GtkMapListModel: add

8 files changed, 1025 insertions, 0 deletions

diff --git a/docs/reference/gtk/gtk4-docs.xml b/docs/reference/gtk/gtk4-docs.xml
index 98f0c897e0..b2e7de2c5f 100644
--- a/docs/reference/gtk/gtk4-docs.xml
+++ b/docs/reference/gtk/gtk4-docs.xml
@@ -45,6 +45,7 @@
       <title>GListModel support</title>
       <xi:include href="xml/gtkfilterlistmodel.xml" />
       <xi:include href="xml/gtkflattenlistmodel.xml" />
+      <xi:include href="xml/gtkmaplistmodel.xml" />
       <xi:include href="xml/gtktreelistmodel.xml" />
     </chapter>
 
diff --git a/docs/reference/gtk/gtk4-sections.txt b/docs/reference/gtk/gtk4-sections.txt
index 23293e2693..5410ec67a4 100644
--- a/docs/reference/gtk/gtk4-sections.txt
+++ b/docs/reference/gtk/gtk4-sections.txt
@@ -1745,6 +1745,27 @@ gtk_link_button_get_type
 </SECTION>
 
 <SECTION>
+<FILE>gtkmaplistmodel</FILE>
+<TITLE>GtkMapListModel</TITLE>
+GtkMapListModel
+GtkMapListModelMapFunc
+gtk_map_list_model_new
+gtk_map_list_model_set_map_func
+gtk_map_list_model_set_model
+gtk_map_list_model_get_model
+gtk_map_list_model_has_map
+<SUBSECTION Standard>
+GTK_MAP_LIST_MODEL
+GTK_IS_MAP_LIST_MODEL
+GTK_TYPE_MAP_LIST_MODEL
+GTK_MAP_LIST_MODEL_CLASS
+GTK_IS_MAP_LIST_MODEL_CLASS
+GTK_MAP_LIST_MODEL_GET_CLASS
+<SUBSECTION Private>
+gtk_map_list_model_get_type
+</SECTION>
+
+<SECTION>
 <FILE>gtkmenu</FILE>
 <TITLE>GtkMenu</TITLE>
 GtkMenu
diff --git a/gtk/gtk.h b/gtk/gtk.h
index 6a5f9b25dd..cde9b4a46b 100644
--- a/gtk/gtk.h
+++ b/gtk/gtk.h
@@ -141,6 +141,7 @@
 #include <gtk/gtkliststore.h>
 #include <gtk/gtklockbutton.h>
 #include <gtk/gtkmain.h>
+#include <gtk/gtkmaplistmodel.h>
 #include <gtk/gtkmediacontrols.h>
 #include <gtk/gtkmediafile.h>
 #include <gtk/gtkmediastream.h>
diff --git a/gtk/gtkmaplistmodel.c b/gtk/gtkmaplistmodel.c
new file mode 100644
index 0000000000..028bc060e4
--- /dev/null
+++ b/gtk/gtkmaplistmodel.c
@@ -0,0 +1,627 @@
+/*
+ * Copyright © 2018 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+#include "config.h"
+
+#include "gtkmaplistmodel.h"
+
+#include "gtkcssrbtreeprivate.h"
+#include "gtkintl.h"
+#include "gtkprivate.h"
+
+/**
+ * SECTION:gtkmaplistmodel
+ * @title: GtkMapListModel
+ * @short_description: a #GListModel that maps items from a child list model to
+ *     a different item
+ * @see_also: #GListModel
+ *
+ * #GtkMapListModel is a list model that takes a list model and maps the items
+ * in that model to different items according to a #GtkMapListModelMapFunc.
+ *
+ * FIXME: Add useful examples here, like turning #GFile into #GFileInfo or #GdkPixmap.
+ *
+ * #GtkMapListModel will attempt to discard the mapped objects as soon as they are no
+ * longer needed and recreate them if necessary.
