gtk2/gtk/gtkpropertyselection.c
Benjamin Otte 541aaa2392 selectionmodel: Add unselect_rest argument to select_callback
This is not just about consistency with other functions.

It is about avoiding reentrancy problems.

GtkListBase first doing an unselect_all() will then force the
SelectionModel to consider a state where all items are unselected
(and potentially deciding to autoselect one) and then cause a
"selection-changed" emission that unselects all items and potentially
updates all the list item widgets in the GtkListBase to the unselected
state.

After this, GtkListBase selects new items, but to the SelectionModel and
the list item widgets this looks like an enitrely new operation and
there is no way to associate it with the previous state, so the
SelectionModel cannot undo any previous actions it took when
unselecting.
And all listitem widgets will now think they were just selected and
start running animations about selecting.
2020-06-08 19:06:56 +02:00

500 lines
15 KiB
C

/*
* 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 <mclasen@redhat.com>
*/
#include "config.h"
#include "gtkpropertyselection.h"
#include "gtkintl.h"
#include "gtkselectionmodel.h"
/**
* SECTION:gtkpropertyselection
* @Short_description: A selection model that uses an item property
* @Title: GtkPropertySelection
* @see_also: #GtkSelectionModel
*
* GtkPropertySelection is an implementation of the #GtkSelectionModel
* interface that stores the selected state for each item in a property
* of the item.
*
* The property named by #GtkPropertySelection:property must be writable
* boolean property of the item type. GtkPropertySelection preserves the
* selected state of items when they are added to the model, but it does
* not listen to changes of the property while the item is a part of the
* model. It assumes that it has *exclusive* access to the property.
*
* The advantage of storing the selected state in item properties is that
* the state is *persistent* -- when an item is removed and re-added to
* the model, it will still have the same selection state. In particular,
* this makes the selection persist across changes of the sort order if
* the underlying model is a #GtkSortListModel.
*/
struct _GtkPropertySelection
{
GObject parent_instance;
GListModel *model;
char *property;
};
struct _GtkPropertySelectionClass
{
GObjectClass parent_class;
};
enum {
PROP_0,
PROP_MODEL,
PROP_PROPERTY,
N_PROPS,
};
static GParamSpec *properties[N_PROPS] = { NULL, };
static GType
gtk_property_selection_get_item_type (GListModel *list)
{
GtkPropertySelection *self = GTK_PROPERTY_SELECTION (list);
return g_list_model_get_item_type (self->model);
}
static guint
gtk_property_selection_get_n_items (GListModel *list)
{
GtkPropertySelection *self = GTK_PROPERTY_SELECTION (list);
return g_list_model_get_n_items (self->model);
}
static gpointer
gtk_property_selection_get_item (GListModel *list,
guint position)
{
GtkPropertySelection *self = GTK_PROPERTY_SELECTION (list);
return g_list_model_get_item (self->model, position);
}
static void
gtk_property_selection_list_model_init (GListModelInterface *iface)
{
iface->get_item_type = gtk_property_selection_get_item_type;
iface->get_n_items = gtk_property_selection_get_n_items;
iface->get_item = gtk_property_selection_get_item;
}
static gboolean
is_selected (GtkPropertySelection *self,
guint position)
{
gpointer item;
gboolean ret;
item = g_list_model_get_item (self->model, position);
g_object_get (item, self->property, &ret, NULL);
g_object_unref (item);
return ret;
}
static void
set_selected (GtkPropertySelection *self,
guint position,
gboolean selected)
{
gpointer item;
item = g_list_model_get_item (self->model, position);
g_object_set (item, self->property, selected, NULL);
g_object_unref (item);
}
static gboolean
gtk_property_selection_is_selected (GtkSelectionModel *model,
guint position)
{
return is_selected (GTK_PROPERTY_SELECTION (model), position);
}
static gboolean
gtk_property_selection_select_range (GtkSelectionModel *model,
guint position,
guint n_items,
