gtk: Add GtkFilterListModel

This is a GListModel implementation that filters the given source model.

11 files changed, 1155 insertions, 0 deletions

diff --git a/docs/reference/gtk/gtk4-docs.xml b/docs/reference/gtk/gtk4-docs.xml
index 2104d147ea..edb2529c6a 100644
--- a/docs/reference/gtk/gtk4-docs.xml
+++ b/docs/reference/gtk/gtk4-docs.xml
@@ -43,6 +43,7 @@
 
     <chapter id="Lists">
       <title>GListModel support</title>
+      <xi:include href="xml/gtkfilterlistmodel.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 382305663c..81f3600f94 100644
--- a/docs/reference/gtk/gtk4-sections.txt
+++ b/docs/reference/gtk/gtk4-sections.txt
@@ -1240,6 +1240,26 @@ gtk_file_filter_get_type
 </SECTION>
 
 <SECTION>
+<FILE>gtkfilterlistmodel</FILE>
+<TITLE>GtkFilterListModel</TITLE>
+GtkFilterListModel
+gtk_filter_list_model_new
+gtk_filter_list_model_get_model
+gtk_filter_list_model_set_filter_func
+gtk_filter_list_model_has_filter
+gtk_filter_list_model_refilter
+<SUBSECTION Standard>
+GTK_FILTER_LIST_MODEL
+GTK_IS_FILTER_LIST_MODEL
+GTK_TYPE_FILTER_LIST_MODEL
+GTK_FILTER_LIST_MODEL_CLASS
+GTK_IS_FILTER_LIST_MODEL_CLASS
+GTK_FILTER_LIST_MODEL_GET_CLASS
+<SUBSECTION Private>
+gtk_filter_list_model_get_type
+</SECTION>
+
+<SECTION>
 <FILE>gtkfixed</FILE>
 <TITLE>GtkFixed</TITLE>
 GtkFixed
diff --git a/gtk/gtk.h b/gtk/gtk.h
index 6363fe8210..704f14238a 100644
--- a/gtk/gtk.h
+++ b/gtk/gtk.h
@@ -104,6 +104,7 @@
 #include <gtk/gtkfilechoosernative.h>
 #include <gtk/gtkfilechooserwidget.h>
 #include <gtk/gtkfilefilter.h>
+#include <gtk/gtkfilterlistmodel.h>
 #include <gtk/gtkflowbox.h>
 #include <gtk/gtkfontbutton.h>
 #include <gtk/gtkfontchooser.h>
diff --git a/gtk/gtkfilterlistmodel.c b/gtk/gtkfilterlistmodel.c
new file mode 100644
index 0000000000..4703d66816
--- /dev/null
+++ b/gtk/gtkfilterlistmodel.c
@@ -0,0 +1,711 @@
+/*
+ * 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 "gtkfilterlistmodel.h"
+
+#include "gtkcssrbtreeprivate.h"
+#include "gtkintl.h"
+#include "gtkprivate.h"
+
+/**
+ * SECTION:gtkfilterlistmodel
+ * @title: GtkFilterListModel
+ * @short_description: a #GListModel that filters its items
+ * @see_also: #GListModel
+ *
+ * #GtkFilterListModel is a list model that filters a given other
+ * listmodel.
+ * It hides some elements from the other elements according to
+ * criteria given by a #GtkFilterListModelFilterFunc.
