists of a background.

import QtQuick 2.6
import QtQuick.Controls 2.1

Pane {
    background: Rectangle {
        color: "#eeeeee"
    }

    Label {
        text: qsTr("Content goes here!")
    }
}

Customizing Popup

Popup consists of a background and content item.

import QtQuick 2.6
import QtQuick.Controls 2.0

Popup {
    id: popup
    background: Rectangle {
        implicitWidth: 200
        implicitHeight: 200
        border.color: "#444"
    }
    contentItem: Column {}
}

Customizing ProgressBar

ProgressBar consists of two visual items: background and content item.

import QtQuick 2.6
import QtQuick.Controls 2.1

ProgressBar {
    id: control
    value: 0.5
    padding: 2

    background: Rectangle {
        implicitWidth: 200
        implicitHeight: 6
        color: "#e6e6e6"
        radius: 3
    }

    contentItem: Item {
        implicitWidth: 200
        implicitHeight: 4

        Rectangle {
            width: control.visualPosition * parent.width
            height: parent.height
            radius: 2
            color: "#17a81a"
        }
    }
}

Customizing RadioButton

RadioButton consists of three visual items: background, content item and indicator.

import QtQuick 2.6
import QtQuick.Controls 2.1

RadioButton {
    id: control
    text: qsTr("RadioButton")
    checked: true

    indicator: Rectangle {
        implicitWidth: 26
        implicitHeight: 26
        x: control.leftPadding
        y: parent.height / 2 - height / 2
        radius: 13
        border.color: control.down ? "#17a81a" : "#21be2b"

        Rectangle {
            width: 14
            height: 14
            x: 6
            y: 6
            radius: 7
            color: control.down ? "#17a81a" : "#21be2b"
            visible: control.checked
        }
    }

    contentItem: Text {
        text: control.text
        font: control.font
        opacity: enabled ? 1.0 : 0.3
        color: control.down ? "#17a81a" : "#21be2b"
        verticalAlignment: Text.AlignVCenter
        leftPadding: control.indicator.width + control.spacing
    }
}

Customizing RadioDelegate

RadioDelegate consists of three visual items: background, contentItem and indicator.

import QtQuick 2.6
import QtQuick.Controls 2.1

RadioDelegate {
    id: control
    text: qsTr("RadioDelegate")
    checked: true

    contentItem: Text {
        rightPadding: control.indicator.width + control.spacing
        text: control.text
        font: control.font
        opacity: enabled ? 1.0 : 0.3
        color: control.down ? "#17a81a" : "#21be2b"
        elide: Text.ElideRight
        verticalAlignment: Text.AlignVCenter
    }

    indicator: Rectangle {
        implicitWidth: 26
        implicitHeight: 26
        x: control.width - width - control.rightPadding
        y: parent.height / 2 - height / 2
        radius: 13
        color: "transparent"
        border.color: control.down ? "#17a81a" : "#21be2b"

        Rectangle {
            width: 14
            height: 14
            x: 6
            y: 6
            radius: 7
            color: control.down ? "#17a81a" : "#21be2b"
            visible: control.checked
        }
    }

    background: Rectangle {
        implicitWidth: 100
        implicitHeight: 40
        visible: control.down || control.highlighted
        color: control.down ? "#bdbebf" : "#eeeeee"
    }
}

Customizing RangeSlider

RangeSlider consists of three visual items: background, first.handle and second.handle.

import QtQuick 2.6
import QtQuick.Controls 2.1

RangeSlider {
    id: control
    first.value: 0.25
    second.value: 0.75

    background: Rectangle {
        x: control.leftPadding
        y: control.topPadding + control.availableHeight / 2 - height / 2
        implicitWidth: 200
        implicitHeight: 4
        width: control.availableWidth
        height: implicitHeight
        radius: 2
        color: "#bdbebf"

