gtk2/gdk/gdksurface.c

/* GDK - The GIMP Drawing Kit
 * Copyright (C) 1995-2007 Peter Mattis, Spencer Kimball,
 * Josh MacDonald, Ryan Lortie
 *
 * 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 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/>.
 */

/*
 * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS
 * file for a list of people on the GTK+ Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
 */

#include "config.h"

#include <cairo-gobject.h>

#include "gdksurface.h"

#include "gdk-private.h"
#include "gdkdeviceprivate.h"
#include "gdkdisplayprivate.h"
#include "gdkdragsurfaceprivate.h"
#include "gdkeventsprivate.h"
#include "gdkframeclockidleprivate.h"
#include "gdkglcontextprivate.h"
#include "gdkinternals.h"
#include "gdkintl.h"
#include "gdkmarshalers.h"
#include "gdkpopupprivate.h"
#include "gdkrectangle.h"
#include "gdktoplevelprivate.h"

#include <math.h>

#include <epoxy/gl.h>

#ifdef GDK_WINDOWING_WAYLAND
#include "wayland/gdkwayland.h"
#endif

/**
 * SECTION:gdksurface
 * @Short_description: Onscreen display areas in the target window system
 * @Title: Surfaces
 *
 * A #GdkSurface is a (usually) rectangular region on the screen.
 * It’s a low-level object, used to implement high-level objects such as
 * #GtkWindow on the GTK level.
 */

/**
 * GdkSurface:
 *
 * The GdkSurface struct contains only private fields and
 * should not be accessed directly.
 */

enum {
  POPUP_LAYOUT_CHANGED,
  SIZE_CHANGED,
  RENDER,
  EVENT,
  ENTER_MONITOR,
  LEAVE_MONITOR,
  LAST_SIGNAL
};

enum {
  PROP_0,
  PROP_CURSOR,
  PROP_DISPLAY,
  PROP_FRAME_CLOCK,
  PROP_MAPPED,
  LAST_PROP
};

/* Global info */

static void gdk_surface_finalize     (GObject      *object);

static void gdk_surface_set_property (GObject      *object,
                                      guint         prop_id,
                                      const GValue *value,
                                      GParamSpec   *pspec);
static void gdk_surface_get_property (GObject      *object,
                                      guint         prop_id,
                                      GValue       *value,
                                      GParamSpec   *pspec);

static void update_cursor               (GdkDisplay *display,
                                         GdkDevice  *device);

static void gdk_surface_set_frame_clock (GdkSurface      *surface,
                                         GdkFrameClock  *clock);


static guint signals[LAST_SIGNAL] = { 0 };
static GParamSpec *properties[LAST_PROP] = { NULL, };

G_DEFINE_ABSTRACT_TYPE (GdkSurface, gdk_surface, G_TYPE_OBJECT)

static gboolean
gdk_surface_real_beep (GdkSurface *surface)
{
  return FALSE;
}

static GdkDisplay *
get_display_for_surface (GdkSurface *primary,
                         GdkSurface *secondary)
{
  GdkDisplay *display = primary->display;

  if (display)
    return display;

  display = secondary->display;

  if (display)
    return display;

  g_warning ("no display for surface, using default");
  return gdk_display_get_default ();
}

static GdkMonitor *
get_monitor_for_rect (GdkDisplay         *display,
                      const GdkRectangle *rect)
{
  gint biggest_area = G_MININT;
  GdkMonitor *best_monitor = NULL;
  GdkMonitor *monitor;
  GdkRectangle workarea;
  GdkRectangle intersection;
  GListModel *monitors;
  guint i;

  monitors = gdk_display_get_monitors (display);
  for (i = 0; i < g_list_model_get_n_items (monitors); i++)
    {
      monitor = g_list_model_get_item (monitors, i);
      gdk_monitor_get_workarea (monitor, &workarea);

      if (gdk_rectangle_intersect (&workarea, rect, &intersection))
        {
          if (intersection.width * intersection.height > biggest_area)
            {
              biggest_area = intersection.width * intersection.height;
              best_monitor = monitor;
            }
        }
      g_object_unref (monitor);
    }

