src/adg/adg-text.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007,2008,2009,2010,2011,2012,2013  Nicola Fontana <ntd at entidi.it>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library 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 GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA  02110-1301, USA.
  18  */
  19
  20
  21 /**
  22  * SECTION:adg-text
  23  * @short_description: A pango based text entity
  24  *
  25  * The #AdgText class is the main class for showing text. It works
  26  * the same way as #AdgToyText but uses pango instead of the so
  27  * called cairo "toy" API.
  28  *
  29  * The text entity is not subject to the local matrix, only its origin is.
  30  *
  31  * <note><para>
  32  * By default, the #AdgText:local-mix property is set to
  33  * #ADG_MIX_ANCESTORS_NORMALIZED on #AdgText entities.
  34  * </para></note>
  35  *
  36  * Since: 1.0
  37  **/
  38
  39 /**
  40  * AdgText:
  41  *
  42  * All fields are privates and should not be used directly.
  43  * Use its public methods instead.
  44  *
  45  * Since: 1.0
  46  **/
  47
  48
  49 #include "adg-internal.h"
  50 #include <pango/pangocairo.h>
  51
  52 #include "adg-dress.h"
  53 #include "adg-style.h"
  54 #include "adg-font-style.h"
  55 #include "adg-pango-style.h"
  56 #include "adg-textual.h"
  57 #include "adg-entity-private.h"
  58
  59 #include "adg-text.h"
  60 #include "adg-text-private.h"
  61
  62
  63 #define _ADG_OLD_OBJECT_CLASS  ((GObjectClass *) adg_text_parent_class)
  64 #define _ADG_OLD_ENTITY_CLASS  ((AdgEntityClass *) adg_text_parent_class)
  65
  66
  67 static void             _adg_iface_init         (AdgTextualIface *iface);
  68
  69
  70 G_DEFINE_TYPE_WITH_CODE(AdgText, adg_text, ADG_TYPE_ENTITY,
  71                         G_IMPLEMENT_INTERFACE(ADG_TYPE_TEXTUAL, _adg_iface_init))
  72
  73 enum {
  74     PROP_0,
  75     PROP_FONT_DRESS,
  76     PROP_TEXT
  77 };
  78
  79
  80 static void             _adg_dispose            (GObject        *object);
  81 static void             _adg_finalize           (GObject        *object);
  82 static void             _adg_get_property       (GObject        *object,
  83                                                  guint           param_id,
  84                                                  GValue         *value,
  85                                                  GParamSpec     *pspec);
  86 static void             _adg_set_property       (GObject        *object,
  87                                                  guint           param_id,
  88                                                  const GValue   *value,
  89                                                  GParamSpec     *pspec);
  90 static void             _adg_global_changed     (AdgEntity      *entity);
  91 static void             _adg_local_changed      (AdgEntity      *entity);
  92 static void             _adg_invalidate         (AdgEntity      *entity);
  93 static void             _adg_arrange            (AdgEntity      *entity);
  94 static void             _adg_render             (AdgEntity      *entity,
  95                                                  cairo_t        *cr);
  96 static void             _adg_set_font_dress     (AdgTextual     *textual,
  97                                                  AdgDress        dress);
  98 static AdgDress         _adg_get_font_dress     (AdgTextual     *textual);
  99 static void             _adg_set_text           (AdgTextual     *textual,
 100                                                  const gchar    *text);
 101 static gchar *          _adg_dup_text           (AdgTextual     *textual);
 102 static void             _adg_refresh_extents    (AdgText        *text);
 103 static void             _adg_clear_layout       (AdgText        *text);
 104
 105
 106 static void
 107 adg_text_class_init(AdgTextClass *klass)
 108 {
 109     GObjectClass *gobject_class;
 110     AdgEntityClass *entity_class;
 111
 112     gobject_class = (GObjectClass *) klass;
 113     entity_class = (AdgEntityClass *) klass;
 114
 115     g_type_class_add_private(klass, sizeof(AdgTextPrivate));
 116
 117     gobject_class->dispose = _adg_dispose;
 118     gobject_class->finalize = _adg_finalize;
 119     gobject_class->get_property = _adg_get_property;
 120     gobject_class->set_property = _adg_set_property;
 121
 122     entity_class->global_changed = _adg_global_changed;
 123     entity_class->local_changed = _adg_local_changed;
 124     entity_class->invalidate = _adg_invalidate;
 125     entity_class->arrange = _adg_arrange;
 126     entity_class->render = _adg_render;
 127
 128     g_object_class_override_property(gobject_class, PROP_FONT_DRESS, "font-dress");
 129     g_object_class_override_property(gobject_class, PROP_TEXT, "text");
 130 }
 131
 132 static void
 133 _adg_iface_init(AdgTextualIface *iface)
 134 {
 135     iface->set_font_dress = _adg_set_font_dress;
 136     iface->get_font_dress = _adg_get_font_dress;