+ */
+
+enum {
+  PROP_0,
+  PROP_HAS_MAP,
+  PROP_ITEM_TYPE,
+  PROP_MODEL,
+  NUM_PROPERTIES
+};
+
+typedef struct _MapNode MapNode;
+typedef struct _MapAugment MapAugment;
+
+struct _MapNode
+{
+  guint n_items;
+  gpointer item; /* can only be set when n_items == 1 */
+};
+
+struct _MapAugment
+{
+  guint n_items;
+};
+
+struct _GtkMapListModel
+{
+  GObject parent_instance;
+
+  GType item_type;
+  GListModel *model;
+  GtkMapListModelMapFunc map_func;
+  gpointer user_data;
+  GDestroyNotify user_destroy;
+
+  GtkCssRbTree *items; /* NULL if map_func == NULL */
+};
+
+struct _GtkMapListModelClass
+{
+  GObjectClass parent_class;
+};
+
+static GParamSpec *properties[NUM_PROPERTIES] = { NULL, };
+
+static MapNode *
+gtk_map_list_model_get_nth (GtkCssRbTree *tree,
+                            guint         position,
+                            guint        *out_start_pos)
+{
+  MapNode *node, *tmp;
+  guint start_pos = position;
+
+  node = gtk_css_rb_tree_get_root (tree);
+
+  while (node)
+    {
+      tmp = gtk_css_rb_tree_get_left (tree, node);
+      if (tmp)
+        {
+          MapAugment *aug = gtk_css_rb_tree_get_augment (tree, tmp);
+          if (position < aug->n_items)
+            {
+              node = tmp;
+              continue;
+            }
+          position -= aug->n_items;
+        }
+
+      if (position < node->n_items)
+        {
+          start_pos -= position;
+          break;
+        }
+      position -= node->n_items;
+
+      node = gtk_css_rb_tree_get_right (tree, node);
+    }
+
+  if (out_start_pos)
+    *out_start_pos = start_pos;
+
+  return node;
+}
+
+static GType
+gtk_map_list_model_get_item_type (GListModel *list)
+{
+  GtkMapListModel *self = GTK_MAP_LIST_MODEL (list);
+
+  return self->item_type;
+}
+
+static guint
+gtk_map_list_model_get_n_items (GListModel *list)
+{
+  GtkMapListModel *self = GTK_MAP_LIST_MODEL (list);
+  
+  if (self->model == NULL)
+    return 0;
+
+  return g_list_model_get_n_items (self->model);
+}
+
+static gpointer
+gtk_map_list_model_get_item (GListModel *list,
+                             guint       position)
+{
+  GtkMapListModel *self = GTK_MAP_LIST_MODEL (list);
+  MapNode *node;
+  guint offset;
+
+  if (self->model == NULL)
+    return NULL;
+
+  if (self->items == NULL)
+    return g_list_model_get_item (self->model, position);
+
+  node = gtk_map_list_model_get_nth (self->items, position, &offset);
+  if (node == NULL)
+    return NULL;
+
+  if (node->item)
+    return g_object_ref (node->item);
+
+  if (offset != position)
+    {
+      MapNode *before = gtk_css_rb_tree_insert_before (self->items, node);
+      before->n_items = position - offset;
+      node->n_items -= before->n_items;
+      gtk_css_rb_tree_mark_dirty (self->items, node);
+    }
+
+  if (node->n_items > 1)
+    {
+      MapNode *after = gtk_css_rb_tree_insert_after (self->items, node);
+      after->n_items = node->n_items - 1;
+      node->n_items = 1;
+      gtk_css_rb_tree_mark_dirty (self->items, node);
+    }
+
+  node->item = self->map_func (g_list_model_get_item (self->model, position), self->user_data);
+  g_object_add_weak_pointer (node->item, &node->item);
+
+  return node->item;
+}
+
+static void
+gtk_map_list_model_model_init (GListModelInterface *iface)
+{
+  iface->get_item_type = gtk_map_list_model_get_item_type;
+  iface->get_n_items = gtk_map_list_model_get_n_items;
+  iface->get_item = gtk_map_list_model_get_item;
+}
+
+G_DEFINE_TYPE_WITH_CODE (GtkMapListModel, gtk_map_list_model, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL, gtk_map_list_model_model_init))
+
+static void
+gtk_map_list_model_items_changed_cb (GListModel      *model,
+                                     guint            position,
+                                     guint            removed,
+                                     guint            added,
+                                     GtkMapListModel *self)
+{
+  MapNode *node;
+  guint start, end;
+
+  if (self->items == NULL)
+    {
+      g_list_model_items_changed (G_LIST_MODEL (self), position, removed, added);
+      return;
+    }
+
+  node = gtk_map_list_model_get_nth (self->items, position, &start);
