gtk2/gtk/gtkwindowcontrols.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

687 lines
18 KiB
C

/*
* Copyright (c) 2020 Alexander Mikhaylenko <alexm@gnome.org>
*
* 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 "gtkwindowcontrols.h"
#include "gtkactionable.h"
#include "gtkboxlayout.h"
#include "gtkbutton.h"
#include "gtkenums.h"
#include "gtkicontheme.h"
#include "gtkimage.h"
#include "gtkintl.h"
#include "gtkprivate.h"
#include "gtkstylecontext.h"
#include "gtktypebuiltins.h"
#include "gtkwindowprivate.h"
/**
* SECTION:gtkwindowcontrols
* @Short_description: A widget displaying window buttons
* @Title: GtkWindowControls
* @See_also: #GtkHeaderBar
*
* GtkWindowControls shows window frame controls, such as minimize, maximize
* and close buttons, and the window icon.
*
* #GtkWindowControls only displays start or end side of the controls (see
* #GtkWindowControls:side), so it's intended to be always used in pair with
* another #GtkWindowControls using the opposite side, for example:
*
* |[
* <object class="GtkBox">
* <child>
* <object class="GtkWindowControls">
* <property name="side">start</property>
* </object>
* </child>
*
* ...
*
* <child>
* <object class="GtkWindowControls">
* <property name="side">end</property>
* </object>
* </child>
* </object>
* ]|
*
* # CSS nodes
*
* |[<!-- language="plain" -->
* windowcontrols
* ├── [image.icon]
* ├── [button.minimize]
* ├── [button.maximize]
* ╰── [button.close]
* ]|
*
* A #GtkWindowControls' CSS node is called windowcontrols. It contains
* subnodes corresponding to each title button. Which of the title buttons
* exist and where they are placed exactly depends on the desktop environment
* and #GtkWindowControls:decoration-layout value.
*
* When #GtkWindowControls:empty is %TRUE, it gets the .empty style class.
*/
struct _GtkWindowControls {
GtkWidget parent_instance;
GtkPackType side;
char *decoration_layout;
gboolean empty;
};
enum {
PROP_0,
PROP_SIDE,
PROP_DECORATION_LAYOUT,
PROP_EMPTY,
LAST_PROP
};
static GParamSpec *props[LAST_PROP] = { NULL, };
#define WINDOW_ICON_SIZE 16
G_DEFINE_TYPE (GtkWindowControls, gtk_window_controls, GTK_TYPE_WIDGET)
static char *
get_layout (GtkWindowControls *self)
{
GtkWidget *widget = GTK_WIDGET (self);
GtkWidget *toplevel;
char *layout_desc, *layout_half;
char **tokens;
toplevel = GTK_WIDGET (gtk_widget_get_root (widget));
if (!GTK_IS_WINDOW (toplevel))
return NULL;
if (self->decoration_layout)
layout_desc = g_strdup (self->decoration_layout);
else
g_object_get (gtk_widget_get_settings (widget),
"gtk-decoration-layout", &layout_desc,
NULL);
tokens = g_strsplit (layout_desc, ":", 2);
switch (self->side)
{
case GTK_PACK_START:
layout_half = g_strdup (tokens[0]);
break;
case GTK_PACK_END:
layout_half = g_strdup (tokens[1]);
break;
default:
g_assert_not_reached ();
}
g_free (layout_desc);
g_strfreev (tokens);
return layout_half;
}
static GdkPaintable *
get_default_icon (GtkWidget *widget)
{
GdkDisplay *display = gtk_widget_get_display (widget);
GtkIconPaintable *info;
int scale = gtk_widget_get_scale_factor (widget);
info = gtk_icon_theme_lookup_icon (gtk_icon_theme_get_for_display (display),
gtk_window_get_default_icon_name (),
NULL,
WINDOW_ICON_SIZE,
scale,
gtk_widget_get_direction (widget),
0);
return GDK_PAINTABLE (info);
}
static gboolean
update_window_icon (GtkWindow *window,
GtkWidget *icon)
{
GdkPaintable *paintable;
if (window)
paintable = gtk_window_get_icon_for_size (window, WINDOW_ICON_SIZE);
else
paintable = get_default_icon (icon);
if (paintable)
{
gtk_image_set_from_paintable (GTK_IMAGE (icon), paintable);
g_object_unref (paintable);
gtk_widget_show (icon);
return TRUE;
}
return FALSE;
}
static void
set_empty (GtkWindowControls *self,
gboolean empty)
{
if (empty == self->empty)
