src/adg/adg-pango-style.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007-2021  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-pango-style
  23  * @short_description: A font style with pango support
  24  *
  25  * Adds pango support to the #AdgFontStyle class.
  26  *
  27  * Since: 1.0
  28  */
  29
  30 /**
  31  * AdgPangoStyle:
  32  *
  33  * All fields are private and should not be used directly.
  34  * Use its public methods instead.
  35  *
  36  * Since: 1.0
  37  **/
  38
  39
  40 #include "adg-internal.h"
  41 #include <pango/pango.h>
  42
  43 #include "adg-style.h"
  44 #include "adg-dress.h"
  45 #include "adg-font-style.h"
  46
  47 #include "adg-pango-style.h"
  48 #include "adg-pango-style-private.h"
  49
  50
  51 #define _ADG_OLD_STYLE_CLASS  ((AdgStyleClass *) adg_pango_style_parent_class)
  52
  53
  54 G_DEFINE_TYPE_WITH_PRIVATE(AdgPangoStyle, adg_pango_style, ADG_TYPE_FONT_STYLE)
  55
  56 enum {
  57     PROP_0,
  58     PROP_SPACING
  59 };
  60
  61
  62 static void             _adg_get_property       (GObject        *object,
  63                                                  guint           prop_id,
  64                                                  GValue         *value,
  65                                                  GParamSpec     *pspec);
  66 static void             _adg_set_property       (GObject        *object,
  67                                                  guint           prop_id,
  68                                                  const GValue   *value,
  69                                                  GParamSpec     *pspec);
  70 static void             _adg_invalidate         (AdgStyle       *style);
  71 static void             _adg_apply              (AdgStyle       *style,
  72                                                  AdgEntity      *entity,
  73                                                  cairo_t        *cr);
  74
  75
  76 static void
  77 adg_pango_style_class_init(AdgPangoStyleClass *klass)
  78 {
  79     GObjectClass *gobject_class;
  80     AdgStyleClass *style_class;
  81     GParamSpec *param;
  82
  83     gobject_class = (GObjectClass *) klass;
  84     style_class = (AdgStyleClass *) klass;
  85
  86     gobject_class->get_property = _adg_get_property;
  87     gobject_class->set_property = _adg_set_property;
  88
  89     style_class->invalidate = _adg_invalidate;
  90     style_class->apply = _adg_apply;
  91
  92     param = g_param_spec_int("spacing",
  93                              P_("Spacing"),
  94                              P_("Amount of spacing between lines on multiline text"),
  95                              G_MININT, G_MAXINT, 0,
  96                              G_PARAM_READWRITE);
  97     g_object_class_install_property(gobject_class, PROP_SPACING, param);
  98 }
  99
 100 static void
 101 adg_pango_style_init(AdgPangoStyle *pango_style)
 102 {
 103     AdgPangoStylePrivate *data = adg_pango_style_get_instance_private(pango_style);
 104     data->font_description = NULL;
 105     data->spacing = 0;
 106 }
 107
 108 static void
 109 _adg_get_property(GObject *object, guint prop_id,
 110                   GValue *value, GParamSpec *pspec)
 111 {
 112     AdgPangoStylePrivate *data = adg_pango_style_get_instance_private((AdgPangoStyle *) object);
 113
 114     switch (prop_id) {
 115     case PROP_SPACING:
 116         g_value_set_int(value, data->spacing);
 117         break;
 118     default:
 119         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 120         break;
 121     }
 122 }
 123
 124 static void
 125 _adg_set_property(GObject *object, guint prop_id,
 126                   const GValue *value, GParamSpec *pspec)
 127 {
 128     AdgPangoStylePrivate *data = adg_pango_style_get_instance_private((AdgPangoStyle *) object);
 129
 130     switch (prop_id) {
 131     case PROP_SPACING:
 132         data->spacing = g_value_get_int(value);
 133         break;
 134     default:
 135         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 136         break;
 137     }
 138 }
 139
 140
 141 /**
 142  * adg_pango_style_new:
 143  *
 144  * Constructs a new pango style initialized with default params.
 145  *
 146  * Returns: a newly created pango style
 147  *
 148  * Since: 1.0
 149  **/
 150 AdgPangoStyle *
 151 adg_pango_style_new(void)
 152 {
 153     return g_object_new(ADG_TYPE_PANGO_STYLE, NULL);
 154 }
 155
 156 /**
 157  * adg_pango_style_get_description:
 158  * @pango_style: an #AdgPangoStyle object
 159  *
 160  * Gets the #PangoFontDescription of @pango_style. The returned font is
 161  * owned by @pango_style and must not be destroyed by the caller.
