Dogcows Code - chaz/openbox/blob - render/font.c

   1 /* -*- indent-tabs-mode: nil; tab-width: 4; c-basic-offset: 4; -*-
   2
   3    font.c for the Openbox window manager
   4    Copyright (c) 2006        Mikael Magnusson
   5    Copyright (c) 2003-2007   Dana Jansens
   6    Copyright (c) 2003        Derek Foreman
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    See the COPYING file for a copy of the GNU General Public License.
  19 */
  20
  21 #include "font.h"
  22 #include "color.h"
  23 #include "mask.h"
  24 #include "theme.h"
  25 #include "geom.h"
  26 #include "instance.h"
  27 #include "gettext.h"
  28
  29 #include <glib.h>
  30 #include <string.h>
  31 #include <stdlib.h>
  32 #include <locale.h>
  33
  34 static void measure_font(const RrInstance *inst, RrFont *f)
  35 {
  36     PangoFontMetrics *metrics;
  37     static PangoLanguage *lang = NULL;
  38
  39     if (lang == NULL) {
  40 #if PANGO_VERSION_MAJOR > 1 || \
  41     (PANGO_VERSION_MAJOR == 1 && PANGO_VERSION_MINOR >= 16)
  42         lang = pango_language_get_default();
  43 #else
  44         gchar *locale, *p;
  45         /* get the default language from the locale
  46            (based on gtk_get_default_language in gtkmain.c) */
  47         locale = g_strdup(setlocale(LC_CTYPE, NULL));
  48         if ((p = strchr(locale, '.'))) *p = '\0'; /* strip off the . */
  49         if ((p = strchr(locale, '@'))) *p = '\0'; /* strip off the @ */
  50         lang = pango_language_from_string(locale);
  51         g_free(locale);
  52 #endif
  53     }
  54
  55     /* measure the ascent and descent */
  56     metrics = pango_context_get_metrics(inst->pango, f->font_desc, lang);
  57     f->ascent = pango_font_metrics_get_ascent(metrics);
  58     f->descent = pango_font_metrics_get_descent(metrics);
  59     pango_font_metrics_unref(metrics);
  60
  61 }
  62
  63 RrFont *RrFontOpen(const RrInstance *inst, const gchar *name, gint size,
  64                    RrFontWeight weight, RrFontSlant slant)
  65 {
  66     RrFont *out;
  67     PangoWeight pweight;
  68     PangoStyle pstyle;
  69     PangoAttrList *attrlist;
  70
  71     out = g_new(RrFont, 1);
  72     out->inst = inst;
  73     out->ref = 1;
  74     out->font_desc = pango_font_description_new();
  75     out->layout = pango_layout_new(inst->pango);
  76     out->shortcut_underline = pango_attr_underline_new(PANGO_UNDERLINE_LOW);
  77     out->shortcut_underline->start_index = 0;
  78     out->shortcut_underline->end_index = 0;
  79
  80     attrlist = pango_attr_list_new();
  81     /* shortcut_underline is owned by the attrlist */
  82     pango_attr_list_insert(attrlist, out->shortcut_underline);
  83     /* the attributes are owned by the layout */
  84     pango_layout_set_attributes(out->layout, attrlist);
  85     pango_attr_list_unref(attrlist);
  86
  87     switch (weight) {
  88     case RR_FONTWEIGHT_LIGHT:     pweight = PANGO_WEIGHT_LIGHT;     break;
  89     case RR_FONTWEIGHT_NORMAL:    pweight = PANGO_WEIGHT_NORMAL;    break;
  90     case RR_FONTWEIGHT_SEMIBOLD:  pweight = PANGO_WEIGHT_SEMIBOLD;  break;
  91     case RR_FONTWEIGHT_BOLD:      pweight = PANGO_WEIGHT_BOLD;      break;
  92     case RR_FONTWEIGHT_ULTRABOLD: pweight = PANGO_WEIGHT_ULTRABOLD; break;
  93     default: g_assert_not_reached();
  94     }
  95
  96     switch (slant) {
  97     case RR_FONTSLANT_NORMAL:  pstyle = PANGO_STYLE_NORMAL;    break;
  98     case RR_FONTSLANT_ITALIC:  pstyle = PANGO_STYLE_ITALIC;    break;
  99     case RR_FONTSLANT_OBLIQUE: pstyle = PANGO_STYLE_OBLIQUE;   break;
