src/adg/adg-arrow.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007,2008,2009,2010,2011  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-arrow
  23  * @short_description: Arrow rendering related stuff
  24  *
  25  * Contains parameters on how to draw arrows, providing a way to register a
  26  * custom rendering callback.
  27  **/
  28
  29 /**
  30  * AdgArrow:
  31  *
  32  * All fields are private and should not be used directly.
  33  * Use its public methods instead.
  34  **/
  35
  36
  37 #include "adg-internal.h"
  38 #include "adg-model.h"
  39 #include "adg-trail.h"
  40 #include "adg-path.h"
  41 #include "adg-marker.h"
  42
  43 #include "adg-arrow.h"
  44 #include "adg-arrow-private.h"
  45
  46
  47 G_DEFINE_TYPE(AdgArrow, adg_arrow, ADG_TYPE_MARKER)
  48
  49 enum {
  50     PROP_0,
  51     PROP_ANGLE
  52 };
  53
  54
  55 static void             _adg_get_property            (GObject        *object,
  56                                                  guint           prop_id,
  57                                                  GValue         *value,
  58                                                  GParamSpec     *pspec);
  59 static void             _adg_set_property            (GObject        *object,
  60                                                  guint           prop_id,
  61                                                  const GValue   *value,
  62                                                  GParamSpec     *pspec);
  63 static void             _adg_arrange            (AdgEntity      *entity);
  64 static void             _adg_render             (AdgEntity      *entity,
  65                                                  cairo_t        *cr);
  66 static AdgModel *       _adg_create_model       (AdgMarker      *marker);
  67
  68
  69 static void
  70 adg_arrow_class_init(AdgArrowClass *klass)
  71 {
  72     GObjectClass *gobject_class;
  73     AdgEntityClass *entity_class;
  74     AdgMarkerClass *marker_class;
  75     GParamSpec *param;
  76
  77     gobject_class = (GObjectClass *) klass;
  78     entity_class = (AdgEntityClass *) klass;
  79     marker_class = (AdgMarkerClass *) klass;
  80
  81     g_type_class_add_private(klass, sizeof(AdgArrowPrivate));
  82
  83     gobject_class->set_property = _adg_set_property;
  84     gobject_class->get_property = _adg_get_property;
  85
  86     entity_class->arrange = _adg_arrange;
  87     entity_class->render = _adg_render;
  88
  89     marker_class->create_model = _adg_create_model;
  90
  91     param = g_param_spec_double("angle",
  92                                 P_("Arrow Angle"),
  93                                 P_("The opening angle of the arrow"),
  94                                 -G_PI, G_PI, G_PI / 6,
  95                                 G_PARAM_READWRITE);
  96     g_object_class_install_property(gobject_class, PROP_ANGLE, param);
  97 }
  98
  99 static void
 100 adg_arrow_init(AdgArrow *arrow)
 101 {
 102     AdgArrowPrivate *data = G_TYPE_INSTANCE_GET_PRIVATE(arrow,
 103                                                         ADG_TYPE_ARROW,
 104                                                         AdgArrowPrivate);
 105
 106     data->angle = G_PI/6;
 107
 108     arrow->data = data;
 109 }
 110
 111 static void
 112 _adg_get_property(GObject *object, guint prop_id,
 113                   GValue *value, GParamSpec *pspec)
 114 {
 115     AdgArrowPrivate *data = ((AdgArrow *) object)->data;
 116
 117     switch (prop_id) {
 118     case PROP_ANGLE:
 119         g_value_set_double(value, data->angle);
 120         break;
 121     default:
 122         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 123         break;
 124     }
 125 }
 126
 127 static void
 128 _adg_set_property(GObject *object, guint prop_id,
 129                   const GValue *value, GParamSpec *pspec)
 130 {
 131     AdgArrowPrivate *data = ((AdgArrow *) object)->data;
 132
 133     switch (prop_id) {
 134     case PROP_ANGLE:
 135         data->angle = cpml_angle(g_value_get_double(value));
 136         break;
 137     default:
 138         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 139         break;
 140     }
 141 }
 142
 143
 144 /**
 145  * adg_arrow_new:
 146  * @trail: the #AdgTrail to arrow
 147  *
 148  * Creates a new undefined arrow entity. The position must be defined
 149  * by setting the #AdgMarker:trail and #AdgMarker:pos properties.
