- Qt 5.5
- Qt Quick Controls
- Qt Quick Controls - Touch Gallery
- Qt 5.5.1 Reference Documentation

# Qt Quick Controls - Touch Gallery

Touch Gallery demonstrates how to implement a UI suitable for touch input using the following Qt Quick Controls:

- ApplicationWindow
- Button
- ProgressBar
- ScrollView
- Slider
- StackView
- Switch
- Tab
- TabView
- TextField

The appearance of the controls is customized by using Qt Quick Controls Styles.

## Running the Example

To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.

## Creating the Main Page

In the main.qml file, we use a Rectangle type within the ApplicationWindow type to create the main page of the application:

    ApplicationWindow {
        visible: true
        width: 800
        height: 1280

        Rectangle {
            color: "#212126"
            anchors.fill: parent
        }

To use the Qt Quick Controls, we must import them:

    import QtQuick.Controls 1.2

The `toolBar` property of the application window holds a BorderImage type that we use to create a separator between the application name and a list of additional pages:

        toolBar: BorderImage {
            border.bottom: 8
            source: "images/toolbar.png"
            width: parent.width
            height: 100

We use an Image type in a Rectangle type to create a back button. We use the `onClicked` signal handler to call the StackView `pop()` function that pops off the page when users tap the button:

            Rectangle {
                id: backButton
                width: opacity ? 60 : 0
                anchors.left: parent.left
                anchors.leftMargin: 20
                opacity: stackView.depth > 1 ? 1 : 0
                anchors.verticalCenter: parent.verticalCenter
                antialiasing: true
                height: 60
                radius: 4
                color: backmouse.pressed ? "#222" : "transparent"
                Behavior on opacity { NumberAnimation{} }
                Image {
                    anchors.verticalCenter: parent.verticalCenter
                    source: "images/navigation_previous_item.png"
                }
                MouseArea {
                    id: backmouse
                    anchors.fill: parent
                    anchors.margins: -10
                    onClicked: stackView.pop()
                }
            }

We use the `opacity` property to hide the back button on the main page.

We use a Text type to display the application name:

            Text {
                font.pixelSize: 42
                Behavior on x { NumberAnimation{ easing.type: Easing.OutCubic} }
                x: backButton.x + backButton.width + 20
                anchors.verticalCenter: parent.verticalCenter
                color: "white"
                text: "Widget Gallery"
            }

The `x` position of the Text type is bound to the position and width of the back button, and animated using a Behavior.

We use a ListModel type that contains ListElement definitions to define titles and source files for the other pages in the application:

        ListModel {
            id: pageModel
            ListElement {
                title: "Buttons"
                page: "content/ButtonPage.qml"
            }
            ListElement {
                title: "Sliders"
                page: "content/SliderPage.qml"
            }
            ListElement {
                title: "ProgressBar"
                page: "content/ProgressBarPage.qml"
            }
            ListElement {
                title: "Tabs"
                page: "content/TabBarPage.qml"
            }
            ListElement {
                title: "TextInput"
                page: "content/TextInputPage.qml"
            }
            ListElement {
                title: "List"
                page: "content/ListPage.qml"
            }
        }

## Navigating in the Application

We implement a stack-based navigation model to link the application pages together. Items are pushed onto the stack as users navigate deeper into the application, and popped off again when they return to the main page.

In main.qml, we add a StackView type as a child of the application window:

        StackView {
            id: stackView
            anchors.fill: parent
            // Implements back key navigation
            focus: true
            Keys.onReleased: if (event.key === Qt.Key_Back && stackView.depth > 1) {
                                 stackView.pop();
                                 event.accepted = true;
                             }

The stack is used by invoking its navigation methods. To load the first item in the stack view, we assign it to `initialItem`:

            initialItem: Item {
                width: parent.width
                height: parent.height
                ListView {
                    model: pageModel
                    anchors.fill: parent
                    delegate: AndroidDelegate {
                        text: title
                        onClicked: stackView.push(Qt.resolvedUrl(page))
                    }
                }
            }
        }

    }

We use a ListView type to display a list of the items provided by `pageModel`. The `AndroidDelegate` custom type defines each item instantiated by the view.

