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ScrollBar

Vertical or horizontal interactive scroll bar. More...

• List of all members, including inherited members

Properties

• active : bool
• horizontal : bool
• interactive : bool
• minimumSize : real
• orientation : enumeration
• policy : enumeration
• position : real
• pressed : bool
• size : real
• snapMode : enumeration
• stepSize : real
• vertical : bool
• visualPosition : real
• visualSize : real

Attached Properties

• horizontal : ScrollBar
• vertical : ScrollBar

Methods

• void decrease()
• void increase()

Detailed Description

ScrollBar is an interactive bar that can be used to scroll to a specific position. A scroll bar can be either vertical or horizontal, and can be attached to any Flickable, such as ListView and GridView. It can also be used with ScrollView.

Flickable {
    // ...
    ScrollBar.vertical: ScrollBar { }
}

Attaching ScrollBar to a Flickable

When ScrollBar is attached vertically or horizontally to a Flickable, its geometry and the following properties are automatically set and updated as appropriate:

• orientation
• position
• size
• active

An attached ScrollBar re-parents itself to the target Flickable. A vertically attached ScrollBar resizes itself to the height of the Flickable, and positions itself to either side of it based on the layout direction. A horizontally attached ScrollBar resizes itself to the width of the Flickable, and positions itself to the bottom. The automatic geometry management can be disabled by specifying another parent for the attached ScrollBar. This can be useful, for example, if the ScrollBar should be placed outside a clipping Flickable. This is demonstrated by the following example:

Flickable {
    id: flickable
    clip: true
    // ...
    ScrollBar.vertical: ScrollBar {
        parent: flickable.parent
        anchors.top: flickable.top
        anchors.left: flickable.right
        anchors.bottom: flickable.bottom
    }
}

Notice that ScrollBar does not filter key events of the Flickable it is attached to. The following example illustrates how to implement scrolling with up and down keys:

Flickable {
    focus: true

    Keys.onUpPressed: scrollBar.decrease()
    Keys.onDownPressed: scrollBar.increase()

    ScrollBar.vertical: ScrollBar { id: scrollBar }
}

Binding the Active State of Horizontal and Vertical Scroll Bars

Horizontal and vertical scroll bars do not share the active state with each other by default. In order to keep both bars visible whilst scrolling to either direction, establish a two-way binding between the active states as presented by the following example:

Flickable {
    anchors.fill: parent

    contentWidth: parent.width * 2
    contentHeight: parent.height * 2

    ScrollBar.horizontal: ScrollBar { id: hbar; active: vbar.active }
    ScrollBar.vertical: ScrollBar { id: vbar; active: hbar.active }
}

Non-attached Scroll Bars

It is possible to create an instance of ScrollBar without using the attached property API. This is useful when the behavior of the attached scroll bar is not sufficient or a Flickable is not in use. In the following example, horizontal and vertical scroll bars are used to scroll over the text without using Flickable:

Rectangle {
    id: frame
    clip: true
    width: 160
    height: 160
    border.color: "black"
    anchors.centerIn: parent

    Text {
        id: content
        text: "ABC"
        font.pixelSize: 160
        x: -hbar.position * width
        y: -vbar.position * height
    }

    ScrollBar {
        id: vbar
        hoverEnabled: true
        active: hovered || pressed
        orientation: Qt.Vertical
        size: frame.height / content.height
        anchors.top: parent.top
        anchors.right: parent.right
        anchors.bottom: parent.bottom
    }

    ScrollBar {
        id: hbar
        hoverEnabled: true
        active: hovered || pressed
        orientation: Qt.Horizontal
        size: frame.width / content.width
        anchors.left: parent.left
        anchors.right: parent.right
        anchors.bottom: parent.bottom
    }
}

When using a non-attached ScrollBar, the following must be done manually:

• Layout the scroll bar (with the x and y or anchors property, for example).
• Set the size and position properties to determine the size and position of the scroll bar in relation to the scrolled item.
• Set the active property to determine when the scroll bar will be visible.

See also ScrollIndicator, ScrollView, Customizing ScrollBar, and Indicator Controls.

Property Documentation

Flickable {
    contentHeight: 2000
    ScrollBar.vertical: ScrollBar {
        policy: ScrollBar.AlwaysOn
    }
}

Attached Property Documentation

Flickable {
    contentWidth: 2000
    ScrollBar.horizontal: ScrollBar { }
}

Flickable {
    contentHeight: 2000
    ScrollBar.vertical: ScrollBar { }
}

Method Documentation