Progress
Programming
Handbook
Sliders
A slider is a rectangular scale that represents a range of INTEGER values. A pointer that resides on the trackbar within the scale indicates the current value. The current value is also displayed in character format near the scale. Only values of type INTEGER can be viewed as sliders.
In a graphical interface, a slider takes on the native look of the windowing system. In a character interface, the location of the pointer on the slider is indicated by reverse video; if the slider has focus, and the current value option is set, square brackets appear around the current value.
The following form of the VIEW–AS phrase defines a slider:
NOTE: The options TIC–MARKS, FREQUENCY, and TOOLTIP presented in the the slider syntax box are supported on Windows only.In both character and graphical interfaces, the slider can be oriented horizontally (with low values to the left and high values to the right) or vertically (with low values at the bottom and high values at the top). The default orientation is horizontal. You can set the orientation by specifying HORIZONTAL or VERTICAL within the VIEW–AS phrase or by setting the HORIZONTAL attribute to TRUE or FALSE before the slider is realized.
Also, in both character and graphical interfaces, you can change the default numeric range from small (minimum) to large (maximum) in addition to changing the default horizontal orientation of the slider. Using the LARGE–TO–SMALL option, you can override the default numeric range as follows:
- When the slider is positioned horizontally, the left-most position on the trackbar displays the maximum value and the right-most position displays the minimum value.
- When the slider is positioned vertically, the bottom-most position on the trackbar displays the maximum value and the top-most position displays the minimum value.
In both interfaces, the NO–CURRENT–VALUE option provides additional flexibility in terms of the slider’s presentation. By default, the current value for a given position on the trackbar displays. However, if you use the NO–CURRENT–VALUE option, you can override this default behavior to indicate that the slider will not automatically display the current value as the pointer moves along the trackbar.
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