view-item-filter: Introduce filter for FileChooser

Instead of reimplementing GtkFileFilter, which conveniently takes
the GVariant format from the FileChooser portal interface, let's
wrap it with a filter of our own which translates NautilusViewItem
into a dummy GFileInfo.

src/meson.build

@@ -133,6 +133,8 @@ libnautilus_sources = [
   'nautilus-view-info.h',
   'nautilus-view-item.c',
   'nautilus-view-item.h',
+  'nautilus-view-item-filter.c',
+  'nautilus-view-item-filter.h',
   'nautilus-view-model.c',
   'nautilus-view-model.h',
   'nautilus-window-slot.c',

src/nautilus-view-item-filter.c

@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2024 GNOME Foundation Inc.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+
+#include "nautilus-view-item-filter.h"
+
+#include <gio/gio.h>
+
+#include "nautilus-view-item.h"
+
+enum
+{
+    PROP_0,
+    PROP_FILE_FILTER,
+    N_PROPS
+};
+
+static GParamSpec *properties[N_PROPS] = { NULL, };
+
+struct _NautilusViewItemFilter
+{
+    GtkFilter parent_instance;
+
+    GtkFilterMatch strictness;
+
+    GtkFileFilter *file_filter;
+    GFileInfo *dummy_object;
+};
+
+G_DEFINE_TYPE (NautilusViewItemFilter, nautilus_view_item_filter, GTK_TYPE_FILTER)
+
+static GtkFilterMatch
+nautilus_view_item_filter_get_strictness (GtkFilter *filter)
+{
+    NautilusViewItemFilter *self = NAUTILUS_VIEW_ITEM_FILTER (filter);
+
+    return self->strictness;
+}
+
+static gboolean
+nautilus_view_item_filter_match (GtkFilter *filter,
+                                 gpointer   item)
+{
+    g_return_val_if_fail (NAUTILUS_IS_VIEW_ITEM (item), FALSE);
+
+    NautilusViewItemFilter *self = NAUTILUS_VIEW_ITEM_FILTER (filter);
+    NautilusFile *file = nautilus_view_item_get_file (NAUTILUS_VIEW_ITEM (item));
+
+    if (nautilus_file_opens_in_view (file))
+    {
+        /* The current use case (FileChooser) never hides folders. */
+        return TRUE;
+    }
+
+    GFileInfo *info = self->dummy_object;
+
+    g_file_info_set_display_name (info, nautilus_file_get_display_name (file));
+    g_file_info_set_content_type (info, nautilus_file_get_mime_type (file));
+
+    return gtk_filter_match (GTK_FILTER (self->file_filter), info);
+}
+
+static void
+nautilus_view_item_filter_finalize (GObject *object)
+{
+    NautilusViewItemFilter *self = NAUTILUS_VIEW_ITEM_FILTER (object);
+
+    g_clear_object (&self->file_filter);
+    g_clear_object (&self->dummy_object);
+
+    G_OBJECT_CLASS (nautilus_view_item_filter_parent_class)->finalize (object);
+}
+
+static void
+nautilus_view_item_filter_set_property (GObject      *object,
+                                        guint         prop_id,
+                                        const GValue *value,
+                                        GParamSpec   *pspec)
+{
+    NautilusViewItemFilter *self = NAUTILUS_VIEW_ITEM_FILTER (object);
+
+    switch (prop_id)
+    {
+        case PROP_FILE_FILTER:
+        {
+            nautilus_view_item_filter_set_file_filter (self, g_value_get_object (value));
+        }
+        break;
+
+        default:
+        {
+            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+        }
+    }
+}
+
+static void
+nautilus_view_item_filter_class_init (NautilusViewItemFilterClass *klass)
+{
+    GObjectClass *object_class = G_OBJECT_CLASS (klass);
+    GtkFilterClass *filter_class = GTK_FILTER_CLASS (klass);
+
+    object_class->finalize = nautilus_view_item_filter_finalize;
+    object_class->set_property = nautilus_view_item_filter_set_property;
+
+    filter_class->get_strictness = nautilus_view_item_filter_get_strictness;
+    filter_class->match = nautilus_view_item_filter_match;
+
+    properties[PROP_FILE_FILTER] = g_param_spec_object ("file-filter", NULL, NULL,
+                                                        GTK_TYPE_FILE_FILTER,
+                                                        G_PARAM_WRITABLE | G_PARAM_STATIC_STRINGS);
+    g_object_class_install_properties (object_class, N_PROPS, properties);
+}
+
+static void
+nautilus_view_item_filter_init (NautilusViewItemFilter *self)
+{
+    self->strictness = GTK_FILTER_MATCH_ALL;
+    self->dummy_object = g_file_info_new ();
+}
+
+NautilusViewItemFilter *
+nautilus_view_item_filter_new (void)
+{
+    return g_object_new (NAUTILUS_TYPE_VIEW_ITEM_FILTER, NULL);
+}
+
+void
+nautilus_view_item_filter_set_file_filter (NautilusViewItemFilter *self,
+                                           GtkFileFilter          *file_filter)
+{
+    g_return_if_fail (NAUTILUS_IS_VIEW_ITEM_FILTER (self));
+
+    if (!g_set_object (&self->file_filter, file_filter))
+    {
+        return;
+    }
+
+    GtkFilterMatch old_strictness = self->strictness;
+    GtkFilterChange change = GTK_FILTER_CHANGE_DIFFERENT;
+
+    self->strictness = (file_filter != NULL ?
+                        GTK_FILTER_MATCH_SOME :
+                        GTK_FILTER_MATCH_ALL);
+
+    if (self->strictness != old_strictness)
+    {
+        change = (self->strictness == GTK_FILTER_MATCH_ALL ?
+                  GTK_FILTER_CHANGE_LESS_STRICT :
+                  GTK_FILTER_CHANGE_MORE_STRICT);
+    }
+
+    gtk_filter_changed (GTK_FILTER (self), change);
+
+    g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_FILE_FILTER]);
+}

src/nautilus-view-item-filter.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2024 GNOME Foundation Inc.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define NAUTILUS_TYPE_VIEW_ITEM_FILTER (nautilus_view_item_filter_get_type())
+
+G_DECLARE_FINAL_TYPE (NautilusViewItemFilter, nautilus_view_item_filter, NAUTILUS, VIEW_ITEM_FILTER, GtkFilter)
+
+NautilusViewItemFilter *
+nautilus_view_item_filter_new (void);
+
+void
+nautilus_view_item_filter_set_file_filter (NautilusViewItemFilter *self,
+                                           GtkFileFilter          *file_filter);
+
+G_END_DECLS