## Creating Push Buttons and Switches

In ButtonPage.qml we use the Button type to create two buttons that change color when users tap them and one that pops off the page and returns the user to the main page:

            Button {
                text: "Press me"
                style: touchStyle
            }

            Button {
                style: touchStyle
                text: "Press me too"
            }

            Button {
                anchors.margins: 20
                style: touchStyle
                text: "Don't press me"
                onClicked: if (stackView) stackView.pop()
            }

We use a Switch type to create two switches that users can turn on and off. They are placed within a Row type to lay them out horizontally:

            Row {
                spacing: 20
                Switch {
                    style: switchStyle
                }
                Switch {
                    style: switchStyle
                }
            }

A ButtonStyle type creates a custom appearance for the buttons:

        Component {
            id: touchStyle
            ButtonStyle {
                panel: Item {
                    implicitHeight: 50
                    implicitWidth: 320
                    BorderImage {
                        anchors.fill: parent
                        antialiasing: true
                        border.bottom: 8
                        border.top: 8
                        border.left: 8
                        border.right: 8
                        anchors.margins: control.pressed ? -4 : 0
                        source: control.pressed ? "../images/button_pressed.png" : "../images/button_default.png"
                        Text {
                            text: control.text
                            anchors.centerIn: parent
                            color: "white"
                            font.pixelSize: 23
                            renderType: Text.NativeRendering
                        }

To use Qt Quick Controls Styles, we must import them:

    import QtQuick.Controls.Styles 1.1

A SwitchStyle type creates a custom appearance for the switches:

        Component {
            id: switchStyle
            SwitchStyle {

                groove: Rectangle {
                    implicitHeight: 50
                    implicitWidth: 152
                    Rectangle {
                        anchors.top: parent.top
                        anchors.left: parent.left
                        anchors.bottom: parent.bottom
                        width: parent.width/2 - 2
                        height: 20
                        anchors.margins: 2
                        color: control.checked ? "#468bb7" : "#222"
                        Behavior on color {ColorAnimation {}}
                        Text {
                            font.pixelSize: 23
                            color: "white"
                            anchors.centerIn: parent
                            text: "ON"
                        }
                    }
                    Item {
                        width: parent.width/2
                        height: parent.height
                        anchors.right: parent.right
                        Text {
                            font.pixelSize: 23
                            color: "white"
                            anchors.centerIn: parent
                            text: "OFF"
                        }
                    }
                    color: "#222"
                    border.color: "#444"
                    border.width: 2
                }
                handle: Rectangle {
                    width: parent.parent.width/2
                    height: control.height
                    color: "#444"
                    border.color: "#555"
                    border.width: 2
                }
            }
        }
    }

The `groove` property holds the background groove of the switch and the `handle` property defines the switch handle.

## Creating Sliders

In SliderPage.qml, we use a Slider type to create three horizontal sliders that are placed within a Column type to lay them out in a column:

        Column {
            spacing: 12
            anchors.centerIn: parent

            Slider {
                anchors.margins: 20
                style: touchStyle
                value: 0
            }
            Slider {
                anchors.margins: 20
                style: touchStyle
                value: 0.5
            }
            Slider {
                anchors.margins: 20
                style: touchStyle
                value: 1.0
            }

        }

The `value` property holds the initial handle position on the slider.

A SliderStyle type creates a custom appearance for the sliders:

        Component {
            id: touchStyle
            SliderStyle {
                handle: Rectangle {
                    width: 30
                    height: 30
                    radius: height
                    antialiasing: true
                    color: Qt.lighter("#468bb7", 1.2)
                }

                groove: Item {
                    implicitHeight: 50
                    implicitWidth: 400
                    Rectangle {
                        height: 8
                        width: parent.width
                        anchors.verticalCenter: parent.verticalCenter
                        color: "#444"
                        opacity: 0.8
                        Rectangle {
                            antialiasing: true
                            radius: 1
                            color: "#468bb7"
                            height: parent.height
                            width: parent.width * control.value / control.maximumValue
                        }
                    }
                }
            }
        }
    }

The `handle` property defines the slider handle and the `groove` property holds the background groove of the slider.

## Indicating Progress

In ProgressBar.qml, we use a ProgressBar type to create three progress bars:

        Column {
            spacing: 40
            anchors.centerIn: parent

            ProgressBar {
                anchors.margins: 20
                style: touchStyle
                width: 400
                value: progress
            }

            ProgressBar {
                anchors.margins: 20
                style: touchStyle
                width: 400
                value: 1 - progress
            }

            ProgressBar {
                anchors.margins: 20
                style: touchStyle
                value: 1
                width: 400
            }

We use a NumberAnimation type with a SequentialAnimation type to run two number animations in a sequence. We apply the animations on the `progress` custom property to animate the current value on the progress bars:

        property real progress: 0
        SequentialAnimation on progress {
            loops: Animation.Infinite
            running: true
            NumberAnimation {
                from: 0
                to: 1
                duration: 3000
            }
            NumberAnimation {
                from: 1
                to: 0
                duration: 3000
            }

A ProgressBarStyle type creates a custom appearance for the progress bars:

