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Diffstat (limited to 'gtk/gtkreverselistmodel.c')
| -rw-r--r-- | gtk/gtkreverselistmodel.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/gtk/gtkreverselistmodel.c b/gtk/gtkreverselistmodel.c new file mode 100644 index 0000000000..ad62d8ca70 --- /dev/null +++ b/gtk/gtkreverselistmodel.c @@ -0,0 +1,290 @@ +/* + * Copyright © 2020 Red Hat, Inc + * + * 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: Matthias Clasen + */ + +#include "config.h" + +#include "gtkreverselistmodel.h" + +#include "gtkintl.h" +#include "gtkprivate.h" + +/** + * SECTION:gtkreverselistmodel + * @title: GtkReverseListModel + * @short_description: A list model that reverses the order of a list model + * @see_also: #GListModel + * + * #GtkReverseListModel is a list model that takes a list model and reverses + * the order of that model. + */ + +enum { + PROP_0, + PROP_MODEL, + NUM_PROPERTIES +}; + +struct _GtkReverseListModel +{ + GObject parent_instance; + + GListModel *model; +}; + +struct _GtkReverseListModelClass +{ + GObjectClass parent_class; +}; + +static GParamSpec *properties[NUM_PROPERTIES] = { NULL, }; + +static GType +gtk_reverse_list_model_get_item_type (GListModel *list) +{ + return G_TYPE_OBJECT; +} + +static guint +gtk_reverse_list_model_get_n_items (GListModel *list) +{ + GtkReverseListModel *self = GTK_REVERSE_LIST_MODEL (list); + + if (self->model == NULL) + return 0; + + return g_list_model_get_n_items (self->model); +} + +static gpointer +gtk_reverse_list_model_get_item (GListModel *list, + guint position) +{ + GtkReverseListModel *self = GTK_REVERSE_LIST_MODEL (list); + guint n_items; + + if (self->model == NULL) + return NULL; + + n_items = g_list_model_get_n_items (self->model); + + if (position >= n_items) + return NULL; + + return g_list_model_get_item (self->model, n_items - 1 - position); +} + +static void +gtk_reverse_list_model_model_init (GListModelInterface *iface) +{ + iface->get_item_type = gtk_reverse_list_model_get_item_type; + iface->get_n_items = gtk_reverse_list_model_get_n_items; + iface->get_item = gtk_reverse_list_model_get_item; +} + +G_DEFINE_TYPE_WITH_CODE (GtkReverseListModel, gtk_reverse_list_model, G_TYPE_OBJECT, + G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL, gtk_reverse_list_model_model_init)) + +static void +gtk_reverse_list_model_items_changed_cb (GListModel *model, + guint position, + guint removed, + guint added, + GtkReverseListModel *self) +{ + guint n_items; + guint position_before; + + n_items = g_list_model_get_n_items (model); + + position_before = (n_items - added + removed) - 1 - (position + removed - 1); + + g_list_model_items_changed (G_LIST_MODEL (self), position_before, removed, added); +} + +static void +gtk_reverse_list_model_set_property (GObject *object, + guint prop_id, + const GValue *value, + GParamSpec *pspec) +{ + GtkReverseListModel *self = GTK_REVERSE_LIST_MODEL (object); + + switch (prop_id) + { + case PROP_MODEL: + gtk_reverse_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_reverse_list_model_get_property (GObject *object, + guint prop_id, + GValue *value, + GParamSpec *pspec) +{ + GtkReverseListModel *self = GTK_REVERSE_LIST_MODEL (object); + + switch (prop_id) + { + 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_reverse_list_model_clear_model (GtkReverseListModel *self) +{ + if (self->model == NULL) + return; + + g_signal_handlers_disconnect_by_func (self->model, gtk_reverse_list_model_items_changed_cb, self); + g_clear_object (&self->model); +} + +static void +gtk_reverse_list_model_dispose (GObject *object) +{ + GtkReverseListModel *self = GTK_REVERSE_LIST_MODEL (object); + + gtk_reverse_list_model_clear_model (self); + + G_OBJECT_CLASS (gtk_reverse_list_model_parent_class)->dispose (object); +}; + +static void +gtk_reverse_list_model_class_init (GtkReverseListModelClass *class) +{ + GObjectClass *gobject_class = G_OBJECT_CLASS (class); + + gobject_class->set_property = gtk_reverse_list_model_set_property; + gobject_class->get_property = gtk_reverse_list_model_get_property; + gobject_class->dispose = gtk_reverse_list_model_dispose; + + /** + * GtkReverseListModel:model: + * + * Child model to revert + */ + properties[PROP_MODEL] = + g_param_spec_object ("model", + P_("Model"), + P_("Child model to revert"), + G_TYPE_LIST_MODEL, + GTK_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY); + + g_object_class_install_properties (gobject_class, NUM_PROPERTIES, properties); +} + +static void +gtk_reverse_list_model_init (GtkReverseListModel *self) +{ +} + +/** + * gtk_reverse_list_model_new: + * @model: (transfer full) (allow-none): The model to use, or %NULL + * + * Creates a new model that presents the items from @model + * in reverse order + * + * Returns: A new #GtkReverseListModel + **/ +GtkReverseListModel * +gtk_reverse_list_model_new (GListModel *model) +{ + GtkReverseListModel *self; + + g_return_val_if_fail (model == NULL || G_IS_LIST_MODEL (model), NULL); + + self = g_object_new (GTK_TYPE_REVERSE_LIST_MODEL, + "model", model, + NULL); + + /* consume the reference */ + g_clear_object (&model); + + return self; +} + +/** + * gtk_reverse_list_model_set_model: + * @self: a #GtkReverseListModel + * @model: (allow-none): The model to be sliced + * + * Sets the model to revert. The model's item type must conform + * to @self's item type. + * + **/ +void +gtk_reverse_list_model_set_model (GtkReverseListModel *self, + GListModel *model) +{ + guint removed, added; + + g_return_if_fail (GTK_IS_REVERSE_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_reverse_list_model_clear_model (self); + + if (model) + { + self->model = g_object_ref (model); + g_signal_connect (model, "items-changed", G_CALLBACK (gtk_reverse_list_model_items_changed_cb), self); + added = g_list_model_get_n_items (G_LIST_MODEL (self)); + } + 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_reverse_list_model_get_model: + * @self: a #GtkReverseListModel + * + * Gets the model that is currently being used or %NULL if none. + * + * Returns: (nullable) (transfer none): The model in use + **/ +GListModel * +gtk_reverse_list_model_get_model (GtkReverseListModel *self) +{ + g_return_val_if_fail (GTK_IS_REVERSE_LIST_MODEL (self), NULL); + + return self->model; +} |