  return best_monitor;
}

static gint
get_anchor_x_sign (GdkGravity anchor)
{
  switch (anchor)
    {
    case GDK_GRAVITY_STATIC:
    case GDK_GRAVITY_NORTH_WEST:
    case GDK_GRAVITY_WEST:
    case GDK_GRAVITY_SOUTH_WEST:
      return -1;

    default:
    case GDK_GRAVITY_NORTH:
    case GDK_GRAVITY_CENTER:
    case GDK_GRAVITY_SOUTH:
      return 0;

    case GDK_GRAVITY_NORTH_EAST:
    case GDK_GRAVITY_EAST:
    case GDK_GRAVITY_SOUTH_EAST:
      return 1;
    }
}

static gint
get_anchor_y_sign (GdkGravity anchor)
{
  switch (anchor)
    {
    case GDK_GRAVITY_STATIC:
    case GDK_GRAVITY_NORTH_WEST:
    case GDK_GRAVITY_NORTH:
    case GDK_GRAVITY_NORTH_EAST:
      return -1;

    default:
    case GDK_GRAVITY_WEST:
    case GDK_GRAVITY_CENTER:
    case GDK_GRAVITY_EAST:
      return 0;

    case GDK_GRAVITY_SOUTH_WEST:
    case GDK_GRAVITY_SOUTH:
    case GDK_GRAVITY_SOUTH_EAST:
      return 1;
    }
}

static gint
maybe_flip_position (gint      bounds_pos,
                     gint      bounds_size,
                     gint      rect_pos,
                     gint      rect_size,
                     gint      surface_size,
                     gint      rect_sign,
                     gint      surface_sign,
                     gint      offset,
                     gboolean  flip,
                     gboolean *flipped)
{
  gint primary;
  gint secondary;

  *flipped = FALSE;
  primary = rect_pos + (1 + rect_sign) * rect_size / 2 + offset - (1 + surface_sign) * surface_size / 2;

  if (!flip || (primary >= bounds_pos && primary + surface_size <= bounds_pos + bounds_size))
    return primary;

  *flipped = TRUE;
  secondary = rect_pos + (1 - rect_sign) * rect_size / 2 - offset - (1 - surface_sign) * surface_size / 2;

  if (secondary >= bounds_pos && secondary + surface_size <= bounds_pos + bounds_size)
    return secondary;

  *flipped = FALSE;
  return primary;
}

void
gdk_surface_layout_popup_helper (GdkSurface     *surface,
                                 int             width,
                                 int             height,
                                 GdkPopupLayout *layout,
                                 GdkRectangle   *out_final_rect)
{
  GdkDisplay *display;
  GdkMonitor *monitor;
  GdkRectangle bounds;
  GdkRectangle root_rect;
  GdkGravity rect_anchor;
  GdkGravity surface_anchor;
  int rect_anchor_dx;
  int rect_anchor_dy;
  GdkAnchorHints anchor_hints;
  GdkRectangle final_rect;
  gboolean flipped_x;
  gboolean flipped_y;
  int x, y;

  g_return_if_fail (GDK_IS_POPUP (surface));

  root_rect = *gdk_popup_layout_get_anchor_rect (layout);
  gdk_surface_get_root_coords (surface->parent,
                               root_rect.x,
                               root_rect.y,
                               &root_rect.x,
                               &root_rect.y);

  display = get_display_for_surface (surface, surface->transient_for);
  monitor = get_monitor_for_rect (display, &root_rect);
  gdk_monitor_get_workarea (monitor, &bounds);

  rect_anchor = gdk_popup_layout_get_rect_anchor (layout);
  surface_anchor = gdk_popup_layout_get_surface_anchor (layout);
  gdk_popup_layout_get_offset (layout, &rect_anchor_dx, &rect_anchor_dy);
  anchor_hints = gdk_popup_layout_get_anchor_hints (layout);