 137     iface->set_text = _adg_set_text;
 138     iface->dup_text = _adg_dup_text;
 139     iface->text_changed = NULL;
 140 }
 141
 142 static void
 143 adg_text_init(AdgText *text)
 144 {
 145     AdgTextPrivate *data = G_TYPE_INSTANCE_GET_PRIVATE(text, ADG_TYPE_TEXT,
 146                                                        AdgTextPrivate);
 147     AdgEntityPrivate *entity_data = ((AdgEntity *) text)->data;
 148
 149     data->font_dress = ADG_DRESS_FONT_TEXT;
 150     data->text = NULL;
 151     data->layout = NULL;
 152
 153     text->data = data;
 154
 155     /* Initialize to custom default some AdgEntity field by directly
 156      * accessing the private struct to avoid notify signal emissions
 157      */
 158     entity_data->local_mix = ADG_MIX_ANCESTORS_NORMALIZED;
 159 }
 160
 161 static void
 162 _adg_dispose(GObject *object)
 163 {
 164     AdgText *text = (AdgText *) object;
 165
 166     _adg_clear_layout(text);
 167
 168     if (_ADG_OLD_OBJECT_CLASS->dispose)
 169         _ADG_OLD_OBJECT_CLASS->dispose(object);
 170 }
 171
 172 static void
 173 _adg_finalize(GObject *object)
 174 {
 175     AdgText *text;
 176     AdgTextPrivate *data;
 177
 178     text = (AdgText *) object;
 179     data = text->data;
 180
 181     g_free(data->text);
 182
 183     if (_ADG_OLD_OBJECT_CLASS->finalize)
 184         _ADG_OLD_OBJECT_CLASS->finalize(object);
 185 }
 186
 187 static void
 188 _adg_get_property(GObject *object, guint prop_id,
 189                   GValue *value, GParamSpec *pspec)
 190 {
 191     AdgTextPrivate *data = ((AdgText *) object)->data;
 192
 193     switch (prop_id) {
 194     case PROP_FONT_DRESS:
 195         g_value_set_enum(value, data->font_dress);
 196         break;
 197     case PROP_TEXT:
 198         g_value_set_string(value, data->text);
 199         break;
 200     default:
 201         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 202         break;
 203     }
 204 }
 205
 206 static void
 207 _adg_set_property(GObject *object, guint prop_id,
 208                   const GValue *value, GParamSpec *pspec)
 209 {
 210     AdgText *text;
 211     AdgTextPrivate *data;
 212
 213     text = (AdgText *) object;
 214     data = text->data;
 215
 216     switch (prop_id) {
 217     case PROP_FONT_DRESS:
 218         data->font_dress = g_value_get_enum(value);
 219         _adg_clear_layout(text);
 220         break;
 221     case PROP_TEXT:
 222         g_free(data->text);
 223         data->text = g_value_dup_string(value);
 224         _adg_clear_layout(text);
 225         break;
 226     default:
 227         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 228         break;
 229     }
 230 }
 231
 232
 233 /**
 234  * adg_text_new:
 235  * @text: the text
 236  *
 237  * Creates a new text entity using @text as its content.
 238  *
 239  * Returns: the newly created text entity
 240  *
 241  * Since: 1.0
 242  **/
 243 AdgText *
 244 adg_text_new(const gchar *text)
 245 {
 246     return g_object_new(ADG_TYPE_TEXT,
 247                         "text", text, NULL);
 248 }
 249
 250
 251 static void
 252 _adg_global_changed(AdgEntity *entity)
 253 {
 254     if (_ADG_OLD_ENTITY_CLASS->global_changed != NULL)
 255         _ADG_OLD_ENTITY_CLASS->global_changed(entity);
 256
 257     _adg_refresh_extents((AdgText *) entity);
 258 }
 259
 260 static void
 261 _adg_local_changed(AdgEntity *entity)
 262 {
 263     if (_ADG_OLD_ENTITY_CLASS->local_changed != NULL)
 264         _ADG_OLD_ENTITY_CLASS->local_changed(entity);
 265
 266     _adg_refresh_extents((AdgText *) entity);
 267 }
 268
 269 static void
 270 _adg_invalidate(AdgEntity *entity)
 271 {
 272     _adg_clear_layout((AdgText *) entity);
 273
 274     if (_ADG_OLD_ENTITY_CLASS->invalidate)
 275         _ADG_OLD_ENTITY_CLASS->invalidate(entity);
 276 }
 277
 278 static void
 279 _adg_arrange(AdgEntity *entity)
 280 {
 281     AdgText *text;
 282     AdgTextPrivate *data;
 283     PangoRectangle size;
 284
 285     text = (AdgText *) entity;
 286     data = text->data;
 287
 288     if (adg_is_string_empty(data->text)) {
 289         /* Undefined text */
 290         CpmlExtents new_extents;
 291         new_extents.is_defined = FALSE;
 292         adg_entity_set_extents(entity, &new_extents);
 293         _adg_clear_layout(text);
 294         return;
 295     } else if (data->layout != NULL) {
 296         /* Cached result */
 297         return;
 298     }
 299
 300     if (data->layout == NULL) {
 301         static PangoFontMap *font_map = NULL;
 302         AdgDress dress;
 303         AdgPangoStyle *pango_style;
 304         PangoFontDescription *font_description;
 305         cairo_font_options_t *options;
 306         PangoContext *context;
 307
 308         /* Keep around a font_map object. The rationale is here:
 309          * https://bugzilla.gnome.org/show_bug.cgi?id=143542
 310          *
 311          * Basically, PangoFontMap is an heavy object and
 312          * creating/destroying it is not the right way.