        Component {
            id: touchStyle
            ProgressBarStyle {
                panel: Rectangle {
                    implicitHeight: 15
                    implicitWidth: 400
                    color: "#444"
                    opacity: 0.8
                    Rectangle {
                        antialiasing: true
                        radius: 1
                        color: "#468bb7"
                        height: parent.height
                        width: parent.width * control.value / control.maximumValue
                    }
                }
            }
        }
    }

## Creating Tabs

In TabBarPage.qml, we use a TabView type with a Tab type to provide a tab-based navigation model for our application. We use tabs to display the ButtonPage, SliderPage, and ProgressBarPage on separate tab pages:

        TabView {
            anchors.fill: parent
            style: touchStyle
            Tab {
                title: "Buttons"
                ButtonPage{ visible: true }
            }
            Tab {
                title: "Sliders"
                SliderPage{ visible: true }
            }
            Tab {
                title: "Progress"
                ProgressBarPage{ visible: true }
            }

A TabViewStyle type creates a custom appearance for the tabs:

        Component {
            id: touchStyle
            TabViewStyle {
                tabsAlignment: Qt.AlignVCenter
                tabOverlap: 0
                frame: Item { }
                tab: Item {
                    implicitWidth: control.width/control.count
                    implicitHeight: 50
                    BorderImage {
                        anchors.fill: parent
                        border.bottom: 8
                        border.top: 8
                        source: styleData.selected ? "../images/tab_selected.png":"../images/tabs_standard.png"
                        Text {
                            anchors.centerIn: parent
                            color: "white"
                            text: styleData.title.toUpperCase()
                            font.pixelSize: 16
                        }
                        Rectangle {
                            visible: index > 0
                            anchors.top: parent.top
                            anchors.bottom: parent.bottom
                            anchors.margins: 10
                            width:1
                            color: "#3a3a3a"
                        }
                    }
                }
            }
        }
    }

## Creating Text Input Fields

In the TextInputPage.qml, we use a TextField type to create an input field and a read-only text field:

        Column {
            spacing: 40
            anchors.centerIn: parent

            TextField {
                anchors.margins: 20
                text: "Text input"
                style: touchStyle
            }

            TextField {
                anchors.margins: 20
                text: "Readonly Text input"
                style: touchStyle
                readOnly: true
            }
        }

A TextFieldStyle creates a custom appearance for the text fields:

        Component {
            id: touchStyle

            TextFieldStyle {
                textColor: "white"
                font.pixelSize: 28
                background: Item {
                    implicitHeight: 50
                    implicitWidth: 320
                    BorderImage {
                        source: "../images/textinput.png"
                        border.left: 8
                        border.right: 8
                        anchors.bottom: parent.bottom
                        anchors.left: parent.left
                        anchors.right: parent.right
                    }
                }
            }
        }
    }

We use a BorderImage type with an image to create borders for the fields.

## Creating Scrolling Lists

In ListPage.qml, we use a ScrollView type to provide a scrolling page with a vertical scoll bar:

    ScrollView {
        width: parent.width
        height: parent.height

        flickableItem.interactive: true

We use a ListView type to display a list of 100 items by specifying an integer as the value of the `model` property. We reuse the `AndroidDelegate` custom type here to define each item instantiated by the view. The `text` property adds the string `Item #` to each list item:

        ListView {
            anchors.fill: parent
            model: 100
            delegate: AndroidDelegate {
                text: "Item #" + modelData
            }
        }

A ScrollViewStyle type creates a custom appearance for the scroll view:

        style: ScrollViewStyle {
            transientScrollBars: true
            handle: Item {
                implicitWidth: 14
                implicitHeight: 26
                Rectangle {
                    color: "#424246"
                    anchors.fill: parent
                    anchors.topMargin: 6
                    anchors.leftMargin: 4
                    anchors.rightMargin: 4
                    anchors.bottomMargin: 6
                }
            }
            scrollBarBackground: Item {
                implicitWidth: 14
                implicitHeight: 26
            }
        }
    }

The `transientScrollBars` property is set to `true` to make the scroll bars appear when the content is scrolled and disappear when they are no longer needed.

The `handle` property controls the appearance of the scroll bar handle and the `scrollBarBackground` property that of the background.

Files:

- touch/main.qml
- touch/content/AndroidDelegate.qml
- touch/content/ButtonPage.qml
- touch/content/ListPage.qml
- touch/content/ProgressBarPage.qml
- touch/content/SliderPage.qml
- touch/content/TabBarPage.qml
- touch/content/TextInputPage.qml
- touch/src/main.cpp
- touch/resources.qrc
- touch/touch.pro
- touch/touch.qmlproject

Images:

- touch/images/button_default.png
- touch/images/button_pressed.png
- touch/images/navigation_next_item.png
- touch/images/navigation_previous_item.png
- touch/images/tab_selected.png
- touch/images/tabs_standard.png
- touch/images/textinput.png
- touch/images/toolbar.png