A slider control, also called a trackbar control, lets a user select from a range of values by moving a slider. The volume controls in the Windows operating system are slider controls.

The window class name for a slider control is TRACKBAR_CLASS, which is defined as "msctls_trackbar" in Commctrl.h.

The contents of the IAccessible properties depend on whether the slider is vertical or horizontal and on which of the following parts of the slider control is queried by the client:

• Slider window
• Slider thumb
• Shaded area above (or to
• Shaded area below (or to the right of) the slider thumb

Supported Properties and Methods

accHitTest

accLocation

accNavigate

accSelect

get_accChild

get_accChildCount

get_accDescription

get_accHelp

get_accHelpTopic

get_accKeyboardShortcut

The KeyboardShortcut property is the slider window's access key, which is an underlined character in the text of the label for the slider. The returned string contains the access key character appended to the string "Alt+".

get_accName

The Name property depends on the part of the slider that is queried.

The parts of a vertical slider have the following names:

Slider part	Name
Slider window	Static text control used as a label
Slider thumb	"Position"
Shaded area above slider thumb	"Page up"
Shaded area below slider thumb	"Page down"

The parts of a horizontal slider have the following names:

Slider part	Name
Slider window	Static text control used as a label
Slider thumb	"Position"
Shaded area to the left of slider thumb	"Page left"
Shaded area to the right of slider thumb	"Page right"

get_accParent

The Parent property of the arrow buttons, scroll thumb, and the shaded area on either side of the thumb is the slider window. The Parent property of the slider window is a window (ROLE_SYSTEM_WINDOW) that surrounds the control and has the same Name property and window class name.

get_accRole

The Role property depends on the part of the slider that is queried.

Slider part	Role
Slider window	ROLE_SYSTEM_SLIDER
Slider thumb	ROLE_SYSTEM_INDICATOR
Shaded areas on either side of the slider thumb	ROLE_SYSTEM_PUSHBUTTON

get_accState

Values for the State property depend on the part of the slider that is queried.

Slider Part	Possible state values
Slider window	STATE_SYSTEM_INVISIBLE | STATE_SYSTEM_UNAVAILABLE | STATE_SYSTEM_FOCUSED | STATE_SYSTEM_FOCUSABLE | STATE_SYSTEM_NORMAL
Slider thumb	Zero (0), which means the object is visible, or STATE_SYSTEM_INVISIBLE | STATE_SYSTEM_UNAVAILABLE | STATE_SYSTEM_NORMAL
Shaded areas on either side of the slider thumb	Zero (0), which means the object is visible, or STATE_SYSTEM_INVISIBLE | STATE_SYSTEM_UNAVAILABLE | STATE_SYSTEM_NORMAL

get_accValue

The Value property for the slider window indicates the position of the thumb and is a string that contains an integer from "0" through "100".

Events Generated

EVENT_OBJECT_VALUECHANGE

See Also

IAccessible Interface Scroll Bar