hinrichs@unc.UUCP (11/21/86)
(***************************************************************************)
(*** ***)
(*** ***)
(*** O S S I ***)
(*** ========== ***)
(*** ***)
(**) DEFINITION MODULE SIAdvancedText; (**)
(*** ================================ ***)
(*** ***)
(*** This module supports advanced text output to windows. ***)
(*** ***)
(***---------------------------------------------------------------------***)
(*** ***)
(*** Hardware: independent ***)
(*** Operating System: independent ***)
(*** Compiler: independent ***)
(*** ***)
(*** Version: 4.0 ***)
(*** Implemented: see copyright ***)
(*** Date: 1986-11-17 ***)
(*** ***)
(***---------------------------------------------------------------------***)
(*** ***)
(*** Copyright 1986 by ***)
(*** E. S. Biagioni ***)
(*** G. Heiser ***)
(*** K. Hinrichs ***)
(*** C. Muller ***)
(*** ***)
(*** Institut fuer Informatik ***)
(*** ETH Zuerich ***)
(*** CH 8092 Zuerich ***)
(*** Switzerland ***)
(*** ***)
(*** Department of Computer Science ***)
(*** University of North Carolina ***)
(*** Chapel Hill, North Carolina 27514 ***)
(*** U.S.A. ***)
(*** ***)
(*** Permission to copy without fee all of this material is granted ***)
(*** provided that the copies are not made or distributed for direct ***)
(*** commercial advantage, that this OSSI copyright notice is ***)
(*** included in the copy, that the module is not modified in any way ***)
(*** except where necessary for compilation on a particular system, ***)
(*** and that the module is always distributed in its original form. ***)
(*** Distribution of this module in a modified form without including ***)
(*** the original version is a violation of this copyright notice. ***)
(*** ***)
(***---------------------------------------------------------------------***)
(*** ***)
(*** Updates: ***)
(*** ***)
(*** ***)
(***************************************************************************)
(* This module supports advanced text output to windows. A window used by
this module has a current pixel position (in window coordinates) which
can be used and changed by procedures of this module only. This pixel
position is different from the (line, column) text position of the
module SISimpleText. The procedures of this module have no influence on
the text position of SISimpleText, and the procedures of SISimpleText
have no influence on the pixel position of this module. Text output by
the procedures of this module is written at the current pixel position
(thereby changing the current pixel position). When a window is created
the pixel position is initialized to (0, 0) (i.e. at the top left corner
of the inner rectangle). Text may be written outside a window; however,
it is clipped to the inner rectangle of the window. *)
FROM SISystem IMPORT
SIResult;
FROM SIWindows IMPORT
Window;
EXPORT QUALIFIED
NameLength,
Name,
Font,
FontDescriptor,
CharDescriptor,
GetAvailableFonts,
DefaultFont,
LoadFont,
ReleaseFont,
GetFontDescriptor,
GetCharDescriptor,
GetPixelPos,
SetPixelPos,
MovePixelPos,
DrawChar,
DrawString,
StringWidth;
CONST NameLength = 16;
TYPE Name = ARRAY [0..NameLength-1] OF CHAR;
Font;
FontDescriptor = RECORD
familyName: Name;
faceType: Name;
size: CARDINAL;
fixedWidth: BOOLEAN;
END (* FontDescriptor *);
CharDescriptor = RECORD
height, advance, ascent, overlap: CARDINAL;
END (* CharDescriptor *);
(* A character is assumed to be contained in a rectangle of appropriate
width. The height of this rectangle is the same for all characters of
a font. After a character has been written, the current pixel
position is moved by advance pixels. When writing normal text
sequentially, the rectangle of a character will overlap the rectangle
of its predecessor by overlap pixels. The total width of a character
is (overlap + advance) pixels. If a character is written at a position
(h, v), the upper left pixel in the character rectangle has coordinate
(h - overlap, v) and the pixel position will be moved to
(h + advance, v). If the vertical component of the current pixel
position is not changed all characters of a font will be written on a
baseline, only characters like p, q, y etc. may extend beyond this
baseline. The number of pixel rows above the baseline in a character
rectangle is given by ascent; it is the same for all characters of a
font. ascent can be used to find the vertical coordinate for an
underline. *)
PROCEDURE GetAvailableFonts (VAR fonts: ARRAY OF FontDescriptor;
VAR totNbrFonts, nbrFontsReturned: CARDINAL);
(* returns the descriptions of available fonts. totNbrFonts returns the
total number of fonts available, nbrFontsReturned the number of font
descriptions returned. The latter may be smaller than the former if
fonts is too small to hold all fonts. *)
PROCEDURE DefaultFont (VAR fD: FontDescriptor);
(* returns the descriptor of the default font. The default font must
be loaded like all other fonts. *)
PROCEDURE LoadFont (fD: FontDescriptor; VAR f: Font; VAR result: SIResult);
(* returns an identifier by which the font can be referenced later on. Note
that this identifier is only valid until the procedure ReleaseFont is
called. *)
PROCEDURE ReleaseFont (VAR f: Font);
(* releases the font and deallocates its resources. f is set to an invalid
value and may not be used later on. *)
PROCEDURE GetFontDescriptor (f: Font; VAR fD: FontDescriptor);
(* returns the description of the font with the given identifier. *)
PROCEDURE GetCharDescriptor (ch: CHAR; f: Font; VAR chD: CharDescriptor);
(* returns the description of the character in a given font. *)
PROCEDURE GetPixelPos (w: Window; VAR h, v: INTEGER);
(* returns current pixel position (in window coordinates). *)
PROCEDURE SetPixelPos (w: Window; h, v: INTEGER);
(* sets pixel position absolutely (in window coordinates). *)
PROCEDURE MovePixelPos (w: Window; dh, dv: INTEGER);
(* sets pixel position relative to the current pixel position. *)
PROCEDURE DrawChar (w: Window; f: Font; ch: CHAR);
(* writes ch at the current pixel position in w using font f and the current
paint mode of w; the pixel position is advanced. Special characters like
EOL, DEL or FF are not interpreted and the result of writing them to a
window is undefined. *)
PROCEDURE DrawString (w: Window; f: Font; s: ARRAY OF CHAR);
(* is equivalent to
FOR i := 0 TO StringLength(s) - 1 DO DrawChar (w, f, s[i]) END
but possibly faster. *)
PROCEDURE StringWidth (f: Font; s: ARRAY OF CHAR): CARDINAL;
(* returns the width of the string in font f. This width is the
sum of the advances of all characters in the string added to
the overlap of the first character. *)
END SIAdvancedText.