Viewing file:  tkFont.h (7.82 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* tkFont.h --
*
* Declarations for interfaces between the generic and platform-specific
* parts of the font package. This information is not visible outside of
* the font package.
*
* Copyright (c) 1996-1997 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*/
#ifndef _TKFONT
#define _TKFONT
/*
* The following structure keeps track of the attributes of a font. It can be
* used to keep track of either the desired attributes or the actual
* attributes gotten when the font was instantiated.
*/
struct TkFontAttributes {
Tk_Uid family; /* Font family, or NULL to represent plaform-
* specific default system font. */
double size; /* Pointsize of font, 0.0 for default size, or
* negative number meaning pixel size. */
int weight; /* Weight flag; see below for def'n. */
int slant; /* Slant flag; see below for def'n. */
int underline; /* Non-zero for underline font. */
int overstrike; /* Non-zero for overstrike font. */
};
/*
* Possible values for the "weight" field in a TkFontAttributes structure.
* Weight is a subjective term and depends on what the company that created
* the font considers bold.
*/
#define TK_FW_NORMAL 0
#define TK_FW_BOLD 1
#define TK_FW_UNKNOWN -1 /* Unknown weight. This value is used for
* error checking and is never actually stored
* in the weight field. */
/*
* Possible values for the "slant" field in a TkFontAttributes structure.
*/
#define TK_FS_ROMAN 0
#define TK_FS_ITALIC 1
#define TK_FS_OBLIQUE 2 /* This value is only used when parsing X font
* names to determine the closest match. It is
* only stored in the XLFDAttributes
* structure, never in the slant field of the
* TkFontAttributes. */
#define TK_FS_UNKNOWN -1 /* Unknown slant. This value is used for error
* checking and is never actually stored in
* the slant field. */
/*
* The following structure keeps track of the metrics for an instantiated
* font. The metrics are the physical properties of the font itself.
*/
typedef struct TkFontMetrics {
int ascent; /* From baseline to top of font. */
int descent; /* From baseline to bottom of font. */
int maxWidth; /* Width of widest character in font. */
int fixed; /* Non-zero if this is a fixed-width font,
* 0 otherwise. */
} TkFontMetrics;
/*
* The following structure is used to keep track of the generic information
* about a font. Each platform-specific font is represented by a structure
* with the following structure at its beginning, plus any platform-specific
* stuff after that.
*/
typedef struct TkFont {
/*
* Fields used and maintained exclusively by generic code.
*/
int resourceRefCount; /* Number of active uses of this font (each
* active use corresponds to a call to
* Tk_AllocFontFromTable or Tk_GetFont). If
* this count is 0, then this TkFont structure
* is no longer valid and it isn't present in
* a hash table: it is being kept around only
* because there are objects referring to it.
* The structure is freed when
* resourceRefCount and objRefCount are both
* 0. */
int objRefCount; /* The number of Tcl objects that reference
* this structure. */
Tcl_HashEntry *cacheHashPtr;/* Entry in font cache for this structure,
* used when deleting it. */
Tcl_HashEntry *namedHashPtr;/* Pointer to hash table entry that
* corresponds to the named font that the
* tkfont was based on, or NULL if the tkfont
* was not based on a named font. */
Screen *screen; /* The screen where this font is valid. */
int tabWidth; /* Width of tabs in this font (pixels). */
int underlinePos; /* Offset from baseline to origin of underline
* bar (used for drawing underlines on a
* non-underlined font). */
int underlineHeight; /* Height of underline bar (used for drawing
* underlines on a non-underlined font). */
/*
* Fields used in the generic code that are filled in by
* platform-specific code.
*/
Font fid; /* For backwards compatibility with XGCValues
* structures. Remove when TkGCValues is
* implemented. */
TkFontAttributes fa; /* Actual font attributes obtained when the
* the font was created, as opposed to the
* desired attributes passed in to
* TkpGetFontFromAttributes(). The desired
* metrics can be determined from the string
* that was used to create this font. */
TkFontMetrics fm; /* Font metrics determined when font was
* created. */
struct TkFont *nextPtr; /* Points to the next TkFont structure with
* the same name. All fonts with the same name
* (but different displays) are chained
* together off a single entry in a hash
* table. */
} TkFont;
/*
* The following structure is used to return attributes when parsing an XLFD.
