lib/font.h

   1 /* Dia -- an diagram creation/manipulation program
   2  * Copyright (C) 1998 Alexander Larsson
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17  */
  18 #ifndef FONT_H
  19 #define FONT_H
  20
  21 #include "diatypes.h"
  22 #include <glib.h>
  23 #include <glib-object.h>
  24 #include <pango/pango.h>
  25 #include "dia-enums.h"
  26 #include "geometry.h"
  27 #include "diavar.h"
  28
  29 /* Do NOT put these strings through the .po mechanism. If you need to add
  30    non-Roman alternatives, please insert them in the list */
  31 #define BASIC_SANS_FONT "arial, helvetica, helv, sans"
  32 #define BASIC_SERIF_FONT "times new roman, times, serif"
  33 #define BASIC_MONOSPACE_FONT "courier new, courier, monospace, fixed"
  34
  35
  36 /**
  37  * In a goodly selection of fonts, 500 is very common, yet Pango doesn't name it.
  38  * I am calling 500 'medium' and 600 'demibold'.
  39  * We should really have a more flexible system where 300 or 400 is normal,
  40  * the next one up bold, or something.  But this will do for now.
  41  * We should probably store the actual weight...
  42  */
  43
  44 /* We are having DIA_FONT_WEIGHT_NORMAL be 0 to avoid having to do
  45  * DIA_FONT_MONOSPACE | DIA_FONT_WEIGHT_NORMAL all over the place.
  46  * This introduces a few hacks in font.c and widgets.c, but not too
  47  * many.
  48  */
  49
  50 /* storing different style info like
  51  * (DIA_FONT_SANS | DIA_FONT_ITALIC | DIA_FONT_BOLD)
  52  */
  53 typedef guint DiaFontStyle;
  54
  55 typedef enum
  56 {
  57   DIA_FONT_FAMILY_ANY = 0,
  58   DIA_FONT_SANS       = 1,
  59   DIA_FONT_SERIF      = 2,
  60   DIA_FONT_MONOSPACE  = 3
  61 } DiaFontFamily;
  62
  63 typedef enum
  64 {
  65   DIA_FONT_NORMAL  = (0<<2),
  66   DIA_FONT_OBLIQUE = (1<<2),
  67   DIA_FONT_ITALIC  = (2<<2)
  68 } DiaFontSlant;
  69
  70 typedef enum
  71 {
  72   DIA_FONT_ULTRALIGHT    = (1<<4),
  73   DIA_FONT_LIGHT         = (2<<4),
  74   DIA_FONT_WEIGHT_NORMAL = (0<<4), /* Deliberately 0 for DIA_FONT_NORMAL */
  75   DIA_FONT_MEDIUM        = (3<<4),
  76   DIA_FONT_DEMIBOLD      = (4<<4),
  77   DIA_FONT_BOLD          = (5<<4),
  78   DIA_FONT_ULTRABOLD     = (6<<4),
  79   DIA_FONT_HEAVY         = (7<<4)
  80 } DiaFontWeight;
  81
  82 /* macros to get a specific style info */
  83 #define DIA_FONT_STYLE_GET_FAMILY(st)    ((st) & (0x3))
  84 #define DIA_FONT_STYLE_GET_SLANT(st)     ((st) & (0x3<<2))
  85 #define DIA_FONT_STYLE_GET_WEIGHT(st)    ((st) & (0x7<<4))
  86
  87 GType dia_font_get_type(void) G_GNUC_CONST;
  88
  89 #define DIA_TYPE_FONT (dia_font_get_type())
  90
  91 #define DIA_FONT(object)    (G_TYPE_CHECK_INSTANCE_CAST ((object), \
  92                                                          DIA_TYPE_FONT, \
  93                                                          DiaFont))
  94 #define DIA_FONT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), \
  95                                                         DIA_TYPE_FONT, \
  96                                                         DiaFontClass))
  97
  98 struct _DiaFontClass {
  99     GObjectClass parent_class;
 100 };
 101
 102 /* Set the PangoContext used to render text.
 103  */
 104 void dia_font_init(PangoContext* pcontext);
 105 /* Start using a new context (for AA rendering) */
 106 void dia_font_push_context(PangoContext *pcontext);
 107 /* Go back to using the old context */
 108 void dia_font_pop_context(void);
 109 /* Retrieve the current context (used for the font widget) */
 110 PangoContext *dia_font_get_context(void);
 111
 112
 113     /* Get a font matching family,style,height. MUST be freed with
 114        dia_font_unref(). */
 115 DiaFont* dia_font_new(const char *family, DiaFontStyle style,
 116                       real height);
 117
 118     /* Get a font matching style. This is the preferred method to
 119      * create default fonts within objects. */
 120 DiaFont* dia_font_new_from_style(DiaFontStyle style, real height);
 121
 122     /* Get a font from a legacy font name */
 123 DiaFont* dia_font_new_from_legacy_name(const char *name);
 124
 125     /* Get a simple font name from a font.
