gtk2/gtk/gtkactionbar.c
Emmanuele Bassi c63087a563 Remove ATK
To build a better world sometimes means having to tear the old one down.
        -- Alexander Pierce, "Captain America: The Winter Soldier"

ATK served us well for nearly 20 years, but the world has changed, and
GTK has changed with it. Now ATK is mostly a hindrance towards improving
the accessibility stack:

 - it maps to a very specific implementation, AT-SPI, which is Linux and
   Unix specific
 - it requires implementing the same functionality in three different
   layers of the stack: AT-SPI, ATK, and GTK
 - only GTK uses it; every other Linux and Unix toolkit and application
   talks to AT-SPI directly, including assistive technologies

Sadly, we cannot incrementally port GTK to a new accessibility stack;
since ATK insulates us entirely from the underlying implementation, we
cannot replace it piecemeal. Instead, we're going to remove everything
and then incrementally build on a clean slate:

 - add an "accessible" interface, implemented by GTK objects directly,
   which describe the accessible role and state changes for every UI
   element
 - add an "assistive technology context" to proxy a native accessibility
   API, and assign it to every widget
 - implement the AT context depending on the platform

For more information, see: https://gitlab.gnome.org/GNOME/gtk/-/issues/2833
2020-07-26 20:31:14 +01:00