  final_rect.width = width - surface->shadow_left - surface->shadow_right;
  final_rect.height = height - surface->shadow_top - surface->shadow_bottom;
  final_rect.x = maybe_flip_position (bounds.x,
                                      bounds.width,
                                      root_rect.x,
                                      root_rect.width,
                                      final_rect.width,
                                      get_anchor_x_sign (rect_anchor),
                                      get_anchor_x_sign (surface_anchor),
                                      rect_anchor_dx,
                                      anchor_hints & GDK_ANCHOR_FLIP_X,
                                      &flipped_x);
  final_rect.y = maybe_flip_position (bounds.y,
                                      bounds.height,
                                      root_rect.y,
                                      root_rect.height,
                                      final_rect.height,
                                      get_anchor_y_sign (rect_anchor),
                                      get_anchor_y_sign (surface_anchor),
                                      rect_anchor_dy,
                                      anchor_hints & GDK_ANCHOR_FLIP_Y,
                                      &flipped_y);

  if (anchor_hints & GDK_ANCHOR_SLIDE_X)
    {
      if (final_rect.x + final_rect.width > bounds.x + bounds.width)
        final_rect.x = bounds.x + bounds.width - final_rect.width;

      if (final_rect.x < bounds.x)
        final_rect.x = bounds.x;
    }

  if (anchor_hints & GDK_ANCHOR_SLIDE_Y)
    {
      if (final_rect.y + final_rect.height > bounds.y + bounds.height)
        final_rect.y = bounds.y + bounds.height - final_rect.height;

      if (final_rect.y < bounds.y)
        final_rect.y = bounds.y;
    }

  if (anchor_hints & GDK_ANCHOR_RESIZE_X)
    {
      if (final_rect.x < bounds.x)
        {
          final_rect.width -= bounds.x - final_rect.x;
          final_rect.x = bounds.x;
        }

      if (final_rect.x + final_rect.width > bounds.x + bounds.width)
        final_rect.width = bounds.x + bounds.width - final_rect.x;
    }

  if (anchor_hints & GDK_ANCHOR_RESIZE_Y)
    {
      if (final_rect.y < bounds.y)
        {
          final_rect.height -= bounds.y - final_rect.y;
          final_rect.y = bounds.y;
        }

      if (final_rect.y + final_rect.height > bounds.y + bounds.height)
        final_rect.height = bounds.y + bounds.height - final_rect.y;
    }

  final_rect.x -= surface->shadow_left;
  final_rect.y -= surface->shadow_top;
  final_rect.width += surface->shadow_left + surface->shadow_right;
  final_rect.height += surface->shadow_top + surface->shadow_bottom;

  gdk_surface_get_origin (surface->parent, &x, &y);
  final_rect.x -= x;
  final_rect.y -= y;

  if (flipped_x)
    {
      rect_anchor = gdk_gravity_flip_horizontally (rect_anchor);
      surface_anchor = gdk_gravity_flip_horizontally (surface_anchor);
    }
  if (flipped_y)
    {
      rect_anchor = gdk_gravity_flip_vertically (rect_anchor);
      surface_anchor = gdk_gravity_flip_vertically (surface_anchor);
    }

  surface->popup.rect_anchor = rect_anchor;
  surface->popup.surface_anchor = surface_anchor;

  *out_final_rect = final_rect;
}

/* Since GdkEvent is a GTypeInstance, GValue can only store it as a pointer,
 * and GClosure does not know how to handle its memory management. To avoid
 * the event going away in the middle of the signal emission, we provide a
 * marshaller that keeps the event alive for the duration of the closure.
 */
static void
gdk_surface_event_marshaller (GClosure     *closure,
                              GValue       *return_value,
                              guint         n_param_values,
                              const GValue *param_values,
                              gpointer      invocation_hint,
                              gpointer      marshal_data)
{
  GdkEvent *event = g_value_get_pointer (&param_values[1]);

  gdk_event_ref (event);

  _gdk_marshal_BOOLEAN__POINTER (closure,
                                 return_value,
                                 n_param_values,
                                 param_values,
                                 invocation_hint,
                                 marshal_data);


  gdk_event_unref (event);
}

static void
gdk_surface_event_marshallerv (GClosure *closure,
                               GValue   *return_value,
                               gpointer  instance,
                               va_list   args,
                               gpointer  marshal_data,
                               int       n_params,
                               GType    *param_types)
{
  va_list args_copy;
  GdkEvent *event;