+  g_assert (start <= position);
+
+  while (removed > 0)
+    {
+      end = start + node->n_items;
+      if (start == position && end <= position + removed)
+        {
+          MapNode *next = gtk_css_rb_tree_get_next (self->items, node);
+          removed -= node->n_items;
+          gtk_css_rb_tree_remove (self->items, node);
+          node = next;
+        }
+      else
+        {
+          if (end >= position + removed)
+            {
+              node->n_items -= removed;
+              removed = 0;
+              gtk_css_rb_tree_mark_dirty (self->items, node);
+            }
+          else if (start < position)
+            {
+              guint overlap = node->n_items - (position - start);
+              node->n_items -= overlap;
+              gtk_css_rb_tree_mark_dirty (self->items, node);
+              removed -= overlap;
+              start = position;
+              node = gtk_css_rb_tree_get_next (self->items, node);
+            }
+        }
+    }
+
+  if (added)
+    {
+      if (node == NULL)
+        node = gtk_css_rb_tree_insert_before (self->items, NULL);
+      else if (node->item)
+        node = gtk_css_rb_tree_insert_after (self->items, node);
+
+      node->n_items += added;
+      gtk_css_rb_tree_mark_dirty (self->items, node);
+    }
+
+  g_list_model_items_changed (G_LIST_MODEL (self), position, removed, added);
+}
+
+static void
+gtk_map_list_model_set_property (GObject      *object,
+                                 guint         prop_id,
+                                 const GValue *value,
+                                 GParamSpec   *pspec)
+{
+  GtkMapListModel *self = GTK_MAP_LIST_MODEL (object);
+
+  switch (prop_id)
+    {
+    case PROP_ITEM_TYPE:
+      self->item_type = g_value_get_gtype (value);
+      break;
+
+    case PROP_MODEL:
+      gtk_map_list_model_set_model (self, g_value_get_object (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void 
+gtk_map_list_model_get_property (GObject     *object,
+                                 guint        prop_id,
+                                 GValue      *value,
+                                 GParamSpec  *pspec)
+{
+  GtkMapListModel *self = GTK_MAP_LIST_MODEL (object);
+
+  switch (prop_id)
+    {
+    case PROP_HAS_MAP:
+      g_value_set_boolean (value, self->items != NULL);
+      break;
+
+    case PROP_ITEM_TYPE:
+      g_value_set_gtype (value, self->item_type);
+      break;
+
+    case PROP_MODEL:
+      g_value_set_object (value, self->model);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_map_list_model_clear_model (GtkMapListModel *self)
+{
+  if (self->model == NULL)
+    return;
+
+  g_signal_handlers_disconnect_by_func (self->model, gtk_map_list_model_items_changed_cb, self);
+  g_clear_object (&self->model);
+}
+
+static void
+gtk_map_list_model_dispose (GObject *object)
+{
+  GtkMapListModel *self = GTK_MAP_LIST_MODEL (object);
+
+  gtk_map_list_model_clear_model (self);
+  if (self->user_destroy)
+    self->user_destroy (self->user_data);
+  self->map_func = NULL;
+  self->user_data = NULL;
+  self->user_destroy = NULL;
+  g_clear_pointer (&self->items, gtk_css_rb_tree_unref);
+
+  G_OBJECT_CLASS (gtk_map_list_model_parent_class)->dispose (object);
+};
+
+static void
+gtk_map_list_model_class_init (GtkMapListModelClass *class)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (class);
+
+  gobject_class->set_property = gtk_map_list_model_set_property;
+  gobject_class->get_property = gtk_map_list_model_get_property;
+  gobject_class->dispose = gtk_map_list_model_dispose;
+
+  /**
+   * GtkMapListModel:has-map:
+   *
+   * If a map is set for this model
+   */
+  properties[PROP_HAS_MAP] =
+      g_param_spec_boolean ("has-map",
+                            P_("has map"),
+                            P_("If a map is set for this model"),
+                            FALSE,
+                            GTK_PARAM_READABLE | G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * GtkMapListModel:item-type:
+   *
+   * The #GType for elements of this object
+   */
+  properties[PROP_ITEM_TYPE] =
+      g_param_spec_gtype ("item-type",
+                          P_("Item type"),