350 lines
10 KiB
C

/*
* Copyright (c) 2013 - 2014 Red Hat, Inc.
*
* This program 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 of the License, or (at your
* option) any later version.
*
* This program 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 program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include "config.h"
#include "gtkactionbar.h"
#include "gtkintl.h"
#include "gtkbuildable.h"
#include "gtktypebuiltins.h"
#include "gtkbox.h"
#include "gtkrevealer.h"
#include "gtkwidgetprivate.h"
#include "gtkprivate.h"
#include "gtkcenterbox.h"
#include "gtkbinlayout.h"
#include <string.h>
/**
* SECTION:gtkactionbar
* @Short_description: A full width bar for presenting contextual actions
* @Title: GtkActionBar
* @See_also: #GtkBox
*
* GtkActionBar is designed to present contextual actions. It is
* expected to be displayed below the content and expand horizontally
* to fill the area.
*
* It allows placing children at the start or the end. In addition, it
* contains an internal centered box which is centered with respect to
* the full width of the box, even if the children at either side take
* up different amounts of space.
*
* # CSS nodes
*
* GtkActionBar has a single CSS node with name actionbar.
*/
typedef struct _GtkActionBarClass GtkActionBarClass;
struct _GtkActionBar
{
GtkWidget parent;
GtkWidget *center_box;
GtkWidget *start_box;
GtkWidget *end_box;
GtkWidget *revealer;
};
struct _GtkActionBarClass
{
GtkWidgetClass parent_class;
};
enum {
PROP_0,
PROP_REVEALED,
LAST_PROP
};
static GParamSpec *props[LAST_PROP] = { NULL, };
static void gtk_action_bar_buildable_interface_init (GtkBuildableIface *iface);
G_DEFINE_TYPE_WITH_CODE (GtkActionBar, gtk_action_bar, GTK_TYPE_WIDGET,
G_IMPLEMENT_INTERFACE (GTK_TYPE_BUILDABLE,
gtk_action_bar_buildable_interface_init))
static void
gtk_action_bar_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkActionBar *self = GTK_ACTION_BAR (object);
switch (prop_id)
{
case PROP_REVEALED:
gtk_action_bar_set_revealed (self, g_value_get_boolean (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_action_bar_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkActionBar *self = GTK_ACTION_BAR (object);
switch (prop_id)
{
case PROP_REVEALED:
g_value_set_boolean (value, gtk_action_bar_get_revealed (self));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_action_bar_dispose (GObject *object)
{
GtkActionBar *self = GTK_ACTION_BAR (object);
g_clear_pointer (&self->revealer, gtk_widget_unparent);
self->center_box = NULL;
self->start_box = NULL;
self->end_box = NULL;
G_OBJECT_CLASS (gtk_action_bar_parent_class)->dispose (object);
}
static void
gtk_action_bar_class_init (GtkActionBarClass *klass)
{
GObjectClass *object_class;
GtkWidgetClass *widget_class;
object_class = G_OBJECT_CLASS (klass);
widget_class = GTK_WIDGET_CLASS (klass);
object_class->set_property = gtk_action_bar_set_property;
object_class->get_property = gtk_action_bar_get_property;
object_class->dispose = gtk_action_bar_dispose;
widget_class->focus = gtk_widget_focus_child;
props[PROP_REVEALED] =
g_param_spec_boolean ("revealed",
P_("Reveal"),
P_("Controls whether the action bar shows its contents or not"),
TRUE,
GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
g_object_class_install_properties (object_class, LAST_PROP, props);
gtk_widget_class_set_layout_manager_type (widget_class, GTK_TYPE_BIN_LAYOUT);
gtk_widget_class_set_css_name (widget_class, I_("actionbar"));
}
static void
gtk_action_bar_init (GtkActionBar *self)
{
GtkWidget *widget = GTK_WIDGET (self);
self->revealer = gtk_revealer_new ();
gtk_widget_set_parent (self->revealer, widget);
gtk_revealer_set_reveal_child (GTK_REVEALER (self->revealer), TRUE);
gtk_revealer_set_transition_type (GTK_REVEALER (self->revealer), GTK_REVEALER_TRANSITION_TYPE_SLIDE_UP);
self->start_box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
self->end_box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
self->center_box = gtk_center_box_new ();
gtk_center_box_set_start_widget (GTK_CENTER_BOX (self->center_box), self->start_box);
gtk_center_box_set_end_widget (GTK_CENTER_BOX (self->center_box), self->end_box);
gtk_revealer_set_child (GTK_REVEALER (self->revealer), self->center_box);
}
static GtkBuildableIface *parent_buildable_iface;
static void
gtk_action_bar_buildable_add_child (GtkBuildable *buildable,
GtkBuilder *builder,
GObject *child,
const char *type)
{
GtkActionBar *self = GTK_ACTION_BAR (buildable);
if (g_strcmp0 (type, "start") == 0)
gtk_action_bar_pack_start (self, GTK_WIDGET (child));
else if (g_strcmp0 (type, "center") == 0)
gtk_action_bar_set_center_widget (self, GTK_WIDGET (child));
else if (g_strcmp0 (type, "end") == 0)
gtk_action_bar_pack_end (self, GTK_WIDGET (child));
else if (type == NULL && GTK_IS_WIDGET (child))
gtk_action_bar_pack_start (self, GTK_WIDGET (child));
else
parent_buildable_iface->add_child (buildable, builder, child, type);
}
static void
gtk_action_bar_buildable_interface_init (GtkBuildableIface *iface)
{
parent_buildable_iface = g_type_interface_peek_parent (iface);
iface->add_child = gtk_action_bar_buildable_add_child;
}
/**
* gtk_action_bar_pack_start:
* @action_bar: A #GtkActionBar
* @child: the #GtkWidget to be added to @action_bar
*
* Adds @child to @action_bar, packed with reference to the
* start of the @action_bar.
*/
void
gtk_action_bar_pack_start (GtkActionBar *action_bar,
GtkWidget *child)
{
gtk_box_append (GTK_BOX (action_bar->start_box), child);
}
/**
* gtk_action_bar_pack_end:
* @action_bar: A #GtkActionBar
* @child: the #GtkWidget to be added to @action_bar
*
* Adds @child to @action_bar, packed with reference to the
* end of the @action_bar.
*/
void
gtk_action_bar_pack_end (GtkActionBar *action_bar,
GtkWidget *child)
{
gtk_box_insert_child_after (GTK_BOX (action_bar->end_box), child, NULL);
}
/**
* gtk_action_bar_remove:
* @action_bar: a #GtkActionBar
* @child: the #GtkWidget to be removed
*
* Removes a child from @action_bar.
*/
void
gtk_action_bar_remove (GtkActionBar *action_bar,
GtkWidget *child)
{
if (gtk_widget_get_parent (child) == action_bar->start_box)
gtk_box_remove (GTK_BOX (action_bar->start_box), child);
else if (gtk_widget_get_parent (child) == action_bar->end_box)
gtk_box_remove (GTK_BOX (action_bar->end_box), child);
else if (child == gtk_center_box_get_center_widget (GTK_CENTER_BOX (action_bar->center_box)))
gtk_center_box_set_center_widget (GTK_CENTER_BOX (action_bar->center_box), NULL);
else
g_warning ("Can't remove non-child %s %p from GtkActionBar %p",
G_OBJECT_TYPE_NAME (child), child, action_bar);
}
/**
* gtk_action_bar_set_center_widget:
* @action_bar: a #GtkActionBar
* @center_widget: (allow-none): a widget to use for the center
*
* Sets the center widget for the #GtkActionBar.
*/
void
gtk_action_bar_set_center_widget (GtkActionBar *action_bar,
GtkWidget *center_widget)
{
gtk_center_box_set_center_widget (GTK_CENTER_BOX (action_bar->center_box), center_widget);
}
/**
* gtk_action_bar_get_center_widget:
* @action_bar: a #GtkActionBar
*
* Retrieves the center bar widget of the bar.
*
* Returns: (transfer none) (nullable): the center #GtkWidget or %NULL.
*/
GtkWidget *
gtk_action_bar_get_center_widget (GtkActionBar *action_bar)
{
g_return_val_if_fail (GTK_IS_ACTION_BAR (action_bar), NULL);
return gtk_center_box_get_center_widget (GTK_CENTER_BOX (action_bar->center_box));
}
/**
* gtk_action_bar_new:
*
* Creates a new #GtkActionBar widget.
*
* Returns: a new #GtkActionBar
*/
GtkWidget *
gtk_action_bar_new (void)
{
return GTK_WIDGET (g_object_new (GTK_TYPE_ACTION_BAR, NULL));
}
/**
* gtk_action_bar_set_revealed:
* @action_bar: a #GtkActionBar
* @revealed: The new value of the property
*
* Sets the #GtkActionBar:revealed property to @revealed. Changing this will
* make @action_bar reveal (%TRUE) or conceal (%FALSE) itself via a sliding
* transition.
*
* Note: this does not show or hide @action_bar in the #GtkWidget:visible sense,
* so revealing has no effect if #GtkWidget:visible is %FALSE.
*/
void
gtk_action_bar_set_revealed (GtkActionBar *action_bar,
gboolean revealed)
{
g_return_if_fail (GTK_IS_ACTION_BAR (action_bar));
if (revealed == gtk_revealer_get_reveal_child (GTK_REVEALER (action_bar->revealer)))
return;
gtk_revealer_set_reveal_child (GTK_REVEALER (action_bar->revealer), revealed);
g_object_notify_by_pspec (G_OBJECT (action_bar), props[PROP_REVEALED]);
}
/**
* gtk_action_bar_get_revealed:
* @action_bar: a #GtkActionBar
*
* Gets the value of the #GtkActionBar:revealed property.
*
* Returns: the current value of the #GtkActionBar:revealed property.
*/
gboolean
gtk_action_bar_get_revealed (GtkActionBar *action_bar)
{
g_return_val_if_fail (GTK_IS_ACTION_BAR (action_bar), FALSE);
return gtk_revealer_get_reveal_child (GTK_REVEALER (action_bar->revealer));
}