gboolean exclusive)
{
GtkPropertySelection *self = GTK_PROPERTY_SELECTION (model);
guint i;
guint n;
n = g_list_model_get_n_items (G_LIST_MODEL (self));
if (exclusive)
{
for (i = 0; i < n; i++)
set_selected (self, i, FALSE);
}
for (i = position; i < position + n_items; i++)
set_selected (self, i, TRUE);
/* FIXME: do better here */
if (exclusive)
gtk_selection_model_selection_changed (model, 0, n);
else
gtk_selection_model_selection_changed (model, position, n_items);
return TRUE;
}
static gboolean
gtk_property_selection_unselect_range (GtkSelectionModel *model,
guint position,
guint n_items)
{
GtkPropertySelection *self = GTK_PROPERTY_SELECTION (model);
guint i;
for (i = position; i < position + n_items; i++)
set_selected (self, i, FALSE);
gtk_selection_model_selection_changed (model, position, n_items);
return TRUE;
}
static gboolean
gtk_property_selection_select_item (GtkSelectionModel *model,
guint position,
gboolean exclusive)
{
return gtk_property_selection_select_range (model, position, 1, exclusive);
}
static gboolean
gtk_property_selection_unselect_item (GtkSelectionModel *model,
guint position)
{
return gtk_property_selection_unselect_range (model, position, 1);
}
static gboolean
gtk_property_selection_select_all (GtkSelectionModel *model)
{
return gtk_property_selection_select_range (model, 0, g_list_model_get_n_items (G_LIST_MODEL (model)), FALSE);
}
static gboolean
gtk_property_selection_unselect_all (GtkSelectionModel *model)
{
return gtk_property_selection_unselect_range (model, 0, g_list_model_get_n_items (G_LIST_MODEL (model)));
}
static gboolean
gtk_property_selection_add_or_remove (GtkSelectionModel *model,
gboolean unselect_rest,
gboolean add,
GtkSelectionCallback callback,
gpointer data)
{
GtkPropertySelection *self = GTK_PROPERTY_SELECTION (model);
guint pos, start, n, n_items;
gboolean in;
guint min, max;
guint i;
n_items = g_list_model_get_n_items (G_LIST_MODEL (self));
if (unselect_rest)
{
for (i = 0; i < n_items; i++)
set_selected (self, i, FALSE);
}
min = G_MAXUINT;
max = 0;
pos = 0;
do
{
callback (pos, &start, &n, &in, data);
if (in)
{
if (start < min)
min = start;
if (start + n - 1 > max)
max = start + n - 1;
for (i = start; i < start + n; i++)
set_selected (self, i, add);
}
pos = start + n;
}
while (n > 0);
/* FIXME: do better here */
if (unselect_rest)
gtk_selection_model_selection_changed (model, 0, n_items);
else if (min <= max)
gtk_selection_model_selection_changed (model, min, max - min + 1);
return TRUE;
}
static gboolean
gtk_property_selection_select_callback (GtkSelectionModel *model,
gboolean unselect_rest,
GtkSelectionCallback callback,
gpointer data)
{
return gtk_property_selection_add_or_remove (model, unselect_rest, TRUE, callback, data);
}
static gboolean
gtk_property_selection_unselect_callback (GtkSelectionModel *model,
GtkSelectionCallback callback,
gpointer data)
{
return gtk_property_selection_add_or_remove (model, FALSE, FALSE, callback, data);
}
static void
gtk_property_selection_query_range (GtkSelectionModel *model,
guint position,
guint *start_range,
guint *n_items,
gboolean *selected)
{
GtkPropertySelection *self = GTK_PROPERTY_SELECTION (model);
guint n;
gboolean sel;
guint start, end;
n = g_list_model_get_n_items (G_LIST_MODEL (self));
sel = is_selected (self, position);
start = position;
while (start > 0)
{
if (is_selected (self, start - 1) != sel)
break;
start--;
}
end = position;
while (end + 1 < n)
{
if (is_selected (self, end + 1) != sel)
break;
end++;
}
*start_range = start;
*n_items = end - start + 1;
*selected = sel;
}
static void
gtk_property_selection_selection_model_init (GtkSelectionModelInterface *iface)
{
iface->is_selected = gtk_property_selection_is_selected;
iface->select_item = gtk_property_selection_select_item;
iface->unselect_item = gtk_property_selection_unselect_item;
iface->select_range = gtk_property_selection_select_range;
iface->unselect_range = gtk_property_selection_unselect_range;
iface->select_all = gtk_property_selection_select_all;
iface->unselect_all = gtk_property_selection_unselect_all;
