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     get_local_matrix        (AdgEntity      *entity,
  65                                          AdgMatrix      *matrix);
  66 static gboolean invalidate              (AdgEntity      *entity);
  67 static gboolean render                  (AdgEntity      *entity,
  68                                          cairo_t        *cr);
  69 static gboolean set_label               (AdgToyText     *toy_text,
  70                                          const gchar    *label);
  71 static void     update_label_cache      (AdgToyText     *toy_text,
  72                                          cairo_t        *cr);
  73 static void     clear_label_cache       (AdgToyText     *toy_text);
  74
  75
  76 G_DEFINE_TYPE(AdgToyText, adg_toy_text, ADG_TYPE_ENTITY);
  77
  78
  79 static void
  80 adg_toy_text_class_init(AdgToyTextClass *klass)
  81 {
  82     GObjectClass *gobject_class;
  83     AdgEntityClass *entity_class;
  84     GParamSpec *param;
  85
  86     gobject_class = (GObjectClass *) klass;
  87     entity_class = (AdgEntityClass *) klass;
  88
  89     g_type_class_add_private(klass, sizeof(AdgToyTextPrivate));
  90
  91     gobject_class->finalize = finalize;
  92     gobject_class->get_property = get_property;
  93     gobject_class->set_property = set_property;
  94
  95     entity_class->get_local_matrix = get_local_matrix;
  96     entity_class->invalidate = invalidate;
  97     entity_class->render = render;
  98
  99     param = adg_param_spec_dress("dress",
 100                                  P_("Dress Style"),
 101                                  P_("The dress style to use for rendering this text"),
 102                                  ADG_DRESS_TEXT_REGULAR,
 103                                  G_PARAM_READWRITE);
 104     g_object_class_install_property(gobject_class, PROP_DRESS, param);
 105
 106     param = g_param_spec_string("label",
 107                                 P_("Label"),
 108                                 P_("The label to display"),
 109                                 NULL,
 110                                 G_PARAM_READWRITE);
 111     g_object_class_install_property(gobject_class, PROP_LABEL, param);
 112 }
 113
 114 static void
 115 adg_toy_text_init(AdgToyText *toy_text)
 116 {
 117     AdgToyTextPrivate *data = G_TYPE_INSTANCE_GET_PRIVATE(toy_text,
 118                                                           ADG_TYPE_TOY_TEXT,
 119                                                           AdgToyTextPrivate);
 120
 121     data->dress = ADG_DRESS_TEXT_REGULAR;
 122     data->label = NULL;
 123     data->glyphs = NULL;
 124
 125     toy_text->data = data;
 126 }
 127
 128 static void
 129 finalize(GObject *object)
 130 {
 131     AdgToyText *toy_text;
 132     AdgToyTextPrivate *data;
 133
 134     toy_text = (AdgToyText *) object;
 135     data = toy_text->data;
 136
 137     g_free(data->label);
 138     clear_label_cache(toy_text);
 139
 140     if (PARENT_OBJECT_CLASS->finalize != NULL)
 141         PARENT_OBJECT_CLASS->finalize(object);
 142 }
 143
 144 static void
 145 get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
 146 {
 147     AdgToyTextPrivate *data = ((AdgToyText *) object)->data;
 148
 149     switch (prop_id) {
 150     case PROP_DRESS:
 151         g_value_set_int(value, data->dress);
 152         break;
 153     case PROP_LABEL:
 154         g_value_set_string(value, data->label);
 155         break;
 156     default:
 157         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 158         break;
 159     }
 160 }
 161
 162 static void
 163 set_property(GObject *object, guint prop_id,
 164              const GValue *value, GParamSpec *pspec)
 165 {
 166     AdgToyText *toy_text;
 167     AdgToyTextPrivate *data;
 168
 169     toy_text = (AdgToyText *) object;
 170     data = toy_text->data;
 171
 172     switch (prop_id) {
 173     case PROP_DRESS:
 174         adg_dress_set(&data->dress, g_value_get_int(value));
 175         break;
 176     case PROP_LABEL:
 177         set_label(toy_text, g_value_get_string(value));
 178         break;
 179     default:
 180         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 181         break;
 182     }
 183 }
 184
 185
 186 /**
 187  * adg_toy_text_new:
 188  * @label: the label text
 189  *
 190  * Creates a new toy text entity using @label as its text
 191  *
 192  * Returns: the newly created toy text entity
 193  **/
 194 AdgToyText *
 195 adg_toy_text_new(const gchar *label)
 196 {
 197     return g_object_new(ADG_TYPE_TOY_TEXT, "label", label, NULL);
 198 }
 199
 200 /**
 201  * adg_toy_text_get_label:
 202  * @toy_text: an #AdgToyText
 203  *
 204  * Gets the label text. The string is internally owned and
 205  * must not be freed or modified.
