path: root/gtk/gtkroot.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>
 */

#include "config.h"

#include "gtkrootprivate.h"
#include "gtkbud.h"
#include "gtkcssnodeprivate.h"
#include "gtkwidgetprivate.h"
#include "gdk/gdk-private.h"
#include "gtkprivate.h"
#include "gtkintl.h"

/**
 * SECTION:gtkroot
 * @Title: GtkRoot
 * @Short_description: Interface for root widgets
 * @See_also: #GtkWindow
 *
 * #GtkRoot is the interface implemented by all widgets that can act as a toplevel
 * widget to a hierarchy of widgets. The root widget takes care of providing the
 * connection to the windowing system and manages layout, drawing and event delivery
 * for its widget hierarchy.
 *
 * The obvious example of a #GtkRoot is #GtkWindow.
 */

G_DEFINE_INTERFACE_WITH_CODE (GtkRoot, gtk_root, GTK_TYPE_WIDGET,
                              g_type_interface_add_prerequisite (g_define_type_id, GTK_TYPE_BUD))

static GdkDisplay *
gtk_root_default_get_display (GtkRoot *self)
{
  return gdk_display_get_default ();
}

static void
gtk_root_default_add_mnemonic (GtkRoot   *self,
                               guint      keyval,
                               GtkWidget *target)
{
}

static void
gtk_root_default_remove_mnemonic (GtkRoot   *self,
                                  guint      keyval,
                                  GtkWidget *target)
{
}

static gboolean
gtk_root_default_activate_key (GtkRoot     *self,
                           GdkEventKey *event)
{
  return FALSE;
}

static void
gtk_root_default_update_pointer_focus (GtkRoot          *root,
                                       GdkDevice        *device,
                                       GdkEventSequence *sequence,
                                       GtkWidget        *target,
                                       double            x,
                                       double            y)
{
}

static void
gtk_root_default_update_pointer_focus_on_state_change (GtkRoot   *root,
                                                       GtkWidget *widget)
{
}

static GtkWidget *
gtk_root_default_lookup_pointer_focus (GtkRoot          *root,
                                       GdkDevice        *device,
                                       GdkEventSequence *sequence)
{
  return NULL;
}

static void
gtk_root_default_init (GtkRootInterface *iface)
{
  iface->get_display = gtk_root_default_get_display;
  iface->add_mnemonic = gtk_root_default_add_mnemonic;
  iface->remove_mnemonic = gtk_root_default_remove_mnemonic;
  iface->activate_key = gtk_root_default_activate_key;
  iface->update_pointer_focus = gtk_root_default_update_pointer_focus;
  iface->update_pointer_focus_on_state_change = gtk_root_default_update_pointer_focus_on_state_change;
  iface->lookup_pointer_focus = gtk_root_default_lookup_pointer_focus;

  g_object_interface_install_property (iface,
      g_param_spec_object ("focus-widget",
                           P_("Focus widget"),
                           P_("The focus widget"),
                           GTK_TYPE_WIDGET,
                           GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY));
}

GdkDisplay *
gtk_root_get_display (GtkRoot *self)
{
  GtkRootInterface *iface;

  g_return_val_if_fail (GTK_IS_ROOT (self), NULL);

  iface = GTK_ROOT_GET_IFACE (self);
  return iface->get_display (self);
}

/**
 * gtk_root_set_focus:
 * @self: a #GtkRoot
 * @focus: (allow-none): widget to be the new focus widget, or %NULL
 *    to unset the focus widget
 *
 * If @focus is not the current focus widget, and is focusable, sets
 * it as the focus widget for the root. If @focus is %NULL, unsets
 * the focus widget for the root.
 *
 * To set the focus to a particular widget in the root, it is usually
 * more convenient to use gtk_widget_grab_focus() instead of this function.
 */
void
gtk_root_set_focus (GtkRoot   *self,
                    GtkWidget *focus)
{
  g_return_if_fail (GTK_IS_ROOT (self));
  g_return_if_fail (focus == NULL || GTK_IS_WIDGET (focus));

