TRACKBAR

Syntax

ctl[n]: TRACKBAR(Class Specific Properties), Other Properties

Description

This user control is a scrollbar with a different design. The filter designer can insert so-called ticks on one or two sides of the handle.

Class Specific Properties

AUTOTICKS
Automatically sets tick marks according to range amount.
BOTH
Sets ticks on adjacent sides of the handle according to orientation (HORZ or VERT).
BOTTOM
Changes orientation of handle and ticks (default)
HORZ
Horizontal scrollbar orientation (default)
LEFT
Changes orientation of handle and ticks.
NOTHUMB
Hides the thumb handle.
NOTICKS
Hides the tick marks of the trackbar.
RIGHT
Changes orientation of handle and ticks (default with VERT active)
TOP
Changes orientation of handle and ticks.
TOPTIP
Displays the trackbar value beside the handle when dragging the handle.
VERT
Vertical scrollbar orientation.

Other Properties

Color
Sets the text background color. (default = COLOR_SCROLLBAR)
NoTrack
Prevents the preview window updating when dragging the scrollbar's handle. (default)
Page
Sets the scrollbar paging jump unit. (default = 10)
Range
Sets the numerical range the scrollbar can return. (default = (0, 255))
Track
Updates the preview window when dragging the scrollbar's handle.
Val
Initializes the scrollbar's value. (default = 0)

Example

ctl[0]: TRACKBAR, Size=(50, 20), Color=Red
ctl[5]: TRACKBAR (VERT, BOTH, TOPTIP, AUTOTICKS), Range=(0, 10), Size=(30, 90), Color=Yellow

Notes

Currently, trackbar values cannot be correctly read if the first item i1 of the Range=(i1,i2) property is greater than the second item i2. These problems will be resolved in future FM versions.
There is also a known issue with trackbars not responding to keyboard events. If the user modifies the trackbar value by using the keyboard, it will not trigger the events that would call the OnCtl handler, (even though this does work for scrollbar controls).

Comments

Everyone can add his comments about his experiences with this function here. Tips for using it are welcome, too.