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OpenEdge Development: AppBuilder
Data-Display/Capture Objects : Slider controls
 
Slider controls
The Slider‑Control widget is a virtual knob‑and‑track device with integrated numeric readout. Moving the knob along the track sets the associated value to a proportional value within the range you have defined on the track. Conversely, setting the value of the associated variable moves the knob to the corresponding position along the track, offering the user a degree of analog, at‑a‑glance information that the number displayed by the readout does not.
Note: You can assign a slider to visualize an INTEGER or INT64 field or variable. However, the slider cannot display values less than -32,768 and greater than 32,767.
Creating a slider-control instance
Because the slider‑control widget is a basic ABL object, creating one is quite simple.
To create the slider-control widget:
1. Click Slider‑Control in the Object Palette.
2. Move the mouse cursor over a bare spot in your workspace and click to place the new object:
3. Configure it, and adjust its size and position appropriately.
Configuring a slider control instance
You can change some basic characteristics of the slider control widget’s appearance and behavior through its property sheet, if the default settings do not meet your needs.
To configure your slider control object, begin by selecting it and choosing ToolsProperty Sheet. The Property Sheet dialog box appears:
Minimal configuration
Although you can accept many default settings, there are some you should change:
*Object — Change the object identifier to one that more closely matches the role of this slider control in your application.
*Min Value/Max Value — By default, the slider control represents the subrange 0100. Unless this already meets your needs, define the subrange you want. The Slider can display any signed integer value from –32768 to 32767.
*Initial value — By default, the slider control is initialized to 0, or to the lowest value in the subrange if 0 is outside the subrange. To initialize to some other value, click the Advanced button and, when that dialog box opens, type in the initial value you desire.
*Tic Marks — By default, the scale (virtual slot) is unmarked. You can choose to add tic marks to either or both sides. If you do, you can also choose the value interval (default is 10, for a 0100 scale).
Help
You can provide additional help to your users with these settings:
*Tooltip — The slider control displays this string whenever the user allows the mouse cursor to hover over the object’s frame.
*Help ID — If you plan to provide context‑sensitive help, type in a unique integer identifier.
Geometry
Reflects the XY origin and size, in character units, of the slider control’s bounding box. By default, the object’s origin is considered to be the upper‑left corner. You can elect to have AppBuilder consider the origin to be the upper‑right corner instead, though this will not change the object’s actual position in any way.
For more information on all the settings on the property sheet, see the online help.
Advanced properties
A slider control widget has only the standard advanced properties, but you can change those that do not meet your needs. See the “Advanced properties” section for more information.