+ */
+
+enum {
+  PROP_0,
+  PROP_HAS_FILTER,
+  PROP_ITEM_TYPE,
+  PROP_MODEL,
+  NUM_PROPERTIES
+};
+
+typedef struct _FilterNode FilterNode;
+typedef struct _FilterAugment FilterAugment;
+
+struct _FilterNode
+{
+  guint visible : 1;
+};
+
+struct _FilterAugment
+{
+  guint n_items;
+  guint n_visible;
+};
+
+struct _GtkFilterListModel
+{
+  GObject parent_instance;
+
+  GType item_type;
+  GListModel *model;
+  GtkFilterListModelFilterFunc filter_func;
+  gpointer user_data;
+  GDestroyNotify user_destroy;
+
+  GtkCssRbTree *items; /* NULL if filter_func == NULL */
+};
+
+struct _GtkFilterListModelClass
+{
+  GObjectClass parent_class;
+};
+
+static GParamSpec *properties[NUM_PROPERTIES] = { NULL, };
+
+static FilterNode *
+gtk_filter_list_model_get_nth_filtered (GtkCssRbTree *tree,
+                                        guint         position,
+                                        guint        *out_unfiltered)
+{
+  FilterNode *node, *tmp;
+  guint unfiltered;
+
+  node = gtk_css_rb_tree_get_root (tree);
+  unfiltered = 0;
+
+  while (node)
+    {
+      tmp = gtk_css_rb_tree_get_left (tree, node);
+      if (tmp)
+        {
+          FilterAugment *aug = gtk_css_rb_tree_get_augment (tree, tmp);
+          if (position < aug->n_visible)
+            {
+              node = tmp;
+              continue;
+            }
+          position -= aug->n_visible;
+          unfiltered += aug->n_items;
+        }
+
+      if (node->visible)
+        {
+          if (position == 0)
+            break;
+          position--;
+        }
+
+      unfiltered++;
+
+      node = gtk_css_rb_tree_get_right (tree, node);
+    }
+
+  if (out_unfiltered)
+    *out_unfiltered = unfiltered;
+
+  return node;
+}
+
+static FilterNode *
+gtk_filter_list_model_get_nth (GtkCssRbTree *tree,
+                               guint         position,
+                               guint        *out_filtered)
+{
+  FilterNode *node, *tmp;
+  guint filtered;
+
+  node = gtk_css_rb_tree_get_root (tree);
+  filtered = 0;
+
+  while (node)
+    {
+      tmp = gtk_css_rb_tree_get_left (tree, node);
+      if (tmp)
+        {
+          FilterAugment *aug = gtk_css_rb_tree_get_augment (tree, tmp);
+          if (position < aug->n_items)
+            {
+              node = tmp;
+              continue;
+            }
+          position -= aug->n_items;
+          filtered += aug->n_visible;
+        }
+
+      if (position == 0)
+        break;
+
+      position--;
+      if (node->visible)
+        filtered++;
+
+      node = gtk_css_rb_tree_get_right (tree, node);
+    }
+
+  if (out_filtered)
+    *out_filtered = filtered;
+
+  return node;
+}
+
+static GType
+gtk_filter_list_model_get_item_type (GListModel *list)
+{
+  GtkFilterListModel *self = GTK_FILTER_LIST_MODEL (list);
+
+  return self->item_type;
+}
+
+static guint
+gtk_filter_list_model_get_n_items (GListModel *list)
+{
+  GtkFilterListModel *self = GTK_FILTER_LIST_MODEL (list);
+  FilterAugment *aug;
+  FilterNode *node;
+
+  if (self->model == NULL)
+    return 0;
+
+  if (!self->items)
+    return g_list_model_get_n_items (self->model);
+
+  node = gtk_css_rb_tree_get_root (self->items);
+  if (node == NULL)
+    return 0;
+
+  aug = gtk_css_rb_tree_get_augment (self->items, node);
+  return aug->n_visible;
+}
+
+static gpointer
+gtk_filter_list_model_get_item (GListModel *list,
+                                guint       position)
+{
+  GtkFilterListModel *self = GTK_FILTER_LIST_MODEL (list);
+  guint unfiltered;
+
+  if (self->model == NULL)
+    return NULL;
+
+  if (self->items)
+    gtk_filter_list_model_get_nth_filtered (self->items, position, &unfiltered);
+  else
+    unfiltered = position;
+
+  return g_list_model_get_item (self->model, unfiltered);
+}
+
+static void
+gtk_filter_list_model_model_init (GListModelInterface *iface)
+{
+  iface->get_item_type = gtk_filter_list_model_get_item_type;
+  iface->get_n_items = gtk_filter_list_model_get_n_items;
+  iface->get_item = gtk_filter_list_model_get_item;
+}
+
+G_DEFINE_TYPE_WITH_CODE (GtkFilterListModel, gtk_filter_list_model, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL, gtk_filter_list_model_model_init))
+
+static gboolean
+gtk_filter_list_model_run_filter (GtkFilterListModel *self,
+                                  guint               position)
+{
+  gpointer item;
+  gboolean visible;
+
+  item = g_list_model_get_item (self->model, position);
+  visible = self->filter_func (item, self->user_data);
+  g_object_unref (item);
+
+  return visible;
+}
+
+static guint
+gtk_filter_list_model_add_items (GtkFilterListModel *self,
+                                 FilterNode         *after,
+                                 guint               position,
+                                 guint               n_items)
+{
+  FilterNode *node;
+  guint i, n_visible;
+
+  n_visible = 0;
+  
+  for (i = 0; i < n_items; i++)
+    {
+      node = gtk_css_rb_tree_insert_before (self->items, after);
+      node->visible = gtk_filter_list_model_run_filter (self, position + i);
+      if (node->visible)
+        n_visible++;
+    }
+
+  return n_visible;
+}
+
+static void
+gtk_filter_list_model_items_changed_cb (GListModel         *model,
