adg/adg-toy-text.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007,2008,2009 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-toy-text
  23  * @short_description: Simple text entity that use the cairo "toy" text API
  24  *
  25  * The #AdgToyText class is a basic class to show simple text. It internally
  26  * uses the so called cairo "toy" API and it shares the same limitations.
  27  *
  28  * The toy text entity is not subject to the local matrix, only its origin is.
  29  **/
  30
  31 /**
  32  * AdgToyText:
  33  *
  34  * All fields are privates and should not be used directly.
  35  * Use its public methods instead.
  36  **/
  37
  38
  39 #include "adg-toy-text.h"
  40 #include "adg-toy-text-private.h"
  41 #include "adg-type-builtins.h"
  42 #include "adg-intl.h"
  43
  44 #define PARENT_OBJECT_CLASS  ((GObjectClass *) adg_toy_text_parent_class)
  45 #define PARENT_ENTITY_CLASS  ((AdgEntityClass *) adg_toy_text_parent_class)
  46
  47
  48 enum {
  49     PROP_0,
  50     PROP_DRESS,
  51     PROP_LABEL
  52 };
  53
  54
  55 static void     finalize                (GObject        *object);
  56 static void     get_property            (GObject        *object,
  57                                          guint           param_id,
  58                                          GValue         *value,
  59                                          GParamSpec     *pspec);
  60 static void     set_property            (GObject        *object,
  61                                          guint           param_id,
  62                                          const GValue   *value,
  63                                          GParamSpec     *pspec);
  64 static void     local_changed           (AdgEntity      *entity);
  65 static void     invalidate              (AdgEntity      *entity);
  66 static void     render                  (AdgEntity      *entity,
  67                                          cairo_t        *cr);
  68 static gboolean set_label               (AdgToyText     *toy_text,
  69                                          const gchar    *label);
  70 static void     update_label_cache      (AdgToyText     *toy_text,
  71                                          cairo_t        *cr);
  72 static void     clear_label_cache       (AdgToyText     *toy_text);
  73
  74
  75 G_DEFINE_TYPE(AdgToyText, adg_toy_text, ADG_TYPE_ENTITY);
  76
  77
  78 static void
  79 adg_toy_text_class_init(AdgToyTextClass *klass)
  80 {
  81     GObjectClass *gobject_class;
  82     AdgEntityClass *entity_class;
  83     GParamSpec *param;
  84
  85     gobject_class = (GObjectClass *) klass;
  86     entity_class = (AdgEntityClass *) klass;
  87
  88     g_type_class_add_private(klass, sizeof(AdgToyTextPrivate));
  89
  90     gobject_class->finalize = finalize;
  91     gobject_class->get_property = get_property;
  92     gobject_class->set_property = set_property;
  93
  94     entity_class->local_changed = local_changed;
  95     entity_class->invalidate = invalidate;
  96     entity_class->render = render;
  97
  98     param = adg_param_spec_dress("dress",
  99                                  P_("Font Dress"),
 100                                  P_("The font dress to use for rendering this text"),
 101                                  ADG_DRESS_TEXT_REGULAR,
 102                                  G_PARAM_READWRITE);
 103     g_object_class_install_property(gobject_class, PROP_DRESS, param);
 104
 105     param = g_param_spec_string("label",
 106                                 P_("Label"),
 107                                 P_("The label to display"),
 108                                 NULL,
 109                                 G_PARAM_READWRITE);
 110     g_object_class_install_property(gobject_class, PROP_LABEL, param);
 111 }
 112
 113 static void
 114 adg_toy_text_init(AdgToyText *toy_text)
 115 {
 116     AdgToyTextPrivate *data = G_TYPE_INSTANCE_GET_PRIVATE(toy_text,
 117                                                           ADG_TYPE_TOY_TEXT,
 118                                                           AdgToyTextPrivate);
 119
