
Title; "Blue" Window Manager changes
Author; David De Vorchik
Distribution; Internal only
History;
        19-Jun-92 DDV Created
        22-Jun-92 DDV Added stuff on Wimp_ReadPalette and new CMOS bit
        26-Jun-92 DDV Added some more reflecting Wimp 3.17
         1-Jul-92 DDV Added stuff about ESG cycling, shift toggle etc.
         6-Aug-92 DDV Some more comments on bips
         7-Aug-92 DDV Some comments on Wimp$Font and Wimp$FontSize


This document outlines the changes made to the Window Manager (Wimp) since
RISC OS 3.10, it covers bug fixes and some API changes.
                    

Window Manager 3.17:

 * Bug fix: Icon with a depressed border type, if depressed when the window
   is deleted it now gets tidied properly rather than address exceptioning
   when the mouse button is released.

 * Mouse polled on 100hz ticker rather than always during poll sequence,
   this improves the null event responce rather.  As the pointer can only
   be updated on the Vsync it makes no sence reading it any quicker.

 * Scroll bars have two new icons, "vblip" and "hblip", these are plotted
   centrally on the scroll bars.  They also have pressed versions which
   are prefixed with a "p".

   When designing these icons you should not attempt to make them too big,
   as they limit the minimum size of the scroll sausage, as they are always
   plotted.

 * Shift toggle now thinks that the window has been fulled, rather than 
   simply setting to a non toggled state.  This means that Shift toggle
   and then toggle again causes the window to return back to its normal
   state.
 
 * Wimp_ReadPalette does not return colour number in bottom bits of 
   palette entry, if depth of mode >= 16 bit per pixel.  

   Applications should use ColourTrans if they require these values,
   this provides a future proof method of working with colours independant
   of the hardware / software being used.

 * Minor changes to select table handling to cope with optimising plot calls
   out.  The routine now looks to see if translation table is > 256 entries,
   if it is then it will not attempt to scan it.

 * The use of Wimp_ReadPixTrans is not advised for generating pixel translation
   tables for sprites.  Mainly because it generates tables that are far to
   big for the existing API.  The PRM states that the call returns a 16 byte
   block which is no use for sprites of a depth greater than 4 bit per pixel.
                    
   Applications authors should use ColourTrans where possible for all 
   colour selection.

 * Shift toggle now controled by a CMOS bit, if bit is set then the effect
   of shift toggle is reversed, so by default it will toggle not to cover
   the icon bar, and shift toggle will toggle to full screen.

 * Caret cycling now takes into account the ESG, only cycling into icons
   of the same ESG rather than through all editable icons within the window.

 * Writeable fields should be no greater than 256 characters in length
   for this version of the Window Manager, esp. when using outline fonts.

In some versions of the Window Manager the following two system variables
can be setup:

 * Wimp$Font now describes which outline font will be used for all desktop
   icons and window gadgets.  If Wimp$Font is not defined then the normal
   VDU 5 text is used (standard mode of operation).

 * Wimp$FontSize defines the size of characters to be used, if this is 
   not defined then 12 point is assumed, otherwise the variable holds
   the font size as a ASCII string in points.
