HTrackBar control

Like a scroll bar, a trackbar is used as a scrolling control, but clicking on the trackbar slider moves it in discrete increments instead of continuously. The HTrackBar control has a series of tick marks along the bottom of the trackbar channel.

To enable this control to be used properly from the keyboard, you must add code to the LineLeft, LineRight, PageLeft, and PageRight events. The code you add should change the slider Position property by the appropriate value and then pass the new slider position to the object or objects you associate with the trackbar control. You must code the Moved event if you want the trackbar control to pass on the slider position after the slider is dragged with a mouse.

Usage note

Use a trackbar when you want the user to select a discrete value. For example, you can use a trackbar to enable a user to select a timer interval or the size of a window.

Properties

HTrackBar property	Datatype	Description
AccessibleDescription	String	A description of the control and/or its purpose for use by accessibility tools such as readers for visually impaired users.
AccessibleName	String	A label that briefly describes the control, such as the text in a button or the name of a menu item.
AccessibleRole	AccessibleRole (enumerated)	Describes what kind of user interface element the control is.
BringToTop	Boolean	Specifies whether PowerBuilder moves the control to the top of the front-to-back order. Values are: TRUE -- Control moved to top. FALSE -- Control not moved to top.
ClassDefinition	PowerObject	An object of type PowerObject containing information about the class definition of the object or control.
DragAuto	Boolean	Specifies whether PowerBuilder puts the control automatically into Drag mode. Values are: TRUE -- When the control is clicked, the control is automatically in Drag mode. FALSE -- When the control is clicked, the control is not automatically in Drag mode. You have to manually put the control into Drag mode by using the Drag function.
DragIcon	String	Specifies the name of the stock icon or the file containing the icon you want to display when the user drags the control (the ICO file). The default icon is a box the size of the control. When the user drags the control, the icon displays when the control is over an area in which the control can be dropped (a valid drop area). When the control is over an area that is not a valid drop area, the No-Drop icon displays.
Height	Integer	Specifies the height of the control, in PowerBuilder units.
LineSize	Integer	Specifies how far the slider moves in response to keyboard input from the arrow keys. Setting LineSize to 1 indicates moving 1 increment in the range of values specified by the MaxPosition and MinPosition properties.
MaxPosition	Integer	Specifies the value of the Position property when the slider is at the right edge of the control.
MinPosition	Integer	Specifies the value of the Position property when the slider is at the left edge of the control.
PageSize	Integer	Specifies how far the slider moves in response to clicking in the slider channel area or pressing the Page keys. The default size is the difference between the MaxPosition and MinPosition properties divided by 5.
Pointer	String	Specifies the name of the stock pointer or file containing the pointer used for the control.
Position	Integer	Specifies a value between MinPosition and MaxPosition specifying the position of the slider.
Slider	Boolean	Specifies whether or not the trackbar contains a slider.
SliderSize	Integer	Specifies the size of the slider on the trackbar. A value of 0 makes the slider the default size.
TabOrder	Integer	Specifies the tab value of the control within the window (0 means the user cannot tab to the control).
Tag	String	Specifies the tag value assigned to the control.
TickFrequency	Integer	Specifies tick mark frequency. Setting TickFrequency to 1 indicates 1 tick mark for each increment in the trackbar range of values.
TickMarks	HTickMarks (enumerated)	Specifies where tickmarks should be displayed. Values are: HTicksOnBottom! HTicksOnTop! HTicksOnBoth! HTicksOnNeither!
Visible	Boolean	Specifies whether the control is visible. Values are: TRUE -- Control is visible. FALSE -- Control is not visible.
Width	Integer	Specifies the width of the control, in PowerBuilder units.
X	Integer	Specifies the X position (the distance from the left edge of the window), in PowerBuilder units.
Y	Integer	Specifies the Y position (the distance from the top of the window), in PowerBuilder units.

Events

HTrackBar event	Occurs
Constructor	Immediately before the Open event occurs in the window
Destructor	Immediately after the Close event occurs in the window
DragDrop	When a dragged control is dropped on the control
DragEnter	When a dragged control enters the control
DragLeave	When a dragged control leaves the control
DragWithin	When a dragged control is within the control
GetFocus	Just before the control receives focus (before it is selected and becomes active)
Help	When the user presses the F1 key or drags the context help button (question mark) from the title bar to a menu item or control
LineLeft	When the left arrow key is clicked
LineRight	When the right arrow key is clicked
LoseFocus	When the control loses focus (becomes inactive)
Moved	When the slider is moved (use the Position property to determine the new location)
Other	When a Windows message occurs that is not a PowerBuilder event
PageLeft	When the Page Up key is clicked or when mouse clicks are made to the left of the slider in the trackbar channel
PageRight	When the Page Down key is clicked or when mouse clicks are made to the right of the slider in the trackbar channel
RButtonDown	When the right mouse button is pressed on the control

Functions

HTrackBar function	Datatype returned	Description
ClassName	String	Returns the name assigned to the control.
Drag	Integer	Starts or ends the dragging of the control.
GetContextService	Integer	Creates a reference to a context-specific instance of the specified service.
GetParent	PowerObject	Returns a reference to the name of the parent object.
Hide	Integer	Makes the control invisible.
Move	Integer	Moves the control to a specified location.
PointerX	Integer	Returns the distance of the pointer from the left edge of the control.
PointerY	Integer	Returns the distance of the pointer from the top of the control.
PostEvent	Boolean	Adds an event to the end of the message queue for control.
Print	Integer	Prints the control.
Resize	Integer	Changes the size of the control.
SelectionRange	Integer	Sets a selection range for the trackbar. When you select a range, a blue line is drawn in the channel of the trackbar and two arrows are drawn where the tickmarks are placed to indicate the beginning and end of the selection range.
SetFocus	Integer	Sets the focus to the control.
SetPosition	Integer	Specifies the position of the control in the front-to-back order of the window.
SetRedraw	Integer	Controls automatic redrawing of the control after each change in its properties.
Show	Integer	Makes the control visible.
TriggerEvent	Integer	Triggers a specified event in the control and executes the script for the event.
TypeOf	Object	Returns the type of the control.

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