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
 150     /* pango_layout_get_pixel_extents lies! this is the right way to get the
 151        size of the text's area */
 152     pango_layout_get_extents(f->layout, NULL, &rect);
 153 #if PANGO_VERSION_MAJOR > 1 || \
 154     (PANGO_VERSION_MAJOR == 1 && PANGO_VERSION_MINOR >= 16)
 155     /* pass the logical rect as the ink rect, this is on purpose so we get the
 156        full area for the text */
 157     pango_extents_to_pixels(&rect, NULL);
 158 #else
 159     rect.width = (rect.width + PANGO_SCALE - 1) / PANGO_SCALE;
 160     rect.height = (rect.height + PANGO_SCALE - 1) / PANGO_SCALE;
 161 #endif
 162     *x = rect.width + ABS(shadow_x) + 4 /* we put a 2 px edge on each side */;
 163     *y = rect.height + ABS(shadow_y);
 164 }
 165
 166 RrSize *RrFontMeasureString(const RrFont *f, const gchar *str,
 167                             gint shadow_x, gint shadow_y)
 168 {
 169     RrSize *size;
 170     size = g_new(RrSize, 1);
 171     font_measure_full(f, str, &size->width, &size->height, shadow_x, shadow_y);
 172     return size;
 173 }
 174
 175 gint RrFontHeight(const RrFont *f, gint shadow_y)
 176 {
 177     return (f->ascent + f->descent) / PANGO_SCALE + ABS(shadow_y);
 178 }
 179
 180 static inline int font_calculate_baseline(RrFont *f, gint height)
 181 {
 182 /* For my own reference:
 183  *   _________
 184  *  ^space/2  ^height     ^baseline
 185  *  v_________|_          |
 186  *            | ^ascent   |   _           _
 187  *            | |         |  | |_ _____ _| |_ _  _
 188  *            | |         |  |  _/ -_) \ /  _| || |
 189  *            | v_________v   \__\___/_\_\\__|\_, |
 190  *            | ^descent                      |__/
 191  *  __________|_v
 192  *  ^space/2  |
 193  *  V_________v
 194  */
 195     return (((height * PANGO_SCALE) /* height of the space in pango units */
 196              - (f->ascent + f->descent)) /* minus space taken up by text */
 197             / 2 /* divided by two -> half of the empty space (this is the top
 198                    of the text) */
 199             + f->ascent) /* now move down to the baseline */
 200         / PANGO_SCALE; /* back to pixels */
 201 }
 202
 203 void RrFontDraw(XftDraw *d, RrTextureText *t, RrRect *area)
 204 {
 205     gint x,y,w,h;
 206     XftColor c;
 207     gint mw;
 208     PangoRectangle rect;
 209     PangoAttrList *attrlist;
 210
 211     /* center the text vertically
 212        We do this centering based on the 'baseline' since different fonts have
 213        different top edges. It looks bad when the whole string is moved when 1
 214        character from a non-default language is included in the string */
 215     y = area->y +
 216         font_calculate_baseline(t->font, area->height);
 217
 218     /* the +2 and -4 leave a small blank edge on the sides */
 219     x = area->x + 2;
 220     w = area->width - 4;
 221     h = area->height;
 222
 223     pango_layout_set_text(t->font->layout, t->string, -1);
 224     pango_layout_set_width(t->font->layout, w * PANGO_SCALE);
 225
 226     /* * * end of setting up the layout * * */
 227
 228     pango_layout_get_pixel_extents(t->font->layout, NULL, &rect);
 229     mw = rect.width;
 230
 231     /* pango_layout_set_alignment doesn't work with
 232        pango_xft_render_layout_line */
 233     switch (t->justify) {
 234     case RR_JUSTIFY_LEFT:
 235         break;
 236     case RR_JUSTIFY_RIGHT:
 237         x += (w - mw);
 238         break;
 239     case RR_JUSTIFY_CENTER:
 240         x += (w - mw) / 2;
 241         break;
 242     }
 243
 244     if (t->shadow_offset_x || t->shadow_offset_y) {
 245         c.color.red = t->shadow_color->r | t->shadow_color->r << 8;
 246         c.color.green = t->shadow_color->g | t->shadow_color->g << 8;
 247         c.color.blue = t->shadow_color->b | t->shadow_color->b << 8;
 248         c.color.alpha = 0xffff * t->shadow_alpha / 255;
 249         c.pixel = t->shadow_color->pixel;
 250
 251         /* see below... */
 252         pango_xft_render_layout_line
 253             (d, &c, pango_layout_get_line(t->font->layout, 0),
 254              (x + t->shadow_offset_x) * PANGO_SCALE,
 255              (y + t->shadow_offset_y) * PANGO_SCALE);
 256     }
 257
 258     c.color.red = t->color->r | t->color->r << 8;
 259     c.color.green = t->color->g | t->color->g << 8;
 260     c.color.blue = t->color->b | t->color->b << 8;
 261     c.color.alpha = 0xff | 0xff << 8; /* fully opaque text */
 262     c.pixel = t->color->pixel;
 263
 264     if (t->shortcut) {
 265         const gchar *c = t->string + t->shortcut_pos;
 266
 267         t->font->shortcut_underline->start_index = t->shortcut_pos;
 268         t->font->shortcut_underline->end_index = t->shortcut_pos +
 269             (g_utf8_next_char(c) - c);
 270
 271         /* the attributes are owned by the layout.
 272            re-add the attributes to the layout after changing the
 273            start and end index */
 274         attrlist = pango_layout_get_attributes(t->font->layout);
 275         pango_attr_list_ref(attrlist);
 276         pango_layout_set_attributes(t->font->layout, attrlist);
 277         pango_attr_list_unref(attrlist);
 278     }
 279
 280     /* layout_line() uses y to specify the baseline
 281        The line doesn't need to be freed, it's a part of the layout */
 282     pango_xft_render_layout_line
 283         (d, &c, pango_layout_get_line(t->font->layout, 0),
 284          x * PANGO_SCALE, y * PANGO_SCALE);
 285
 286     if (t->shortcut) {
 287         t->font->shortcut_underline->start_index = 0;
 288         t->font->shortcut_underline->end_index = 0;
 289         /* the attributes are owned by the layout.
 290            re-add the attributes to the layout after changing the
 291            start and end index */
 292         attrlist = pango_layout_get_attributes(t->font->layout);
 293         pango_attr_list_ref(attrlist);
 294         pango_layout_set_attributes(t->font->layout, attrlist);
 295         pango_attr_list_unref(attrlist);
 296     }
 297 }