  G_VA_COPY (args_copy, args);
  event = va_arg (args_copy, gpointer);

  gdk_event_ref (event);

  _gdk_marshal_BOOLEAN__POINTERv (closure,
                                  return_value,
                                  instance,
                                  args,
                                  marshal_data,
                                  n_params,
                                  param_types);

  gdk_event_unref (event);

  va_end (args_copy);
}

static void
gdk_surface_init (GdkSurface *surface)
{
  /* 0-initialization is good for all other fields. */

  surface->state = GDK_SURFACE_STATE_WITHDRAWN;
  surface->fullscreen_mode = GDK_FULLSCREEN_ON_CURRENT_MONITOR;
  surface->width = 1;
  surface->height = 1;

  surface->alpha = 255;

  surface->device_cursor = g_hash_table_new_full (NULL, NULL,
                                                 NULL, g_object_unref);
}

static void
gdk_surface_class_init (GdkSurfaceClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  object_class->finalize = gdk_surface_finalize;
  object_class->set_property = gdk_surface_set_property;
  object_class->get_property = gdk_surface_get_property;

  klass->beep = gdk_surface_real_beep;

  /**
   * GdkSurface:cursor:
   *
   * The mouse pointer for a #GdkSurface. See gdk_surface_set_cursor() and
   * gdk_surface_get_cursor() for details.
   */
  properties[PROP_CURSOR] =
      g_param_spec_object ("cursor",
                           P_("Cursor"),
                           P_("Cursor"),
                           GDK_TYPE_CURSOR,
                           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);

  /**
   * GdkSurface:display:
   *
   * The #GdkDisplay connection of the surface. See gdk_surface_get_display()
   * for details.
   */
  properties[PROP_DISPLAY] =
      g_param_spec_object ("display",
                           P_("Display"),
                           P_("Display"),
                           GDK_TYPE_DISPLAY,
                           G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);

  properties[PROP_FRAME_CLOCK] =
      g_param_spec_object ("frame-clock",
                           P_("Frame Clock"),
                           P_("Frame Clock"),
                           GDK_TYPE_FRAME_CLOCK,
                           G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);

  properties[PROP_MAPPED] =
      g_param_spec_boolean ("mapped",
                            P_("Mapped"),
                            P_("Mapped"),
                            FALSE,
                            G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);

  g_object_class_install_properties (object_class, LAST_PROP, properties);

  /**
   * GdkSurface::popup-layout-changed
   * @surface: the #GdkSurface that was laid out
   *
   * Emitted when the layout of a popup @surface has changed, e.g. if the popup
   * layout was reactive and after the parent moved causing the popover to end
   * up partially off-screen.
   *
   */
  signals[POPUP_LAYOUT_CHANGED] =
    g_signal_new (g_intern_static_string ("popup-layout-changed"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_FIRST,
                  0,
                  NULL,
                  NULL,
                  NULL,
                  G_TYPE_NONE,
                  0);

  /**
   * GdkSurface::size-changed:
   * @surface: the #GdkSurface
   * @width: the new width
   * @height: the new height
   *
   * Emitted when the size of @surface is changed.
   *
   * Surface size is reported in ”application pixels”, not
   * ”device pixels” (see gdk_surface_get_scale_factor()).
   */
  signals[SIZE_CHANGED] =
    g_signal_new (g_intern_static_string ("size-changed"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_FIRST,
                  0,
                  NULL,
                  NULL,
                  NULL,
                  G_TYPE_NONE,
                  2,
                  G_TYPE_INT,
                  G_TYPE_INT);

  /**
   * GdkSurface::render:
   * @surface: the #GdkSurface
   * @region: the region that needs to be redrawn
   *
   * Emitted when part of the surface needs to be redrawn.
   *
   * Returns: %TRUE to indicate that the signal has been handled
   */ 
  signals[RENDER] =
    g_signal_new (g_intern_static_string ("render"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  0,
                  g_signal_accumulator_true_handled,
                  NULL,
                  _gdk_marshal_BOOLEAN__BOXED,
                  G_TYPE_BOOLEAN,
                  1,
                  CAIRO_GOBJECT_TYPE_REGION);
  g_signal_set_va_marshaller (signals[RENDER],
                              G_OBJECT_CLASS_TYPE (object_class),
                              _gdk_marshal_BOOLEAN__BOXEDv);

