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
  62     out = g_new(RrFont, 1);
  63     out->inst = inst;
  64     out->ref = 1;
  65     out->font_desc = pango_font_description_new();
  66     out->layout = pango_layout_new(inst->pango);
  67
  68     switch (weight) {
  69     case RR_FONTWEIGHT_LIGHT:     pweight = PANGO_WEIGHT_LIGHT;     break;
  70     case RR_FONTWEIGHT_NORMAL:    pweight = PANGO_WEIGHT_NORMAL;    break;
  71     case RR_FONTWEIGHT_SEMIBOLD:  pweight = PANGO_WEIGHT_SEMIBOLD;  break;
  72     case RR_FONTWEIGHT_BOLD:      pweight = PANGO_WEIGHT_BOLD;      break;
  73     case RR_FONTWEIGHT_ULTRABOLD: pweight = PANGO_WEIGHT_ULTRABOLD; break;
  74     default: g_assert_not_reached();
  75     }
  76
  77     switch (slant) {
  78     case RR_FONTSLANT_NORMAL:  pstyle = PANGO_STYLE_NORMAL;    break;
  79     case RR_FONTSLANT_ITALIC:  pstyle = PANGO_STYLE_ITALIC;    break;
  80     case RR_FONTSLANT_OBLIQUE: pstyle = PANGO_STYLE_OBLIQUE;   break;
  81     default: g_assert_not_reached();
  82     }
  83
  84     /* setup the font */
  85     pango_font_description_set_family(out->font_desc, name);
  86     pango_font_description_set_weight(out->font_desc, pweight);
  87     pango_font_description_set_style(out->font_desc, pstyle);
  88     pango_font_description_set_size(out->font_desc, size * PANGO_SCALE);
  89
  90     /* setup the layout */
  91     pango_layout_set_font_description(out->layout, out->font_desc);
  92     pango_layout_set_single_paragraph_mode(out->layout, TRUE);
  93     pango_layout_set_ellipsize(out->layout, PANGO_ELLIPSIZE_MIDDLE);
  94
  95     /* get the ascent and descent */
  96     measure_font(inst, out);
  97
  98     return out;
  99 }
 100
 101 RrFont *RrFontOpenDefault(const RrInstance *inst)
 102 {
 103     return RrFontOpen(inst, RrDefaultFontFamily, RrDefaultFontSize,
 104                       RrDefaultFontWeight, RrDefaultFontSlant);
 105 }
 106
 107 void RrFontRef(RrFont *f)
 108 {
 109     ++f->ref;
 110 }
 111
 112 void RrFontClose(RrFont *f)
 113 {
 114     if (f) {
 115         if (--f->ref < 1) {
 116             g_object_unref(f->layout);
 117             pango_font_description_free(f->font_desc);
 118             g_free(f);
 119         }
 120     }
 121 }
 122
 123 static void font_measure_full(const RrFont *f, const gchar *str,
 124                               gint *x, gint *y, gint shadow_x, gint shadow_y)
 125 {
 126     PangoRectangle rect;
 127
 128     pango_layout_set_text(f->layout, str, -1);
 129     pango_layout_set_width(f->layout, -1);
 130     pango_layout_get_pixel_extents(f->layout, NULL, &rect);
 131     *x = rect.width + ABS(shadow_x);
 132     *y = rect.height + ABS(shadow_y);
 133 }
 134
 135 RrSize *RrFontMeasureString(const RrFont *f, const gchar *str,
 136                             gint shadow_x, gint shadow_y)
 137 {
 138     RrSize *size;
 139     size = g_new(RrSize, 1);
 140     font_measure_full(f, str, &size->width, &size->height, shadow_x, shadow_y);
 141     return size;
 142 }
 143
 144 gint RrFontHeight(const RrFont *f, gint shadow_y)
 145 {
 146     return (f->ascent + f->descent) / PANGO_SCALE + ABS(shadow_y);
 147 }
 148
 149 static inline int font_calculate_baseline(RrFont *f, gint height)
 150 {
 151 /* For my own reference:
 152  *   _________
 153  *  ^space/2  ^height     ^baseline
 154  *  v_________|_          |
 155  *            | ^ascent   |   _           _
 156  *            | |         |  | |_ _____ _| |_ _  _
 157  *            | |         |  |  _/ -_) \ /  _| || |
 158  *            | v_________v   \__\___/_\_\\__|\_, |
 159  *            | ^descent                      |__/
 160  *  __________|_v
 161  *  ^space/2  |
 162  *  V_________v
 163  */
 164     return (((height * PANGO_SCALE) /* height of the space in pango units */
