Qt 5.9 | Qt Quick Controls 2 | QML Types | ScrollIndicator QML Type

Qt 5.9.2 Reference Documentation

# ScrollIndicator QML Type

Vertical or horizontal non-interactive scroll indicator. More...

Import Statement: | import QtQuick.Controls 2.2
Since: | Qt 5.7
Inherits: | Control

- List of all members, including inherited members

## Properties

- active : bool
- orientation : enumeration
- position : real
- size : real

## Attached Properties

- horizontal : ScrollIndicator
- vertical : ScrollIndicator

## Detailed Description

ScrollIndicator is a non-interactive indicator that indicates the current scroll position. A scroll indicator can be either vertical or horizontal, and can be attached to any Flickable, such as ListView and GridView.

      Flickable {
          // ...
          ScrollIndicator.vertical: ScrollIndicator { }
      }

## Attaching ScrollIndicator to a Flickable

Note: When ScrollIndicator 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 ScrollIndicator re-parents itself to the target Flickable. A vertically attached ScrollIndicator resizes itself to the height of the Flickable, and positions itself to either side of it based on the layout direction. A horizontally attached ScrollIndicator 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 ScrollIndicator. This can be useful, for example, if the ScrollIndicator should be placed outside a clipping Flickable. This is demonstrated by the following example:

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

## Binding the Active State of Horizontal and Vertical Scroll Indicators

Horizontal and vertical scroll indicators do not share the active state with each other by default. In order to keep both indicators 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

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

## Non-attached Scroll Indicators

It is possible to create an instance of ScrollIndicator without using the attached property API. This is useful when the behavior of the attached scoll indicator is not sufficient or a Flickable is not in use. In the following example, horizontal and vertical scroll indicators are used to indicate how far the user has scrolled over the text (using MouseArea instead of Flickable):

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

          Text {
              id: content
              text: "ABC"
              font.pixelSize: 169

              MouseArea {
                  id: mouseArea
                  drag.target: content
                  drag.minimumX: frame.width - width
                  drag.minimumY: frame.height - height
                  drag.maximumX: 0
                  drag.maximumY: 0
                  anchors.fill: content
              }
          }

          ScrollIndicator {
              id: verticalIndicator
              active: mouseArea.pressed
              orientation: Qt.Vertical
              size: frame.height / content.height
              position: -content.y / content.height
              anchors { top: parent.top; right: parent.right; bottom: parent.bottom }
          }

          ScrollIndicator {
              id: horizontalIndicator
              active: mouseArea.pressed
              orientation: Qt.Horizontal
              size: frame.width / content.width
              position: -content.x / content.width
              anchors { left: parent.left; right: parent.right; bottom: parent.bottom }
          }
      }

See also ScrollBar, Customizing ScrollIndicator, and Indicator Controls.

## Property Documentation

active : bool

This property holds whether the indicator is active, that is, when the attached Flickable is moving.

It is possible to keep both horizontal and vertical indicators visible while scrolling in either direction.

This property is automatically set when the scroll indicator is attached to a flickable.

orientation : enumeration

This property holds the orientation of the indicator.

Possible values:

Constant | Description
--- | ---
`Qt.Horizontal` | Horizontal
`Qt.Vertical` | Vertical (default)

This property is automatically set when the scroll indicator is attached to a flickable.

position : real

This property holds the position of the indicator, scaled to `0.0 - 1.0`.

This property is automatically set when the scroll indicator is attached to a flickable.

See also Flickable::visibleArea.

size : real

This property holds the size of the indicator, scaled to `0.0 - 1.0`.

This property is automatically set when the scroll indicator is attached to a flickable.

See also Flickable::visibleArea.

## Attached Property Documentation

ScrollIndicator.horizontal : ScrollIndicator

This property attaches a horizontal scroll indicator to a Flickable.

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

See also Attaching ScrollIndicator to a Flickable.

ScrollIndicator.vertical : ScrollIndicator

This property attaches a vertical scroll indicator to a Flickable.

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

See also Attaching ScrollIndicator to a Flickable.