gtk2/gtk/gtksingleselection.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 "gtksingleselection.h"
#include "gtkbitset.h"
#include "gtkintl.h"
#include "gtkselectionmodel.h"
/**
* SECTION:gtksingleselection
* @Short_description: A selection model that allows selecting a single item
* @Title: GtkSingleSelection
* @see_also: #GtkSelectionModel
*
* GtkSingleSelection is an implementation of the #GtkSelectionModel interface
* that allows selecting a single element. It is the default selection method
* used by list widgets in GTK.
*
* Note that the selection is *persistent* -- if the selected item is removed
* and re-added in the same ::items-changed emission, it stays selected. In
* particular, this means that changing the sort order of an underlying sort
* model will preserve the selection.
*/
struct _GtkSingleSelection
{
GObject parent_instance;
GListModel *model;
guint selected;
gpointer selected_item;
guint autoselect : 1;
guint can_unselect : 1;
};
struct _GtkSingleSelectionClass
{
GObjectClass parent_class;
};
enum {
PROP_0,
PROP_AUTOSELECT,
PROP_CAN_UNSELECT,
PROP_SELECTED,
PROP_SELECTED_ITEM,
PROP_MODEL,
N_PROPS
};
static GParamSpec *properties[N_PROPS] = { NULL, };
static GType
gtk_single_selection_get_item_type (GListModel *list)
{
return G_TYPE_OBJECT;
}
static guint
gtk_single_selection_get_n_items (GListModel *list)
{
GtkSingleSelection *self = GTK_SINGLE_SELECTION (list);
if (self->model == NULL)
return 0;
return g_list_model_get_n_items (self->model);
}
static gpointer
gtk_single_selection_get_item (GListModel *list,
guint position)
{
GtkSingleSelection *self = GTK_SINGLE_SELECTION (list);
if (self->model == NULL)
return NULL;
return g_list_model_get_item (self->model, position);
}
static void
gtk_single_selection_list_model_init (GListModelInterface *iface)
{
iface->get_item_type = gtk_single_selection_get_item_type;
iface->get_n_items = gtk_single_selection_get_n_items;
iface->get_item = gtk_single_selection_get_item;
}
static gboolean
gtk_single_selection_is_selected (GtkSelectionModel *model,
guint position)
{
GtkSingleSelection *self = GTK_SINGLE_SELECTION (model);
return self->selected == position;
}
static GtkBitset *
gtk_single_selection_get_selection_in_range (GtkSelectionModel *model,
guint position,
guint n_items)
{
GtkSingleSelection *self = GTK_SINGLE_SELECTION (model);
GtkBitset *result;
result = gtk_bitset_new_empty ();
if (self->selected != GTK_INVALID_LIST_POSITION)
gtk_bitset_add (result, self->selected);
return result;
}
static gboolean
gtk_single_selection_select_item (GtkSelectionModel *model,
guint position,
gboolean exclusive)
{
GtkSingleSelection *self = GTK_SINGLE_SELECTION (model);
/* XXX: Should we check that position < n_items here? */
gtk_single_selection_set_selected (self, position);
return TRUE;
}
static gboolean
gtk_single_selection_unselect_item (GtkSelectionModel *model,
guint position)
{
GtkSingleSelection *self = GTK_SINGLE_SELECTION (model);
if (!self->can_unselect)
return FALSE;
if (self->selected == position)
gtk_single_selection_set_selected (self, GTK_INVALID_LIST_POSITION);
return TRUE;
}
static void
gtk_single_selection_selection_model_init (GtkSelectionModelInterface *iface)
{
iface->is_selected = gtk_single_selection_is_selected;
iface->get_selection_in_range = gtk_single_selection_get_selection_in_range;
iface->select_item = gtk_single_selection_select_item;
iface->unselect_item = gtk_single_selection_unselect_item;
}
G_DEFINE_TYPE_EXTENDED (GtkSingleSelection, gtk_single_selection, G_TYPE_OBJECT, 0,
G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL,
gtk_single_selection_list_model_init)
G_IMPLEMENT_INTERFACE (GTK_TYPE_SELECTION_MODEL,
gtk_single_selection_selection_model_init))
static void
gtk_single_selection_items_changed_cb (GListModel *model,
guint position,
guint removed,
guint added,
GtkSingleSelection *self)
{
g_object_freeze_notify (G_OBJECT (self));
if (self->selected_item == NULL)
{
if (self->autoselect)
{
self->selected_item = g_list_model_get_item (self->model, 0);
if (self->selected_item)
{
self->selected = 0;
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED]);
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED_ITEM]);
}
}
}
else if (self->selected < position)
{
/* unchanged */
}
else if (self->selected >= position + removed)
{
self->selected += added - removed;
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED]);
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED_ITEM]);
}
else
{
guint i;
for (i = 0; i < added; i++)
{
gpointer item = g_list_model_get_item (model, position + i);
if (item == self->selected_item)
{
/* the item moved */
if (self->selected != position + i)
{
self->selected = position + i;
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED]);
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED_ITEM]);
}
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g_object_unref (item);
break;
}
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g_object_unref (item);
}
if (i == added)
{
/* the item really was deleted */
g_clear_object (&self->selected_item);
if (self->autoselect)
{
self->selected = position + (self->selected - position) * added / removed;
self->selected_item = g_list_model_get_item (self->model, self->selected);
if (self->selected_item == NULL)
{
if (position > 0)
{
self->selected = position - 1;
self->selected_item = g_list_model_get_item (self->model, self->selected);
g_assert (self->selected_item);
/* We pretend the newly selected item was part of the original model change.