+                                        guint               position,
+                                        guint               removed,
+                                        guint               added,
+                                        GtkFilterListModel *self)
+{
+  FilterNode *node;
+  guint i, filter_position, filter_removed, filter_added;
+
+  if (self->items == NULL)
+    {
+      g_list_model_items_changed (G_LIST_MODEL (self), position, removed, added);
+      return;
+    }
+
+  node = gtk_filter_list_model_get_nth (self->items, position, &filter_position);
+
+  filter_removed = 0;
+  for (i = 0; i < removed; i++)
+    {
+      FilterNode *next = gtk_css_rb_tree_get_next (self->items, node);
+      if (node->visible)
+        filter_removed++;
+      gtk_css_rb_tree_remove (self->items, node);
+      node = next;
+    }
+
+  filter_added = gtk_filter_list_model_add_items (self, node, position, added);
+
+  if (filter_removed > 0 || filter_added > 0)
+    g_list_model_items_changed (G_LIST_MODEL (self), filter_position, filter_removed, filter_added);
+}
+
+static void
+gtk_filter_list_model_set_property (GObject      *object,
+                                    guint         prop_id,
+                                    const GValue *value,
+                                    GParamSpec   *pspec)
+{
+  GtkFilterListModel *self = GTK_FILTER_LIST_MODEL (object);
+
+  switch (prop_id)
+    {
+    case PROP_ITEM_TYPE:
+      self->item_type = g_value_get_gtype (value);
+      break;
+
+    case PROP_MODEL:
+      gtk_filter_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_filter_list_model_get_property (GObject     *object,
+                                    guint        prop_id,
+                                    GValue      *value,
+                                    GParamSpec  *pspec)
+{
+  GtkFilterListModel *self = GTK_FILTER_LIST_MODEL (object);
+
+  switch (prop_id)
+    {
+    case PROP_HAS_FILTER:
+      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_filter_list_model_clear_model (GtkFilterListModel *self)
+{
+  if (self->model == NULL)
+    return;
+
+  g_signal_handlers_disconnect_by_func (self->model, gtk_filter_list_model_items_changed_cb, self);
+  g_clear_object (&self->model);
+  if (self->items)
+    gtk_css_rb_tree_remove_all (self->items);
+}
+
+static void
+gtk_filter_list_model_dispose (GObject *object)
+{
+  GtkFilterListModel *self = GTK_FILTER_LIST_MODEL (object);
+
+  gtk_filter_list_model_clear_model (self);
+  if (self->user_destroy)
+    self->user_destroy (self->user_data);
+  self->filter_func = NULL;
+  self->user_data = NULL;
+  self->user_destroy = NULL;
+  g_clear_pointer (&self->items, gtk_css_rb_tree_unref);
+
+  G_OBJECT_CLASS (gtk_filter_list_model_parent_class)->dispose (object);
+};
+
+static void
+gtk_filter_list_model_class_init (GtkFilterListModelClass *class)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (class);
+
+  gobject_class->set_property = gtk_filter_list_model_set_property;
+  gobject_class->get_property = gtk_filter_list_model_get_property;
+  gobject_class->dispose = gtk_filter_list_model_dispose;
+
+  /**
+   * GtkFilterListModel:has-filter:
+   *
+   * If a filter is set for this model
+   */
+  properties[PROP_HAS_FILTER] =
+      g_param_spec_boolean ("has-filter",
+                            P_("has filter"),
+                            P_("If a filter is set for this model"),
+                            FALSE,
+                            GTK_PARAM_READABLE | G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * GtkFilterListModel: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);
+
+  /**
+   * GtkFilterListModel:model:
+   *
+   * The model being filtered
+   */
+  properties[PROP_MODEL] =
+      g_param_spec_object ("model",
+                           P_("Model"),
+                           P_("The model being filtered"),
+                           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_filter_list_model_init (GtkFilterListModel *self)
+{
+}
+
+
+static void
+gtk_filter_list_model_augment (GtkCssRbTree *filter,
+                               gpointer      _aug,
+                               gpointer      _node,
+                               gpointer      left,
+                               gpointer      right)
+{
+  FilterNode *node= _node;
+  FilterAugment *aug = _aug;
+
+  aug->n_items = 1;
+  aug->n_visible = node->visible ? 1 : 0;
+
+  if (left)
+    {
+      FilterAugment *left_aug = gtk_css_rb_tree_get_augment (filter, left);
+      aug->n_items += left_aug->n_items;
+      aug->n_visible += left_aug->n_visible;
+    }
+  if (right)
+    {
+      FilterAugment *right_aug = gtk_css_rb_tree_get_augment (filter, right);
+      aug->n_items += right_aug->n_items;
+      aug->n_visible += right_aug->n_visible;
+    }
+}
+
+/**
+ * gtk_filter_list_model_new:
+ * @model: the model to sort
+ * @filter_func: (allow-none): filter function or %NULL to not filter items
+ * @user_data: user data passed to @filter_func
+ * @destroy: destroy notifier for @user_data
+ *
+ * Creates a new #GtkFilterListModel that will filter @model using the given
+ * @filter_func.
