[gtk/matthiasc/for-master: 4/6] flattenlistmodel: Give access to child models

[Matthias Clasen <matthiasc src gnome org>]

commit 1308ecb0aee7880d6d1a1d9a979c1331eceec6c2
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Mar 22 13:19:55 2020 -0400

    flattenlistmodel: Give access to child models
    
    Add an api to retrieve the model containing a given
    item in a flatten listmodel. This is useful when the
    individual items in the list don't have backpointers.

 docs/reference/gtk/gtk4-sections.txt |  1 +
 gtk/gtkflattenlistmodel.c            | 25 +++++++++++++++++++++++++
 gtk/gtkflattenlistmodel.h            |  4 ++++
 3 files changed, 30 insertions(+)
---
diff --git a/docs/reference/gtk/gtk4-sections.txt b/docs/reference/gtk/gtk4-sections.txt
index 13b3f831f6..1f243f2797 100644
--- a/docs/reference/gtk/gtk4-sections.txt
+++ b/docs/reference/gtk/gtk4-sections.txt
@@ -1316,6 +1316,7 @@ GtkFlattenListModel
 gtk_flatten_list_model_new
 gtk_flatten_list_model_set_model
 gtk_flatten_list_model_get_model
+gtk_flatten_list_model_get_model_for_item
 <SUBSECTION Standard>
 GTK_FLATTEN_LIST_MODEL
 GTK_IS_FLATTEN_LIST_MODEL
diff --git a/gtk/gtkflattenlistmodel.c b/gtk/gtkflattenlistmodel.c
index 3204f5b5ea..f557cb2232 100644
--- a/gtk/gtkflattenlistmodel.c
+++ b/gtk/gtkflattenlistmodel.c
@@ -539,3 +539,28 @@ gtk_flatten_list_model_get_model (GtkFlattenListModel *self)
 
   return self->model;
 }
+
+/**
+ * gtk_flatten_list_model_get_model_for_item:
+ * @self: a #GtkFlattenListModel
+ * @position: a position
+ *
+ * Returns the model containing the item at the given position.
+ *
+ * Returns: (transfer none): the model containing the item at @position
+ */
+GListModel *
+gtk_flatten_list_model_get_model_for_item (GtkFlattenListModel *self,
+                                           guint                position)
+{
+  FlattenNode *node;
+
+  if (!self->items)
+    return NULL;
+
+  node = gtk_flatten_list_model_get_nth (self->items, position, NULL);
+  if (node == NULL)
+    return NULL;
+
+  return node->model;
+}
diff --git a/gtk/gtkflattenlistmodel.h b/gtk/gtkflattenlistmodel.h
index 75e39404d7..ec1eaaa84e 100644
--- a/gtk/gtkflattenlistmodel.h
+++ b/gtk/gtkflattenlistmodel.h
@@ -45,6 +45,10 @@ void                    gtk_flatten_list_model_set_model        (GtkFlattenListM
 GDK_AVAILABLE_IN_ALL
 GListModel *            gtk_flatten_list_model_get_model        (GtkFlattenListModel    *self);
 
+GDK_AVAILABLE_IN_ALL
+GListModel *            gtk_flatten_list_model_get_model_for_item (GtkFlattenListModel    *self,
+                                                                   guint                   position);
+
 G_END_DECLS
 
 #endif /* __GTK_FLATTEN_LIST_MODEL_H__ */