        Rectangle {
            x: control.first.visualPosition * parent.width
            width: control.second.visualPosition * parent.width - x
            height: parent.height
            color: "#21be2b"
            radius: 2
        }
    }

    first.handle: Rectangle {
        x: control.leftPadding + first.visualPosition * (control.availableWidth - width)
        y: control.topPadding + control.availableHeight / 2 - height / 2
        implicitWidth: 26
        implicitHeight: 26
        radius: 13
        color: first.pressed ? "#f0f0f0" : "#f6f6f6"
        border.color: "#bdbebf"
    }

    second.handle: Rectangle {
        x: control.leftPadding + second.visualPosition * (control.availableWidth - width)
        y: control.topPadding + control.availableHeight / 2 - height / 2
        implicitWidth: 26
        implicitHeight: 26
        radius: 13
        color: second.pressed ? "#f0f0f0" : "#f6f6f6"
        border.color: "#bdbebf"
    }
}

Customizing RoundButton

RoundButton can be customized in the same manner as Button.

Customizing ScrollBar

ScrollBar consists of two visual items: background and content item.

import QtQuick 2.6
import QtQuick.Controls 2.1

ScrollBar {
    id: control
    size: 0.3
    position: 0.2
    active: true
    orientation: Qt.Vertical

    contentItem: Rectangle {
        implicitWidth: 6
        implicitHeight: 100
        radius: width / 2
        color: control.pressed ? "#81e889" : "#c2f4c6"
    }
}

Customizing ScrollIndicator

ScrollIndicator consists of two visual items: background and content item.

import QtQuick 2.6
import QtQuick.Controls 2.1

ScrollIndicator {
    id: control
    size: 0.3
    position: 0.2
    active: true
    orientation: Qt.Vertical

    contentItem: Rectangle {
        implicitWidth: 2
        implicitHeight: 100
        color: "#c2f4c6"
    }
}

Customizing ScrollView

ScrollView consists of a background item, and horizontal and vertical scroll bars.

ScrollView {
    id: control

    width: 200
    height: 200
    focus: true

    Label {
        text: "ABC"
        font.pixelSize: 224
    }

    ScrollBar.vertical: ScrollBar {
        parent: control
        x: control.mirrored ? 0 : control.width - width
        y: control.topPadding
        height: control.availableHeight
        active: control.ScrollBar.horizontal.active
    }

    ScrollBar.horizontal: ScrollBar {
        parent: control
        x: control.leftPadding
        y: control.height - height
        width: control.availableWidth
        active: control.ScrollBar.vertical.active
    }

    background: Rectangle {
        border.color: control.activeFocus ? "#21be2b" : "#bdbebf"
    }
}

Customizing Slider

Slider consists of two visual items: background, and handle.

import QtQuick 2.6
import QtQuick.Controls 2.1

Slider {
    id: control
    value: 0.5

    background: Rectangle {
        x: control.leftPadding
        y: control.topPadding + control.availableHeight / 2 - height / 2
        implicitWidth: 200
        implicitHeight: 4
        width: control.availableWidth
        height: implicitHeight
        radius: 2
        color: "#bdbebf"

        Rectangle {
            width: control.visualPosition * parent.width
            height: parent.height
            color: "#21be2b"
            radius: 2
        }
    }

    handle: Rectangle {
        x: control.leftPadding + control.visualPosition * (control.availableWidth - width)
        y: control.topPadding + control.availableHeight / 2 - height / 2
        implicitWidth: 26
        implicitHeight: 26
        radius: 13
        color: control.pressed ? "#f0f0f0" : "#f6f6f6"
        border.color: "#bdbebf"
    }
}

Customizing SpinBox

SpinBox consists of four visual items: background, contentItem, up indicator, and down indicator.

import QtQuick 2.6
import QtQuick.Controls 2.1

SpinBox {
    id: control
    value: 50
    editable: true

    contentItem: TextInput {
        z: 2
        text: control.textFromValue(control.value, control.locale)

        font: control.font
        color: "#21be2b"
        selectionColor: "#21be2b"
        selectedTextColor: "#ffffff"
        horizontalAlignment: Qt.AlignHCenter
        verticalAlignment: Qt.AlignVCenter

        readOnly: !control.editable
        validator: control.validator
        inputMethodHints: Qt.ImhFormattedNumbersOnly
    }

    up.indicator: Rectangle {
        x: control.mirrored ? 0 : parent.width - width
        height: parent.height
        implicitWidth: 40
        implicitHeight: 40
        color: control.up.pressed ? "#e4e4e4" : "#f6f6f6"
        border.color: enabled ? "#21be2b" : "#bdbebf"