 206  *
 207  * Returns: the label text
 208  **/
 209 const gchar *
 210 adg_toy_text_get_label(AdgToyText *toy_text)
 211 {
 212     AdgToyTextPrivate *data;
 213
 214     g_return_val_if_fail(ADG_IS_TOY_TEXT(toy_text), NULL);
 215
 216     data = toy_text->data;
 217
 218     return data->label;
 219 }
 220
 221 /**
 222  * adg_toy_text_set_label:
 223  * @toy_text: an #AdgToyText
 224  * @label: the label text
 225  *
 226  * Sets a new label for @toy_text. @label can be also %NULL,
 227  * in which case will be treated as an empty string.
 228  **/
 229 void
 230 adg_toy_text_set_label(AdgToyText *toy_text, const gchar *label)
 231 {
 232     g_return_if_fail(ADG_IS_TOY_TEXT(toy_text));
 233
 234     if (set_label(toy_text, label))
 235         g_object_notify((GObject *) toy_text, "label");
 236 }
 237
 238 /**
 239  * adg_toy_text_get_extents:
 240  * @toy_text: an #AdgToyText
 241  * @cr: a cairo context
 242  * @extents: where to store the extents
 243  *
 244  * Computes the extents of @toy_text and returns the result in @extents.
 245  * The cairo context is required for font computation.
 246  **/
 247 void
 248 adg_toy_text_get_extents(AdgToyText *toy_text, cairo_t *cr,
 249                          cairo_text_extents_t *extents)
 250 {
 251     AdgToyTextPrivate *data;
 252
 253     g_return_if_fail(ADG_IS_TOY_TEXT(toy_text));
 254     g_return_if_fail(extents != NULL);
 255
 256     update_label_cache(toy_text, cr);
 257
 258     data = toy_text->data;
 259     *extents = data->extents;
 260 }
 261
 262
 263 static void
 264 get_local_matrix(AdgEntity *entity, AdgMatrix *matrix)
 265 {
 266     PARENT_ENTITY_CLASS->get_local_matrix(entity, matrix);
 267     cairo_matrix_init_translate(matrix, matrix->x0, matrix->y0);
 268 }
 269
 270 static gboolean
 271 invalidate(AdgEntity *entity)
 272 {
 273     clear_label_cache((AdgToyText *) entity);
 274
 275     if (PARENT_ENTITY_CLASS->invalidate != NULL)
 276         return PARENT_ENTITY_CLASS->invalidate(entity);
 277
 278     return TRUE;
 279 }
 280
 281 static gboolean
 282 render(AdgEntity *entity, cairo_t *cr)
 283 {
 284     AdgToyText *toy_text;
 285     AdgToyTextPrivate *data;
 286
 287     toy_text = (AdgToyText *) entity;
 288     data = toy_text->data;
 289
 290     if (data->label != NULL && data->label[0] != '\0') {
 291         update_label_cache(toy_text, cr);
 292
 293         cairo_save(cr);
 294         adg_entity_apply_local_matrix(entity, cr);
 295         cairo_show_glyphs(cr, data->glyphs, data->num_glyphs);
 296         cairo_restore(cr);
 297     }
 298
 299     return TRUE;
 300 }
 301
 302
 303 static gboolean
 304 set_label(AdgToyText *toy_text, const gchar *label)
 305 {
 306     AdgToyTextPrivate *data = toy_text->data;
 307
 308     /* Check if the new label differs from the current label */
 309     if (adg_strcmp(label, data->label) == 0)
 310         return FALSE;
 311
 312     g_free(data->label);
 313     data->label = g_strdup(label);
 314
 315     clear_label_cache(toy_text);
 316     return TRUE;
 317 }
 318
 319 static void
 320 update_label_cache(AdgToyText *toy_text, cairo_t *cr)
 321 {
 322     AdgToyTextPrivate *data;
 323     cairo_status_t status;
 324
 325     data = toy_text->data;
 326
 327     adg_entity_apply_dress((AdgEntity *) toy_text, data->dress, cr);
 328
 329     if (data->glyphs != NULL)
 330         return;
 331
 332     status = cairo_scaled_font_text_to_glyphs(cairo_get_scaled_font(cr),
 333                                               0, 0, data->label, -1,
 334                                               &data->glyphs,
 335                                               &data->num_glyphs,
 336                                               NULL, NULL, NULL);
 337
 338     if (status != CAIRO_STATUS_SUCCESS) {
 339         clear_label_cache(toy_text);
 340         g_error("Unable to build glyphs (cairo message: %s)",
 341                 cairo_status_to_string(status));
 342         return;
 343     }
 344
 345     cairo_glyph_extents(cr, data->glyphs, data->num_glyphs, &data->extents);
 346 }
 347
 348 static void
 349 clear_label_cache(AdgToyText *toy_text)
 350 {
 351     AdgToyTextPrivate *data = toy_text->data;
 352
 353     if (data->glyphs != NULL) {
 354         cairo_glyph_free(data->glyphs);
 355         data->glyphs = NULL;
 356     }
 357
 358     data->num_glyphs = 0;
 359     memset(&data->extents, 0, sizeof(data->extents));
 360 }