+                          P_("The type of elements of this object"),
+                          G_TYPE_OBJECT,
+                          GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * GtkMapListModel:model:
+   *
+   * The model being mapped
+   */
+  properties[PROP_MODEL] =
+      g_param_spec_object ("model",
+                           P_("Model"),
+                           P_("The model being mapped"),
+                           G_TYPE_LIST_MODEL,
+                           GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_EXPLICIT_NOTIFY);
+
+  g_object_class_install_properties (gobject_class, NUM_PROPERTIES, properties);
+}
+
+static void
+gtk_map_list_model_init (GtkMapListModel *self)
+{
+}
+
+
+static void
+gtk_map_list_model_augment (GtkCssRbTree *map,
+                            gpointer      _aug,
+                            gpointer      _node,
+                            gpointer      left,
+                            gpointer      right)
+{
+  MapNode *node= _node;
+  MapAugment *aug = _aug;
+
+  aug->n_items = node->n_items;
+
+  if (left)
+    {
+      MapAugment *left_aug = gtk_css_rb_tree_get_augment (map, left);
+      aug->n_items += left_aug->n_items;
+    }
+  if (right)
+    {
+      MapAugment *right_aug = gtk_css_rb_tree_get_augment (map, right);
+      aug->n_items += right_aug->n_items;
+    }
+}
+
+/**
+ * gtk_map_list_model_new:
+ * @item_type: the #GType to use as the model's item type
+ * @model: (allow-none): The model to map or %NULL for none
+ * @map_func: (allow-none): map function or %NULL to not map items
+ * @user_data: user data passed to @map_func
+ * @destroy: destroy notifier for @user_data
+ *
+ * Creates a new #GtkMapListModel for the given arguments.
+ *
+ * Returns: a new #GtkMapListModel
+ **/
+GtkMapListModel *
+gtk_map_list_model_new (GType                   item_type,
+                        GListModel             *model,
+                        GtkMapListModelMapFunc  map_func,
+                        gpointer                data,
+                        GDestroyNotify          data_destroy)
+{
+  GtkMapListModel *result;
+
+  g_return_val_if_fail (g_type_is_a (item_type, G_TYPE_OBJECT), NULL);
+  g_return_val_if_fail (model == NULL || G_IS_LIST_MODEL (model), NULL);
+
+  result = g_object_new (GTK_TYPE_MAP_LIST_MODEL,
+                         "item-type", item_type,
+                         "model", model,
+                         NULL);
+
+  if (map_func)
+    gtk_map_list_model_set_map_func (result, map_func, data, data_destroy);
+
+  return result;
+}
+
+static void
+gtk_map_list_model_clear_node (gpointer _node)
+{
+  MapNode *node = _node;
+
+  if (node->item)
+    g_object_remove_weak_pointer (node->item, &node->item);
+}
+
+static void
+gtk_map_list_model_init_items (GtkMapListModel *self)
+{
+  if (self->map_func && self->model)
+    {
+      guint n_items;
+
+      if (self->items)
+        {
+          gtk_css_rb_tree_remove_all (self->items);
+        }
+      else
+        {
+          self->items = gtk_css_rb_tree_new (MapNode,
+                                             MapAugment, 
+                                             gtk_map_list_model_augment,
+                                             gtk_map_list_model_clear_node,
+                                             NULL);
+        }
+
+      n_items = g_list_model_get_n_items (self->model);
+      if (n_items)
+        {
+          MapNode *node = gtk_css_rb_tree_insert_before (self->items, NULL);
+          node->n_items = g_list_model_get_n_items (self->model);
+          gtk_css_rb_tree_mark_dirty (self->items, node);
+        }
+    }
+  else
+    {
+      g_clear_pointer (&self->items, gtk_css_rb_tree_unref);
+    }
+}
+
+/**
+ * gtk_map_list_model_set_map_func:
+ * @self: a #GtkMapListModel
+ * @map_func: (allow-none): map function or %NULL to not map items
+ * @user_data: user data passed to @map_func
+ * @destroy: destroy notifier for @user_data
+ *
+ * Sets the function used to map items. The function will be called whenever
+ * an item needs to be mapped and must return the item to use for the given
+ * input item.