+ *
+ * Returns: a new #GtkFilterListModel
+ **/
+GtkFilterListModel *
+gtk_filter_list_model_new (GListModel                   *model,
+                           GtkFilterListModelFilterFunc  filter_func,
+                           gpointer                      user_data,
+                           GDestroyNotify                user_destroy)
+{
+  GtkFilterListModel *result;
+
+  g_return_val_if_fail (G_IS_LIST_MODEL (model), NULL);
+
+  result = g_object_new (GTK_TYPE_FILTER_LIST_MODEL,
+                         "item-type", g_list_model_get_item_type (model),
+                         "model", model,
+                         NULL);
+
+  if (filter_func)
+    gtk_filter_list_model_set_filter_func (result, filter_func, user_data, user_destroy);
+
+  return result;
+}
+
+/**
+ * gtk_filter_list_model_new_for_type:
+ * @item_type: the type of the items that will be returned
+ *
+ * Creates a new empty filter list model set up to return items of type @item_type.
+ * It is up to the application to set a proper filter function and model to ensure
+ * the item type is matched.
+ *
+ * Returns: a new #GtkFilterListModel
+ **/
+GtkFilterListModel *
+gtk_filter_list_model_new_for_type (GType item_type)
+{
+  g_return_val_if_fail (g_type_is_a (item_type, G_TYPE_OBJECT), NULL);
+
+  return g_object_new (GTK_TYPE_FILTER_LIST_MODEL,
+                       "item-type", item_type,
+                       NULL);
+}
+
+/**
+ * gtk_filter_list_model_set_filter_func:
+ * @self: a #GtkFilterListModel
+ * @filter_func: (allow-none): filter function or %NULL to not filter items
+ * @user_data: user data passed to @filter_func
+ * @destroy: destroy notifier for @user_data
+ *
+ * Sets the function used to filter items. The function will be called for every
+ * item and if it returns %TRUE the item is considered visible.
+ **/
+void
+gtk_filter_list_model_set_filter_func (GtkFilterListModel           *self,
+                                       GtkFilterListModelFilterFunc  filter_func,
+                                       gpointer                      user_data,
+                                       GDestroyNotify                user_destroy)
+{
+  gboolean was_filtered, will_be_filtered;
+
+  g_return_if_fail (GTK_IS_FILTER_LIST_MODEL (self));
+  g_return_if_fail (filter_func != NULL || (user_data == NULL && !user_destroy));
+
+  was_filtered = self->filter_func != NULL;
+  will_be_filtered = filter_func != NULL;
+
+  if (!was_filtered && !will_be_filtered)
+    return;
+
+  if (self->user_destroy)
+    self->user_destroy (self->user_data);
+
+  self->filter_func = filter_func;
+  self->user_data = user_data;
+  self->user_destroy = user_destroy;
+  
+  if (!will_be_filtered)
+    {
+      g_clear_pointer (&self->items, gtk_css_rb_tree_unref);
+    }
+  else if (!was_filtered)
+    {
+      guint i, n_items;
+
+      self->items = gtk_css_rb_tree_new (FilterNode,
+                                         FilterAugment, 
+                                         gtk_filter_list_model_augment,
+                                         NULL, NULL);
+      if (self->model)
+        {
+          n_items = g_list_model_get_n_items (self->model);
+          for (i = 0; i < n_items; i++)
+            {
+              FilterNode *node = gtk_css_rb_tree_insert_before (self->items, NULL);
+              node->visible = TRUE;
+            }
+        }
+    }
+
+  gtk_filter_list_model_refilter (self);
+
+  if (was_filtered != will_be_filtered)
+    g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_HAS_FILTER]);
+}
+
+/**
+ * gtk_filter_list_model_set_model:
+ * @self: a #GtkFilterListModel
+ * @model: (allow-none): The model to be filtered
+ *
+ * Sets the model to be filtered.
