atk-tests/AtkObject_parent_child.c

   1 #include "AtkObject_parent_child.h"
   2
   3 //implementation
   4 static AtkObjectClass *atk_object_parent_class = NULL;
   5 //redefines 'set_parent' function, and defines functions, which absents in AtkObject
   6
   7 static void my_parent_child_set_parent(AtkObject *accessible, AtkObject *parent);
   8
   9 static gint my_parent_child_get_n_children(AtkObject *accessible);
  10
  11 static AtkObject* my_parent_child_ref_child(AtkObject *accessible, gint i);
  12
  13 static gint my_parent_child_get_index_in_parent(AtkObject *accessible);
  14
  15 //function, needed in instance_finalize()
  16 static void my_unref1(gpointer data, gpointer user_data)
  17 {
  18     g_object_unref(data);
  19 }
  20 //add/remove child to/from array of parent(for internal use)
  21 static void my_parent_child_add_child(MyParentChild* parent, MyParentChild* child)
  22 {
  23     g_ptr_array_add(parent->children, child);
  24     g_object_ref(child);
  25
  26     g_signal_emit_by_name(parent, "children-changed::add",
  27         parent->children->len - 1, child);
  28 }
  29 static void my_parent_child_remove_child(MyParentChild* parent, MyParentChild* child)
  30 {
  31     gint i;
  32     for(i = parent->children->len - 1; i >= 0; i--)
  33     {
  34         if(g_ptr_array_index(parent->children, i) == child) break;
  35     }
  36     if(i < 0)return;
  37
  38     g_ptr_array_remove_index(parent->children, i);
  39     g_object_unref(child);
  40     g_signal_emit_by_name(parent, "children-changed::remove",
  41         i, child);
  42 }
  43
  44 static void my_parent_child_instance_init(GTypeInstance *obj, gpointer g_class)
  45 {
  46     MyParentChild *self = (MyParentChild*)obj;
  47
  48     self->children = g_ptr_array_sized_new(10);
  49 }
  50
  51 static void my_parent_child_instance_finalize(GObject *obj)
  52 {
  53     MyParentChild *self = (MyParentChild*) obj;
  54     //unrefs all children
  55     g_ptr_array_foreach(self->children, my_unref1, NULL);
  56     //then free array (without frees pointers)
  57     g_ptr_array_free(self->children, FALSE);
  58     //chain to parent class
  59     G_OBJECT_CLASS(atk_object_parent_class)->finalize(obj);
  60 }
  61
  62 void my_parent_child_class_init(gpointer g_class, gpointer g_class_data)
  63 {
  64     AtkObjectClass *atkObjectClass = (AtkObjectClass*)g_class;
  65
  66     ((GObjectClass*)g_class)->finalize = my_parent_child_instance_finalize;
  67     //set pointers to new functions in table of virtuals functions
  68     atkObjectClass->set_parent = my_parent_child_set_parent;
  69     atkObjectClass->get_n_children = my_parent_child_get_n_children;
  70     atkObjectClass->ref_child = my_parent_child_ref_child;
  71     atkObjectClass->get_index_in_parent = my_parent_child_get_index_in_parent;
  72
  73     atk_object_parent_class = g_type_class_peek_parent(g_class);
  74 }
  75
  76 static void my_parent_child_set_parent(AtkObject *accessible, AtkObject *parent)
  77 {
  78     //applicable only with corresponding type of parent
  79     g_return_if_fail(parent == NULL || MY_IS_PARENT_CHILD(parent));
  80
  81     MyParentChild *self = MY_PARENT_CHILD(accessible);
  82     AtkObject *parent_old = (atk_object_get_parent(accessible));
  83
  84     if(parent_old == parent)
  85     {
  86         //nothing to do because parent does not change
  87         return;
  88     }
  89
  90     //set field 'parent' in child using 'base-method'
  91     atk_object_parent_class->set_parent(accessible, parent);
  92
  93     if(parent_old != NULL)
  94     {
  95         my_parent_child_remove_child((MyParentChild*)parent_old, self);
  96     }
  97     if(parent != NULL)
  98     {
  99         my_parent_child_add_child((MyParentChild*)parent, self);
 100     }
 101 }
 102
 103 static gint my_parent_child_get_n_children(AtkObject *accessible)
 104 {
 105     return MY_PARENT_CHILD(accessible)->children->len;
 106 }
 107
 108 static AtkObject* my_parent_child_ref_child(AtkObject *accessible, gint i)
 109 {
 110     MyParentChild *self = MY_PARENT_CHILD(accessible);
 111     if(i < 0 || i >= self->children->len)
 112     {
 113         printf("ref_child: Incorrect index of child.\n");
 114         return NULL;
 115     }
 116
 117     AtkObject* child = (AtkObject*)
 118         g_ptr_array_index(self->children, i);
 119
 120     return (child == NULL) ? NULL : g_object_ref(child);
 121 }
 122
 123 static gint my_parent_child_get_index_in_parent(AtkObject *accessible)
 124 {
 125     AtkObject *parent = atk_object_get_parent(accessible);
 126     if(parent == NULL) return -1;//no parent
 127
 128     MyParentChild *parent_my = MY_PARENT_CHILD(parent);
 129
 130     int i = parent_my->children->len;
 131     for(; i>=0; i--)
 132     {
 133         if(g_ptr_array_index(parent_my->children,i) == accessible)
 134             break;
 135     }
 136     if(i < 0)printf("Something wrong in parent-child strucutre.\n");
 137     return i;//if error, i will be equal to -1
 138 }
 139
 140 GType my_parent_child_get_type()
 141 {
 142     static GType type = 0;
 143     if(type == 0)
 144     {
 145         static const GTypeInfo typeInfo =
 146         {
 147             sizeof(MyParentChildClass),
 148             NULL, //base_init
 149             NULL, //base_finalize
 150             my_parent_child_class_init, //class_init
 151             NULL, //class_finalize
 152             NULL, //class_data
 153             sizeof(MyParentChild),
 154             0, //n_preallocs
 155             my_parent_child_instance_init //instance_init
 156         };
 157         type = g_type_register_static(ATK_TYPE_OBJECT,"MyParentChild",&typeInfo,0);
 158     }
 159     return type;
 160 }