return;
self->empty = empty;
if (empty)
gtk_widget_add_css_class (GTK_WIDGET (self), "empty");
else
gtk_widget_remove_css_class (GTK_WIDGET (self), "empty");
g_object_notify_by_pspec (G_OBJECT (self), props[PROP_EMPTY]);
}
static void
clear_controls (GtkWindowControls *self)
{
GtkWidget *child = gtk_widget_get_first_child (GTK_WIDGET (self));
while (child)
{
GtkWidget *next = gtk_widget_get_next_sibling (child);
gtk_widget_unparent (child);
child = next;
}
}
static void
update_window_buttons (GtkWindowControls *self)
{
GtkWidget *widget = GTK_WIDGET (self);
GtkWidget *toplevel;
char *layout;
char **tokens;
int i;
gboolean is_sovereign_window;
gboolean maximized;
gboolean resizable;
gboolean deletable;
gboolean empty = TRUE;
GtkWindow *window = NULL;
toplevel = GTK_WIDGET (gtk_widget_get_root (widget));
if (!GTK_IS_WINDOW (toplevel))
{
set_empty (self, TRUE);
return;
}
clear_controls (self);
if (GTK_IS_WINDOW (toplevel))
{
window = GTK_WINDOW (toplevel);
is_sovereign_window = !gtk_window_get_modal (window) &&
gtk_window_get_transient_for (window) == NULL;
maximized = gtk_window_is_maximized (window);
resizable = gtk_window_get_resizable (window);
deletable = gtk_window_get_deletable (window);
}
else
{
is_sovereign_window = TRUE;
maximized = FALSE;
resizable = TRUE;
deletable = TRUE;
}
layout = get_layout (self);
if (!layout)
{
set_empty (self, TRUE);
return;
}
tokens = g_strsplit (layout, ",", -1);
for (i = 0; tokens[i]; i++)
{
GtkWidget *button = NULL;
GtkWidget *image = NULL;
if (strcmp (tokens[i], "icon") == 0 &&
is_sovereign_window)
{
button = gtk_image_new ();
gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
gtk_widget_add_css_class (button, "icon");
if (!update_window_icon (window, button))
{
g_object_ref_sink (button);
g_object_unref (button);
button = NULL;
}
}
else if (strcmp (tokens[i], "minimize") == 0 &&
is_sovereign_window)
{
button = gtk_button_new ();
gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
gtk_widget_add_css_class (button, "minimize");
image = gtk_image_new_from_icon_name ("window-minimize-symbolic");
g_object_set (image, "use-fallback", TRUE, NULL);
gtk_button_set_child (GTK_BUTTON (button), image);
gtk_widget_set_can_focus (button, FALSE);
gtk_actionable_set_action_name (GTK_ACTIONABLE (button),
"window.minimize");
}
else if (strcmp (tokens[i], "maximize") == 0 &&
resizable &&
is_sovereign_window)
{
const char *icon_name;
icon_name = maximized ? "window-restore-symbolic" : "window-maximize-symbolic";
button = gtk_button_new ();
gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
gtk_widget_add_css_class (button, "maximize");
image = gtk_image_new_from_icon_name (icon_name);
g_object_set (image, "use-fallback", TRUE, NULL);
gtk_button_set_child (GTK_BUTTON (button), image);
gtk_widget_set_can_focus (button, FALSE);
gtk_actionable_set_action_name (GTK_ACTIONABLE (button),
"window.toggle-maximized");
}
else if (strcmp (tokens[i], "close") == 0 &&
deletable)
{
button = gtk_button_new ();
gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
image = gtk_image_new_from_icon_name ("window-close-symbolic");
gtk_widget_add_css_class (button, "close");
g_object_set (image, "use-fallback", TRUE, NULL);
gtk_button_set_child (GTK_BUTTON (button), image);
gtk_widget_set_can_focus (button, FALSE);
gtk_actionable_set_action_name (GTK_ACTIONABLE (button),
"window.close");
}
if (button)
{
gtk_widget_set_parent (button, widget);
empty = FALSE;
}
}
g_free (layout);
g_strfreev (tokens);
set_empty (self, empty);
}
static void
window_notify_cb (GtkWindowControls *self,
GParamSpec *pspec,
GtkWindow *window)
{
if (pspec->name == I_("deletable") ||
pspec->name == I_("icon-name") ||
pspec->name == I_("is-maximized") ||
pspec->name == I_("modal") ||