 313          *
 314          * In reality, the blocking issue for me was the following
 315          * line make the adg-demo program crash on MinGW32:
 316          * g_object_unref(font_map);
 317          */
 318         if (font_map == NULL)
 319             font_map = pango_cairo_font_map_new();
 320
 321         dress = data->font_dress;
 322         pango_style = (AdgPangoStyle *) adg_entity_style(entity, dress);
 323         font_description = adg_pango_style_get_description(pango_style);
 324
 325         context = pango_context_new();
 326         pango_context_set_font_map(context, font_map);
 327         pango_cairo_context_set_resolution(context, 72);
 328
 329         options = adg_font_style_new_options((AdgFontStyle *) pango_style);
 330         pango_cairo_context_set_font_options(context, options);
 331         cairo_font_options_destroy(options);
 332
 333         data->layout = pango_layout_new(context);
 334         g_object_unref(context);
 335
 336         pango_layout_set_text(data->layout, data->text, -1);
 337         pango_layout_set_font_description(data->layout, font_description);
 338     }
 339
 340     pango_layout_get_extents(data->layout, NULL, &size);
 341
 342     data->raw_extents.org.x = pango_units_to_double(size.x);
 343     data->raw_extents.org.y = pango_units_to_double(size.y);
 344     data->raw_extents.size.x = pango_units_to_double(size.width);
 345     data->raw_extents.size.y = pango_units_to_double(size.height);
 346     data->raw_extents.is_defined = TRUE;
 347
 348     _adg_refresh_extents((AdgText *) entity);
 349 }
 350
 351 static void
 352 _adg_render(AdgEntity *entity, cairo_t *cr)
 353 {
 354     AdgText *text;
 355     AdgTextPrivate *data;
 356
 357     text = (AdgText *) entity;
 358     data = text->data;
 359
 360     if (data->layout != NULL) {
 361         adg_entity_apply_dress(entity, data->font_dress, cr);
 362         cairo_transform(cr, adg_entity_get_global_matrix(entity));
 363         cairo_transform(cr, adg_entity_get_local_matrix(entity));
 364
 365         /* Realign the text to follow the cairo toy text convention:
 366          * use bottom/left corner as reference (pango uses top/left). */
 367         cairo_translate(cr, 0, -data->raw_extents.size.y);
 368
 369         pango_cairo_update_layout(cr, data->layout);
 370         pango_cairo_show_layout(cr, data->layout);
 371     }
 372 }
 373
 374 static void
 375 _adg_set_font_dress(AdgTextual *textual, AdgDress dress)
 376 {
 377     g_object_set(textual, "font-dress", dress, NULL);
 378 }
 379
 380 static AdgDress
 381 _adg_get_font_dress(AdgTextual *textual)
 382 {
 383     AdgTextPrivate *data = ((AdgText *) textual)->data;
 384     return data->font_dress;
 385 }
 386
 387 static void
 388 _adg_set_text(AdgTextual *textual, const gchar *text)
 389 {
 390     g_object_set(textual, "text", text, NULL);
 391 }
 392
 393 static gchar *
 394 _adg_dup_text(AdgTextual *textual)
 395 {
 396     AdgTextPrivate *data = ((AdgText *) textual)->data;
 397     return g_strdup(data->text);
 398 }
 399
 400 static void
 401 _adg_refresh_extents(AdgText *text)
 402 {
 403     AdgTextPrivate *data;
 404     AdgEntity *entity;
 405     cairo_matrix_t ctm;
 406     CpmlExtents new_extents;
 407
 408     data = text->data;
 409
 410     if (! data->raw_extents.is_defined)
 411         return;
 412
 413     entity = (AdgEntity *) text;
 414
 415     adg_matrix_copy(&ctm, adg_entity_get_global_matrix(entity));
 416     adg_matrix_transform(&ctm, adg_entity_get_local_matrix(entity),
 417                          ADG_TRANSFORM_AFTER);
 418     cpml_extents_copy(&new_extents, &data->raw_extents);
 419
 420     /* Realign the text to follow the cairo toy text convention:
 421      * use bottom/left corner as reference (pango uses top/left). */
 422     new_extents.org.y -= new_extents.size.y;
 423
 424     cpml_extents_transform(&new_extents, &ctm);
 425     adg_entity_set_extents(entity, &new_extents);
 426 }
 427
 428 static void
 429 _adg_clear_layout(AdgText *text)
 430 {
 431     AdgTextPrivate *data = text->data;
 432
 433     if (data->layout != NULL) {
 434         g_object_unref(data->layout);
 435         data->layout = NULL;
 436     }
 437 }