  g_object_set (self, "focus-widget", focus, NULL);
}

/**
 * gtk_root_get_focus:
 * @self: a #GtkRoot
 *
 * Retrieves the current focused widget within the root.
 *
 * Note that this is the widget that would have the focus
 * if the root is active; if the root is not focused then
 * `gtk_widget_has_focus (widget)` will be %FALSE for the
 * widget.
 *
 * Returns: (nullable) (transfer none): the currently focused widget,
 *    or %NULL if there is none.
 */
GtkWidget *
gtk_root_get_focus (GtkRoot *self)
{
  GtkWidget *focus;

  g_return_val_if_fail (GTK_IS_ROOT (self), NULL);

  g_object_get (self, "focus-widget", &focus, NULL);

  if (focus)
    g_object_unref (focus);

  return focus;
}

/**
 * gtk_root_activate_focus:
 * @self: a #GtkRoot
 *
 * Activates the current focused widget within the root.
 *
 * Returns: %TRUE if a widget got activated.
 **/
gboolean
gtk_root_activate_focus (GtkRoot *self)
{
  GtkWidget *focus_widget;

  g_return_val_if_fail (GTK_IS_ROOT (self), FALSE);

  focus_widget = gtk_root_get_focus (self);

  if (focus_widget && gtk_widget_is_sensitive (focus_widget))
    return gtk_widget_activate (focus_widget);

  return FALSE;
}

guint
gtk_root_install_properties (GObjectClass *object_class,
                             guint         first_prop)
{
  g_object_class_override_property (object_class, first_prop + GTK_ROOT_PROP_FOCUS_WIDGET, "focus-widget");
  return GTK_ROOT_NUM_PROPERTIES;
}

static gboolean
gtk_root_get_restyle_pending (GtkRoot *root)
{
  return GPOINTER_TO_INT (g_object_get_data (G_OBJECT (root), "restyle-pending"));
}

static void
gtk_root_set_restyle_pending (GtkRoot  *root,
                              gboolean  pending)
{
  g_object_set_data (G_OBJECT (root), "restyle-pending", GINT_TO_POINTER (pending));
}

static gboolean
gtk_root_needs_layout_phase (GtkRoot *root)
{
  return gtk_root_get_restyle_pending (root) ||
         gtk_widget_needs_allocate (GTK_WIDGET (root));
}

static void
gtk_root_do_layout_phase (GdkFrameClock *clock,
                          GtkRoot       *root)
{
  /* We validate the style contexts in a single loop before even trying
   * to handle resizes instead of doing validations inline.
   * This is mostly necessary for compatibility reasons with old code,
   * because both style_updated and size_allocate functions often change
   * styles and so could cause infinite loops in this function.
   *
   * It's important to note that even an invalid style context returns
   * sane values. So the result of an invalid style context will never be
   * a program crash, but only a wrong layout or rendering.
   */

  if (gtk_root_get_restyle_pending (root))
    {
      gtk_root_set_restyle_pending (root, FALSE);
      gtk_css_node_validate (gtk_widget_get_css_node (GTK_WIDGET (root)));
    }

  /* we may be invoked with a container_resize_queue of NULL, because
   * queue_resize could have been adding an extra idle function while
   * the queue still got processed. we better just ignore such case
   * than trying to explicitly work around them with some extra flags,
   * since it doesn't cause any actual harm.
   */
  if (gtk_widget_needs_allocate (GTK_WIDGET (root)))
    gtk_bud_check_resize (GTK_BUD (root));

  if (!gtk_root_needs_layout_phase (root))
    gtk_root_stop_layout_phase (root);
  else
    gdk_frame_clock_request_phase (clock, GDK_FRAME_CLOCK_PHASE_LAYOUT);
}

void
gtk_root_start_layout_phase (GtkRoot *root)
{
  GdkFrameClock *clock;
  guint resize_handler;

  resize_handler = GPOINTER_TO_UINT (g_object_get_data (G_OBJECT (root), "resize-handler"));
  if (resize_handler != 0)
    return;

  if (!gtk_root_needs_layout_phase (root))
    return;

  clock = gtk_widget_get_frame_clock (GTK_WIDGET (root));
  if (clock == NULL)
    return;

  resize_handler = g_signal_connect (clock, "layout", G_CALLBACK (gtk_root_do_layout_phase), root);
  g_object_set_data (G_OBJECT (root), "resize-handler", GUINT_TO_POINTER (resize_handler));
  gdk_frame_clock_request_phase (clock, GDK_FRAME_CLOCK_PHASE_LAYOUT);
}

