adg/adg-positionable.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007-2008, 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:positionable
  23  * @title: AdgPositionable
  24  * @short_description: Interface for positionable entities
  25  *
  26  * The #AdgPositionableIface interface gives a common way to manage entities
  27  * with an origin point.
  28  **/
  29
  30 /**
  31  * AdgPositionableIface:
  32  * @base_iface:         the base interface
  33  * @org:                the origin point accessor
  34  *
  35  * The virtual methods @org must be defined by all the types which
  36  * implement this interface.
  37  **/
  38
  39 #include "adg-positionable.h"
  40 #include "adg-intl.h"
  41
  42
  43 enum {
  44     ORG_MOVED,
  45     LAST_SIGNAL
  46 };
  47
  48 static void      iface_base     (AdgPositionableIface   *iface);
  49 static void      iface_init     (AdgPositionableIface   *iface);
  50 static AdgPoint *org            (AdgPositionable        *positionable);
  51
  52
  53 static guint    signals[LAST_SIGNAL] = { 0 };
  54
  55
  56 GType
  57 adg_positionable_get_type(void)
  58 {
  59     static GType positionable_type = 0;
  60
  61     if (G_UNLIKELY(positionable_type == 0)) {
  62         static const GTypeInfo positionable_info = {
  63             sizeof(AdgPositionableIface),
  64             (GBaseInitFunc) iface_base,
  65             NULL,
  66             (GClassInitFunc) iface_init,
  67             NULL,
  68         };
  69
  70         positionable_type = g_type_register_static(G_TYPE_INTERFACE,
  71                                                    "AdgPositionable",
  72                                                    &positionable_info, 0);
  73     }
  74
  75     return positionable_type;
  76 }
  77
  78 static void
  79 iface_base(AdgPositionableIface *iface)
  80 {
  81     static gboolean initialized = FALSE;
  82     GParamSpec *param;
  83     GType param_types[1];
  84
  85     if (initialized) {
  86         return;
  87     }
  88     initialized = TRUE;
  89
  90     param = g_param_spec_object("org",
  91                                 P_("Org"),
  92                                 P_("Origin point"),
  93                                 ADG_TYPE_POINT,
  94                                 G_PARAM_READWRITE);
  95     g_object_interface_install_property(iface, param);
  96
  97     /**
  98      * AdgPositionable::org-moved:
  99      * @positionable: an entity implementing #AdgPositionable
 100      *
 101      * Emitted whenever the origin has changed.
 102      **/
 103     param_types[0] = ADG_TYPE_POINT;
 104     signals[ORG_MOVED] = g_signal_newv("org-moved", ADG_TYPE_POSITIONABLE,
 105                                        G_SIGNAL_RUN_FIRST,
 106                                        NULL, NULL, NULL,
 107                                        g_cclosure_marshal_VOID__OBJECT,
 108                                        G_TYPE_NONE, 1, param_types);
 109 }
 110
 111 static void
 112 iface_init (AdgPositionableIface *iface)
 113 {
 114     iface->org = org;
 115 }
 116
 117
 118 static AdgPoint *
 119 org(AdgPositionable *positionable)
 120 {
 121     g_warning("AdgPositionable::org not implemented for `%s'",
 122               g_type_name(G_TYPE_FROM_INSTANCE(positionable)));
 123     return NULL;
 124 }
 125
 126 /**
 127  * adg_positionable_get_org:
 128  * @positionable: an entity implementing AdgPositionable
 129  *
 130  * Gets the origin point of @positionable.
 131  *
 132  * Return value: A pointer to the internal origin point
 133  **/
 134 const AdgPoint *
 135 adg_positionable_get_org(AdgPositionable *positionable)
 136 {
 137     g_return_val_if_fail(ADG_IS_POSITIONABLE(positionable), NULL);
 138
 139     return ADG_POSITIONABLE_GET_IFACE(positionable)->org(positionable);
 140 }
 141
 142 /**
 143  * adg_positionable_set_org:
 144  * @positionable: an entity implementing AdgPositionable
 145  * @org: the new origin
 146  *
 147  * Sets the origin of @positionable to @org. An "org-moved" signal is emitted.
 148  **/
 149 void
 150 adg_positionable_set_org(AdgPositionable *positionable, const AdgPoint *org)
 151 {
 152     AdgPoint *current_org;
 153     AdgPoint old_org;
 154
 155     g_return_if_fail(ADG_IS_POSITIONABLE(positionable));
 156
 157     current_org = ADG_POSITIONABLE_GET_IFACE(positionable)->org(positionable);
 158
 159     adg_point_copy(current_org, &old_org);
 160     adg_point_copy(org, current_org);
 161     g_signal_emit(positionable, signals[ORG_MOVED], 0, &old_org);
 162 }
 163
 164 /**
 165  * adg_positionable_set_org_explicit:
 166  * @positionable: an entity implementing AdgPositionable
 167  * @model_x: the new x position in model space
 168  * @model_y: the new y position in model space
 169  * @paper_x: the new x position in paper space
 170  * @paper_y: the new y position in paper space
 171  *
 172  * Sets the origin of @positionable to the new coordinates. It calls
 173  * adg_positionable_set_org() internally.
 174  **/
 175 void
 176 adg_positionable_set_org_explicit(AdgPositionable *positionable,
 177                                   gdouble model_x, gdouble model_y,
 178                                   gdouble paper_x, gdouble paper_y)
 179 {
 180     AdgPoint org;
 181
 182     org.model.x = model_x;
 183     org.model.y = model_y;
 184     org.paper.x = paper_x;
 185     org.paper.y = paper_y;
 186
 187     adg_positionable_set_org(positionable, &org);
 188 }