  /**
   * GdkSurface::event:
   * @surface: the #GdkSurface
   * @event: (type Gdk.Event): an input event
   *
   * Emitted when GDK receives an input event for @surface.
   *
   * Returns: %TRUE to indicate that the event has been handled
   */ 
  signals[EVENT] =
    g_signal_new (g_intern_static_string ("event"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  0,
                  g_signal_accumulator_true_handled,
                  NULL,
                  gdk_surface_event_marshaller,
                  G_TYPE_BOOLEAN,
                  1,
                  G_TYPE_POINTER);
  g_signal_set_va_marshaller (signals[EVENT],
                              G_OBJECT_CLASS_TYPE (object_class),
                              gdk_surface_event_marshallerv);

  /**
   * GdkSurface::enter-monitor:
   * @surface: the #GdkSurface
   * @monitor: the monitor
   *
   * Emitted when @surface starts being present on the monitor.
   */ 
  signals[ENTER_MONITOR] =
    g_signal_new (g_intern_static_string ("enter-monitor"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_FIRST,
                  0,
                  NULL,
                  NULL,
                  NULL,
                  G_TYPE_NONE,
                  1,
                  GDK_TYPE_MONITOR);

  /**
   * GdkSurface::leave-monitor:
   * @surface: the #GdkSurface
   * @monitor: the monitor
   *
   * Emitted when @surface stops being present on the monitor.
   */ 
  signals[LEAVE_MONITOR] =
    g_signal_new (g_intern_static_string ("leave-monitor"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_FIRST,
                  0,
                  NULL,
                  NULL,
                  NULL,
                  G_TYPE_NONE,
                  1,
                  GDK_TYPE_MONITOR);
}

static void
seat_removed_cb (GdkDisplay *display,
                 GdkSeat    *seat,
                 GdkSurface  *surface)
{
  GdkDevice *device = gdk_seat_get_pointer (seat);

  surface->devices_inside = g_list_remove (surface->devices_inside, device);
  g_hash_table_remove (surface->device_cursor, device);
}

static void
gdk_surface_finalize (GObject *object)
{
  GdkSurface *surface = GDK_SURFACE (object);

  g_signal_handlers_disconnect_by_func (surface->display,
                                        seat_removed_cb, surface);

  if (!GDK_SURFACE_DESTROYED (surface))
    {
      g_warning ("losing last reference to undestroyed surface");
      _gdk_surface_destroy (surface, FALSE);
    }

  if (surface->input_region)
    cairo_region_destroy (surface->input_region);

  if (surface->cursor)
    g_object_unref (surface->cursor);

  if (surface->device_cursor)
    g_hash_table_destroy (surface->device_cursor);

  if (surface->devices_inside)
    g_list_free (surface->devices_inside);

  g_clear_object (&surface->display);

  if (surface->opaque_region)
    cairo_region_destroy (surface->opaque_region);

  if (surface->parent)
    surface->parent->children = g_list_remove (surface->parent->children, surface);

  G_OBJECT_CLASS (gdk_surface_parent_class)->finalize (object);
}

static void
gdk_surface_set_property (GObject      *object,
                          guint         prop_id,
                          const GValue *value,
                          GParamSpec   *pspec)
{
  GdkSurface *surface = GDK_SURFACE (object);

  switch (prop_id)
    {
    case PROP_CURSOR:
      gdk_surface_set_cursor (surface, g_value_get_object (value));
      break;

    case PROP_DISPLAY:
      surface->display = g_value_dup_object (value);
      g_assert (surface->display != NULL);
      g_signal_connect (surface->display, "seat-removed",
                        G_CALLBACK (seat_removed_cb), surface);
      break;

    case PROP_FRAME_CLOCK:
      gdk_surface_set_frame_clock (surface, GDK_FRAME_CLOCK (g_value_get_object (value)));
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }
}