+ *
+ * Note that #GtkMapListModel may call this function multiple times on the
+ * same item, because it may delete items it doesn't need anymore.
+ *
+ * GTK makes no effort to ensure that @map_func conforms to the item type
+ * of @self. It assumes that the caller knows what they are doing and the map
+ * function returns items of the appropriate type.
+ **/
+void
+gtk_map_list_model_set_map_func (GtkMapListModel        *self,
+                                 GtkMapListModelMapFunc  map_func,
+                                 gpointer                user_data,
+                                 GDestroyNotify          user_destroy)
+{
+  gboolean was_maped, will_be_maped;
+  guint n_items;
+
+  g_return_if_fail (GTK_IS_MAP_LIST_MODEL (self));
+  g_return_if_fail (map_func != NULL || (user_data == NULL && !user_destroy));
+
+  was_maped = self->map_func != NULL;
+  will_be_maped = map_func != NULL;
+
+  if (!was_maped && !will_be_maped)
+    return;
+
+  if (self->user_destroy)
+    self->user_destroy (self->user_data);
+
+  self->map_func = map_func;
+  self->user_data = user_data;
+  self->user_destroy = user_destroy;
+  
+  gtk_map_list_model_init_items (self);
+
+  if (self->model)
+    n_items = g_list_model_get_n_items (self->model);
+  else
+    n_items = 0;
+  if (n_items)
+    g_list_model_items_changed (G_LIST_MODEL (self), 0, n_items, n_items);
+
+  if (was_maped != will_be_maped)
+    g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_HAS_MAP]);
+}
+
+/**
+ * gtk_map_list_model_set_model:
+ * @self: a #GtkMapListModel
+ * @model: (allow-none): The model to be mapped
+ *
+ * Sets the model to be mapped.
+ *
+ * GTK makes no effort to ensure that @model conforms to the item type
+ * expected by the map function. It assumes that the caller knows what
+ * they are doing and have set up an appropriate map function.
+ **/
+void
+gtk_map_list_model_set_model (GtkMapListModel *self,
+                              GListModel      *model)
+{
+  guint removed, added;
+
+  g_return_if_fail (GTK_IS_MAP_LIST_MODEL (self));
+  g_return_if_fail (model == NULL || G_IS_LIST_MODEL (model));
+
+  if (self->model == model)
+    return;
+
+  removed = g_list_model_get_n_items (G_LIST_MODEL (self));
+  gtk_map_list_model_clear_model (self);
+
+  if (model)
+    {
+      self->model = g_object_ref (model);
+      g_signal_connect (model, "items-changed", G_CALLBACK (gtk_map_list_model_items_changed_cb), self);
+      added = g_list_model_get_n_items (model);
+    }
+  else
+    {
+      added = 0;
+    }
+
+  gtk_map_list_model_init_items (self);
+  
+  if (removed > 0 || added > 0)
+    g_list_model_items_changed (G_LIST_MODEL (self), 0, removed, added);
+
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_MODEL]);
+}
+
+/**
+ * gtk_map_list_model_get_model:
+ * @self: a #GtkMapListModel
+ *
+ * Gets the model that is curently being mapped or %NULL if none.
+ *
+ * Returns: (nullable) (transfer none): The model that gets mapped
+ **/
+GListModel *
+gtk_map_list_model_get_model (GtkMapListModel *self)
+{
+  g_return_val_if_fail (GTK_IS_MAP_LIST_MODEL (self), NULL);
+
+  return self->model;
+}
+
+/**
+ * gtk_map_list_model_has_map:
+ * @self: a #GtkMapListModel
+ *
+ * Checks if a map function is currently set on @self
+ *
+ * Returns: %TRUE if a map function is set
+ **/
+gboolean
+gtk_map_list_model_has_map (GtkMapListModel *self)
+{
+  g_return_val_if_fail (GTK_IS_MAP_LIST_MODEL (self), FALSE);
+
+  return self->map_func != NULL;
+}
diff --git a/gtk/gtkmaplistmodel.h b/gtk/gtkmaplistmodel.h
new file mode 100644
index 0000000000..185c8ed0da
--- /dev/null
+++ b/gtk/gtkmaplistmodel.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright © 2018 Benjamin Otte
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte@gnome.org>
+ */
+
+#ifndef __GTK_MAP_LIST_MODEL_H__
+#define __GTK_MAP_LIST_MODEL_H__
+
+
+#if !defined (__GTK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gtk/gtk.h> can be included directly."