        Text {
            text: "+"
            font.pixelSize: control.font.pixelSize * 2
            color: "#21be2b"
            anchors.fill: parent
            fontSizeMode: Text.Fit
            horizontalAlignment: Text.AlignHCenter
            verticalAlignment: Text.AlignVCenter
        }
    }

    down.indicator: Rectangle {
        x: control.mirrored ? parent.width - width : 0
        height: parent.height
        implicitWidth: 40
        implicitHeight: 40
        color: control.down.pressed ? "#e4e4e4" : "#f6f6f6"
        border.color: enabled ? "#21be2b" : "#bdbebf"

        Text {
            text: "-"
            font.pixelSize: control.font.pixelSize * 2
            color: "#21be2b"
            anchors.fill: parent
            fontSizeMode: Text.Fit
            horizontalAlignment: Text.AlignHCenter
            verticalAlignment: Text.AlignVCenter
        }
    }

    background: Rectangle {
        implicitWidth: 140
        border.color: "#bdbebf"
    }
}

Customizing StackView

StackView can have a visual background item, and it allows customizing the transitions that are used for push, pop, and replace operations.

import QtQuick 2.6
import QtQuick.Controls 2.1

StackView {
    id: control

    popEnter: Transition {
        XAnimator {
            from: (control.mirrored ? -1 : 1) * -control.width
            to: 0
            duration: 400
            easing.type: Easing.OutCubic
        }
    }

    popExit: Transition {
        XAnimator {
            from: 0
            to: (control.mirrored ? -1 : 1) * control.width
            duration: 400
            easing.type: Easing.OutCubic
        }
    }
}

Customizing SwipeDelegate

SwipeDelegate consists of six visual items: background, content item, indicator, swipe.left, swipe.right, and swipe.behind.

import QtQuick 2.6
import QtQuick.Controls 2.1

SwipeDelegate {
    id: control
    text: qsTr("SwipeDelegate")

    Component {
        id: component

        Rectangle {
            color: SwipeDelegate.pressed ? "#333" : "#444"
            width: parent.width
            height: parent.height
            clip: true

            Label {
                text: qsTr("Press me!")
                color: "#21be2b"
                anchors.centerIn: parent
            }
        }
    }

    swipe.left: component
    swipe.right: component

    contentItem: Text {
        text: control.text
        font: control.font
        color: control.enabled ? (control.down ? "#17a81a" : "#21be2b") : "#bdbebf"
        elide: Text.ElideRight
        verticalAlignment: Text.AlignVCenter

        Behavior on x {
            enabled: !control.down
            NumberAnimation {
                easing.type: Easing.InOutCubic
                duration: 400
            }
        }
    }
}

Customizing SwipeView

SwipeView can have a visual background item. The navigation is implemented by the content item.

import QtQuick 2.6
import QtQuick.Controls 2.1

SwipeView {
    id: control

    background: Rectangle {
        color: "#eeeeee"
    }
}

Customizing Switch

Switch consists of three visual items: background, content item and indicator.

import QtQuick 2.6
import QtQuick.Controls 2.1

Switch {
    id: control
    text: qsTr("Switch")

    indicator: Rectangle {
        implicitWidth: 48
        implicitHeight: 26
        x: control.leftPadding
        y: parent.height / 2 - height / 2
        radius: 13
        color: control.checked ? "#17a81a" : "#ffffff"
        border.color: control.checked ? "#17a81a" : "#cccccc"