iface->select_callback = gtk_property_selection_select_callback;
iface->unselect_callback = gtk_property_selection_unselect_callback;
iface->query_range = gtk_property_selection_query_range;
}
G_DEFINE_TYPE_EXTENDED (GtkPropertySelection, gtk_property_selection, G_TYPE_OBJECT, 0,
G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL,
gtk_property_selection_list_model_init)
G_IMPLEMENT_INTERFACE (GTK_TYPE_SELECTION_MODEL,
gtk_property_selection_selection_model_init))
static void
gtk_property_selection_items_changed_cb (GListModel *model,
guint position,
guint removed,
guint added,
GtkPropertySelection *self)
{
g_list_model_items_changed (G_LIST_MODEL (self), position, removed, added);
}
static void
gtk_property_selection_clear_model (GtkPropertySelection *self)
{
if (self->model == NULL)
return;
g_signal_handlers_disconnect_by_func (self->model,
gtk_property_selection_items_changed_cb,
self);
g_clear_object (&self->model);
}
static void
gtk_property_selection_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkPropertySelection *self = GTK_PROPERTY_SELECTION (object);
switch (prop_id)
{
case PROP_MODEL:
self->model = g_value_dup_object (value);
g_warn_if_fail (self->model != NULL);
g_signal_connect (self->model,
"items-changed",
G_CALLBACK (gtk_property_selection_items_changed_cb),
self);
break;
case PROP_PROPERTY:
{
GObjectClass *class;
GParamSpec *prop;
self->property = g_value_dup_string (value);
g_warn_if_fail (self->property != NULL);
class = g_type_class_ref (g_list_model_get_item_type (self->model));
prop = g_object_class_find_property (class, self->property);
g_warn_if_fail (prop != NULL &&
prop->value_type == G_TYPE_BOOLEAN &&
((prop->flags & (G_PARAM_READABLE|G_PARAM_WRITABLE|G_PARAM_CONSTRUCT_ONLY)) ==
(G_PARAM_READABLE|G_PARAM_WRITABLE)));
g_type_class_unref (class);
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_property_selection_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkPropertySelection *self = GTK_PROPERTY_SELECTION (object);
switch (prop_id)
{
case PROP_MODEL:
g_value_set_object (value, self->model);
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_selection_dispose (GObject *object)
{
GtkPropertySelection *self = GTK_PROPERTY_SELECTION (object);
gtk_property_selection_clear_model (self);
g_free (self->property);
G_OBJECT_CLASS (gtk_property_selection_parent_class)->dispose (object);
}
static void
gtk_property_selection_class_init (GtkPropertySelectionClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->get_property = gtk_property_selection_get_property;
gobject_class->set_property = gtk_property_selection_set_property;
gobject_class->dispose = gtk_property_selection_dispose;
/**
* GtkPropertySelection:model
*
* The list managed by this selection
*/
properties[PROP_MODEL] =
g_param_spec_object ("model",
P_("Model"),
P_("List managed by this selection"),
G_TYPE_LIST_MODEL,
G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
properties[PROP_PROPERTY] =
g_param_spec_string ("property",
P_("Property"),
P_("Item property to store selection state in"),
NULL,
G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
g_object_class_install_properties (gobject_class, N_PROPS, properties);
}
static void
gtk_property_selection_init (GtkPropertySelection *self)
{
}
/**
* gtk_property_selection_new:
* @model: (transfer none): the #GListModel to manage
* @property: the item property to use
*
* Creates a new property selection to handle @model.
*
* @property must be the name of a writable boolean property
* of the item type of @model.
*
* Note that GtkPropertySelection does not monitor the property
* for changes while the item is part of the model, but it does
* inherit the initial value when an item is added to the model.
*
* Returns: (transfer full) (type GtkPropertySelection): a new #GtkPropertySelection
**/
GListModel *
gtk_property_selection_new (GListModel *model,
const char *property)
{
g_return_val_if_fail (G_IS_LIST_MODEL (model), NULL);
return g_object_new (GTK_TYPE_PROPERTY_SELECTION,
"model", model,
"property", property,
NULL);
}