gtk2/gtk/gtklistitemfactory.c

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/*
* 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 "gtklistitemfactoryprivate.h"
#include "gtklistitemprivate.h"
/**
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* GtkListItemFactory:
*
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* A `GtkListItemFactory` creates widgets for the items taken from a `GListModel`.
*
* This is one of the core concepts of handling list widgets such
* as [class@Gtk.ListView] or [class@Gtk.GridView].
*
* The `GtkListItemFactory` is tasked with creating widgets for items
* taken from the model when the views need them and updating them as
* the items displayed by the view change.
*
* A view is usually only able to display anything after both a factory
* and a model have been set on the view. So it is important that you do
* not skip this step when setting up your first view.
*
* Because views do not display the whole list at once but only a few
* items, they only need to maintain a few widgets at a time. They will
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* instruct the `GtkListItemFactory` to create these widgets and bind them
* to the items that are currently displayed.
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*
* As the list model changes or the user scrolls to the list, the items will
* change and the view will instruct the factory to bind the widgets to those
* new items.
*
* The actual widgets used for displaying those widgets is provided by you.
*
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* When the factory needs widgets created, it will create a `GtkListItem`
* and hand it to your code to set up a widget for. This list item will provide
* various properties with information about what item to display and provide
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* you with some opportunities to configure its behavior. See the
* [class@Gtk.ListItem] documentation for further details.
*
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* Various implementations of `GtkListItemFactory` exist to allow you different
* ways to provide those widgets. The most common implementations are
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* [class@Gtk.BuilderListItemFactory] which takes a `GtkBuilder` .ui file
* and then creates widgets and manages everything automatically from the
* information in that file and [class@Gtk.SignalListItemFactory] which allows
* you to connect to signals with your own code and retain full control over
* how the widgets are setup and managed.
*
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* A `GtkListItemFactory` is supposed to be final - that means its behavior should
* not change and the first widget created from it should behave the same way as
* the last widget created from it.
* If you intend to do changes to the behavior, it is recommended that you create
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* a new `GtkListItemFactory` which will allow the views to recreate its widgets.
*
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* Once you have chosen your factory and created it, you need to set it
* on the view widget you want to use it with, such as via
* [method@Gtk.ListView.set_factory]. Reusing factories across different
* views is allowed, but very uncommon.
*/
G_DEFINE_TYPE (GtkListItemFactory, gtk_list_item_factory, G_TYPE_OBJECT)
static void
gtk_list_item_factory_default_setup (GtkListItemFactory *self,
GtkListItemWidget *widget,
GtkListItem *list_item)
{
gtk_list_item_widget_default_setup (widget, list_item);
}
static void
gtk_list_item_factory_default_teardown (GtkListItemFactory *self,
GtkListItemWidget *widget,
GtkListItem *list_item)
{
gtk_list_item_widget_default_teardown (widget, list_item);
gtk_list_item_set_child (list_item, NULL);
}
static void
gtk_list_item_factory_default_update (GtkListItemFactory *self,
GtkListItemWidget *widget,
GtkListItem *list_item,
guint position,
gpointer item,
gboolean selected)
{
gtk_list_item_widget_default_update (widget, list_item, position, item, selected);
}
static void
gtk_list_item_factory_class_init (GtkListItemFactoryClass *klass)
{
klass->setup = gtk_list_item_factory_default_setup;
klass->teardown = gtk_list_item_factory_default_teardown;
klass->update = gtk_list_item_factory_default_update;
}
static void
gtk_list_item_factory_init (GtkListItemFactory *self)
{
}
void
gtk_list_item_factory_setup (GtkListItemFactory *self,
GtkListItemWidget *widget)
{
GtkListItem *list_item;
g_return_if_fail (GTK_IS_LIST_ITEM_FACTORY (self));
list_item = gtk_list_item_new ();
GTK_LIST_ITEM_FACTORY_GET_CLASS (self)->setup (self, widget, list_item);
}
void
gtk_list_item_factory_teardown (GtkListItemFactory *self,
GtkListItemWidget *widget)
{
GtkListItem *list_item;
g_return_if_fail (GTK_IS_LIST_ITEM_FACTORY (self));
list_item = gtk_list_item_widget_get_list_item (widget);
GTK_LIST_ITEM_FACTORY_GET_CLASS (self)->teardown (self, widget, list_item);
g_object_unref (list_item);
}
void
gtk_list_item_factory_update (GtkListItemFactory *self,
GtkListItemWidget *widget,
guint position,
gpointer item,
gboolean selected)
{
GtkListItem *list_item;
g_return_if_fail (GTK_IS_LIST_ITEM_FACTORY (self));
g_return_if_fail (GTK_IS_LIST_ITEM_WIDGET (widget));
list_item = gtk_list_item_widget_get_list_item (widget);
GTK_LIST_ITEM_FACTORY_GET_CLASS (self)->update (self, widget, list_item, position, item, selected);
}