        Rectangle {
            x: control.checked ? parent.width - width : 0
            width: 26
            height: 26
            radius: 13
            color: control.down ? "#cccccc" : "#ffffff"
            border.color: control.checked ? (control.down ? "#17a81a" : "#21be2b") : "#999999"
        }
    }

    contentItem: Text {
        text: control.text
        font: control.font
        opacity: enabled ? 1.0 : 0.3
        color: control.down ? "#17a81a" : "#21be2b"
        verticalAlignment: Text.AlignVCenter
        leftPadding: control.indicator.width + control.spacing
    }
}

Customizing SwitchDelegate

SwitchDelegate consists of three visual items: background, contentItem and indicator.

import QtQuick 2.6
import QtQuick.Controls 2.1

SwitchDelegate {
    id: control
    text: qsTr("SwitchDelegate")
    checked: true

    contentItem: Text {
        rightPadding: control.indicator.width + control.spacing
        text: control.text
        font: control.font
        opacity: enabled ? 1.0 : 0.3
        color: control.down ? "#17a81a" : "#21be2b"
        elide: Text.ElideRight
        verticalAlignment: Text.AlignVCenter
    }

    indicator: Rectangle {
        implicitWidth: 48
        implicitHeight: 26
        x: control.width - width - control.rightPadding
        y: parent.height / 2 - height / 2
        radius: 13
        color: control.checked ? "#17a81a" : "transparent"
        border.color: control.checked ? "#17a81a" : "#cccccc"

        Rectangle {
            x: control.checked ? parent.width - width : 0
            width: 26
            height: 26
            radius: 13
            color: control.down ? "#cccccc" : "#ffffff"
            border.color: control.checked ? (control.down ? "#17a81a" : "#21be2b") : "#999999"
        }
    }

    background: Rectangle {
        implicitWidth: 100
        implicitHeight: 40
        visible: control.down || control.highlighted
        color: control.down ? "#bdbebf" : "#eeeeee"
    }
}

Customizing TabBar

TabBar consists of two visual items: background, and contentItem.

import QtQuick 2.6
import QtQuick.Controls 2.1

TabBar {
    id: control

    background: Rectangle {
        color: "#eeeeee"
    }

    TabButton {
        text: qsTr("Home")
    }
    TabButton {
        text: qsTr("Discover")
    }
    TabButton {
        text: qsTr("Activity")
    }
}

Customizing TabButton

TabButton can be customized in the same manner as Button.

Customizing TextArea

TextArea consists of a background item.

import QtQuick 2.6
import QtQuick.Controls 2.1

TextArea {
    id: control
    placeholderText: qsTr("Enter description")

    background: Rectangle {
        implicitWidth: 200
        implicitHeight: 40
        border.color: control.enabled ? "#21be2b" : "transparent"
    }
}

Customizing TextField

TextField consists of a background item.

import QtQuick 2.6
import QtQuick.Controls 2.1

TextField {
    id: control
    placeholderText: qsTr("Enter description")

    background: Rectangle {
        implicitWidth: 200
        implicitHeight: 40
        color: control.enabled ? "transparent" : "#353637"
        border.color: control.enabled ? "#21be2b" : "transparent"
    }
}

Customizing ToolBar

ToolBar consists of one visual item: background.

ToolBar {
    id: control

    background: Rectangle {
        implicitHeight: 40
        color: "#eeeeee"

        Rectangle {
            width: parent.width
            height: 1
            anchors.bottom: parent.bottom
            color: "transparent"
            border.color: "#21be2b"
        }
    }

    RowLayout {
        anchors.fill: parent
        ToolButton {
            text: qsTr("Undo")
        }
        ToolButton {
            text: qsTr("Redo")
        }
    }
}

Customizing ToolButton

ToolButton consists of two visual items: background and content item.

import QtQuick 2.6
import QtQuick.Controls 2.1

ToolButton {
    id: control
    text: qsTr("ToolButton")
    width: 120

    contentItem: Text {
        text: control.text
        font: control.font
        opacity: enabled ? 1.0 : 0.3
        color: control.down ? "#17a81a" : "#21be2b"
        horizontalAlignment: Text.AlignHCenter
        verticalAlignment: Text.AlignVCenter
        elide: Text.ElideRight
    }

    background: Rectangle {
        implicitWidth: 40
        implicitHeight: 40
        color: Qt.darker("#33333333", control.enabled && (control.checked || control.highlighted) ? 1.5 : 1.0)
        opacity: enabled ? 1 : 0.3
        visible: control.down || (control.enabled && (control.checked || control.highlighted))
    }
}

Customizing ToolSeparator

ToolSeparator consists of two visual items: background and content item.

