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        Ben 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
 179     /* center the text vertically
 180        We do this centering based on the 'baseline' since different fonts have
 181        different top edges. It looks bad when the whole string is moved when 1
 182        character from a non-default language is included in the string */
 183     y = area->y +
 184         font_calculate_baseline(t->font, area->height);
 185
 186     /* the +2 and -4 leave a small blank edge on the sides */
 187     x = area->x + 2;
 188     w = area->width - 4;
 189     h = area->height;
 190
 191     pango_layout_set_text(t->font->layout, t->string, -1);
 192     pango_layout_set_width(t->font->layout, w * PANGO_SCALE);
 193
 194     pango_layout_get_pixel_extents(t->font->layout, NULL, &rect);
 195     mw = rect.width;
 196
 197     /* pango_layout_set_alignment doesn't work with
 198        pango_xft_render_layout_line */
 199     switch (t->justify) {
 200     case RR_JUSTIFY_LEFT:
 201         break;
 202     case RR_JUSTIFY_RIGHT:
 203         x += (w - mw);
 204         break;
 205     case RR_JUSTIFY_CENTER:
 206         x += (w - mw) / 2;
 207         break;
 208     }
 209
 210     if (t->shadow_offset_x || t->shadow_offset_y) {
 211         c.color.red = t->shadow_color->r | t->shadow_color->r << 8;
 212         c.color.green = t->shadow_color->g | t->shadow_color->g << 8;
 213         c.color.blue = t->shadow_color->b | t->shadow_color->b << 8;
 214         c.color.alpha = 0xffff * t->shadow_alpha / 255;
 215         c.pixel = t->shadow_color->pixel;
 216         /* see below... */
 217         pango_xft_render_layout_line
 218             (d, &c, pango_layout_get_line(t->font->layout, 0),
 219              (x + t->shadow_offset_x) * PANGO_SCALE,
 220              (y + t->shadow_offset_y) * PANGO_SCALE);
 221     }
 222
 223     c.color.red = t->color->r | t->color->r << 8;
 224     c.color.green = t->color->g | t->color->g << 8;
 225     c.color.blue = t->color->b | t->color->b << 8;
 226     c.color.alpha = 0xff | 0xff << 8; /* fully opaque text */
 227     c.pixel = t->color->pixel;
 228
 229     /* layout_line() uses y to specify the baseline
 230        The line doesn't need to be freed, it's a part of the layout */
 231     pango_xft_render_layout_line
 232         (d, &c, pango_layout_get_line(t->font->layout, 0),
 233          x * PANGO_SCALE, y * PANGO_SCALE);
 234 }