ScrollBar Class

The scroll bar control provides easy navigation through a long list of items or a large amount of information. It can also provide an analog representation of current position.

You can use a scroll bar as an input device or as an indicator of speed or quantity.

The HScroll and VScroll classes (the horizontal and vertical scroll bar control classes) are subclasses of the ScrollBar class (a subclass of the Control class). These classes therefore inherit all of the properties and methods defined in the ScrollBar, Control, and Window classes.

The horizontal and vertical scroll bar controls are not supported on forms defined as web pages and they are ignored when HTML is generated.

When you use a scroll bar as an indicator of quantity or speed or as an input device, use the max property and the min property to set the appropriate range of the control.

As scroll bars use the Windows scroll bar API calls that set the thumb size to a size that reflects the size of the scroll bar range and the value of the largeChange property, the larger the value of the largeChange property, the larger the thumb size. To specify the amount of change to report in a scroll bar, use the largeChange property for clicking in the scroll bar and the smallChange property for clicking the arrows at the ends of the scroll bar. The value property increases or decreases by the amounts set for the largeChange and smallChange properties.

You can position the scroll bar at run time, by setting the value property.

For details about the support of mouse wheel requests to scroll up, down, or across a form or control, see "Window Class", earlier in this document. For details about dragging the scroll bar thumb of ListBox and Table controls when an Array, Dictionary, or Set collection is attached to the list box or table, see the displayCollection method.

From Jade release 2022.0.03, scroll bars and spin‑style (Style_SpinBox) combo boxes support accessibility by exposing each of their child elements including names, locations, and values.

To enable or disable enhanced accessibility features, use the EnhancedAccessibilityEnabled parameter in the [Jade] section of the Jade initialization file.

For a summary of the properties and events defined in the ScrollBar class, see "ScrollBar Properties" and "ScrollBar Events", in the following subsections.