+ *
+ * Note that GTK makes no effort to ensure that @model conforms to
+ * the item type of @self. It assumes that the caller knows what they
+ * are doing and have set up an appropriate filter function to ensure
+ * that item types match.
+ **/
+void
+gtk_filter_list_model_set_model (GtkFilterListModel *self,
+                                 GListModel         *model)
+{
+  guint removed, added;
+
+  g_return_if_fail (GTK_IS_FILTER_LIST_MODEL (self));
+  g_return_if_fail (model == NULL || G_IS_LIST_MODEL (model));
+  /* Note: We don't check for matching item type here, we just assume the
+   * filter func takes care of filtering wrong items. */
+
+  if (self->model == model)
+    return;
+
+  removed = g_list_model_get_n_items (G_LIST_MODEL (self));
+  gtk_filter_list_model_clear_model (self);
+
+  if (model)
+    {
+      self->model = g_object_ref (model);
+      g_signal_connect (model, "items-changed", G_CALLBACK (gtk_filter_list_model_items_changed_cb), self);
+      if (self->items)
+        added = gtk_filter_list_model_add_items (self, NULL, 0, g_list_model_get_n_items (model));
+      else
+        added = g_list_model_get_n_items (model);
+    }
+  else
+    added = 0;
+  
+  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_filter_list_model_get_model:
+ * @self: a #GtkFilterListModel
+ *
+ * Gets the model currently filtered or %NULL if none.
+ *
+ * Returns: (nullable) (transfer none): The model that gets filtered
+ **/
+GListModel *
+gtk_filter_list_model_get_model (GtkFilterListModel *self)
+{
+  g_return_val_if_fail (GTK_IS_FILTER_LIST_MODEL (self), NULL);
+
+  return self->model;
+}
+
+/**
+ * gtk_filter_list_model_has_filter:
+ * @self: a #GtkFilterListModel
+ *
+ * Checks if a filter function is currently set on @self
+ *
+ * Returns: %TRUE if a filter function is set
+ **/
+gboolean
+gtk_filter_list_model_has_filter (GtkFilterListModel *self)
+{
+  g_return_val_if_fail (GTK_IS_FILTER_LIST_MODEL (self), FALSE);
+
+  return self->filter_func != NULL;
+}
+
+/**
+ * gtk_filter_list_model_refilter:
+ * @self: a #GtkFilterListModel
+ *
+ * Causes @self to refilter all items in the model.
+ *
+ * Calling this function is necessary when data used by the filter
+ * function has changed.
+ **/
+void
+gtk_filter_list_model_refilter (GtkFilterListModel *self)
+{
+  FilterNode *node;
+  guint i, first_change, last_change;
+  guint n_is_visible, n_was_visible;
+  gboolean visible;
+
+  g_return_if_fail (GTK_IS_FILTER_LIST_MODEL (self));
+  
+  if (self->items == NULL || self->model == NULL)
+    return;
+
+  first_change = G_MAXUINT;
+  last_change = 0;
+  n_is_visible = 0;
+  n_was_visible = 0;
+  for (i = 0, node = gtk_css_rb_tree_get_first (self->items);
+       node != NULL;
+       i++, node = gtk_css_rb_tree_get_next (self->items, node))
+    {
+      visible = gtk_filter_list_model_run_filter (self, i);
+      if (visible == node->visible)
+        {
+          if (visible)
+            {
+              n_is_visible++;
+              n_was_visible++;
+            }
+          continue;
+        }
+
+      node->visible = visible;
+      gtk_css_rb_tree_mark_dirty (self->items, node);
+      first_change = MIN (n_is_visible, first_change);
+      if (visible)
+        n_is_visible++;
+      else
+        n_was_visible++;
+      last_change = MAX (n_is_visible, last_change);
+    }
+
+  if (first_change <= last_change)
+    {
+      g_list_model_items_changed (G_LIST_MODEL (self),
+                                  first_change,
+                                  last_change - first_change + n_was_visible - n_is_visible,
+                                  last_change - first_change);
+    }
+}
+
diff --git a/gtk/gtkfilterlistmodel.h b/gtk/gtkfilterlistmodel.h
new file mode 100644