#define GDK_SURFACE_IS_STICKY(surface) (((surface)->state & GDK_SURFACE_STATE_STICKY))

static void
gdk_surface_get_property (GObject    *object,
                          guint       prop_id,
                          GValue     *value,
                          GParamSpec *pspec)
{
  GdkSurface *surface = GDK_SURFACE (object);

  switch (prop_id)
    {
    case PROP_CURSOR:
      g_value_set_object (value, gdk_surface_get_cursor (surface));
      break;

    case PROP_DISPLAY:
      g_value_set_object (value, surface->display);
      break;

    case PROP_FRAME_CLOCK:
      g_value_set_object (value, surface->frame_clock);
      break;

    case PROP_MAPPED:
      g_value_set_boolean (value, GDK_SURFACE_IS_MAPPED (surface));
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }
}

void
_gdk_surface_update_size (GdkSurface *surface)
{
  GSList *l;

  for (l = surface->draw_contexts; l; l = l->next)
    gdk_draw_context_surface_resized (l->data);
}

static GdkSurface *
gdk_surface_new (GdkDisplay     *display,
                 GdkSurfaceType  surface_type,
                 GdkSurface     *parent,
                 int             x,
                 int             y,
                 int             width,
                 int             height)
{
  return gdk_display_create_surface (display,
                                     surface_type,
                                     parent,
                                     x, y, width, height);
}

/**
 * gdk_surface_new_toplevel: (constructor)
 * @display: the display to create the surface on
 * @width: width of new surface
 * @height: height of new surface
 *
 * Creates a new toplevel surface.
 *
 * Returns: (transfer full): the new #GdkSurface
 **/
GdkSurface *
gdk_surface_new_toplevel (GdkDisplay *display,
                          gint        width,
                          gint        height)
{
  g_return_val_if_fail (GDK_IS_DISPLAY (display), NULL);

  return gdk_surface_new (display, GDK_SURFACE_TOPLEVEL,
                          NULL, 0, 0, width, height);
}

/**
 * gdk_surface_new_temp: (constructor)
 * @display: the display to create the surface on
 * @position: position of the surface on screen
 *
 * Creates a new temporary surface.
 * The surface will bypass surface management.
 *
 * Returns: (transfer full): the new #GdkSurface
 **/
GdkSurface *
gdk_surface_new_temp (GdkDisplay         *display,
                      const GdkRectangle *position)
{
  g_return_val_if_fail (GDK_IS_DISPLAY (display), NULL);
  g_return_val_if_fail (position != NULL, NULL);

  return gdk_surface_new (display, GDK_SURFACE_TEMP,
                          NULL,
                          position->x, position->y,
                          position->width, position->height);
}

/**
 * gdk_surface_new_popup: (constructor)
 * @parent: the parent surface to attach the surface to
 * @autohide: whether to hide the surface on outside clicks
 *
 * Create a new popup surface.
 *
 * The surface will be attached to @parent and can be positioned relative to it
 * using gdk_surface_show_popup() or later using gdk_surface_layout_popup().
 *
 * Returns: (transfer full): a new #GdkSurface
 */
GdkSurface *
gdk_surface_new_popup (GdkSurface *parent,
                       gboolean    autohide)
{
  GdkSurface *surface;

  g_return_val_if_fail (GDK_IS_SURFACE (parent), NULL);

  surface = gdk_surface_new (parent->display, GDK_SURFACE_POPUP,
                             parent, 0, 0, 100, 100);

  surface->autohide = autohide;

  return surface;
}

static void
update_pointer_info_foreach (GdkDisplay           *display,
                             GdkDevice            *device,
                             GdkPointerSurfaceInfo *pointer_info,
                             gpointer              user_data)
{
  GdkSurface *surface = user_data;

  if (pointer_info->surface_under_pointer == surface)
    {
      g_object_unref (pointer_info->surface_under_pointer);
      pointer_info->surface_under_pointer = NULL;
    }
}

static void
surface_remove_from_pointer_info (GdkSurface  *surface,
                                  GdkDisplay *display)
{
  _gdk_display_pointer_info_foreach (display,
                                     update_pointer_info_foreach,
                                     surface);
}