* This way we get around inconsistent state (no item selected) during
* the items-changed emission. */
position--;
removed++;
added++;
}
else
self->selected = GTK_INVALID_LIST_POSITION;
}
else
{
if (self->selected == position + added)
{
/* We pretend the newly selected item was part of the original model change.
* This way we get around inconsistent state (no item selected) during
* the items-changed emission. */
removed++;
added++;
}
}
}
else
{
g_clear_object (&self->selected_item);
self->selected = GTK_INVALID_LIST_POSITION;
}
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED]);
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED_ITEM]);
}
}
g_list_model_items_changed (G_LIST_MODEL (self), position, removed, added);
g_object_thaw_notify (G_OBJECT (self));
}
static void
gtk_single_selection_clear_model (GtkSingleSelection *self)
{
if (self->model == NULL)
return;
g_signal_handlers_disconnect_by_func (self->model,
gtk_single_selection_items_changed_cb,
self);
g_clear_object (&self->model);
}
static void
gtk_single_selection_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkSingleSelection *self = GTK_SINGLE_SELECTION (object);
switch (prop_id)
{
case PROP_AUTOSELECT:
gtk_single_selection_set_autoselect (self, g_value_get_boolean (value));
break;
case PROP_CAN_UNSELECT:
gtk_single_selection_set_can_unselect (self, g_value_get_boolean (value));
break;
case PROP_MODEL:
gtk_single_selection_set_model (self, g_value_get_object (value));
break;
case PROP_SELECTED:
gtk_single_selection_set_selected (self, g_value_get_uint (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_single_selection_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkSingleSelection *self = GTK_SINGLE_SELECTION (object);
switch (prop_id)
{
case PROP_AUTOSELECT:
g_value_set_boolean (value, self->autoselect);
break;
case PROP_CAN_UNSELECT:
g_value_set_boolean (value, self->can_unselect);
break;
case PROP_MODEL:
g_value_set_object (value, self->model);
break;
case PROP_SELECTED:
g_value_set_uint (value, self->selected);
break;
case PROP_SELECTED_ITEM:
g_value_set_object (value, self->selected_item);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_single_selection_dispose (GObject *object)
{
GtkSingleSelection *self = GTK_SINGLE_SELECTION (object);
gtk_single_selection_clear_model (self);
self->selected = GTK_INVALID_LIST_POSITION;
g_clear_object (&self->selected_item);
G_OBJECT_CLASS (gtk_single_selection_parent_class)->dispose (object);
}
static void
gtk_single_selection_class_init (GtkSingleSelectionClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->get_property = gtk_single_selection_get_property;
gobject_class->set_property = gtk_single_selection_set_property;
gobject_class->dispose = gtk_single_selection_dispose;
/**
* GtkSingleSelection:autoselect:
*
* If the selection will always select an item
*/
properties[PROP_AUTOSELECT] =
g_param_spec_boolean ("autoselect",
P_("Autoselect"),
P_("If the selection will always select an item"),
TRUE,
G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
/**
* GtkSingleSelection:can-unselect:
*
* If unselecting the selected item is allowed
*/
properties[PROP_CAN_UNSELECT] =
g_param_spec_boolean ("can-unselect",
P_("Can unselect"),
P_("If unselecting the selected item is allowed"),
FALSE,
G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
/**
* GtkSingleSelection:selected:
*
* Position of the selected item
*/
properties[PROP_SELECTED] =
g_param_spec_uint ("selected",
P_("Selected"),
P_("Position of the selected item"),
0, G_MAXUINT, GTK_INVALID_LIST_POSITION,
G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
/**
* GtkSingleSelection:selected-item:
*