 162  *
 163  * Returns: the font description
 164  *
 165  * Since: 1.0
 166  **/
 167 PangoFontDescription *
 168 adg_pango_style_get_description(AdgPangoStyle *pango_style)
 169 {
 170     AdgPangoStylePrivate *data;
 171
 172     g_return_val_if_fail(ADG_IS_PANGO_STYLE(pango_style), NULL);
 173
 174     data = adg_pango_style_get_instance_private(pango_style);
 175
 176     if (data->font_description == NULL) {
 177         AdgFontStyle *font_style;
 178         const gchar *family;
 179         cairo_font_slant_t slant;
 180         cairo_font_weight_t weight;
 181         gdouble size;
 182
 183         font_style = (AdgFontStyle *) pango_style;
 184         family = adg_font_style_get_family(font_style);
 185         slant = adg_font_style_get_slant(font_style);
 186         weight = adg_font_style_get_weight(font_style);
 187         size = adg_font_style_get_size(font_style);
 188
 189         data->font_description = pango_font_description_new();
 190
 191         pango_font_description_set_family(data->font_description, family);
 192
 193         switch (slant) {
 194         case CAIRO_FONT_SLANT_NORMAL:
 195             pango_font_description_set_style(data->font_description,
 196                                              PANGO_STYLE_NORMAL);
 197             break;
 198         case CAIRO_FONT_SLANT_ITALIC:
 199             pango_font_description_set_style(data->font_description,
 200                                              PANGO_STYLE_ITALIC);
 201             break;
 202         case CAIRO_FONT_SLANT_OBLIQUE:
 203             pango_font_description_set_style(data->font_description,
 204                                              PANGO_STYLE_OBLIQUE);
 205             break;
 206         default:
 207             g_warning(_("Unhandled slant value (%d)"), slant);
 208         }
 209
 210         switch (weight) {
 211         case CAIRO_FONT_WEIGHT_NORMAL:
 212             pango_font_description_set_weight(data->font_description,
 213                                               PANGO_WEIGHT_NORMAL);
 214             break;
 215         case CAIRO_FONT_WEIGHT_BOLD:
 216             pango_font_description_set_weight(data->font_description,
 217                                               PANGO_WEIGHT_BOLD);
 218             break;
 219         default:
 220             g_warning(_("Unhandled weight value (%d)"), weight);
 221         }
 222
 223         pango_font_description_set_size(data->font_description,
 224                                         size * PANGO_SCALE);
 225     }
 226
 227     return data->font_description;
 228 }
 229
 230 /**
 231  * adg_pango_style_set_spacing:
 232  * @pango_style: an #AdgPangoStyle object
 233  * @spacing: the new spacing
 234  *
 235  * Sets the new spacing to @spacing on @pango_style.
 236  *
 237  * Since: 1.0
 238  **/
 239 void
 240 adg_pango_style_set_spacing(AdgPangoStyle *pango_style, gint spacing)
 241 {
 242     g_return_if_fail(ADG_IS_PANGO_STYLE(pango_style));
 243     g_object_set(pango_style, "spacing", spacing, NULL);
 244 }
 245
 246 /**
 247  * adg_pango_style_get_spacing:
 248  * @pango_style: an #AdgPangoStyle object
 249  *
 250  * Gets the spacing of @pango_style.
 251  *
 252  * Returns: (type gint): the current spacing value.
 253  *
 254  * Since: 1.0
 255  **/
 256 gint
 257 adg_pango_style_get_spacing(AdgPangoStyle *pango_style)
 258 {
 259     AdgPangoStylePrivate *data;
 260
 261     g_return_val_if_fail(ADG_IS_PANGO_STYLE(pango_style), 0);
 262
 263     data = adg_pango_style_get_instance_private(pango_style);
 264     return data->spacing;
 265 }
 266
 267
 268 static void
 269 _adg_invalidate(AdgStyle *style)
 270 {
 271     AdgPangoStyle *pango_style = (AdgPangoStyle *) style;
 272     AdgPangoStylePrivate *data = adg_pango_style_get_instance_private(pango_style);
 273
 274     if (data->font_description != NULL) {
 275         pango_font_description_free(data->font_description);
 276         data->font_description = NULL;
 277     }
 278
 279     if (_ADG_OLD_STYLE_CLASS->invalidate != NULL)
 280         _ADG_OLD_STYLE_CLASS->invalidate(style);
 281 }
 282
 283 static void
 284 _adg_apply(AdgStyle *style, AdgEntity *entity, cairo_t *cr)
 285 {
 286     AdgFontStyle *font_style;
 287     AdgDress color_dress;
 288
 289     font_style = (AdgFontStyle *) style;
 290     color_dress = adg_font_style_get_color_dress(font_style);
 291
 292     adg_entity_apply_dress(entity, color_dress, cr);
 293 }