Learning_GTK4_tree/gtk/gtkpropertylookuplistmodel.c

493 lines
14 KiB
C

/*
* 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>
*/
/*
* GtkPropertyLookupListModel:
*
* `GtkPropertyLookupListModel` is a `GListModel` implementation that takes an
* object and a property and then recursively looks up the next element using
* the property on the previous object.
*
* For example, one could use this list model with the GtkWidget:parent property
* to get a list of a widgets and all its ancestors.
**/
#include "config.h"
#include "gtkpropertylookuplistmodelprivate.h"
#include "gtkprivate.h"
enum {
PROP_0,
PROP_ITEM_TYPE,
PROP_N_ITEMS,
PROP_OBJECT,
PROP_PROPERTY,
NUM_PROPERTIES
};
struct _GtkPropertyLookupListModel
{
GObject parent_instance;
GType item_type;
char *property;
GPtrArray *items; /* list of items - lazily expanded if there's a NULL sentinel */
};
struct _GtkPropertyLookupListModelClass
{
GObjectClass parent_class;
};
static GParamSpec *properties[NUM_PROPERTIES] = { NULL, };
static GType
gtk_property_lookup_list_model_get_item_type (GListModel *list)
{
GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (list);
return self->item_type;
}
static gboolean
gtk_property_lookup_list_model_is_infinite (GtkPropertyLookupListModel *self)
{
if (self->items->len == 0)
return FALSE;
return g_ptr_array_index (self->items, self->items->len - 1) == NULL;
}
static void
gtk_property_lookup_list_model_notify_cb (GObject *object,
GParamSpec *pspec,
GtkPropertyLookupListModel *self);
static guint
gtk_property_lookup_list_model_clear (GtkPropertyLookupListModel *self,
guint remaining)
{
guint i;
for (i = remaining; i < self->items->len; i++)
{
gpointer object = g_ptr_array_index (self->items, i);
if (object == NULL)
break;
g_signal_handlers_disconnect_by_func (object, gtk_property_lookup_list_model_notify_cb, self);
g_object_unref (object);
}
/* keeps the sentinel, yay! */
g_ptr_array_remove_range (self->items, remaining, i - remaining);
return i - remaining;
}
static guint
gtk_property_lookup_list_model_append (GtkPropertyLookupListModel *self,
guint n_items)
{
gpointer last, next;
guint i, start;
g_assert (self->items->len > 0);
g_assert (!gtk_property_lookup_list_model_is_infinite (self));
last = g_ptr_array_index (self->items, self->items->len - 1);
start = self->items->len;
for (i = start; i < n_items; i++)
{
g_object_get (last, self->property, &next, NULL);
if (next == NULL)
return i - start;
g_signal_connect_closure_by_id (next,
g_signal_lookup ("notify", G_OBJECT_TYPE (next)),
g_quark_from_static_string (self->property),
g_cclosure_new (G_CALLBACK (gtk_property_lookup_list_model_notify_cb), G_OBJECT (self), NULL),
FALSE);
g_ptr_array_add (self->items, next);
last = next;
}
return i - start;
}
static void
gtk_property_lookup_list_model_ensure (GtkPropertyLookupListModel *self,
guint n_items)
{
if (!gtk_property_lookup_list_model_is_infinite (self))
return;
if (self->items->len - 1 >= n_items)
return;
/* remove NULL sentinel */
g_ptr_array_remove_index (self->items, self->items->len - 1);
if (self->items->len == 0)
return;
if (gtk_property_lookup_list_model_append (self, n_items) == n_items)
{
/* re-add NULL sentinel */
g_ptr_array_add (self->items, NULL);
}
}
static void
gtk_property_lookup_list_model_notify_cb (GObject *object,
GParamSpec *pspec,
GtkPropertyLookupListModel *self)
{
guint position, removed, added;
if (!g_ptr_array_find (self->items, object, &position))
{
/* can only happen if we forgot to disconnect a signal handler */
g_assert_not_reached ();
}
/* we found the position of the item that notified, but the first change
* is its child.