* The selected item
*/
properties[PROP_SELECTED_ITEM] =
g_param_spec_object ("selected-item",
P_("Selected Item"),
P_("The selected item"),
G_TYPE_OBJECT,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
/**
* GtkSingleSelection:model:
*
* The model being managed
*/
properties[PROP_MODEL] =
g_param_spec_object ("model",
P_("The model"),
P_("The model being managed"),
G_TYPE_LIST_MODEL,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
g_object_class_install_properties (gobject_class, N_PROPS, properties);
}
static void
gtk_single_selection_init (GtkSingleSelection *self)
{
self->selected = GTK_INVALID_LIST_POSITION;
self->autoselect = TRUE;
}
/**
* gtk_single_selection_new:
* @model: (transfer none): the #GListModel to manage
*
* Creates a new selection to handle @model.
*
* Returns: (transfer full) (type GtkSingleSelection): a new #GtkSingleSelection
**/
GtkSingleSelection *
gtk_single_selection_new (GListModel *model)
{
g_return_val_if_fail (G_IS_LIST_MODEL (model), NULL);
return g_object_new (GTK_TYPE_SINGLE_SELECTION,
"model", model,
NULL);
}
/**
* gtk_single_selection_get_model:
* @self: a #GtkSingleSelection
*
* Gets the model that @self is wrapping.
*
* Returns: (transfer none): The model being wrapped
**/
GListModel *
gtk_single_selection_get_model (GtkSingleSelection *self)
{
g_return_val_if_fail (GTK_IS_SINGLE_SELECTION (self), NULL);
return self->model;
}
/**
* gtk_single_selection_set_model:
* @self: a #GtkSingleSelection
* @model: (allow-none): A #GListModel to wrap
*
* Sets the model that @self should wrap. If @model is %NULL, @self
* will be empty.
**/
void
gtk_single_selection_set_model (GtkSingleSelection *self,
GListModel *model)
{
guint n_items_before;
g_return_if_fail (GTK_IS_SINGLE_SELECTION (self));
g_return_if_fail (model == NULL || G_IS_LIST_MODEL (model));
if (self->model == model)
return;
g_object_freeze_notify (G_OBJECT (self));
n_items_before = self->model ? g_list_model_get_n_items (self->model) : 0;
gtk_single_selection_clear_model (self);
if (model)
{
self->model = g_object_ref (model);
g_signal_connect (self->model, "items-changed",
G_CALLBACK (gtk_single_selection_items_changed_cb), self);
gtk_single_selection_items_changed_cb (self->model,
0,
n_items_before,
g_list_model_get_n_items (model),
self);
}
else
{
if (self->selected != GTK_INVALID_LIST_POSITION)
{
self->selected = GTK_INVALID_LIST_POSITION;
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED]);
}
if (self->selected_item)
{
g_clear_object (&self->selected_item);
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED_ITEM]);
}
g_list_model_items_changed (G_LIST_MODEL (self), 0, n_items_before, 0);
}
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_MODEL]);
g_object_thaw_notify (G_OBJECT (self));
}
/**
* gtk_single_selection_get_selected:
* @self: a #GtkSingleSelection
*
* Gets the position of the selected item. If no item is selected,
* #GTK_INVALID_LIST_POSITION is returned.
*
* Returns: The position of the selected item
**/
guint
gtk_single_selection_get_selected (GtkSingleSelection *self)
{
g_return_val_if_fail (GTK_IS_SINGLE_SELECTION (self), GTK_INVALID_LIST_POSITION);
return self->selected;
}
/**
* gtk_single_selection_set_selected:
* @self: a #GtkSingleSelection
* @position: the item to select or #GTK_INVALID_LIST_POSITION
*
* Selects the item at the given position. If the list does not have an item at
* @position or #GTK_INVALID_LIST_POSITION is given, the behavior depends on the
* value of the GtkSingleSelection:autoselect property: If it is set, no change
* will occur and the old item will stay selected. If it is unset, the selection
* will be unset and no item will be selected.
