definition module StdPrintText

//	********************************************************************************
//	Clean Standard Object I/O library, version 1.2
//	
//	StdPrintText specifies functions to print text.
//	********************************************************************************

from	StdPictureDef	import FontDef, FontName, FontStyle, FontSize
import	StdPrint
from	StdString import String


:: WrapMode :== Int

NoWrap 			:== 0
LeftJustify 	:== 1
RightJustify 	:== 2

class CharStreams cs
where
	getChar		:: !*cs -> (!Bool,!Char,!*cs)
		//	returns the charstreams next character, and whether this operation was
		//	successful 
	savePos		:: !*cs -> *cs
		//	saves actual position of charstream to be enable the restorePos function
		//	to restore it then.
	restorePos	:: !*cs -> *cs
	eos			:: !*cs -> (!Bool,!*cs)
		//	end of stream

instance CharStreams FileCharStream

:: *FileCharStream

fileToCharStream :: !*File -> *FileCharStream
charStreamToFile :: !*FileCharStream -> *File


printText1 :: !Bool !WrapMode !FontDef !Int !*charStream !PrintSetup !*printEnv
		 ->   (!(!*charStream,!PrintSetup),!*printEnv)
		 | CharStreams charStream & PrintEnvironments printEnv

/* 	printText1 doDialog wrapMode font spacesPerTab charStream printSetup env
	prints a CharStream:
	doDialog:
		identical to print (StdPrint)
	wrapMode:
		controls word wrapping in case lines do not fit. NoWrap suppresses wrapping.
		LeftJustify and RightJustify wrap text to the left and right respectively.
	font:
		the text will be printed in this font.
	spacesPerTab:
		the number of spaces a tab symbol represents.
	charStream:
		the charStream to be printed.
	printSetup, env:
		identical to print (StdPrint)
*/


printText2	::	!String !String !Bool !WrapMode !FontDef !Int !*charStream !PrintSetup
				!*printEnv
			->  (!(!*charStream,!PrintSetup),!*printEnv)
			|	CharStreams charStream & PrintEnvironments printEnv

/*	printText2 titleStr pageStr doDialog wrapMode fontParams spacesPerTab charStream
			   printSetup env
	prints a charStream with a header on each page.
	titleStr:
		this String will be printed on each page at the left corner of the header
	pageStr:
		this String and the actual page number are printed on the right corner of 
		the header
	The other parameters are identical to printText1.
*/


printText3 ::!Bool !WrapMode !FontDef !Int 
			 .(PrintInfo *Picture -> (state, (Int,Int), *Picture))
			 (state Int *Picture -> *Picture)
			 !*charStream
			 !PrintSetup !*printEnv
		 ->  (!(!*charStream,!PrintSetup),!*printEnv)
		 | CharStreams charStream & PrintEnvironments printEnv

/*	printText3 doDialog wrapMode font spacesPerTab textRange eachPageDraw charStream
			   printSetup env
	prints a charStream with a header and trailer on each page. 
	textRange:
		this function takes a PrintInfo record and the printer Picture on which the 
		text will be printed. It returns a triple (state,range,picture):
		state:
			a value of arbitrary type that can be used to pass data to the page 
			printing function pages. 
		range:
			a pair (top,bottom), where top<bottom. The printed text will appear 
			within these y-coordinates only, so a header and a trailer can be 
			printed for each page.
	eachPageDraw:
		this function draws the header and/or trailer for the current page. Its 
		arguments are the data produced by textRange, the actual page number, and an
		initial printer Picture. This function is applied by printText3 before each new
		page receives its text. 
	The other parameters are identical to printText1.
*/


/*	If a file is openend with FReadData, then all possible newline conventions
	(unix,mac,dos) will be recognized. All these printing functions will replace
	nonprintable characters of the font with ASCII spaces. Exceptions are: newline,
	formfeed and tab. So the ASCII space has to be a printable character in the used
	font. A form feed character will cause a form feed, and it will also end a line.
*/