pspec->name == I_("resizable") ||
pspec->name == I_("scale-factor") ||
pspec->name == I_("transient-for"))
update_window_buttons (self);
}
static void
gtk_window_controls_root (GtkWidget *widget)
{
GtkSettings *settings;
GtkWidget *root;
GTK_WIDGET_CLASS (gtk_window_controls_parent_class)->root (widget);
settings = gtk_widget_get_settings (widget);
g_signal_connect_swapped (settings, "notify::gtk-decoration-layout",
G_CALLBACK (update_window_buttons), widget);
root = GTK_WIDGET (gtk_widget_get_root (widget));
if (GTK_IS_WINDOW (root))
g_signal_connect_swapped (root, "notify",
G_CALLBACK (window_notify_cb), widget);
update_window_buttons (GTK_WINDOW_CONTROLS (widget));
}
static void
gtk_window_controls_unroot (GtkWidget *widget)
{
GtkSettings *settings;
settings = gtk_widget_get_settings (widget);
g_signal_handlers_disconnect_by_func (settings, update_window_buttons, widget);
g_signal_handlers_disconnect_by_func (gtk_widget_get_root (widget), window_notify_cb, widget);
GTK_WIDGET_CLASS (gtk_window_controls_parent_class)->unroot (widget);
}
static void
gtk_window_controls_dispose (GObject *object)
{
GtkWindowControls *self = GTK_WINDOW_CONTROLS (object);
clear_controls (self);
G_OBJECT_CLASS (gtk_window_controls_parent_class)->dispose (object);
}
static void
gtk_window_controls_finalize (GObject *object)
{
GtkWindowControls *self = GTK_WINDOW_CONTROLS (object);
g_free (self->decoration_layout);
G_OBJECT_CLASS (gtk_window_controls_parent_class)->finalize (object);
}
static void
gtk_window_controls_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkWindowControls *self = GTK_WINDOW_CONTROLS (object);
switch (prop_id)
{
case PROP_SIDE:
g_value_set_enum (value, gtk_window_controls_get_side (self));
break;
case PROP_DECORATION_LAYOUT:
g_value_set_string (value, gtk_window_controls_get_decoration_layout (self));
break;
case PROP_EMPTY:
g_value_set_boolean (value, gtk_window_controls_get_empty (self));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_window_controls_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkWindowControls *self = GTK_WINDOW_CONTROLS (object);
switch (prop_id)
{
case PROP_SIDE:
gtk_window_controls_set_side (self, g_value_get_enum (value));
break;
case PROP_DECORATION_LAYOUT:
gtk_window_controls_set_decoration_layout (self, g_value_get_string (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_window_controls_class_init (GtkWindowControlsClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
object_class->dispose = gtk_window_controls_dispose;
object_class->finalize = gtk_window_controls_finalize;
object_class->get_property = gtk_window_controls_get_property;
object_class->set_property = gtk_window_controls_set_property;
widget_class->root = gtk_window_controls_root;
widget_class->unroot = gtk_window_controls_unroot;
/**
* GtkWindowControls:side:
*
* Whether the widget shows start or end side of the decoration layout.
*
* See gtk_window_controls_set_decoration_layout().
*/
props[PROP_SIDE] =
g_param_spec_enum ("side",
P_("Side"),
P_("Whether the widget shows start or end portion of the decoration layout"),
GTK_TYPE_PACK_TYPE,
GTK_PACK_START,
GTK_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkWindowControls:decoration-layout:
*
* The decoration layout for window buttons. If this property is not set,
* the #GtkSettings:gtk-decoration-layout setting is used.
*
* See gtk_window_controls_set_decoration_layout() for information
* about the format of this string.
*/
props[PROP_DECORATION_LAYOUT] =
g_param_spec_string ("decoration-layout",
P_("Decoration Layout"),
P_("The layout for window decorations"),
NULL,
GTK_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
/**
* GtkWindowControls:empty:
*
* Whether the widget has any window buttons.
