[gtk/wip/otte/listview: 6/147] filter: Add a custom filter

[Benjamin Otte <otte src gnome org>]

commit 9466318710137d65e1d32bf0e36f77dae6639849
Author: Benjamin Otte <otte redhat com>
Date:   Sun Nov 10 01:30:02 2019 +0100

    filter: Add a custom filter

 docs/reference/gtk/gtk4-sections.txt |   2 +
 gtk/gtk.h                            |   1 +
 gtk/gtkfilters.c                     | 103 +++++++++++++++++++++++++++++++++++
 gtk/gtkfilters.h                     |  55 +++++++++++++++++++
 gtk/meson.build                      |   2 +
 5 files changed, 163 insertions(+)
---
diff --git a/docs/reference/gtk/gtk4-sections.txt b/docs/reference/gtk/gtk4-sections.txt
index 1ceff7828c..946744459a 100644
--- a/docs/reference/gtk/gtk4-sections.txt
+++ b/docs/reference/gtk/gtk4-sections.txt
@@ -1398,6 +1398,8 @@ GtkFilter
 gtk_filter_filter
 <SUBSECTION>
 gtk_filter_changed
+<SUBSECTION>
+gtk_custom_filter_new
 <SUBSECTION Standard>
 GTK_FILTER
 GTK_IS_FILTER
diff --git a/gtk/gtk.h b/gtk/gtk.h
index d711d4cd1e..d995766113 100644
--- a/gtk/gtk.h
+++ b/gtk/gtk.h
@@ -117,6 +117,7 @@
 #include <gtk/gtkfilefilter.h>
 #include <gtk/gtkfilter.h>
 #include <gtk/gtkfilterlistmodel.h>
+#include <gtk/gtkfilters.h>
 #include <gtk/gtkflattenlistmodel.h>
 #include <gtk/gtkflowbox.h>
 #include <gtk/gtkfontbutton.h>
diff --git a/gtk/gtkfilters.c b/gtk/gtkfilters.c
new file mode 100644
index 0000000000..5750717d08
--- /dev/null
+++ b/gtk/gtkfilters.c
@@ -0,0 +1,103 @@
+/*
+ * 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 "gtkfilters.h"
+
+#include "gtkintl.h"
+#include "gtktypebuiltins.h"
+
+struct _GtkCustomFilter
+{
+  GtkFilter parent_instance;
+
+  GtkCustomFilterFunc filter_func;
+  gpointer user_data;
+  GDestroyNotify user_destroy;
+};
+
+G_DEFINE_TYPE (GtkCustomFilter, gtk_custom_filter, GTK_TYPE_FILTER)
+
+static gboolean
+gtk_custom_filter_filter (GtkFilter *filter,
+                          gpointer   item)
+{
+  GtkCustomFilter *self = GTK_CUSTOM_FILTER (filter);
+
+  return self->filter_func (item, self->user_data);
+}
+
+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->filter = gtk_custom_filter_filter;
+
+  object_class->dispose = gtk_custom_filter_dispose;
+}
+
+static void
+gtk_custom_filter_init (GtkCustomFilter *self)
+{
+}
+
+/**
+ * gtk_custom_filter_new:
+ * @filter_func: 
+ * @user_data: (allow none): user data to pass to @filter_func
+ * @user_destroy: destory notify 
+ *
+ * Creates a new filter using the given @filter_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     filter_func,
+                       gpointer                user_data,
+                       GDestroyNotify          user_destroy)
+{
+  GtkCustomFilter *result;
+
+  result = g_object_new (GTK_TYPE_CUSTOM_FILTER, NULL);
+
+  result->filter_func = filter_func;
+  result->user_data = user_data;
+  result->user_destroy = user_destroy;
+
+  return GTK_FILTER (result);
+}
+
diff --git a/gtk/gtkfilters.h b/gtk/gtkfilters.h
new file mode 100644
index 0000000000..b86f53b7ba
--- /dev/null
+++ b/gtk/gtkfilters.h
@@ -0,0 +1,55 @@
+/*
+ * 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_FILTERS_H__
+#define __GTK_FILTERS_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 that may be filtered
+ * @user_data: user data
+ *
+ * User function that is called to determine if the @item should be visible.
+ * If it should be visible, 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     filter_func,
+                                                                 gpointer                user_data,
+                                                                 GDestroyNotify          user_destroy);
+
+
+G_END_DECLS
+
+#endif /* __GTK_FILTERS_H__ */
diff --git a/gtk/meson.build b/gtk/meson.build
index a71cf9e965..9f53c83084 100644
--- a/gtk/meson.build
+++ b/gtk/meson.build
@@ -239,6 +239,7 @@ gtk_public_sources = files([
   'gtkfilefilter.c',
   'gtkfilter.c',
   'gtkfilterlistmodel.c',
+  'gtkfilters.c',
   'gtkfixed.c',
   'gtkfixedlayout.c',
   'gtkflattenlistmodel.c',
@@ -508,6 +509,7 @@ gtk_public_headers = files([
   'gtkfilefilter.h',
   'gtkfilter.h',
   'gtkfilterlistmodel.h',
+  'gtkfilters.h',
   'gtkfixed.h',
   'gtkfixedlayout.h',
   'gtkflattenlistmodel.h',