 165              - (f->ascent + f->descent)) /* minus space taken up by text */
 166             / 2 /* divided by two -> half of the empty space (this is the top
 167                    of the text) */
 168             + f->ascent) /* now move down to the baseline */
 169         / PANGO_SCALE; /* back to pixels */
 170 }
 171
 172 void RrFontDraw(XftDraw *d, RrTextureText *t, RrRect *area)
 173 {
 174     gint x,y,w,h;
 175     XftColor c;
 176     gint mw;
 177     PangoRectangle rect;
 178     PangoAttrList* attrs = NULL;
 179
 180     /* center the text vertically
 181        We do this centering based on the 'baseline' since different fonts have
 182        different top edges. It looks bad when the whole string is moved when 1
 183        character from a non-default language is included in the string */
 184     y = area->y +
 185         font_calculate_baseline(t->font, area->height);
 186
 187     /* the +2 and -4 leave a small blank edge on the sides */
 188     x = area->x + 2;
 189     w = area->width - 4;
 190     h = area->height;
 191
 192     /* * * set up the layout * * */
 193
 194     if (t->shortcut) {
 195         gchar *i;
 196         gchar *lowertext;
 197
 198         lowertext = g_utf8_strdown(t->string, -1);
 199         i = g_utf8_strchr(lowertext, -1, t->shortcut);
 200         if (i != NULL) {
 201             PangoAttribute *a;
 202
 203             a = pango_attr_underline_new(PANGO_UNDERLINE_LOW);
 204             a->start_index = i - lowertext;
 205             a->end_index = i - lowertext +
 206                 g_unichar_to_utf8(t->shortcut, NULL);
 207
 208             attrs = pango_attr_list_new();
 209             pango_attr_list_insert(attrs, a);
 210         }
 211         g_free(lowertext);
 212     }
 213
 214     pango_layout_set_text(t->font->layout, t->string, -1);
 215     pango_layout_set_width(t->font->layout, w * PANGO_SCALE);
 216
 217     /* * * end of setting up the layout * * */
 218
 219     pango_layout_get_pixel_extents(t->font->layout, NULL, &rect);
 220     mw = rect.width;
 221
 222     /* pango_layout_set_alignment doesn't work with
 223        pango_xft_render_layout_line */
 224     switch (t->justify) {
 225     case RR_JUSTIFY_LEFT:
 226         break;
 227     case RR_JUSTIFY_RIGHT:
 228         x += (w - mw);
 229         break;
 230     case RR_JUSTIFY_CENTER:
 231         x += (w - mw) / 2;
 232         break;
 233     }
 234
 235     if (t->shadow_offset_x || t->shadow_offset_y) {
 236         c.color.red = t->shadow_color->r | t->shadow_color->r << 8;
 237         c.color.green = t->shadow_color->g | t->shadow_color->g << 8;
 238         c.color.blue = t->shadow_color->b | t->shadow_color->b << 8;
 239         c.color.alpha = 0xffff * t->shadow_alpha / 255;
 240         c.pixel = t->shadow_color->pixel;
 241
 242         pango_layout_set_attributes(t->font->layout, NULL);
 243
 244         /* see below... */
 245         pango_xft_render_layout_line
 246             (d, &c, pango_layout_get_line(t->font->layout, 0),
 247              (x + t->shadow_offset_x) * PANGO_SCALE,
 248              (y + t->shadow_offset_y) * PANGO_SCALE);
 249     }
 250
 251     c.color.red = t->color->r | t->color->r << 8;
 252     c.color.green = t->color->g | t->color->g << 8;
 253     c.color.blue = t->color->b | t->color->b << 8;
 254     c.color.alpha = 0xff | 0xff << 8; /* fully opaque text */
 255     c.pixel = t->color->pixel;
 256
 257     pango_layout_set_attributes(t->font->layout, attrs);
 258     if (attrs != NULL) pango_attr_list_unref(attrs);
 259
 260     /* layout_line() uses y to specify the baseline
 261        The line doesn't need to be freed, it's a part of the layout */
 262     pango_xft_render_layout_line
 263         (d, &c, pango_layout_get_line(t->font->layout, 0),
 264          x * PANGO_SCALE, y * PANGO_SCALE);
 265 }