--- /dev/null
+/*
+ * Copyright © 2019 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 "gtkcustomfilter.h"
+
+#include "gtkintl.h"
+#include "gtktypebuiltins.h"
+
+/**
+ * SECTION:gtkcustomfilter
+ * @Title: GtkCustomFilter
+ * @Short_description: Filtering with callbacks
+ *
+ * #GtkCustomFilter is a #GtkFilter that uses a callback to determine whether
+ * to include an item or not.
+ */
+struct _GtkCustomFilter
+{
+ GtkFilter parent_instance;
+
+ GtkCustomFilterFunc match_func;
+ gpointer user_data;
+ GDestroyNotify user_destroy;
+};
+
+G_DEFINE_TYPE (GtkCustomFilter, gtk_custom_filter, GTK_TYPE_FILTER)
+
+static gboolean
+gtk_custom_filter_match (GtkFilter *filter,
+ gpointer item)
+{
+ GtkCustomFilter *self = GTK_CUSTOM_FILTER (filter);
+
+ if (!self->match_func)
+ return TRUE;
+
+ return self->match_func (item, self->user_data);
+}
+
+static GtkFilterMatch
+gtk_custom_filter_get_strictness (GtkFilter *filter)
+{
+ GtkCustomFilter *self = GTK_CUSTOM_FILTER (filter);
+
+ if (!self->match_func)
+ return GTK_FILTER_MATCH_ALL;
+
+ return GTK_FILTER_MATCH_SOME;
+}
+
+static void
+gtk_custom_filter_dispose (GObject *object)
+{
+ GtkCustomFilter *self = GTK_CUSTOM_FILTER (object);
+
+ if (self->user_destroy)
+ self->user_destroy (self->user_data);
+
+ G_OBJECT_CLASS (gtk_custom_filter_parent_class)->dispose (object);
+}
+
+static void
+gtk_custom_filter_class_init (GtkCustomFilterClass *class)
+{
+ GtkFilterClass *filter_class = GTK_FILTER_CLASS (class);
+ GObjectClass *object_class = G_OBJECT_CLASS (class);
+
+ filter_class->match = gtk_custom_filter_match;
+ filter_class->get_strictness = gtk_custom_filter_get_strictness;
+
+ object_class->dispose = gtk_custom_filter_dispose;
+}
+
+static void
+gtk_custom_filter_init (GtkCustomFilter *self)
+{
+}
+
+/**
+ * gtk_custom_filter_new:
+ * @match_func: (nullable): function to filter items
+ * @user_data: (nullable): user data to pass to @match_func
+ * @user_destroy: destory notify
+ *
+ * Creates a new filter using the given @match_func to filter
+ * items.
+ *
+ * If the filter func changes its filtering behavior,
+ * gtk_filter_changed() needs to be called.
+ *
+ * Returns: a new #GtkFilter
+ **/
+GtkFilter *
+gtk_custom_filter_new (GtkCustomFilterFunc match_func,
+ gpointer user_data,
+ GDestroyNotify user_destroy)
+{
+ GtkCustomFilter *result;
+
+ result = g_object_new (GTK_TYPE_CUSTOM_FILTER, NULL);
+
+ gtk_custom_filter_set_filter_func (result, match_func, user_data, user_destroy);
+
+ return GTK_FILTER (result);
+}
+
+/**
+ * gtk_custom_filter_set_filter_func:
+ * @self: a #GtkCustomFilter
+ * @match_func: (nullable): function to filter items
+ * @user_data: (nullable): user data to pass to @match_func
+ * @user_destroy: destory notify
+ *
+ * Sets (or unsets) the function used for filtering items.
+ *
+ * If the filter func changes its filtering behavior,
+ * gtk_filter_changed() needs to be called.
+ *
+ * If a previous function was set, its @user_destroy will be
+ * called now.
+ **/
+void
+gtk_custom_filter_set_filter_func (GtkCustomFilter *self,
+ GtkCustomFilterFunc match_func,
+ gpointer user_data,
+ GDestroyNotify user_destroy)
+{
+ g_return_if_fail (GTK_IS_CUSTOM_FILTER (self));
+ g_return_if_fail (match_func || (user_data == NULL && !user_destroy));
+
+ if (self->user_destroy)
+ self->user_destroy (self->user_data);
+
+ self->match_func = match_func;
+ self->user_data = user_data;
+ self->user_destroy = user_destroy;
+
+ gtk_filter_changed (GTK_FILTER (self), GTK_FILTER_CHANGE_DIFFERENT);
+}
--- /dev/null
+/*
+ * Copyright © 2019 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_CUSTOM_FILTER_H__
+#define __GTK_CUSTOM_FILTER_H__
+
+#if !defined (__GTK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gtk/gtk.h> can be included directly."
+#endif
+
+#include <gtk/gtkfilter.h>
+
+G_BEGIN_DECLS
+
+/**
+ * GtkCustomFilterFunc:
+ * @item: (type GObject): The item to be matched
+ * @user_data: user data
+ *
+ * User function that is called to determine if the @item should be matched.
+ * If the filter matches the item, this function must return %TRUE. If the
+ * item should be filtered out, %FALSE must be returned.
+ *
+ * Returns: %TRUE to keep the item around
+ */
+typedef gboolean (* GtkCustomFilterFunc) (gpointer item, gpointer user_data);
+
+#define GTK_TYPE_CUSTOM_FILTER (gtk_custom_filter_get_type ())
+GDK_AVAILABLE_IN_ALL
+G_DECLARE_FINAL_TYPE (GtkCustomFilter, gtk_custom_filter, GTK, CUSTOM_FILTER, GtkFilter)
+GDK_AVAILABLE_IN_ALL
+GtkFilter * gtk_custom_filter_new (GtkCustomFilterFunc match_func,
+ gpointer user_data,
+ GDestroyNotify user_destroy);
+
+GDK_AVAILABLE_IN_ALL
+void gtk_custom_filter_set_filter_func (GtkCustomFilter *self,
+ GtkCustomFilterFunc match_func,
+ gpointer user_data,
+ GDestroyNotify user_destroy);
+
+G_END_DECLS
+
+#endif /* __GTK_CUSTOM_FILTER_H__ */