void
gtk_root_stop_layout_phase (GtkRoot *root)
{
  guint resize_handler;

  resize_handler = GPOINTER_TO_UINT (g_object_get_data (G_OBJECT (root), "resize-handler"));
  if (resize_handler == 0)
    return;

  g_signal_handler_disconnect (gtk_widget_get_frame_clock (GTK_WIDGET (root)), resize_handler);
  g_object_set_data (G_OBJECT (root), "resize-handler", NULL);
}

void
gtk_root_queue_restyle (GtkRoot *root)
{
  g_return_if_fail (GTK_ROOT (root));

  if (gtk_root_get_restyle_pending (root))
    return;

  gtk_root_set_restyle_pending (root, TRUE);
  gtk_root_start_layout_phase (root);
}

/**
 * gtk_root_add_mnemonic:
 * @root: a #GtkRoot
 * @keyval: the mnemonic
 * @target: the widget that gets activated by the mnemonic
 *
 * Adds a mnemonic to this root.
 */
void
gtk_root_add_mnemonic (GtkRoot   *root,
                       guint      keyval,
                       GtkWidget *target)
{
  g_return_if_fail (GTK_ROOT (root));

  GTK_ROOT_GET_IFACE (root)->add_mnemonic (root, keyval, target);
}

/**
 * gtk_root_remove_mnemonic:
 * @root: a #GtkRoot
 * @keyval: the mnemonic
 * @target: the widget that gets activated by the mnemonic
 *
 * Removes a mnemonic from this root.
 */
void
gtk_root_remove_mnemonic (GtkRoot   *root,
                          guint      keyval,
                          GtkWidget *target)
{
  g_return_if_fail (GTK_ROOT (root));

  GTK_ROOT_GET_IFACE (root)->remove_mnemonic (root, keyval, target);
}

gboolean
gtk_root_activate_key (GtkRoot     *root,
                       GdkEventKey *event)
{
  g_return_val_if_fail (GTK_ROOT (root), FALSE);

  return GTK_ROOT_GET_IFACE (root)->activate_key (root, event);
}

void
gtk_root_update_pointer_focus (GtkRoot          *root,
                               GdkDevice        *device,
                               GdkEventSequence *sequence,
                               GtkWidget        *target,
                               double            x,
                               double            y)
{
  GTK_ROOT_GET_IFACE (root)->update_pointer_focus (root, device, sequence, target, x, y);
}

void
gtk_root_update_pointer_focus_on_state_change (GtkRoot   *root,
                                               GtkWidget *widget)
{
  GTK_ROOT_GET_IFACE (root)->update_pointer_focus_on_state_change (root, widget);
}

GtkWidget *
gtk_root_lookup_pointer_focus (GtkRoot          *root,
                               GdkDevice        *device,
                               GdkEventSequence *sequence)
{
  return GTK_ROOT_GET_IFACE (root)->lookup_pointer_focus (root, device, sequence);
}

GtkWidget *
gtk_root_lookup_pointer_focus_implicit_grab (GtkRoot          *root,
                                             GdkDevice        *device,
                                             GdkEventSequence *sequence)
{
  return GTK_ROOT_GET_IFACE (root)->lookup_pointer_focus_implicit_grab (root, device, sequence);
}

GtkWidget *
gtk_root_lookup_effective_pointer_focus (GtkRoot          *root,
                                         GdkDevice        *device,
                                         GdkEventSequence *sequence)
{
  return GTK_ROOT_GET_IFACE (root)->lookup_effective_pointer_focus (root, device, sequence);
}

void
gtk_root_set_pointer_focus_grab (GtkRoot          *root,
                                 GdkDevice        *device,
                                 GdkEventSequence *sequence,
                                 GtkWidget        *target)
{
  GTK_ROOT_GET_IFACE (root)->set_pointer_focus_grab (root, device, sequence, target);
}

void
gtk_root_maybe_update_cursor (GtkRoot   *root,
                              GtkWidget *widget,
                              GdkDevice *device)
{
  GTK_ROOT_GET_IFACE (root)->maybe_update_cursor (root, widget, device);
}