 150  * By default, an arrow as #AdgEntity:local-method set to #ADG_MIX_PARENT.
 151  *
 152  * Returns: the newly created arrow entity
 153  **/
 154 AdgArrow *
 155 adg_arrow_new(void)
 156 {
 157     return g_object_new(ADG_TYPE_ARROW,
 158                         "local-method", ADG_MIX_PARENT,
 159                         NULL);
 160 }
 161
 162 /**
 163  * adg_arrow_new_with_trail:
 164  * @trail: the #AdgTrail where the arrow should be added
 165  * @pos: the position ratio on @trail
 166  *
 167  * Creates a new arrow on the first segment on @trail at position
 168  * @pos, where @pos is a ratio of the @trail length (being %0 the
 169  * start point, %1 the end point, %0.5 the middle point and so on).
 170  * By default, an arrow as #AdgEntity:local-method set to #ADG_MIX_PARENT.
 171  *
 172  * Returns: the newly created arrow entity
 173  **/
 174 AdgArrow *
 175 adg_arrow_new_with_trail(AdgTrail *trail, gdouble pos)
 176 {
 177     return g_object_new(ADG_TYPE_ARROW,
 178                         "local-method", ADG_MIX_PARENT,
 179                         "trail", trail,
 180                         "n-segment", 1,
 181                         "pos", pos,
 182                         NULL);
 183 }
 184
 185 /**
 186  * adg_arrow_set_angle:
 187  * @arrow: an #AdgArrow
 188  * @angle: the new angle
 189  *
 190  * Sets a new angle: @angle will be the new opening angle of @arrow.
 191  * Changing the arrow angle will invalidate @arrow.
 192  **/
 193 void
 194 adg_arrow_set_angle(AdgArrow *arrow, gdouble angle)
 195 {
 196     g_return_if_fail(ADG_IS_ARROW(arrow));
 197     g_object_set(arrow, "angle", angle, NULL);
 198 }
 199
 200 /**
 201  * adg_arrow_get_angle:
 202  * @arrow: an #AdgArrow
 203  *
 204  * Gets the current angle of @arrow.
 205  *
 206  * Returns: the arrow angle, in radians
 207  **/
 208 gdouble
 209 adg_arrow_get_angle(AdgArrow *arrow)
 210 {
 211     AdgArrowPrivate *data;
 212
 213     g_return_val_if_fail(ADG_IS_ARROW(arrow), 0);
 214
 215     data = arrow->data;
 216
 217     return data->angle;
 218 }
 219
 220
 221 static void
 222 _adg_arrange(AdgEntity *entity)
 223 {
 224     /* TODO */
 225 }
 226
 227 static void
 228 _adg_render(AdgEntity *entity, cairo_t *cr)
 229 {
 230     AdgModel *model;
 231     const cairo_path_t *cairo_path;
 232
 233     model = adg_marker_model((AdgMarker *) entity);
 234     cairo_path = adg_trail_get_cairo_path((AdgTrail *) model);
 235
 236     if (cairo_path != NULL) {
 237         cairo_save(cr);
 238         cairo_transform(cr, adg_entity_get_global_matrix(entity));
 239         cairo_transform(cr, adg_entity_get_local_matrix(entity));
 240         cairo_append_path(cr, cairo_path);
 241         cairo_restore(cr);
 242
 243         cairo_fill(cr);
 244     }
 245 }
 246
 247 static AdgModel *
 248 _adg_create_model(AdgMarker *marker)
 249 {
 250     AdgArrowPrivate *data;
 251     AdgPath *path;
 252     CpmlPair p1, p2;
 253
 254     data = ((AdgArrow *) marker)->data;
 255     path = adg_path_new();
 256     cpml_vector_from_angle(&p1, data->angle / 2);
 257     p2.x = p1.x;
 258     p2.y = -p1.y;
 259
 260     adg_path_move_to_explicit(path, 0, 0);
 261     adg_path_line_to(path, &p1);
 262     adg_path_line_to(path, &p2);
 263     adg_path_close(path);
 264
 265     return (AdgModel *) path;
 266 }