lib/textline.c

   1 /* Dia -- an diagram creation/manipulation program
   2  * Copyright (C) 1998 Alexander Larsson
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17  */
  18 #include <config.h>
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <glib.h>
  24 #include <math.h>
  25
  26 #include <gdk/gdkkeysyms.h>
  27
  28 #include "propinternals.h"
  29 #include "text.h"
  30 #include "message.h"
  31 #include "diarenderer.h"
  32 #include "diagramdata.h"
  33 #include "objchange.h"
  34 #include "textline.h"
  35
  36 static void text_line_dirty_cache(TextLine *text_line);
  37 static void text_line_cache_values(TextLine *text_line);
  38
  39 /** Sets this object to display a particular string.
  40  * @param text_line The object to change.
  41  * @param string The string to display.  This string will be copied.
  42  */
  43 void
  44 text_line_set_string(TextLine *text_line, const gchar *string)
  45 {
  46   if (text_line->chars == NULL ||
  47       strcmp(text_line->chars, string)) {
  48     if (text_line->chars != NULL) {
  49       g_free(text_line->chars);
  50     }
  51
  52     text_line->chars = g_strdup(string);
  53
  54     text_line_dirty_cache(text_line);
  55   }
  56 }
  57
  58 /** Sets the font used by this object.
  59  * @param text_line The object to change.
  60  * @param font The font to use for displaying this object.
  61  */
  62 void
  63 text_line_set_font(TextLine *text_line, DiaFont *font)
  64 {
  65   if (text_line->font != font) {
  66     DiaFont *old_font = text_line->font;
  67     dia_font_ref(font);
  68     text_line->font = font;
  69     if (old_font != NULL) {
  70       dia_font_unref(old_font);
  71     }
  72     text_line_dirty_cache(text_line);
  73   }
  74 }
  75
  76 /** Sets the font height used by this object.
  77  * @param text_line The object to change.
  78  * @param height The font height to use for displaying this object
  79  * (in cm, from baseline to baseline)
  80  */
  81 void
  82 text_line_set_height(TextLine *text_line, real height)
  83 {
  84   if (fabs(text_line->height - height) > 0.00001) {
  85     text_line->height = height;
  86     text_line_dirty_cache(text_line);
  87   }
  88 }
  89
  90 /** Creates a new TextLine object from its components.
  91  * @param string the string to display
  92  * @param font the font to display the string with.
  93  * @param height the height of the font, in cm from baseline to baseline.
  94  */
  95 TextLine *
  96 text_line_new(const gchar *string, DiaFont *font, real height)
  97 {
  98   TextLine *text_line = g_new0(TextLine, 1);
  99
 100   text_line_set_string(text_line, string);
 101   text_line_set_font(text_line, font);
 102   text_line_set_height(text_line, height);
 103
 104   return text_line;
 105 }
 106
 107 TextLine *
 108 text_line_copy(TextLine *text_line)
 109 {
 110   return text_line_new(text_line->chars, text_line->font, text_line->height);
 111 }
 112
 113 /** Destroy a text_line object, deallocating all memory used and unreffing
 114  * reffed objects.
 115  * @param text_line the object to kill.
 116  */
 117 void
 118 text_line_destroy(TextLine *text_line)
 119 {
 120   if (text_line->chars != NULL) {
 121     g_free(text_line->chars);
 122   }
 123   if (text_line->font != NULL) {
 124     dia_font_unref(text_line->font);
 125   }
 126   /* TODO: Handle renderer's cached content. */
 127   g_free(text_line);
 128 }
 129
 130 /** Calculate the bounding box size of this object.  Since a text object has no
 131  * position or alignment, this collapses to just a size.
 132  * @param text_line
 133  * @param size A place to store the width and height of the text.
 134  */
 135 void
 136 text_line_calc_boundingbox_size(TextLine *text_line, Point *size)
 137 {
 138   text_line_cache_values(text_line);
 139
 140   size->x = text_line->width;
 141   size->y = text_line->ascent + text_line->descent;
 142 }
 143
 144 /** Draw a line of text at a given position and in a given color.
 145  * @param renderer
 146  * @param text_line
 147  * @param pos
 148  * @param color
 149  */
 150 void
 151 text_line_draw(DiaRenderer *renderer, TextLine *text_line,
 152                Point *pos, Color *color)
 153 {
 154 #ifdef DIRECT_TEXT_LINE
 155   DIA_RENDERER_GET_CLASS(renderer)->draw_text_line(renderer,
 156                                                    text_line,
 157                                                    pos, color);
 158 #else
 159   DIA_RENDERER_GET_CLASS(renderer)->set_font(renderer, text_line->font,
 160                                              text_line->height);
 161   DIA_RENDERER_GET_CLASS(renderer)->draw_string(renderer,
 162                                                 text_line->chars,
 163                                                 pos, ALIGN_LEFT, color);
 164 #endif
 165 }
 166
 167 gchar *
 168 text_line_get_string(TextLine *text_line)
 169 {
 170   return text_line->chars;
 171 }
 172
 173 DiaFont *
 174 text_line_get_font(TextLine *text_line)
 175 {
 176   return text_line->font;
 177 }
 178
 179 real
 180 text_line_get_height(TextLine *text_line)
 181 {
 182   return text_line->height;
 183 }
 184
 185 real
 186 text_line_get_width(TextLine *text_line)
 187 {
 188   text_line_cache_values(text_line);
 189   return text_line->width;
 190 }
 191
 192 real
 193 text_line_get_ascent(TextLine *text_line)
 194 {
 195   text_line_cache_values(text_line);
 196   return text_line->ascent;
 197 }
 198
 199 real
 200 text_line_get_descent(TextLine *text_line)
 201 {
 202   text_line_cache_values(text_line);
 203   return text_line->descent;
 204 }
 205
 206 /* **** Private functions **** */
 207 /** Mark this object as needing update before usage.
 208  * @param text_line the object that has changed.
 209  */
 210 static void
 211 text_line_dirty_cache(TextLine *text_line)
 212 {
 213   text_line->clean = FALSE;
 214 }
 215
 216 static void
 217 text_line_cache_values(TextLine *text_line)
 218 {
 219   if (!text_line->clean ||
 220       text_line->chars != text_line->chars_cache ||
 221       text_line->font != text_line->font_cache ||
 222       text_line->height != text_line->height_cache) {
 223     int n_offsets;
 224
 225     if (text_line->offsets != NULL) {
 226       g_free(text_line->offsets);
 227     }
 228     if (text_line->chars == NULL ||
 229         text_line->chars[0] == '\0') {
 230       text_line->offsets = g_new(real, 0);
 231       text_line->ascent = text_line->height * .5;
 232       text_line->descent = text_line->height * .5;
 233       text_line->width = 0;
 234     } else {
 235       text_line->offsets =
 236         dia_font_get_sizes(text_line->chars, text_line->font, text_line->height,
 237                            &text_line->width, &text_line->ascent,
 238                            &text_line->descent, &n_offsets);
 239     }
 240     text_line->clean = TRUE;
 241     text_line->chars_cache = text_line->chars;
 242     text_line->font_cache = text_line->font;
 243     text_line->height_cache = text_line->height;
 244   }
 245 }