*/
position++;
removed = gtk_property_lookup_list_model_clear (self, position);
if (!gtk_property_lookup_list_model_is_infinite (self))
added = gtk_property_lookup_list_model_append (self, G_MAXUINT);
else
added = 0;
if (removed > 0 || added > 0)
g_list_model_items_changed (G_LIST_MODEL (self), position, removed, added);
if (removed != added)
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_N_ITEMS]);
}
static guint
gtk_property_lookup_list_model_get_n_items (GListModel *list)
{
GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (list);
gtk_property_lookup_list_model_ensure (self, G_MAXUINT);
return self->items->len;
}
static gpointer
gtk_property_lookup_list_model_get_item (GListModel *list,
guint position)
{
GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (list);
gtk_property_lookup_list_model_ensure (self, position + 1);
if (position >= self->items->len)
return NULL;
return g_object_ref (g_ptr_array_index (self->items, position));
}
static void
gtk_property_lookup_list_model_list_model_init (GListModelInterface *iface)
{
iface->get_item_type = gtk_property_lookup_list_model_get_item_type;
iface->get_n_items = gtk_property_lookup_list_model_get_n_items;
iface->get_item = gtk_property_lookup_list_model_get_item;
}
G_DEFINE_TYPE_WITH_CODE (GtkPropertyLookupListModel, gtk_property_lookup_list_model,
G_TYPE_OBJECT,
G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL, gtk_property_lookup_list_model_list_model_init))
static gboolean
check_pspec (GType type,
GParamSpec *pspec)
{
if (pspec == NULL)
return FALSE;
if (!G_IS_PARAM_SPEC_OBJECT (pspec))
return FALSE;
if (!g_type_is_a (G_PARAM_SPEC (pspec)->value_type, type))
return FALSE;
return TRUE;
}
static gboolean
lookup_pspec (GType type,
const char *name)
{
gboolean result;
if (g_type_is_a (type, G_TYPE_INTERFACE))
{
gpointer iface;
GParamSpec *pspec;
iface = g_type_default_interface_ref (type);
pspec = g_object_interface_find_property (iface, name);
result = check_pspec (type, pspec);
g_type_default_interface_unref (iface);
}
else
{
GObjectClass *klass;
GParamSpec *pspec;
klass = g_type_class_ref (type);
g_return_val_if_fail (klass != NULL, FALSE);
pspec = g_object_class_find_property (klass, name);
result = check_pspec (type, pspec);
g_type_class_unref (klass);
}
return result;
}
static void
gtk_property_lookup_list_model_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (object);
switch (prop_id)
{
case PROP_ITEM_TYPE:
self->item_type = g_value_get_gtype (value);
g_return_if_fail (self->item_type != 0);
break;
case PROP_OBJECT:
gtk_property_lookup_list_model_set_object (self, g_value_get_object (value));
break;
case PROP_PROPERTY:
self->property = g_value_dup_string (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
if (self->property && self->item_type &&
!lookup_pspec (self->item_type, self->property))
{
g_critical ("type %s has no property named \"%s\"", g_type_name (self->item_type), self->property);
}
}
static void
gtk_property_lookup_list_model_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (object);
switch (prop_id)
{
case PROP_ITEM_TYPE:
g_value_set_gtype (value, self->item_type);
break;
case PROP_N_ITEMS:
g_value_set_uint (value, gtk_property_lookup_list_model_get_n_items (G_LIST_MODEL (self)));
break;
case PROP_OBJECT:
g_value_set_object (value, gtk_property_lookup_list_model_get_object (self));
break;
case PROP_PROPERTY:
g_value_set_string (value, self->property);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_property_lookup_list_model_dispose (GObject *object)
{
GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (object);
gtk_property_lookup_list_model_clear (self, 0);
G_OBJECT_CLASS (gtk_property_lookup_list_model_parent_class)->dispose (object);
}
static void
gtk_property_lookup_list_model_finalize (GObject *object)
{
GtkPropertyLookupListModel *self = GTK_PROPERTY_LOOKUP_LIST_MODEL (object);
g_ptr_array_unref (self->items);
g_free (self->property);
G_OBJECT_CLASS (gtk_property_lookup_list_model_parent_class)->finalize (object);
}
static void
gtk_property_lookup_list_model_class_init (GtkPropertyLookupListModelClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->get_property = gtk_property_lookup_list_model_get_property;
object_class->set_property = gtk_property_lookup_list_model_set_property;
object_class->dispose = gtk_property_lookup_list_model_dispose;
object_class->finalize = gtk_property_lookup_list_model_finalize;
/**
* GtkPropertyLookupListModel:item-type:
*
* The `GType` for elements of this object. See [method@Gio.ListModel.get_item_type].