index 0000000000..f19607fd70
--- /dev/null
+++ b/gtk/gtkfilterlistmodel.h
@@ -0,0 +1,67 @@
+/*
+ * 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_FILTER_LIST_MODEL_H__
+#define __GTK_FILTER_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_FILTER_LIST_MODEL (gtk_filter_list_model_get_type ())
+
+GDK_AVAILABLE_IN_ALL
+G_DECLARE_FINAL_TYPE (GtkFilterListModel, gtk_filter_list_model, GTK, FILTER_LIST_MODEL, GObject)
+
+typedef gboolean (* GtkFilterListModelFilterFunc) (gpointer item, gpointer data);
+
+GDK_AVAILABLE_IN_ALL
+GtkFilterListModel *    gtk_filter_list_model_new               (GListModel             *model,
+                                                                 GtkFilterListModelFilterFunc filter_func,
+                                                                 gpointer                user_data,
+                                                                 GDestroyNotify          user_destroy);
+GDK_AVAILABLE_IN_ALL
+GtkFilterListModel *    gtk_filter_list_model_new_for_type      (GType                   item_type);
+
+GDK_AVAILABLE_IN_ALL
+void                    gtk_filter_list_model_set_filter_func   (GtkFilterListModel     *self,
+                                                                 GtkFilterListModelFilterFunc filter_func,
+                                                                 gpointer                user_data,
+                                                                 GDestroyNotify          user_destroy);
+GDK_AVAILABLE_IN_ALL
+void                    gtk_filter_list_model_set_model         (GtkFilterListModel     *self,
+                                                                 GListModel             *model);
+GDK_AVAILABLE_IN_ALL
+GListModel *            gtk_filter_list_model_get_model         (GtkFilterListModel     *self);
+GDK_AVAILABLE_IN_ALL
+gboolean                gtk_filter_list_model_has_filter        (GtkFilterListModel     *self);
+
+GDK_AVAILABLE_IN_ALL
+void                    gtk_filter_list_model_refilter          (GtkFilterListModel     *self);
+
+G_END_DECLS
+
+#endif /* __GTK_FILTER_LIST_MODEL_H__ */
diff --git a/gtk/meson.build b/gtk/meson.build
index d191922f5b..cd962dc411 100644
--- a/gtk/meson.build
+++ b/gtk/meson.build
@@ -229,6 +229,7 @@ gtk_public_sources = files([
   'gtkfilechoosernative.c',
   'gtkfilechooserwidget.c',
   'gtkfilefilter.c',
+  'gtkfilterlistmodel.c',
   'gtkfixed.c',
   'gtkflowbox.c',
   'gtkfontbutton.c',
@@ -472,6 +473,7 @@ gtk_public_headers = files([
   'gtkfilechoosernative.h',
   'gtkfilechooserwidget.h',
   'gtkfilefilter.h',
+  'gtkfilterlistmodel.h',
   'gtkfixed.h',
   'gtkflowbox.h',
   'gtkfontbutton.h',
diff --git a/testsuite/gtk/defaultvalue.c b/testsuite/gtk/defaultvalue.c
index 4b559a0d23..f4c335037f 100644
--- a/testsuite/gtk/defaultvalue.c
+++ b/testsuite/gtk/defaultvalue.c
@@ -108,6 +108,14 @@ test_type (gconstpointer data)
       instance = G_OBJECT (g_object_ref (gdk_surface_new_popup (display,
                                                                 &(GdkRectangle) { 0, 0, 100, 100 })));
     }
+  else if (g_type_is_a (type, GTK_TYPE_FILTER_LIST_MODEL))
+    {
+      GListStore *list_store = g_list_store_new (G_TYPE_OBJECT);
+      instance = g_object_new (type,
+                               "model", list_store,
+                               NULL);
+      g_object_unref (list_store);
+    }
   else if (g_type_is_a (type, GDK_TYPE_CLIPBOARD) ||
            g_str_equal (g_type_name (type), "GdkX11Cursor"))
     instance = g_object_new (type, "display", display, NULL);
@@ -230,6 +238,10 @@ G_GNUC_BEGIN_IGNORE_DEPRECATIONS
 
 G_GNUC_END_IGNORE_DEPRECATIONS
 
+      if (g_type_is_a (type, GTK_TYPE_FILTER_LIST_MODEL) &&