 120     data->dress = ADG_DRESS_TEXT_REGULAR;
 121     data->label = NULL;
 122     data->glyphs = NULL;
 123
 124     toy_text->data = data;
 125 }
 126
 127 static void
 128 finalize(GObject *object)
 129 {
 130     AdgToyText *toy_text;
 131     AdgToyTextPrivate *data;
 132
 133     toy_text = (AdgToyText *) object;
 134     data = toy_text->data;
 135
 136     g_free(data->label);
 137     clear_label_cache(toy_text);
 138
 139     if (PARENT_OBJECT_CLASS->finalize != NULL)
 140         PARENT_OBJECT_CLASS->finalize(object);
 141 }
 142
 143 static void
 144 get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
 145 {
 146     AdgToyTextPrivate *data = ((AdgToyText *) object)->data;
 147
 148     switch (prop_id) {
 149     case PROP_DRESS:
 150         g_value_set_int(value, data->dress);
 151         break;
 152     case PROP_LABEL:
 153         g_value_set_string(value, data->label);
 154         break;
 155     default:
 156         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 157         break;
 158     }
 159 }
 160
 161 static void
 162 set_property(GObject *object, guint prop_id,
 163              const GValue *value, GParamSpec *pspec)
 164 {
 165     AdgToyText *toy_text;
 166     AdgToyTextPrivate *data;
 167
 168     toy_text = (AdgToyText *) object;
 169     data = toy_text->data;
 170
 171     switch (prop_id) {
 172     case PROP_DRESS:
 173         adg_dress_set(&data->dress, g_value_get_int(value));
 174         break;
 175     case PROP_LABEL:
 176         set_label(toy_text, g_value_get_string(value));
 177         break;
 178     default:
 179         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 180         break;
 181     }
 182 }
 183
 184
 185 /**
 186  * adg_toy_text_new:
 187  * @label: the label text
 188  *
 189  * Creates a new toy text entity using @label as its text
 190  *
 191  * Returns: the newly created toy text entity
 192  **/
 193 AdgToyText *
 194 adg_toy_text_new(const gchar *label)
 195 {
 196     return g_object_new(ADG_TYPE_TOY_TEXT, "label", label, NULL);
 197 }
 198
 199 /**
 200  * adg_toy_text_get_dress:
 201  * @toy_text: an #AdgToyText
 202  *
 203  * Gets the font dress to be used in rendering @toy_text.
 204  *
 205  * Returns: the current font dress
 206  **/
 207 AdgDress
 208 adg_toy_text_get_dress(AdgToyText *toy_text)
 209 {
 210     AdgToyTextPrivate *data;
 211
 212     g_return_val_if_fail(ADG_IS_TOY_TEXT(toy_text), ADG_DRESS_UNDEFINED);
 213
 214     data = toy_text->data;
 215
 216     return data->dress;
 217 }
 218
 219 /**
 220  * adg_toy_text_set_dress:
 221  * @toy_text: an #AdgToyText
 222  * @dress: the new #AdgDress to use
 223  *
 224  * Sets a new font dress for rendering @toy_text. The new dress
 225  * must be related to the original dress for this property:
 226  * you cannot set a dress used for line styles to a dress
 227  * managing fonts.
 228  *
 229  * The check is done by calling adg_dress_are_related() with
 230  * @dress and the previous dress as arguments. Check out its
 231  * documentation for details on what is a related dress.
 232  **/
 233 void
 234 adg_toy_text_set_dress(AdgToyText *toy_text, AdgDress dress)
 235 {
 236     AdgToyTextPrivate *data;
 237
 238     g_return_if_fail(ADG_IS_TOY_TEXT(toy_text));
 239
 240     data = toy_text->data;
 241
 242     if (adg_dress_set(&data->dress, dress))
 243         g_object_notify((GObject *) toy_text, "dress");
 244 }
 245
 246 /**
 247  * adg_toy_text_get_label:
 248  * @toy_text: an #AdgToyText
 249  *
 250  * Gets the label text. The string is internally owned and
 251  * must not be freed or modified.
 252  *
 253  * Returns: the label text
 254  **/
 255 const gchar *
 256 adg_toy_text_get_label(AdgToyText *toy_text)
 257 {
 258     AdgToyTextPrivate *data;
 259
 260     g_return_val_if_fail(ADG_IS_TOY_TEXT(toy_text), NULL);
 261
 262     data = toy_text->data;
 263
 264     return data->label;
 265 }
 266
 267 /**
 268  * adg_toy_text_set_label:
 269  * @toy_text: an #AdgToyText
 270  * @label: the label text
 271  *
 272  * Sets a new label for @toy_text. @label can be also %NULL,
 273  * in which case will be treated as an empty string.