* The extra information is of interest to the Unix-specific code when
* attempting to find the closest matching font.
*/
typedef struct TkXLFDAttributes {
Tk_Uid foundry; /* The foundry of the font. */
int slant; /* The tristate value for the slant, which is
* significant under X. */
int setwidth; /* The proportionate width, see below for
* definition. */
Tk_Uid charset; /* The actual charset string. */
} TkXLFDAttributes;
/*
* Possible values for the "setwidth" field in a TkXLFDAttributes structure.
* The setwidth is whether characters are considered wider or narrower than
* normal.
*/
#define TK_SW_NORMAL 0
#define TK_SW_CONDENSE 1
#define TK_SW_EXPAND 2
#define TK_SW_UNKNOWN 3 /* Unknown setwidth. This value may be stored
* in the setwidth field. */
/*
* The following defines specify the meaning of the fields in a fully
* qualified XLFD.
*/
#define XLFD_FOUNDRY 0
#define XLFD_FAMILY 1
#define XLFD_WEIGHT 2
#define XLFD_SLANT 3
#define XLFD_SETWIDTH 4
#define XLFD_ADD_STYLE 5
#define XLFD_PIXEL_SIZE 6
#define XLFD_POINT_SIZE 7
#define XLFD_RESOLUTION_X 8
#define XLFD_RESOLUTION_Y 9
#define XLFD_SPACING 10
#define XLFD_AVERAGE_WIDTH 11
#define XLFD_CHARSET 12
#define XLFD_NUMFIELDS 13 /* Number of fields in XLFD. */
/*
* Helper macro. How to correctly round a double to a short.
*/
#define ROUND16(x) ((short) floor((x) + 0.5))
/*
* Low-level API exported by generic code to platform-specific code.
*/
#define TkInitFontAttributes(fa) memset((fa), 0, sizeof(TkFontAttributes));
#define TkInitXLFDAttributes(xa) memset((xa), 0, sizeof(TkXLFDAttributes));
MODULE_SCOPE int TkFontParseXLFD(const char *string,
TkFontAttributes *faPtr, TkXLFDAttributes *xaPtr);
MODULE_SCOPE const char *const * TkFontGetAliasList(const char *faceName);
MODULE_SCOPE const char *const *const * TkFontGetFallbacks(void);
MODULE_SCOPE double TkFontGetPixels(Tk_Window tkwin, double size);
MODULE_SCOPE double TkFontGetPoints(Tk_Window tkwin, double size);
MODULE_SCOPE const char *const * TkFontGetGlobalClass(void);
MODULE_SCOPE const char *const * TkFontGetSymbolClass(void);
MODULE_SCOPE int TkCreateNamedFont(Tcl_Interp *interp, Tk_Window tkwin,
const char *name, TkFontAttributes *faPtr);
MODULE_SCOPE int TkDeleteNamedFont(Tcl_Interp *interp,
Tk_Window tkwin, const char *name);
MODULE_SCOPE int TkFontGetFirstTextLayout(Tk_TextLayout layout,
Tk_Font *font, char *dst);
/*
* Low-level API exported by platform-specific code to generic code.
*/
MODULE_SCOPE void TkpDeleteFont(TkFont *tkFontPtr);
MODULE_SCOPE void TkpFontPkgInit(TkMainInfo *mainPtr);
MODULE_SCOPE TkFont * TkpGetFontFromAttributes(TkFont *tkFontPtr,
Tk_Window tkwin, const TkFontAttributes *faPtr);
MODULE_SCOPE void TkpGetFontFamilies(Tcl_Interp *interp,
Tk_Window tkwin);
MODULE_SCOPE TkFont * TkpGetNativeFont(Tk_Window tkwin, const char *name);
#endif /* _TKFONT */
|