Mnemonics
Overview  
  ProvideX mnemonics deliver special control sequences to a display device or printer. Discussions on the creation, format, and use of mnemonics begin on the following page. For groupings see Mnemonic Categories.

Using Mnemonics
 
Mnemonics are generally inserted within a PRINT or INPUT statement to invoke such functions as clearing the screen, positioning the cursor, changing the colour of characters, setting/resetting various attributes, or enabling/disabling I/O modes.
 
All mnemonics are enclosed within single quotes. Some require arguments (e.g., PRINT 'CIRCLE'(720,600,100,1)). Some are represented by more than one keyword: a long form or short form (e.g., use either the 'PUSH' or 'WC' to copy the current window).
 
Use of an invalid mnemonic, or one that is not applicable to a particular device, results in Error#29:InvalidMnemonicorposition specification.

*Note* Mnemonics are specific to the channel on which they are defined and are only valid while the channel remains open. When the channel is closed, the mnemonics are cleared.
Creating and Redefining Mnemonics Use the MNEMONIC directive to define/redefine 2-character mnemonics for any file or device. For example, to assign settings for the ProvideX mnemonics 'CP' and 'SP':

MNEMONIC(0)'CP'="Courier New,-8":120,40
MNEMONIC(0)'SP'="*":80,25
 
When a defined mnemonic is encountered in a PRINT or INPUT statement, the system converts it to the character string specified. Some 2-character mnemonics are predefined. For example, 'CR', 'LF', and 'FF are predefined as $00$, $0A$, and $0C$ respectively.
 
All 2-character mnemonics listed in this reference that are used for character display can also be used for character printing. This is provided that the mnemonic is defined for the printer output channel using the correct escape sequence for the device specified.
 
Many motion/editing operations will be emulated when they are not actually supported by the device specified. However, it is still better to define mnemonics using the correct motion/editing sequences that are available for the specific device. Emulation of some sequences may result in slower performance.
 
For further details on mnemonic definitions, refer to the MNEMONIC Directive, and the [WDX] Tag.
   
X,Y Coordinates When using GUI mnemonics, the values for x, y, and radius are considered logical screen coordinates not line/column coordinates. In ProvideX, these are known as graphical units (similar to pixels). Use @X( ) / @Y( ) functions, to convert line/column values to graphical units ; e.g.,
 
0110 LET RADIUS=(100)
0120 LET X=@X(45)! X=graphical units for column value 45
0130 LET Y=@Y(20)! Y=graphical units for line value 20
0140 PRINT @(45,15),'CIRCLE'(X,Y,RADIUS,1)
   
Mnemonic Settings, Window / Region When you send output to the screen, ProvideX remembers all graphic mnemonics until a 'CS' Clear Screen, is performed or the window is destroyed. This enables Windows to repaint the window properly when required.
   
Windows API Frame Styles ProvideX has three Windows API frame styles available to it. The mnemonic 'WINDOW' or 'WA' Mnemonics uses WS_BORDER frame style, which is not popular with everyone. However, it has advantages: it maintains a global menu and buttons and is always relative to the main window. The mnemonic 'DIALOGUE' Mnemonic, on the other hand, uses WS_DLGFRAME, which is more popular, but requires absolute screen position and doesn't allow global menus and buttons.
 
To change the look of the window frame without losing 'WINDOW' functionality, you can use the WS_THICKFRAME style. To do this, add OPT="Z" to the 'WINDOW' mnemonic:
 
PRINT 'WINDOW'(10,10,40,10,"Title",OPT="Z")