 126        Name will be valid for the duration of the DiaFont* lifetime. */
 127 G_CONST_RETURN char* dia_font_get_legacy_name(const DiaFont* font);
 128
 129     /* Same attributes */
 130 DiaFont *dia_font_copy(const DiaFont* font);
 131
 132 DiaFont* dia_font_ref(DiaFont* font);
 133 void dia_font_unref(DiaFont* font);
 134
 135     /* Retrieves the style of the font */
 136 DiaFontStyle dia_font_get_style(const DiaFont* font);
 137
 138     /* Retrieves the family of the font. Caller must NOT free. */
 139 G_CONST_RETURN char* dia_font_get_family(const DiaFont* font);
 140 /* Acessor for the PangoFontDescription */
 141 G_CONST_RETURN PangoFontDescription *dia_font_get_description (const DiaFont* font);
 142
 143     /* Retrieves the height of the font */
 144 real dia_font_get_height(const DiaFont* font);
 145     /* Change the height inside a font record. */
 146 void dia_font_set_height(DiaFont* font, real height);
 147
 148     /* Changes the slant of an existing font */
 149 void dia_font_set_slant(DiaFont* font, DiaFontSlant slant);
 150     /* Changes the weight of an existing font */
 151 void dia_font_set_weight(DiaFont* font, DiaFontWeight weight);
 152     /* Changes the family of an existing font to one of the three standard
 153        families */
 154 void dia_font_set_family(DiaFont* font, DiaFontFamily family);
 155     /* Changes the family of an existing font to any family, but the name could
 156        be system-dependent. */
 157 void dia_font_set_any_family(DiaFont* font, const char* family);
 158
 159     /* FIXME: what do we do with this, actually ?
 160        Name lives for as long as the DiaFont lives. */
 161 G_CONST_RETURN char *dia_font_get_psfontname(const DiaFont *font);
 162
 163     /* returns a static string suitable for SVG */
 164 G_CONST_RETURN char *dia_font_get_weight_string(const DiaFont* font);
 165
 166     /* returns a static string suitable for SVG */
 167 G_CONST_RETURN char *dia_font_get_slant_string(const DiaFont* font);
 168
 169     /* uses an SVG style string */
 170 void dia_font_set_weight_from_string(DiaFont* font, const char* weight);
 171
 172     /* uses an SVG style string */
 173 void dia_font_set_slant_from_string(DiaFont* font, const char* slant);
 174
 175 /* -------- Font and string functions - unscaled versions.
 176    Use these version in Objects, primarily. */
 177
 178     /* Get the width of the string with the given font in cm */
 179 real dia_font_string_width(const char* string, DiaFont* font,
 180                           real height);
 181     /* Get the ascent of this string in cm (a positive number). */
 182 real dia_font_ascent(const char* string, DiaFont* font, real height);
 183     /* Get the descent of the font in cm (a positive number) */
 184 real dia_font_descent(const char* string, DiaFont* font, real height);
 185
 186     /* prepares a layout of the text, in font 'font'. */
 187 PangoLayout* dia_font_build_layout(const char* string, DiaFont* font,
 188                                    real height);
 189
 190 /* -------- Font and string functions - scaled versions.
 191    Use these version in Renderers, exclusively. */
 192
 193     /* Call once at the beginning of a rendering pass, to let dia know
 194      what is 1:1 scale. zoom_factor will then be divided by size_one. */
 195 void dia_font_set_nominal_zoom_factor(real size_one);
 196
 197     /* Get the width of the string with the given font in cm */
 198 real dia_font_scaled_string_width(const char* string, DiaFont* font,
 199                                   real height, real zoom_factor);
 200     /* Get the max ascent of the font in cm (a positive number).
 201
 202     FIXME: may turn out that we need to pass a string here as well. */
 203 real dia_font_scaled_ascent(const char* string, DiaFont* font,
 204                             real height, real zoom_factor);
 205     /* Get the max descent of the font in cm (a positive number)
 206        FIXME: may turn out that we need to pass a string here as well. */
 207 real dia_font_scaled_descent(const char* string, DiaFont* font,
 208                              real height, real zoom_factor);
 209
 210     /* prepares a layout of the text, in font 'font'.
 211
 212     When zoom_factor != 1.0, may tweak the font's size or stretch so that its
 213     bounding box is actually linear with respect to the zoom factor (kerning,
 214     ligaturing and other wild beasts usually get in the way of linear
 215     scaling). */
 216 PangoLayout* dia_font_scaled_build_layout(const char *string, DiaFont* font,
 217                                           real height, real zoom_factor);
 218
 219
 220 #endif /* FONT_H */