 100     default: g_assert_not_reached();
 101     }
 102
 103     /* setup the font */
 104     pango_font_description_set_family(out->font_desc, name);
 105     pango_font_description_set_weight(out->font_desc, pweight);
 106     pango_font_description_set_style(out->font_desc, pstyle);
 107     pango_font_description_set_size(out->font_desc, size * PANGO_SCALE);
 108
 109     /* setup the layout */
 110     pango_layout_set_font_description(out->layout, out->font_desc);
 111     pango_layout_set_single_paragraph_mode(out->layout, TRUE);
 112     pango_layout_set_ellipsize(out->layout, PANGO_ELLIPSIZE_MIDDLE);
 113
 114     /* get the ascent and descent */
 115     measure_font(inst, out);
 116
 117     return out;
 118 }
 119
 120 RrFont *RrFontOpenDefault(const RrInstance *inst)
 121 {
 122     return RrFontOpen(inst, RrDefaultFontFamily, RrDefaultFontSize,
 123                       RrDefaultFontWeight, RrDefaultFontSlant);
 124 }
 125
 126 void RrFontRef(RrFont *f)
 127 {
 128     ++f->ref;
 129 }
 130
 131 void RrFontClose(RrFont *f)
 132 {
 133     if (f) {
 134         if (--f->ref < 1) {
 135             g_object_unref(f->layout);
 136             pango_font_description_free(f->font_desc);
 137             g_free(f);
 138         }
 139     }
 140 }
 141
 142 static void font_measure_full(const RrFont *f, const gchar *str,
 143                               gint *x, gint *y, gint shadow_x, gint shadow_y)
 144 {
 145     PangoRectangle rect;
 146
 147     pango_layout_set_text(f->layout, str, -1);
 148     pango_layout_set_width(f->layout, -1);
 149     pango_layout_get_pixel_extents(f->layout, NULL, &rect);
 150     *x = rect.width + ABS(shadow_x) + 4 /* we put a 2 px edge on each side */;
 151     *y = rect.height + ABS(shadow_y);
 152 }
 153
 154 RrSize *RrFontMeasureString(const RrFont *f, const gchar *str,
 155                             gint shadow_x, gint shadow_y)
 156 {
 157     RrSize *size;
 158     size = g_new(RrSize, 1);
 159     font_measure_full(f, str, &size->width, &size->height, shadow_x, shadow_y);
 160     return size;
 161 }
 162
 163 gint RrFontHeight(const RrFont *f, gint shadow_y)
 164 {
 165     return (f->ascent + f->descent) / PANGO_SCALE + ABS(shadow_y);
 166 }
 167
 168 static inline int font_calculate_baseline(RrFont *f, gint height)
 169 {
 170 /* For my own reference:
 171  *   _________
 172  *  ^space/2  ^height     ^baseline
 173  *  v_________|_          |
 174  *            | ^ascent   |   _           _
 175  *            | |         |  | |_ _____ _| |_ _  _
 176  *            | |         |  |  _/ -_) \ /  _| || |
 177  *            | v_________v   \__\___/_\_\\__|\_, |
 178  *            | ^descent                      |__/
 179  *  __________|_v
 180  *  ^space/2  |
 181  *  V_________v
 182  */
 183     return (((height * PANGO_SCALE) /* height of the space in pango units */
 184              - (f->ascent + f->descent)) /* minus space taken up by text */
 185             / 2 /* divided by two -> half of the empty space (this is the top
 186                    of the text) */
 187             + f->ascent) /* now move down to the baseline */
 188         / PANGO_SCALE; /* back to pixels */
 189 }
 190
 191 void RrFontDraw(XftDraw *d, RrTextureText *t, RrRect *area)
 192 {
 193     gint x,y,w,h;
 194     XftColor c;
 195     gint mw;
 196     PangoRectangle rect;
 197     PangoAttrList *attrlist;
 198
 199     /* center the text vertically
 200        We do this centering based on the 'baseline' since different fonts have