+#endif
+
+#include <gio/gio.h>
+#include <gtk/gtkwidget.h>
+
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_MAP_LIST_MODEL (gtk_map_list_model_get_type ())
+
+GDK_AVAILABLE_IN_ALL
+G_DECLARE_FINAL_TYPE (GtkMapListModel, gtk_map_list_model, GTK, MAP_LIST_MODEL, GObject)
+
+/**
+ * GtkMapListModelMapFunc:
+ * @item: (transfer full): The item to map
+ * @data: user data
+ *
+ * User function that is called to map an @item of the original model.
+ *
+ * Returns: (transfer full): The item to map to. This function may not return %NULL
+ */
+typedef gpointer (* GtkMapListModelMapFunc) (gpointer item, gpointer data);
+
+GDK_AVAILABLE_IN_ALL
+GtkMapListModel *       gtk_map_list_model_new                  (GType                   item_type,
+                                                                 GListModel             *model,
+                                                                 GtkMapListModelMapFunc  map_func,
+                                                                 gpointer                user_data,
+                                                                 GDestroyNotify          user_destroy);
+
+GDK_AVAILABLE_IN_ALL
+void                    gtk_map_list_model_set_map_func         (GtkMapListModel        *self,
+                                                                 GtkMapListModelMapFunc  map_func,
+                                                                 gpointer                user_data,
+                                                                 GDestroyNotify          user_destroy);
+GDK_AVAILABLE_IN_ALL
+void                    gtk_map_list_model_set_model            (GtkMapListModel        *self,
+                                                                 GListModel             *model);
+GDK_AVAILABLE_IN_ALL
+GListModel *            gtk_map_list_model_get_model            (GtkMapListModel        *self);
+GDK_AVAILABLE_IN_ALL
+gboolean                gtk_map_list_model_has_map              (GtkMapListModel        *self);
+
+G_END_DECLS
+
+#endif /* __GTK_MAP_LIST_MODEL_H__ */
diff --git a/gtk/meson.build b/gtk/meson.build
index 9d0f517b49..386d72dbed 100644
--- a/gtk/meson.build
+++ b/gtk/meson.build
@@ -271,6 +271,7 @@ gtk_public_sources = files([
   'gtkliststore.c',
   'gtklockbutton.c',
   'gtkmain.c',
+  'gtkmaplistmodel.c',
   'gtkmediacontrols.c',
   'gtkmediafile.c',
   'gtkmediastream.c',
@@ -514,6 +515,7 @@ gtk_public_headers = files([
   'gtkliststore.h',
   'gtklockbutton.h',
   'gtkmain.h',
+  'gtkmaplistmodel.h',
   'gtkmediacontrols.h',
   'gtkmediafile.h',
   'gtkmediastream.h',
diff --git a/testsuite/gtk/maplistmodel.c b/testsuite/gtk/maplistmodel.c
new file mode 100644
index 0000000000..b32d95b128
--- /dev/null
+++ b/testsuite/gtk/maplistmodel.c
@@ -0,0 +1,300 @@
+/* GtkRBTree tests.
+ *
+ * Copyright (C) 2011, Red Hat, Inc.