*/
properties[PROP_ITEM_TYPE] =
g_param_spec_gtype ("item-type", NULL, NULL,
G_TYPE_OBJECT,
GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkPropertyLookupListModel:n-items:
*
* The number of items. See [method@Gio.ListModel.get_n_items].
*
* Since: 4.8
**/
properties[PROP_N_ITEMS] =
g_param_spec_uint ("n-items", NULL, NULL,
0, G_MAXUINT, 0,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
/**
* GtkPropertyLookupListModel:property:
*
* Name of the property used for lookups
*/
properties[PROP_PROPERTY] =
g_param_spec_string ("property", NULL, NULL,
NULL,
GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkPropertyLookupListModel:object:
*
* The root object
*/
properties[PROP_OBJECT] =
g_param_spec_object ("object", NULL, NULL,
G_TYPE_OBJECT,
GTK_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
g_object_class_install_properties (object_class, NUM_PROPERTIES, properties);
}
static void
gtk_property_lookup_list_model_init (GtkPropertyLookupListModel *self)
{
self->item_type = G_TYPE_OBJECT;
self->items = g_ptr_array_new ();
/* add sentinel */
g_ptr_array_add (self->items, NULL);
}
GtkPropertyLookupListModel *
gtk_property_lookup_list_model_new (GType item_type,
const char *property_name)
{
g_return_val_if_fail (g_type_is_a (item_type, G_TYPE_OBJECT), NULL);
g_return_val_if_fail (property_name != NULL, NULL);
return g_object_new (GTK_TYPE_PROPERTY_LOOKUP_LIST_MODEL,
"item-type", item_type,
"property", property_name,
NULL);
}
void
gtk_property_lookup_list_model_set_object (GtkPropertyLookupListModel *self,
gpointer object)
{
guint removed, added;
g_return_if_fail (GTK_IS_PROPERTY_LOOKUP_LIST_MODEL (self));
if (object)
{
if (self->items->len != 0 &&
g_ptr_array_index (self->items, 0) == object)
return;
removed = gtk_property_lookup_list_model_clear (self, 0);
g_ptr_array_insert (self->items, 0, g_object_ref (object));
g_signal_connect_closure_by_id (object,
g_signal_lookup ("notify", G_OBJECT_TYPE (object)),
g_quark_from_static_string (self->property),
g_cclosure_new (G_CALLBACK (gtk_property_lookup_list_model_notify_cb), G_OBJECT (self), NULL),
FALSE);
added = 1;
if (!gtk_property_lookup_list_model_is_infinite (self))
added += gtk_property_lookup_list_model_append (self, G_MAXUINT);
}
else
{
if (self->items->len == 0 ||
g_ptr_array_index (self->items, 0) == NULL)
return;
removed = gtk_property_lookup_list_model_clear (self, 0);
added = 0;
}
g_assert (removed != 0 || added != 0);
g_list_model_items_changed (G_LIST_MODEL (self), 0, removed, added);
if (removed != added)
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_N_ITEMS]);
}
gpointer
gtk_property_lookup_list_model_get_object (GtkPropertyLookupListModel *self)
{
g_return_val_if_fail (GTK_IS_PROPERTY_LOOKUP_LIST_MODEL (self), NULL);
if (self->items->len == 0)
return NULL;
return g_ptr_array_index (self->items, 0);
}