*/
props[PROP_EMPTY] =
g_param_spec_boolean ("empty",
P_("Empty"),
P_("Whether the widget has any window buttons"),
TRUE,
GTK_PARAM_READABLE | 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_BOX_LAYOUT);
gtk_widget_class_set_css_name (widget_class, I_("windowcontrols"));
}
static void
gtk_window_controls_init (GtkWindowControls *self)
{
self->decoration_layout = NULL;
self->side = GTK_PACK_START;
self->empty = TRUE;
gtk_widget_add_css_class (GTK_WIDGET (self), "empty");
gtk_widget_add_css_class (GTK_WIDGET (self), "start");
gtk_widget_set_can_focus (GTK_WIDGET (self), FALSE);
}
/**
* gtk_window_controls_new:
* @side: the side
*
* Creates a new #GtkWindowControls.
*
* Returns: a new #GtkWindowControls.
**/
GtkWidget *
gtk_window_controls_new (GtkPackType side)
{
return g_object_new (GTK_TYPE_WINDOW_CONTROLS,
"side", side,
NULL);
}
/**
* gtk_window_controls_get_side:
* @self: a #GtkWindowControls
*
* Gets the side set with gtk_window_controls_set_side().
*
* Returns: the side
*/
GtkPackType
gtk_window_controls_get_side (GtkWindowControls *self)
{
g_return_val_if_fail (GTK_IS_WINDOW_CONTROLS (self), GTK_PACK_START);
return self->side;
}
/**
* gtk_window_controls_set_side:
* @self: a #GtkWindowControls
* @side: a side
*
* Sets the side for @self, determining which part of decoration layout it uses.
*
* See gtk_window_controls_set_decoration_layout()
*/
void
gtk_window_controls_set_side (GtkWindowControls *self,
GtkPackType side)
{
g_return_if_fail (GTK_IS_WINDOW_CONTROLS (self));
if (self->side == side)
return;
self->side = side;
switch (side)
{
case GTK_PACK_START:
gtk_widget_add_css_class (GTK_WIDGET (self), "start");
gtk_widget_remove_css_class (GTK_WIDGET (self), "end");
break;
case GTK_PACK_END:
gtk_widget_add_css_class (GTK_WIDGET (self), "end");
gtk_widget_remove_css_class (GTK_WIDGET (self), "start");
break;
default:
g_warning ("Unexpected side: %d", side);
break;
}
update_window_buttons (self);
g_object_notify_by_pspec (G_OBJECT (self), props[PROP_SIDE]);
}
/**
* gtk_window_controls_get_decoration_layout:
* @self: a #GtkWindowControls
*
* Gets the decoration layout set with
* gtk_window_controls_set_decoration_layout().
*
* Returns: the decoration layout
*/
const char *
gtk_window_controls_get_decoration_layout (GtkWindowControls *self)
{
g_return_val_if_fail (GTK_IS_WINDOW_CONTROLS (self), NULL);
return self->decoration_layout;
}
/**
* gtk_window_controls_set_decoration_layout:
* @self: a #GtkWindowControls
* @layout: (allow-none): a decoration layout, or %NULL to
* unset the layout
*
* Sets the decoration layout for the title buttons, overriding
* the #GtkSettings:gtk-decoration-layout setting.
*
* The format of the string is button names, separated by commas.
* A colon separates the buttons that should appear on the left
* from those on the right. Recognized button names are minimize,
* maximize, close and icon (the window icon).
*
* For example, “icon:minimize,maximize,close” specifies a icon
* on the left, and minimize, maximize and close buttons on the right.
*
* If #GtkWindowControls:side value is @GTK_PACK_START, @self will
* display the part before the colon, otherwise after that.
*/
void
gtk_window_controls_set_decoration_layout (GtkWindowControls *self,
const char *layout)
{
g_return_if_fail (GTK_IS_WINDOW_CONTROLS (self));
g_free (self->decoration_layout);
self->decoration_layout = g_strdup (layout);
update_window_buttons (self);
g_object_notify_by_pspec (G_OBJECT (self), props[PROP_DECORATION_LAYOUT]);
}
/**
* gtk_window_controls_get_empty:
* @self: a #GtkWindowControls
*
* Gets whether the widget has any window buttons.
*
* Returns: %TRUE if the widget has window buttons, otherwise %FALSE
*/
gboolean
gtk_window_controls_get_empty (GtkWindowControls *self)
{
g_return_val_if_fail (GTK_IS_WINDOW_CONTROLS (self), FALSE);
return self->empty;
}