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_wrap(out->layout, PANGO_WRAP_WORD_CHAR);
 112
 113     /* get the ascent and descent */
 114     measure_font(inst, out);
 115
 116     return out;
 117 }
 118
 119 RrFont *RrFontOpenDefault(const RrInstance *inst)
 120 {
 121     return RrFontOpen(inst, RrDefaultFontFamily, RrDefaultFontSize,
 122                       RrDefaultFontWeight, RrDefaultFontSlant);
 123 }
 124
 125 void RrFontRef(RrFont *f)
 126 {
 127     ++f->ref;
 128 }
 129
 130 void RrFontClose(RrFont *f)
 131 {
 132     if (f) {
 133         if (--f->ref < 1) {
 134             g_object_unref(f->layout);
 135             pango_font_description_free(f->font_desc);
 136             g_free(f);
 137         }
 138     }
 139 }
 140
 141 static void font_measure_full(const RrFont *f, const gchar *str,
 142                               gint *x, gint *y, gint shadow_x, gint shadow_y,
 143                               gboolean flow, gint maxwidth)
 144 {
 145     PangoRectangle rect;
 146
 147     pango_layout_set_text(f->layout, str, -1);
 148     if (flow) {
 149         pango_layout_set_single_paragraph_mode(f->layout, FALSE);
 150         pango_layout_set_width(f->layout, maxwidth * PANGO_SCALE);
 151         pango_layout_set_ellipsize(f->layout, PANGO_ELLIPSIZE_NONE);
 152     }
 153     else {
 154         /* single line mode */
 155         pango_layout_set_single_paragraph_mode(f->layout, TRUE);
 156         pango_layout_set_width(f->layout, -1);
 157         pango_layout_set_ellipsize(f->layout, PANGO_ELLIPSIZE_MIDDLE);
 158     }
 159
 160     /* pango_layout_get_pixel_extents lies! this is the right way to get the
 161        size of the text's area */
 162     pango_layout_get_extents(f->layout, NULL, &rect);
 163 #if PANGO_VERSION_MAJOR > 1 || \
 164     (PANGO_VERSION_MAJOR == 1 && PANGO_VERSION_MINOR >= 16)
 165     /* pass the logical rect as the ink rect, this is on purpose so we get the
 166        full area for the text */
 167     pango_extents_to_pixels(&rect, NULL);
 168 #else
 169     rect.width = (rect.width + PANGO_SCALE - 1) / PANGO_SCALE;
 170     rect.height = (rect.height + PANGO_SCALE - 1) / PANGO_SCALE;
 171 #endif
 172     *x = rect.width + ABS(shadow_x) + 4 /* we put a 2 px edge on each side */;
 173     *y = rect.height + ABS(shadow_y);
 174 }
 175
 176 RrSize *RrFontMeasureString(const RrFont *f, const gchar *str,
 177                             gint shadow_x, gint shadow_y,
 178                             gboolean flow, gint maxwidth)
 179 {
 180     RrSize *size;
 181
 182     g_assert(!flow || maxwidth > 0);
 183
 184     size = g_new(RrSize, 1);
 185     font_measure_full(f, str, &size->width, &size->height, shadow_x, shadow_y,
 186                       flow, maxwidth);
 187     return size;
 188 }
 189
 190 gint RrFontHeight(const RrFont *f, gint shadow_y)
 191 {
 192     return (f->ascent + f->descent) / PANGO_SCALE + ABS(shadow_y);
 193 }
 194
 195 static inline int font_calculate_baseline(RrFont *f, gint height)
 196 {
 197 /* For my own reference:
 198  *   _________
 199  *  ^space/2  ^height     ^baseline
 200  *  v_________|_          |
 201  *            | ^ascent   |   _           _
 202  *            | |         |  | |_ _____ _| |_ _  _
 203  *            | |         |  |  _/ -_) \ /  _| || |
 204  *            | v_________v   \__\___/_\_\\__|\_, |
 205  *            | ^descent                      |__/
 206  *  __________|_v
 207  *  ^space/2  |
 208  *  V_________v
 209  */
 210     return (((height * PANGO_SCALE) /* height of the space in pango units */
 211              - (f->ascent + f->descent)) /* minus space taken up by text */
 212             / 2 /* divided by two -> half of the empty space (this is the top
 213                    of the text) */
 214             + f->ascent) /* now move down to the baseline */
 215         / PANGO_SCALE; /* back to pixels */
 216 }
 217
 218 void RrFontDraw(XftDraw *d, RrTextureText *t, RrRect *area)
 219 {
 220     gint x,y,w,h;
 221     XftColor c;
 222     gint mw;
 223     PangoRectangle rect;
 224     PangoAttrList *attrlist;
 225     PangoEllipsizeMode ell;
 226
 227     g_assert(!t->flow || t->maxwidth > 0);
 228
 229     y = area->y;
 230     if (!t->flow)
 231         /* center the text vertically
 232            We do this centering based on the 'baseline' since different fonts
 233            have different top edges. It looks bad when the whole string is
 234            moved when 1 character from a non-default language is included in
 235            the string */
 236         y += font_calculate_baseline(t->font, area->height);
 237
 238     /* the +2 and -4 leave a small blank edge on the sides */
 239     x = area->x + 2;
 240     w = area->width;
 241     if (t->flow) w = MAX(w, t->maxwidth);
 242     w -= 4;
 243     h = area->height;
 244
 245     if (t->flow)
 246         ell = PANGO_ELLIPSIZE_NONE;
 247     else {
 248         switch (t->ellipsize) {
 249         case RR_ELLIPSIZE_NONE:
 250             ell = PANGO_ELLIPSIZE_NONE;
 251             break;
 252         case RR_ELLIPSIZE_START:
 253             ell = PANGO_ELLIPSIZE_START;