+ * Authors: Benjamin Otte <otte@gnome.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <locale.h>
+
+#include <gtk/gtk.h>
+
+static GQuark number_quark;
+static GQuark changes_quark;
+
+static guint
+get (GListModel *model,
+     guint       position)
+{
+  GObject *object = g_list_model_get_item (model, position);
+  g_assert (object != NULL);
+  return GPOINTER_TO_UINT (g_object_get_qdata (object, number_quark));
+}
+
+static char *
+model_to_string (GListModel *model)
+{
+  GString *string = g_string_new (NULL);
+  guint i;
+
+  for (i = 0; i < g_list_model_get_n_items (model); i++)
+    {
+      if (i > 0)
+        g_string_append (string, " ");
+      g_string_append_printf (string, "%u", get (model, i));
+    }
+
+  return g_string_free (string, FALSE);
+}
+
+static GListStore *
+new_store (guint start,
+           guint end,
+           guint step);
+
+#if 0
+static void
+splice (GListStore *store,
+        guint       pos,
+        guint       removed,
+        guint      *numbers,
+        guint       added)
+{
+  GObject *objects[added];
+  guint i;
+
+  for (i = 0; i < added; i++)
+    {
+      /* 0 cannot be differentiated from NULL, so don't use it */
+      g_assert (numbers[i] != 0);
+      objects[i] = g_object_new (G_TYPE_OBJECT, NULL);
+      g_object_set_qdata (objects[i], number_quark, GUINT_TO_POINTER (numbers[i]));
+    }
+
+  g_list_store_splice (store, pos, removed, (gpointer *) objects, added);
+
+  for (i = 0; i < added; i++)
+    g_object_unref (objects[i]);
+}
+#endif
+
+static void
+add (GListStore *store,
+     guint       number)
+{
+  GObject *object;
+
+  /* 0 cannot be differentiated from NULL, so don't use it */
+  g_assert (number != 0);
+
+  object = g_object_new (G_TYPE_OBJECT, NULL);
+  g_object_set_qdata (object, number_quark, GUINT_TO_POINTER (number));
+  g_list_store_append (store, object);
+  g_object_unref (object);
+}
+
+#define assert_model(model, expected) G_STMT_START{ \
+  char *s = model_to_string (G_LIST_MODEL (model)); \
+  if (!g_str_equal (s, expected)) \
+     g_assertion_message_cmpstr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, \
+         #model " == " #expected, s, "==", expected); \
+  g_free (s); \
+}G_STMT_END
+
+#define assert_changes(model, expected) G_STMT_START{ \
+  GString *changes = g_object_get_qdata (G_OBJECT (model), changes_quark); \
+  if (!g_str_equal (changes->str, expected)) \
+     g_assertion_message_cmpstr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, \
+         #model " == " #expected, changes->str, "==", expected); \
+  g_string_set_size (changes, 0); \
+}G_STMT_END
+
+static GListStore *
+new_empty_store (void)
+{
+  return g_list_store_new (G_TYPE_OBJECT);
+}
+
+static GListStore *
+new_store (guint start,
+           guint end,
+           guint step)
+{
+  GListStore *store = new_empty_store ();
+  guint i;
+
+  for (i = start; i <= end; i += step)
+    add (store, i);
+
+  return store;
+}
+
+static void
+items_changed (GListModel *model,
+               guint       position,
+               guint       removed,
+               guint       added,
+               GString    *changes)
+{
+  g_assert (removed != 0 || added != 0);
+
+  if (changes->len)
+    g_string_append (changes, ", ");
+
+  if (removed == 1 && added == 0)
+    {
+      g_string_append_printf (changes, "-%u", position);
+    }
+  else if (removed == 0 && added == 1)
+    {
+      g_string_append_printf (changes, "+%u", position);
+    }
+  else
+    {
+      g_string_append_printf (changes, "%u", position);
+      if (removed > 0)
+        g_string_append_printf (changes, "-%u", removed);
+      if (added > 0)
+        g_string_append_printf (changes, "+%u", added);
+    }
+}
+
+static void
+free_changes (gpointer data)
+{
+  GString *changes = data;