+          strcmp (pspec->name, "model") == 0)
+        continue;
+
       /* This is set in init() */
       if (g_type_is_a (type, GTK_TYPE_FONT_CHOOSER_WIDGET) &&
           strcmp (pspec->name, "tweak-action") == 0)
diff --git a/testsuite/gtk/filterlistmodel.c b/testsuite/gtk/filterlistmodel.c
new file mode 100644
index 0000000000..1e259789dc
--- /dev/null
+++ b/testsuite/gtk/filterlistmodel.c
@@ -0,0 +1,324 @@
+/* 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);
+
+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 GtkFilterListModel *
+new_model (guint                        size,
+           GtkFilterListModelFilterFunc filter_func,
+           gpointer                     data)
+{
+  GtkFilterListModel *result;
+  GString *changes;
+
+  result = gtk_filter_list_model_new (G_LIST_MODEL (new_store (1, size, 1)), filter_func, data, 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 gboolean
+is_smaller_than (gpointer item,
+                 gpointer data)
+{
+  return g_object_get_qdata (item, number_quark) < data;
+}
+
+static gboolean
+is_larger_than (gpointer item,
+                gpointer data)
+{
+  return g_object_get_qdata (item, number_quark) > data;
+}
+
+static gboolean
+is_near (gpointer item,
+         gpointer data)
+{
+  return ABS (g_object_get_qdata (item, number_quark) - data) <= 2;
+}
+
+static gboolean
+is_not_near (gpointer item,
+             gpointer data)
+{
+  return ABS (g_object_get_qdata (item, number_quark) - data) > 2;
+}
+
+static void
+test_create (void)
+{
+  GtkFilterListModel *filter;
+  
+  filter = new_model (10, NULL, NULL);
+  assert_model (filter, "1 2 3 4 5 6 7 8 9 10");
+  assert_changes (filter, "");
+  g_object_unref (filter);
+
+  filter = new_model (10, is_smaller_than, GUINT_TO_POINTER (20));
+  assert_model (filter, "1 2 3 4 5 6 7 8 9 10");
+  assert_changes (filter, "");
+  g_object_unref (filter);
+
+  filter = new_model (10, is_smaller_than, GUINT_TO_POINTER (7));
+  assert_model (filter, "1 2 3 4 5 6");
+  assert_changes (filter, "");
+  g_object_unref (filter);
+
+  filter = new_model (10, is_smaller_than, GUINT_TO_POINTER (0));
+  assert_model (filter, "");
+  assert_changes (filter, "");
+  g_object_unref (filter);
+}
+
+static void
+test_empty_set_filter_func (void)
+{
+  GtkFilterListModel *filter;
+  
+  filter = new_model (10, NULL, NULL);
+  gtk_filter_list_model_set_filter_func (filter, is_smaller_than, GUINT_TO_POINTER (20), NULL);
+  assert_model (filter, "1 2 3 4 5 6 7 8 9 10");
+  assert_changes (filter, "");
+  g_object_unref (filter);
+
+  filter = new_model (10, NULL, NULL);
+  gtk_filter_list_model_set_filter_func (filter, is_smaller_than, GUINT_TO_POINTER (7), NULL);
+  assert_model (filter, "1 2 3 4 5 6");
+  assert_changes (filter, "6-4");
+  g_object_unref (filter);
+
+  filter = new_model (10, NULL, NULL);
+  gtk_filter_list_model_set_filter_func (filter, is_smaller_than, GUINT_TO_POINTER (0), NULL);
+  assert_model (filter, "");
+  assert_changes (filter, "0-10");
+  g_object_unref (filter);
+
+  filter = new_model (10, NULL, NULL);
+  gtk_filter_list_model_set_filter_func (filter, is_larger_than, GUINT_TO_POINTER (0), NULL);
+  assert_model (filter, "1 2 3 4 5 6 7 8 9 10");
+  assert_changes (filter, "");
+  g_object_unref (filter);
+
+  filter = new_model (10, NULL, NULL);
+  gtk_filter_list_model_set_filter_func (filter, is_larger_than, GUINT_TO_POINTER (3), NULL);
+  assert_model (filter, "4 5 6 7 8 9 10");
+  assert_changes (filter, "0-3");
+  g_object_unref (filter);
+
+  filter = new_model (10, NULL, NULL);
+  gtk_filter_list_model_set_filter_func (filter, is_larger_than, GUINT_TO_POINTER (20), NULL);
+  assert_model (filter, "");
+  assert_changes (filter, "0-10");
+  g_object_unref (filter);
+
+  filter = new_model (10, NULL, NULL);
