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     gchar *locale, *p;
  38
  39     /* get the default language from the locale
  40        (based on gtk_get_default_language in gtkmain.c) */
  41     locale = g_strdup(setlocale(LC_CTYPE, NULL));
  42     if ((p = strchr(locale, '.'))) *p = '\0'; /* strip off the . */
  43     if ((p = strchr(locale, '@'))) *p = '\0'; /* strip off the @ */
  44
  45     /* measure the ascent and descent */
  46     metrics = pango_context_get_metrics(inst->pango, f->font_desc,
  47                                         pango_language_from_string(locale));
  48     f->ascent = pango_font_metrics_get_ascent(metrics);
  49     f->descent = pango_font_metrics_get_descent(metrics);
  50     pango_font_metrics_unref(metrics);
  51
  52     g_free(locale);
  53 }
  54
  55 RrFont *RrFontOpen(const RrInstance *inst, const gchar *name, gint size,
  56                    RrFontWeight weight, RrFontSlant slant)
  57 {
  58     RrFont *out;
  59     PangoWeight pweight;
  60     PangoStyle pstyle;
  61     PangoAttrList *attrlist;
  62
  63     out = g_new(RrFont, 1);
  64     out->inst = inst;
  65     out->ref = 1;
  66     out->font_desc = pango_font_description_new();
  67     out->layout = pango_layout_new(inst->pango);
  68     out->shortcut_underline = pango_attr_underline_new(PANGO_UNDERLINE_LOW);
  69
  70     attrlist = pango_attr_list_new();
  71     /* shortcut_underline is owned by the attrlist */
  72     pango_attr_list_insert(attrlist, out->shortcut_underline);
  73     /* the attributes are owned by the layout */
  74     pango_layout_set_attributes(out->layout, attrlist);
  75     pango_attr_list_unref(attrlist);
  76
  77     switch (weight) {
  78     case RR_FONTWEIGHT_LIGHT:     pweight = PANGO_WEIGHT_LIGHT;     break;
  79     case RR_FONTWEIGHT_NORMAL:    pweight = PANGO_WEIGHT_NORMAL;    break;
  80     case RR_FONTWEIGHT_SEMIBOLD:  pweight = PANGO_WEIGHT_SEMIBOLD;  break;
  81     case RR_FONTWEIGHT_BOLD:      pweight = PANGO_WEIGHT_BOLD;      break;
  82     case RR_FONTWEIGHT_ULTRABOLD: pweight = PANGO_WEIGHT_ULTRABOLD; break;
  83     default: g_assert_not_reached();
  84     }
  85
  86     switch (slant) {
  87     case RR_FONTSLANT_NORMAL:  pstyle = PANGO_STYLE_NORMAL;    break;
  88     case RR_FONTSLANT_ITALIC:  pstyle = PANGO_STYLE_ITALIC;    break;
  89     case RR_FONTSLANT_OBLIQUE: pstyle = PANGO_STYLE_OBLIQUE;   break;
  90     default: g_assert_not_reached();
  91     }
  92
  93     /* setup the font */
  94     pango_font_description_set_family(out->font_desc, name);
  95     pango_font_description_set_weight(out->font_desc, pweight);
  96     pango_font_description_set_style(out->font_desc, pstyle);
  97     pango_font_description_set_size(out->font_desc, size * PANGO_SCALE);
  98
  99     /* setup the layout */
 100     pango_layout_set_font_description(out->layout, out->font_desc);
 101     pango_layout_set_single_paragraph_mode(out->layout, TRUE);
 102     pango_layout_set_ellipsize(out->layout, PANGO_ELLIPSIZE_MIDDLE);
 103
 104     /* get the ascent and descent */
 105     measure_font(inst, out);
 106
 107     return out;
 108 }
 109
 110 RrFont *RrFontOpenDefault(const RrInstance *inst)
 111 {
 112     return RrFontOpen(inst, RrDefaultFontFamily, RrDefaultFontSize,
 113                       RrDefaultFontWeight, RrDefaultFontSlant);
 114 }
 115
 116 void RrFontRef(RrFont *f)
 117 {
 118     ++f->ref;
 119 }
 120
 121 void RrFontClose(RrFont *f)
 122 {
 123     if (f) {
 124         if (--f->ref < 1) {
 125             g_object_unref(f->layout);
 126             pango_font_description_free(f->font_desc);
 127             g_free(f);
 128         }
 129     }
 130 }
 131
 132 static void font_measure_full(const RrFont *f, const gchar *str,
