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Menus and Control Widgets

Widget is a generic term for the part of a GUI that allows the user to interface with the application and operating system. Typical widgets include buttons, dialog boxes, pop-up windows, pull-down menus, icons, scroll bars, resizable window edges, menu bars, toggle switches and forms.

Among the most important NeXtMidas features for GUI front-end implementation are soft controls (widgets), which are the screen versions of familiar hardware knobs, switches, and readouts. The two primary execution threads in NeXtMidas associated with GUI controls are control creation and control event processing. In terms of code complexity, control event handling is much simpler than the control creation process.

In response to mouse clicks on control widgets, messages are sent for appropriate event processing. Simulated mouse clicks may be generated by setting the ACTION (i.e. set gc.CONTROLNAME.action option1 )

Type Purpose Screen Shot
ALERT Pop-up button with optional timeout.  
BEAN Allows external controls to be called generically.  
BUTTON Like MENUs but with a button look and feel.
CALENDAR Graphical calendar.  
CHOICE Allows a single choice from an option list (may be configured for manual entry).
DIALOG Groups other widgets into a single popup window, alters their states, and performs an action while the window is closed.  
FILE Selects files.  
LABEL Groups all subsequent widgets into a roll-down/roll-up until the next LABEL.
LIST Menu with a scrollbar.  
MENU Traditional menu control widget.
PANEL Area for other graphical displays such as PLOT or LIST.
PIPEMON Real-time monitoring or pipe parameters.
PROMPT Prompts for text entry.
QUERY Allows introspection of objects and provides data access through the public methods of the class.  
TABLE Edits a table.  
xVAL Numerical valuator widget:
  DVAL - Double (64-bit) numbers.
  LVAL - Integer (32-bit) numbers.
  FVAL - Float (32-bit) numbers.
  TVAL - Time numbers.
The above screen shots were taken while running the DEMO macro in the SYS option tree.

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