 201        different top edges. It looks bad when the whole string is moved when 1
 202        character from a non-default language is included in the string */
 203     y = area->y +
 204         font_calculate_baseline(t->font, area->height);
 205
 206     /* the +2 and -4 leave a small blank edge on the sides */
 207     x = area->x + 2;
 208     w = area->width - 4;
 209     h = area->height;
 210
 211     pango_layout_set_text(t->font->layout, t->string, -1);
 212     pango_layout_set_width(t->font->layout, w * PANGO_SCALE);
 213
 214     /* * * end of setting up the layout * * */
 215
 216     pango_layout_get_pixel_extents(t->font->layout, NULL, &rect);
 217     mw = rect.width;
 218
 219     /* pango_layout_set_alignment doesn't work with
 220        pango_xft_render_layout_line */
 221     switch (t->justify) {
 222     case RR_JUSTIFY_LEFT:
 223         break;
 224     case RR_JUSTIFY_RIGHT:
 225         x += (w - mw);
 226         break;
 227     case RR_JUSTIFY_CENTER:
 228         x += (w - mw) / 2;
 229         break;
 230     }
 231
 232     if (t->shadow_offset_x || t->shadow_offset_y) {
 233         c.color.red = t->shadow_color->r | t->shadow_color->r << 8;
 234         c.color.green = t->shadow_color->g | t->shadow_color->g << 8;
 235         c.color.blue = t->shadow_color->b | t->shadow_color->b << 8;
 236         c.color.alpha = 0xffff * t->shadow_alpha / 255;
 237         c.pixel = t->shadow_color->pixel;
 238
 239         /* see below... */
 240         pango_xft_render_layout_line
 241             (d, &c, pango_layout_get_line(t->font->layout, 0),
 242              (x + t->shadow_offset_x) * PANGO_SCALE,
 243              (y + t->shadow_offset_y) * PANGO_SCALE);
 244     }
 245
 246     c.color.red = t->color->r | t->color->r << 8;
 247     c.color.green = t->color->g | t->color->g << 8;
 248     c.color.blue = t->color->b | t->color->b << 8;
 249     c.color.alpha = 0xff | 0xff << 8; /* fully opaque text */
 250     c.pixel = t->color->pixel;
 251
 252     if (t->shortcut) {
 253         const gchar *c = t->string + t->shortcut_pos;
 254
 255         t->font->shortcut_underline->start_index = t->shortcut_pos;
 256         t->font->shortcut_underline->end_index = t->shortcut_pos +
 257             (g_utf8_next_char(c) - c);
 258
 259         /* the attributes are owned by the layout.
 260            re-add the attributes to the layout after changing the
 261            start and end index */
 262         attrlist = pango_layout_get_attributes(t->font->layout);
 263         pango_attr_list_ref(attrlist);
 264         pango_layout_set_attributes(t->font->layout, attrlist);
 265         pango_attr_list_unref(attrlist);
 266     }
 267
 268     /* layout_line() uses y to specify the baseline
 269        The line doesn't need to be freed, it's a part of the layout */
 270     pango_xft_render_layout_line
 271         (d, &c, pango_layout_get_line(t->font->layout, 0),
 272          x * PANGO_SCALE, y * PANGO_SCALE);
 273
 274     if (t->shortcut) {
 275         t->font->shortcut_underline->start_index = 0;
 276         t->font->shortcut_underline->end_index = 0;
 277         /* the attributes are owned by the layout.
 278            re-add the attributes to the layout after changing the
 279            start and end index */
 280         attrlist = pango_layout_get_attributes(t->font->layout);
 281         pango_attr_list_ref(attrlist);
 282         pango_layout_set_attributes(t->font->layout, attrlist);
 283         pango_attr_list_unref(attrlist);
 284     }
 285 }