**/
void
gtk_single_selection_set_selected (GtkSingleSelection *self,
guint position)
{
gpointer new_selected = NULL;
guint old_position;
g_return_if_fail (GTK_IS_SINGLE_SELECTION (self));
if (self->selected == position)
return;
if (self->model)
new_selected = g_list_model_get_item (self->model, position);
if (new_selected == NULL)
position = GTK_INVALID_LIST_POSITION;
if (self->selected == position)
return;
old_position = self->selected;
self->selected = position;
g_clear_object (&self->selected_item);
self->selected_item = new_selected;
if (old_position == GTK_INVALID_LIST_POSITION)
gtk_selection_model_selection_changed (GTK_SELECTION_MODEL (self), position, 1);
else if (position == GTK_INVALID_LIST_POSITION)
gtk_selection_model_selection_changed (GTK_SELECTION_MODEL (self), old_position, 1);
else if (position < old_position)
gtk_selection_model_selection_changed (GTK_SELECTION_MODEL (self), position, old_position - position + 1);
else
gtk_selection_model_selection_changed (GTK_SELECTION_MODEL (self), old_position, position - old_position + 1);
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED]);
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SELECTED_ITEM]);
}
/**
* gtk_single_selection_get_selected_item:
* @self: a #GtkSingleSelection
*
* Gets the selected item. If no item is selected, %NULL is returned.
*
* Returns: (transfer none): The selected item
*/
gpointer
gtk_single_selection_get_selected_item (GtkSingleSelection *self)
{
g_return_val_if_fail (GTK_IS_SINGLE_SELECTION (self), NULL);
return self->selected_item;
}
/**
* gtk_single_selection_get_autoselect:
* @self: a #GtkSingleSelection
*
* Checks if autoselect has been enabled or disabled via
* gtk_single_selection_set_autoselect().
*
* Returns: %TRUE if autoselect is enabled
**/
gboolean
gtk_single_selection_get_autoselect (GtkSingleSelection *self)
{
g_return_val_if_fail (GTK_IS_SINGLE_SELECTION (self), TRUE);
return self->autoselect;
}
/**
* gtk_single_selection_set_autoselect:
* @self: a #GtkSingleSelection
* @autoselect: %TRUE to always select an item
*
* If @autoselect is %TRUE, @self will enforce that an item is always
* selected. It will select a new item when the currently selected
* item is deleted and it will disallow unselecting the current item.
**/
void
gtk_single_selection_set_autoselect (GtkSingleSelection *self,
gboolean autoselect)
{
g_return_if_fail (GTK_IS_SINGLE_SELECTION (self));
if (self->autoselect == autoselect)
return;
self->autoselect = autoselect;
g_object_freeze_notify (G_OBJECT (self));
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_AUTOSELECT]);
if (self->autoselect && !self->selected_item)
gtk_single_selection_set_selected (self, 0);
g_object_thaw_notify (G_OBJECT (self));
}
/**
* gtk_single_selection_get_can_unselect:
* @self: a #GtkSingleSelection
*
* If %TRUE, gtk_selection_model_unselect_item() is supported and allows
* unselecting the selected item.
*
* Returns: %TRUE to support unselecting
**/
gboolean
gtk_single_selection_get_can_unselect (GtkSingleSelection *self)
{
g_return_val_if_fail (GTK_IS_SINGLE_SELECTION (self), FALSE);
return self->can_unselect;
}
/**
* gtk_single_selection_set_can_unselect:
* @self: a #GtkSingleSelection
* @can_unselect: %TRUE to allow unselecting
*
* If %TRUE, unselecting the current item via
* gtk_selection_model_unselect_item() is supported.
*
* Note that setting GtkSingleSelection:autoselect will cause the
* unselecting to not work, so it practically makes no sense to set
* both at the same time the same time..
**/
void
gtk_single_selection_set_can_unselect (GtkSingleSelection *self,
gboolean can_unselect)
{
g_return_if_fail (GTK_IS_SINGLE_SELECTION (self));
if (self->can_unselect == can_unselect)
return;
self->can_unselect = can_unselect;
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_CAN_UNSELECT]);
}