 254             break;
 255         case RR_ELLIPSIZE_MIDDLE:
 256             ell = PANGO_ELLIPSIZE_MIDDLE;
 257             break;
 258         case RR_ELLIPSIZE_END:
 259             ell = PANGO_ELLIPSIZE_END;
 260             break;
 261         }
 262     }
 263
 264     pango_layout_set_text(t->font->layout, t->string, -1);
 265     pango_layout_set_width(t->font->layout, w * PANGO_SCALE);
 266     pango_layout_set_ellipsize(t->font->layout, ell);
 267     pango_layout_set_single_paragraph_mode(t->font->layout, !t->flow);
 268
 269     /* * * end of setting up the layout * * */
 270
 271     pango_layout_get_pixel_extents(t->font->layout, NULL, &rect);
 272     mw = rect.width;
 273
 274     /* pango_layout_set_alignment doesn't work with
 275        pango_xft_render_layout_line */
 276     switch (t->justify) {
 277     case RR_JUSTIFY_LEFT:
 278         break;
 279     case RR_JUSTIFY_RIGHT:
 280         x += (w - mw);
 281         break;
 282     case RR_JUSTIFY_CENTER:
 283         x += (w - mw) / 2;
 284         break;
 285     }
 286
 287     if (t->shadow_offset_x || t->shadow_offset_y) {
 288         /* From nvidia's readme (chapter 23):
 289
 290            When rendering to a 32-bit window, keep in mind that the X RENDER
 291            extension, used by most composite managers, expects "premultiplied
 292            alpha" colors. This means that if your color has components (r,g,b)
 293            and alpha value a, then you must render (a*r, a*g, a*b, a) into the
 294            target window.
 295         */
 296         c.color.red = (t->shadow_color->r | t->shadow_color->r << 8) *
 297             t->shadow_alpha / 255;
 298         c.color.green = (t->shadow_color->g | t->shadow_color->g << 8) *
 299             t->shadow_alpha / 255;
 300         c.color.blue = (t->shadow_color->b | t->shadow_color->b << 8) *
 301             t->shadow_alpha / 255;
 302         c.color.alpha = 0xffff * t->shadow_alpha / 255;
 303         c.pixel = t->shadow_color->pixel;
 304
 305         /* see below... */
 306         if (!t->flow) {
 307             pango_xft_render_layout_line
 308                 (d, &c,
 309 #if PANGO_VERSION_MAJOR > 1 || \
 310     (PANGO_VERSION_MAJOR == 1 && PANGO_VERSION_MINOR >= 16)
 311                  pango_layout_get_line_readonly(t->font->layout, 0),
 312 #else
 313                  pango_layout_get_line(t->font->layout, 0),
 314 #endif
 315                  (x + t->shadow_offset_x) * PANGO_SCALE,
 316                  (y + t->shadow_offset_y) * PANGO_SCALE);
 317         }
 318         else {
 319             pango_xft_render_layout(d, &c, t->font->layout,
 320                                     (x + t->shadow_offset_x) * PANGO_SCALE,
 321                                     (y + t->shadow_offset_y) * PANGO_SCALE);
 322         }
 323     }
 324
 325     c.color.red = t->color->r | t->color->r << 8;
 326     c.color.green = t->color->g | t->color->g << 8;
 327     c.color.blue = t->color->b | t->color->b << 8;
 328     c.color.alpha = 0xff | 0xff << 8; /* fully opaque text */
 329     c.pixel = t->color->pixel;
 330
 331     if (t->shortcut) {
 332         const gchar *s = t->string + t->shortcut_pos;
 333
 334         t->font->shortcut_underline->start_index = t->shortcut_pos;
 335         t->font->shortcut_underline->end_index = t->shortcut_pos +
 336             (g_utf8_next_char(s) - s);
 337
 338         /* the attributes are owned by the layout.
 339            re-add the attributes to the layout after changing the
 340            start and end index */
 341         attrlist = pango_layout_get_attributes(t->font->layout);
 342         pango_attr_list_ref(attrlist);
 343         pango_layout_set_attributes(t->font->layout, attrlist);
 344         pango_attr_list_unref(attrlist);
 345     }
 346
 347     /* layout_line() uses y to specify the baseline
 348        The line doesn't need to be freed, it's a part of the layout */
 349     if (!t->flow) {
 350         pango_xft_render_layout_line
 351             (d, &c,
 352 #if PANGO_VERSION_MAJOR > 1 || \
 353     (PANGO_VERSION_MAJOR == 1 && PANGO_VERSION_MINOR >= 16)
 354              pango_layout_get_line_readonly(t->font->layout, 0),
 355 #else
 356              pango_layout_get_line(t->font->layout, 0),
 357 #endif
 358              x * PANGO_SCALE,
 359              y * PANGO_SCALE);
 360     }
 361     else {
 362         pango_xft_render_layout(d, &c, t->font->layout,
 363                                 x * PANGO_SCALE,
 364                                 y * PANGO_SCALE);
 365     }
 366
 367     if (t->shortcut) {
 368         t->font->shortcut_underline->start_index = 0;
 369         t->font->shortcut_underline->end_index = 0;
 370         /* the attributes are owned by the layout.
 371            re-add the attributes to the layout after changing the
 372            start and end index */
 373         attrlist = pango_layout_get_attributes(t->font->layout);
 374         pango_attr_list_ref(attrlist);
 375         pango_layout_set_attributes(t->font->layout, attrlist);
 376         pango_attr_list_unref(attrlist);
 377     }
 378 }