+  gtk_filter_list_model_set_filter_func (filter, is_near, GUINT_TO_POINTER (5), NULL);
+  assert_model (filter, "3 4 5 6 7");
+  assert_changes (filter, "0-10+5");
+  g_object_unref (filter);
+
+  filter = new_model (10, NULL, NULL);
+  gtk_filter_list_model_set_filter_func (filter, is_not_near, GUINT_TO_POINTER (5), NULL);
+  assert_model (filter, "1 2 8 9 10");
+  assert_changes (filter, "2-5");
+  g_object_unref (filter);
+}
+
+static void
+test_change_filter_func (void)
+{
+  GtkFilterListModel *filter;
+  
+  filter = new_model (10, is_not_near, GUINT_TO_POINTER (5));
+  assert_model (filter, "1 2 8 9 10");
+  assert_changes (filter, "");
+
+  gtk_filter_list_model_set_filter_func (filter, is_not_near, GUINT_TO_POINTER (6), NULL);
+  assert_model (filter, "1 2 3 9 10");
+  assert_changes (filter, "2-1+1");
+
+  gtk_filter_list_model_set_filter_func (filter, is_not_near, GUINT_TO_POINTER (9), NULL);
+  assert_model (filter, "1 2 3 4 5 6");
+  assert_changes (filter, "3-2+3");
+
+  gtk_filter_list_model_set_filter_func (filter, is_smaller_than, GUINT_TO_POINTER (6), NULL);
+  assert_model (filter, "1 2 3 4 5");
+  assert_changes (filter, "-5");
+
+  gtk_filter_list_model_set_filter_func (filter, is_larger_than, GUINT_TO_POINTER (4), NULL);
+  assert_model (filter, "5 6 7 8 9 10");
+  assert_changes (filter, "0-5+6");
+
+  gtk_filter_list_model_set_filter_func (filter, is_not_near, GUINT_TO_POINTER (2), NULL);
+  assert_model (filter, "5 6 7 8 9 10");
+  assert_changes (filter, "");
+
+  gtk_filter_list_model_set_filter_func (filter, is_not_near, GUINT_TO_POINTER (4), NULL);
+  assert_model (filter, "1 7 8 9 10");
+  assert_changes (filter, "0-2+1");
+
+  g_object_unref (filter);
+}
+
+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 ("/filterlistmodel/create", test_create);
+  g_test_add_func ("/filterlistmodel/empty_set_filter_func", test_empty_set_filter_func);
+  g_test_add_func ("/filterlistmodel/change_filter_func", test_change_filter_func);
+
+  return g_test_run ();
+}
diff --git a/testsuite/gtk/meson.build b/testsuite/gtk/meson.build
index 963355cfbe..de1bcb15a7 100644
--- a/testsuite/gtk/meson.build
+++ b/testsuite/gtk/meson.build
@@ -19,6 +19,7 @@ tests = [
   ['cssprovider'],
   ['defaultvalue'],
   ['entry'],
+  ['filterlistmodel'],
   ['firefox-stylecontext'],
   ['floating'],
   ['focus'],
diff --git a/testsuite/gtk/notify.c b/testsuite/gtk/notify.c
index 13d5954fb5..6474e2656f 100644
--- a/testsuite/gtk/notify.c
+++ b/testsuite/gtk/notify.c
@@ -430,6 +430,14 @@ test_type (gconstpointer data)
                                NULL);
       gdk_content_formats_unref (formats);
     }
+  else if (g_type_is_a (type, GTK_TYPE_FILTER_LIST_MODEL))
+    {
+      GListStore *list_store = g_list_store_new (G_TYPE_OBJECT);
+      instance = g_object_new (type,
+                               "model", list_store,
+                               NULL);
+      g_object_unref (list_store);
+    }
   else
     instance = g_object_new (type, NULL);
 
diff --git a/testsuite/gtk/objects-finalize.c b/testsuite/gtk/objects-finalize.c
index 9e91fcca5f..cced1ccd46 100644
--- a/testsuite/gtk/objects-finalize.c
+++ b/testsuite/gtk/objects-finalize.c
@@ -64,6 +64,14 @@ test_finalize_object (gconstpointer data)
                              NULL);
       gdk_content_formats_unref (formats);
     }
+  else if (g_type_is_a (test_type, GTK_TYPE_FILTER_LIST_MODEL))
+    {
+      GListStore *list_store = g_list_store_new (G_TYPE_OBJECT);
+      object = g_object_new (test_type,
+                             "model", list_store,
+                             NULL);
+      g_object_unref (list_store);
+    }
   else
     object = g_object_new (test_type, NULL);
   g_assert (G_IS_OBJECT (object));