 274  **/
 275 void
 276 adg_toy_text_set_label(AdgToyText *toy_text, const gchar *label)
 277 {
 278     g_return_if_fail(ADG_IS_TOY_TEXT(toy_text));
 279
 280     if (set_label(toy_text, label))
 281         g_object_notify((GObject *) toy_text, "label");
 282 }
 283
 284 /**
 285  * adg_toy_text_get_extents:
 286  * @toy_text: an #AdgToyText
 287  * @cr: a cairo context
 288  * @extents: where to store the extents
 289  *
 290  * Computes the extents of @toy_text and returns the result in @extents.
 291  * The cairo context is required for font computation.
 292  **/
 293 void
 294 adg_toy_text_get_extents(AdgToyText *toy_text, cairo_t *cr,
 295                          cairo_text_extents_t *extents)
 296 {
 297     AdgToyTextPrivate *data;
 298
 299     g_return_if_fail(ADG_IS_TOY_TEXT(toy_text));
 300     g_return_if_fail(extents != NULL);
 301
 302     update_label_cache(toy_text, cr);
 303
 304     data = toy_text->data;
 305     *extents = data->extents;
 306 }
 307
 308
 309 static void
 310 local_changed(AdgEntity *entity)
 311 {
 312     AdgMatrix matrix;
 313
 314     PARENT_ENTITY_CLASS->local_changed(entity);
 315
 316     adg_entity_get_local_matrix(entity, &matrix);
 317     cairo_matrix_init_translate(&matrix, matrix.x0, matrix.y0);
 318     adg_entity_set_local_matrix(entity, &matrix);
 319 }
 320
 321 static void
 322 invalidate(AdgEntity *entity)
 323 {
 324     clear_label_cache((AdgToyText *) entity);
 325
 326     if (PARENT_ENTITY_CLASS->invalidate != NULL)
 327         return PARENT_ENTITY_CLASS->invalidate(entity);
 328 }
 329
 330 static void
 331 render(AdgEntity *entity, cairo_t *cr)
 332 {
 333     AdgToyText *toy_text;
 334     AdgToyTextPrivate *data;
 335
 336     toy_text = (AdgToyText *) entity;
 337     data = toy_text->data;
 338
 339     if (data->label != NULL && data->label[0] != '\0') {
 340         update_label_cache(toy_text, cr);
 341
 342         cairo_save(cr);
 343         adg_entity_apply_local_matrix(entity, cr);
 344         cairo_show_glyphs(cr, data->glyphs, data->num_glyphs);
 345         cairo_restore(cr);
 346     }
 347 }
 348
 349
 350 static gboolean
 351 set_label(AdgToyText *toy_text, const gchar *label)
 352 {
 353     AdgToyTextPrivate *data = toy_text->data;
 354
 355     /* Check if the new label differs from the current label */
 356     if (adg_strcmp(label, data->label) == 0)
 357         return FALSE;
 358
 359     g_free(data->label);
 360     data->label = g_strdup(label);
 361
 362     clear_label_cache(toy_text);
 363     return TRUE;
 364 }
 365
 366 static void
 367 update_label_cache(AdgToyText *toy_text, cairo_t *cr)
 368 {
 369     AdgToyTextPrivate *data;
 370     cairo_status_t status;
 371
 372     data = toy_text->data;
 373
 374     adg_entity_apply_dress((AdgEntity *) toy_text, data->dress, cr);
 375
 376     if (data->glyphs != NULL)
 377         return;
 378
 379     status = cairo_scaled_font_text_to_glyphs(cairo_get_scaled_font(cr),
 380                                               0, 0, data->label, -1,
 381                                               &data->glyphs,
 382                                               &data->num_glyphs,
 383                                               NULL, NULL, NULL);
 384
 385     if (status != CAIRO_STATUS_SUCCESS) {
 386         clear_label_cache(toy_text);
 387         g_error("Unable to build glyphs (cairo message: %s)",
 388                 cairo_status_to_string(status));
 389         return;
 390     }
 391
 392     cairo_glyph_extents(cr, data->glyphs, data->num_glyphs, &data->extents);
 393 }
 394
 395 static void
 396 clear_label_cache(AdgToyText *toy_text)
 397 {
 398     AdgToyTextPrivate *data = toy_text->data;
 399
 400     if (data->glyphs != NULL) {
 401         cairo_glyph_free(data->glyphs);
 402         data->glyphs = NULL;
 403     }
 404
 405     data->num_glyphs = 0;
 406     memset(&data->extents, 0, sizeof(data->extents));
 407 }