+
+  /* all changes must have been checked via assert_changes() before */
+  g_assert_cmpstr (changes->str, ==, "");
+
+  g_string_free (changes, TRUE);
+}
+
+static gpointer
+map_multiply (gpointer item,
+              gpointer factor)
+{
+  GObject *object;
+  guint num;
+
+  object = g_object_new (G_TYPE_OBJECT, NULL);
+  num = GPOINTER_TO_UINT (g_object_get_qdata (item, number_quark));
+  g_object_set_qdata (object, number_quark, GUINT_TO_POINTER (GPOINTER_TO_UINT (factor) * num));
+  g_object_unref (item);
+
+  return object;
+}
+
+static GtkMapListModel *
+new_model (GListStore *store)
+{
+  GtkMapListModel *result;
+  GString *changes;
+
+  result = gtk_map_list_model_new (G_TYPE_OBJECT, G_LIST_MODEL (store), map_multiply, GUINT_TO_POINTER (2), NULL);
+  changes = g_string_new ("");
+  g_object_set_qdata_full (G_OBJECT(result), changes_quark, changes, free_changes);
+  g_signal_connect (result, "items-changed", G_CALLBACK (items_changed), changes);
+
+  return result;
+}
+
+static void
+test_create_empty (void)
+{
+  GtkMapListModel *map;
+
+  map = new_model (NULL);
+  assert_model (map, "");
+  assert_changes (map, "");
+
+  g_object_unref (map);
+}
+
+static void
+test_create (void)
+{
+  GtkMapListModel *map;
+  GListStore *store;
+  
+  store = new_store (1, 5, 1);
+  map = new_model (store);
+  assert_model (map, "2 4 6 8 10");
+  assert_changes (map, "");
+
+  g_object_unref (store);
+  assert_model (map, "2 4 6 8 10");
+  assert_changes (map, "");
+
+  g_object_unref (map);
+}
+
+static void
+test_set_model (void)
+{
+  GtkMapListModel *map;
+  GListStore *store;
+  
+  map = new_model (NULL);
+  assert_model (map, "");
+  assert_changes (map, "");
+
+  store = new_store (1, 5, 1);
+  gtk_map_list_model_set_model (map, G_LIST_MODEL (store));
+  assert_model (map, "2 4 6 8 10");
+  assert_changes (map, "0+5");
+
+  gtk_map_list_model_set_model (map, NULL);
+  assert_model (map, "");
+  assert_changes (map, "0-5");
+
+  g_object_unref (store);
+  g_object_unref (map);
+}
+
+static void
+test_set_map_func (void)
+{
+  GtkMapListModel *map;
+  GListStore *store;
+  
+  store = new_store (1, 5, 1);
+  map = new_model (store);
+  assert_model (map, "2 4 6 8 10");
+  assert_changes (map, "");
+
+  gtk_map_list_model_set_map_func (map, map_multiply, GUINT_TO_POINTER (3), NULL);
+  assert_model (map, "3 6 9 12 15");
+  assert_changes (map, "0-5+5");
+
+  gtk_map_list_model_set_map_func (map, NULL, NULL, NULL);
+  assert_model (map, "1 2 3 4 5");
+  assert_changes (map, "0-5+5");
+
+  gtk_map_list_model_set_map_func (map, map_multiply, GUINT_TO_POINTER (2), NULL);
+  assert_model (map, "2 4 6 8 10");
+  assert_changes (map, "0-5+5");
+
+  g_object_unref (store);
+  g_object_unref (map);
+}
+
+int
+main (int argc, char *argv[])
+{
+  g_test_init (&argc, &argv, NULL);
+  setlocale (LC_ALL, "C");
+  g_test_bug_base ("http://bugzilla.gnome.org/show_bug.cgi?id=%s");
+
+  number_quark = g_quark_from_static_string ("Hell and fire was spawned to be released.");
+  changes_quark = g_quark_from_static_string ("What did I see? Can I believe what I saw?");
+
+  g_test_add_func ("/maplistmodel/create_empty", test_create_empty);
+  g_test_add_func ("/maplistmodel/create", test_create);
+  g_test_add_func ("/maplistmodel/set-model", test_set_model);
+  g_test_add_func ("/maplistmodel/set-map-func", test_set_map_func);
+
+  return g_test_run ();
+}
diff --git a/testsuite/gtk/meson.build b/testsuite/gtk/meson.build
index e8171ea571..2323a158f6 100644
--- a/testsuite/gtk/meson.build
+++ b/testsuite/gtk/meson.build
@@ -31,6 +31,7 @@ tests = [
   ['keyhash', ['../../gtk/gtkkeyhash.c', gtkresources, '../../gtk/gtkprivate.c'], gtk_cargs],
   ['listbox'],
   ['main'],
+  ['maplistmodel'],
   ['notify'],
   ['no-gtk-init'],
   ['object'],