 133                               gint *x, gint *y, gint shadow_x, gint shadow_y)
 134 {
 135     PangoRectangle rect;
 136
 137     pango_layout_set_text(f->layout, str, -1);
 138     pango_layout_set_width(f->layout, -1);
 139     pango_layout_get_pixel_extents(f->layout, NULL, &rect);
 140     *x = rect.width + ABS(shadow_x);
 141     *y = rect.height + ABS(shadow_y);
 142 }
 143
 144 RrSize *RrFontMeasureString(const RrFont *f, const gchar *str,
 145                             gint shadow_x, gint shadow_y)
 146 {
 147     RrSize *size;
 148     size = g_new(RrSize, 1);
 149     font_measure_full(f, str, &size->width, &size->height, shadow_x, shadow_y);
 150     return size;
 151 }
 152
 153 gint RrFontHeight(const RrFont *f, gint shadow_y)
 154 {
 155     return (f->ascent + f->descent) / PANGO_SCALE + ABS(shadow_y);
 156 }
 157
 158 static inline int font_calculate_baseline(RrFont *f, gint height)
 159 {
 160 /* For my own reference:
 161  *   _________
 162  *  ^space/2  ^height     ^baseline
 163  *  v_________|_          |
 164  *            | ^ascent   |   _           _
 165  *            | |         |  | |_ _____ _| |_ _  _
 166  *            | |         |  |  _/ -_) \ /  _| || |
 167  *            | v_________v   \__\___/_\_\\__|\_, |
 168  *            | ^descent                      |__/
 169  *  __________|_v
 170  *  ^space/2  |
 171  *  V_________v
 172  */
 173     return (((height * PANGO_SCALE) /* height of the space in pango units */
 174              - (f->ascent + f->descent)) /* minus space taken up by text */
 175             / 2 /* divided by two -> half of the empty space (this is the top
 176                    of the text) */
 177             + f->ascent) /* now move down to the baseline */
 178         / PANGO_SCALE; /* back to pixels */
 179 }
 180
 181 void RrFontDraw(XftDraw *d, RrTextureText *t, RrRect *area)
 182 {
 183     gint x,y,w,h;
 184     XftColor c;
 185     gint mw;
 186     PangoRectangle rect;
 187     PangoAttrList *attrlist;
 188
 189     /* center the text vertically
 190        We do this centering based on the 'baseline' since different fonts have
 191        different top edges. It looks bad when the whole string is moved when 1
 192        character from a non-default language is included in the string */
 193     y = area->y +
 194         font_calculate_baseline(t->font, area->height);
 195
 196     /* the +2 and -4 leave a small blank edge on the sides */
 197     x = area->x + 2;
 198     w = area->width - 4;
 199     h = area->height;
 200
 201     pango_layout_set_text(t->font->layout, t->string, -1);
 202     pango_layout_set_width(t->font->layout, w * PANGO_SCALE);
 203
 204     /* * * end of setting up the layout * * */
 205
 206     pango_layout_get_pixel_extents(t->font->layout, NULL, &rect);
 207     mw = rect.width;
 208
 209     /* pango_layout_set_alignment doesn't work with
 210        pango_xft_render_layout_line */
 211     switch (t->justify) {
 212     case RR_JUSTIFY_LEFT:
 213         break;
 214     case RR_JUSTIFY_RIGHT:
 215         x += (w - mw);
 216         break;
 217     case RR_JUSTIFY_CENTER:
 218         x += (w - mw) / 2;
 219         break;
 220     }
 221
 222     t->font->shortcut_underline->start_index = 0;
 223     t->font->shortcut_underline->end_index = 0;
 224     /* the attributes are owned by the layout.
 225        re-add the attributes to the layout after changing the
 226        start and end index */
 227     attrlist = pango_layout_get_attributes(t->font->layout);
 228     pango_attr_list_ref(attrlist);
 229     pango_layout_set_attributes(t->font->layout, attrlist);
 230     pango_attr_list_unref(attrlist);
 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 }