ToolBar {
    RowLayout {
        anchors.fill: parent

        ToolButton {
            text: qsTr("Action 1")
        }
        ToolButton {
            text: qsTr("Action 2")
        }

        ToolSeparator {
            padding: vertical ? 10 : 2
            topPadding: vertical ? 2 : 10
            bottomPadding: vertical ? 2 : 10

            contentItem: Rectangle {
                implicitWidth: parent.vertical ? 1 : 24
                implicitHeight: parent.vertical ? 24 : 1
                color: "#c3c3c3"
            }
        }

        ToolButton {
            text: qsTr("Action 3")
        }
        ToolButton {
            text: qsTr("Action 4")
        }

        Item {
            Layout.fillWidth: true
        }
    }
}

Customizing ToolTip

ToolTip consists of two visual items: background and content item.

import QtQuick 2.6
import QtQuick.Controls 2.1

ToolTip {
    id: control
    text: qsTr("A descriptive tool tip of what the button does")

    contentItem: Text {
        text: control.text
        font: control.font
        color: "#21be2b"
    }

    background: Rectangle {
        border.color: "#21be2b"
    }
}

Customizing Tumbler

Tumbler consists of three visual items: background, contentItem, and delegate.

import QtQuick 2.6
import QtQuick.Controls 2.1

Tumbler {
    id: control
    model: 15

    background: Item {
        Rectangle {
            opacity: control.enabled ? 0.2 : 0.1
            border.color: "#000000"
            width: parent.width
            height: 1
            anchors.top: parent.top
        }

        Rectangle {
            opacity: control.enabled ? 0.2 : 0.1
            border.color: "#000000"
            width: parent.width
            height: 1
            anchors.bottom: parent.bottom
        }
    }

    delegate: Text {
        text: qsTr("Item %1").arg(modelData + 1)
        font: control.font
        horizontalAlignment: Text.AlignHCenter
        verticalAlignment: Text.AlignVCenter
        opacity: 1.0 - Math.abs(Tumbler.displacement) / (control.visibleItemCount / 2)
    }

    Rectangle {
        anchors.horizontalCenter: control.horizontalCenter
        y: control.height * 0.4
        width: 40
        height: 1
        color: "#21be2b"
    }

    Rectangle {
        anchors.horizontalCenter: control.horizontalCenter
        y: control.height * 0.6
        width: 40
        height: 1
        color: "#21be2b"
    }
}

If you want to define your own contentItem, use either a ListView or PathView as the root item. For a wrapping Tumbler, use PathView:

Tumbler {
    id: tumbler

    contentItem: PathView {
        id: pathView
        model: tumbler.model
        delegate: tumbler.delegate
        clip: true
        pathItemCount: tumbler.visibleItemCount + 1
        preferredHighlightBegin: 0.5
        preferredHighlightEnd: 0.5
        dragMargin: width / 2

        path: Path {
            startX: pathView.width / 2
            startY: -pathView.delegateHeight / 2
            PathLine {
                x: pathView.width / 2
                y: pathView.pathItemCount * pathView.delegateHeight - pathView.delegateHeight / 2
            }
        }

        property real delegateHeight: tumbler.availableHeight / tumbler.visibleItemCount
    }
}

For a non-wrapping Tumbler, use ListView:

Tumbler {
    id: tumbler

    contentItem: ListView {
        model: tumbler.model
        delegate: tumbler.delegate

        snapMode: ListView.SnapToItem
        highlightRangeMode: ListView.StrictlyEnforceRange
        preferredHighlightBegin: height / 2 - (height / tumbler.visibleItemCount / 2)
        preferredHighlightEnd: height / 2 + (height / tumbler.visibleItemCount / 2)
        clip: true
    }
}