Class TreeModelSort

Whenever the source_property is changed the target_property is updated using the same value. For instance:

  g_object_bind_property (action, "active", widget, "sensitive", 0);

Will result in the "sensitive" property of the widget #GObject instance to be updated with the same value of the "active" property of the action #GObject instance.

If flags contains %G_BINDING_BIDIRECTIONAL then the binding will be mutual: if target_property on target changes then the source_property on source will be updated as well.

The binding will automatically be removed when either the source or the target instances are finalized. To remove the binding without affecting the source and the target you can just call g_object_unref() on the returned #GBinding instance.

Removing the binding by calling g_object_unref() on it must only be done if the binding, source and target are only used from a single thread and it is clear that both source and target outlive the binding. Especially it is not safe to rely on this if the binding, source or target can be finalized from different threads. Keep another reference to the binding and use g_binding_unbind() instead to be on the safe side.

A #GObject can have multiple bindings.

This function is the language bindings friendly version of g_object_bind_property_full(), using #GClosures instead of function pointers.

If func returns %TRUE, then the tree ceases to be walked, and gtk_tree_model_foreach() returns.

This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.

The flags are a bitwise combination of GtkTreeModelFlags. The flags supported should not change during the lifetime of the tree_model.

If path does not exist, iter is set to an invalid iterator and %FALSE is returned.

Returns %FALSE if the tree is empty, %TRUE otherwise.

Otherwise, iter is left invalid and %FALSE is returned.

This path should be freed with gtk_tree_path_free().

The value can be:

• an empty #GValue initialized by %G_VALUE_INIT, which will be automatically initialized with the expected type of the property (since GLib 2.60)
• a #GValue initialized with the expected type of the property
• a #GValue initialized with a type to which the expected type of the property can be transformed

In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling g_value_unset().

Note that g_object_get_property() is really intended for language bindings, g_object_get() is much more convenient for C programming.

This string is a “:” separated list of numbers. For example, “4:10:0:3” would be an acceptable return value for this string.

When done with value, g_value_unset() needs to be called to free any allocated memory.

If parent has no children, %FALSE is returned and iter is set to be invalid. parent will remain a valid node after this function has been called.

If parent is %NULL returns the first node, equivalent to gtk_tree_model_get_iter_first (tree_model, iter);

As a special case, if iter is %NULL, then the number of toplevel nodes is returned.

If there is no next iter, %FALSE is returned and iter is set to be invalid.

The first index is 0. If n is too big, or parent has no children, iter is set to an invalid iterator and %FALSE is returned. parent will remain a valid node after this function has been called. As a special case, if parent is %NULL, then the n-th root node is set.

If child is at the toplevel, and doesn’t have a parent, then iter is set to an invalid iterator and %FALSE is returned. child will remain a valid node after this function has been called.

iter will be initialized before the lookup is performed, so child and iter cannot point to the same memory location.

If there is no previous iter, %FALSE is returned and iter is set to be invalid.

When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.

Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.

This function omits the property name lookup, hence it is faster than g_object_notify().

One way to avoid using g_object_notify() from within the class that registered the properties, and using g_object_notify_by_pspec() instead, is to store the GParamSpec used with g_object_class_install_property() inside a static array, e.g.:

  enum
  {
    PROP_0,
    PROP_FOO,
    PROP_LAST
  };

  static GParamSpec *properties[PROP_LAST];

  static void
  my_object_class_init (MyObjectClass *klass)
  {
    properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
                                             0, 100,
                                             50,
                                             G_PARAM_READWRITE);
    g_object_class_install_property (gobject_class,
                                     PROP_FOO,
                                     properties[PROP_FOO]);
  }

and then notify a change on the "foo" property with:

  g_object_notify_by_pspec (self, properties[PROP_FOO]);

Since GLib 2.56, if GLIB_VERSION_MAX_ALLOWED is 2.56 or greater, the type of object will be propagated to the return type (using the GCC typeof() extension), so any casting the caller needs to do on the return type must be explicit.

This is an optional method for models to implement. To be more specific, models may ignore this call as it exists primarily for performance reasons.

This function is primarily meant as a way for views to let caching models know when nodes are being displayed (and hence, whether or not to cache that node). Being displayed means a node is in an expanded branch, regardless of whether the node is currently visible in the viewport. For example, a file-system based model would not want to keep the entire file-hierarchy in memory, just the sections that are currently being displayed by every current view.

A model should be expected to be able to get an iter independent of its reffed state.

In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.

Since GLib 2.56, the type of object will be propagated to the return type under the same conditions as for g_object_ref().

See [signalGtk.TreeModel::row-changed].

See [signalGtk.TreeModel::row-deleted].

This should be called by models after a row has been removed. The location pointed to by path should be the location that the row previously was at. It may not be a valid location anymore.

Nodes that are deleted are not unreffed, this means that any outstanding references on the deleted node should not be released.

See [signalGtk.TreeModel::row-has-child-toggled].

This should be called by models after the child state of a node changes.

See [signalGtk.TreeModel::row-inserted].

See [signalGtk.TreeModel::rows-reordered].

This should be called by models when their rows have been reordered.

This function should only be called from object system implementations.

If the object already had an association with that name, the old association will be destroyed.

Internally, the key is converted to a #GQuark using g_quark_from_string(). This means a copy of key is kept permanently (even after object has been finalized) — so it is recommended to only use a small, bounded set of values for key in your program, to avoid the #GQuark storage growing unbounded.

If sort_func is %NULL, then there will be no default comparison function. This means that once the model has been sorted, it can’t go back to the default state. In this case, when the current sort column id of sortable is %GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID, the model will be unsorted.

• %GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID: the default sort function will be used, if it is set

• %GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID: no sorting will occur

void
object_add_to_user_list (GObject     *object,
                         const gchar *new_string)
{
  // the quark, naming the object data
  GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
  // retrieve the old string list
  GList *list = g_object_steal_qdata (object, quark_string_list);

  // prepend new string
  list = g_list_prepend (list, g_strdup (new_string));
  // this changed 'list', so we need to set it again
  g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
}
static void
free_string_list (gpointer data)
{
  GList *node, *list = data;

  for (node = list; node; node = node->next)
    g_free (node->data);
  g_list_free (list);
}

Using g_object_get_qdata() in the above example, instead of g_object_steal_qdata() would have left the destroy function set, and thus the partial string list would have been freed upon g_object_set_qdata_full().

Duplicate notifications for each property are squashed so that at most one #GObject::notify signal is emitted for each property, in the reverse order in which they have been queued.

It is an error to call this function when the freeze count is zero.

If the pointer to the #GObject may be reused in future (for example, if it is an instance variable of another object), it is recommended to clear the pointer to %NULL rather than retain a dangling pointer to a potentially invalid #GObject instance. Use g_clear_object() for this.

This is an optional method for models to implement. To be more specific, models may ignore this call as it exists primarily for performance reasons. For more information on what this means, see gtk_tree_model_ref_node().

Please note that nodes that are deleted are not unreffed.