/**
 * _gdk_surface_destroy_hierarchy:
 * @surface: a #GdkSurface
 * @recursing_native: If %TRUE, then this is being called because a native parent
 *            was destroyed. This generally means that the call to the
 *            windowing system to destroy the surface can be omitted, since
 *            it will be destroyed as a result of the parent being destroyed.
 *            Unless @foreign_destroy.
 * @foreign_destroy: If %TRUE, the surface or a parent was destroyed by some
 *            external agency. The surface has already been destroyed and no
 *            windowing system calls should be made. (This may never happen
 *            for some windowing systems.)
 *
 * Internal function to destroy a surface. Like gdk_surface_destroy(),
 * but does not drop the reference count created by gdk_surface_new().
 **/
static void
_gdk_surface_destroy_hierarchy (GdkSurface *surface,
                                gboolean   foreign_destroy)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (GDK_SURFACE_DESTROYED (surface))
    return;

  GDK_SURFACE_GET_CLASS (surface)->destroy (surface, foreign_destroy);

  if (surface->gl_paint_context)
    {
      /* Make sure to destroy if current */
      g_object_run_dispose (G_OBJECT (surface->gl_paint_context));
      g_object_unref (surface->gl_paint_context);
      surface->gl_paint_context = NULL;
    }

  if (surface->frame_clock)
    {
      if (surface->parent == NULL)
        g_object_run_dispose (G_OBJECT (surface->frame_clock));
      gdk_surface_set_frame_clock (surface, NULL);
    }

  _gdk_surface_clear_update_area (surface);

  surface->state |= GDK_SURFACE_STATE_WITHDRAWN;
  surface->destroyed = TRUE;

  surface_remove_from_pointer_info (surface, surface->display);

  if (GDK_IS_TOPLEVEL (surface))
    g_object_notify (G_OBJECT (surface), "state");
  g_object_notify_by_pspec (G_OBJECT (surface), properties[PROP_MAPPED]);
}

/**
 * _gdk_surface_destroy:
 * @surface: a #GdkSurface
 * @foreign_destroy: If %TRUE, the surface or a parent was destroyed by some
 *            external agency. The surface has already been destroyed and no
 *            windowing system calls should be made. (This may never happen
 *            for some windowing systems.)
 *
 * Internal function to destroy a surface. Like gdk_surface_destroy(),
 * but does not drop the reference count created by gdk_surface_new().
 **/
void
_gdk_surface_destroy (GdkSurface *surface,
                      gboolean   foreign_destroy)
{
  _gdk_surface_destroy_hierarchy (surface, foreign_destroy);
}

/**
 * gdk_surface_destroy:
 * @surface: a #GdkSurface
 *
 * Destroys the window system resources associated with @surface and decrements @surface's
 * reference count. The window system resources for all children of @surface are also
 * destroyed, but the children’s reference counts are not decremented.
 *
 * Note that a surface will not be destroyed automatically when its reference count
 * reaches zero. You must call this function yourself before that happens.
 *
 **/
void
gdk_surface_destroy (GdkSurface *surface)
{
  _gdk_surface_destroy_hierarchy (surface, FALSE);
  g_object_unref (surface);
}

void
gdk_surface_set_widget (GdkSurface *surface,
                        gpointer    widget)
{
  surface->widget = widget;
}

gpointer
gdk_surface_get_widget (GdkSurface *surface)
{
  return surface->widget;
}

/**
 * gdk_surface_get_display:
 * @surface: a #GdkSurface
 * 
 * Gets the #GdkDisplay associated with a #GdkSurface.
 * 
 * Returns: (transfer none): the #GdkDisplay associated with @surface
 **/
GdkDisplay *
gdk_surface_get_display (GdkSurface *surface)
{
  g_return_val_if_fail (GDK_IS_SURFACE (surface), NULL);

  return surface->display;
}
/**
 * gdk_surface_is_destroyed:
 * @surface: a #GdkSurface
 *
 * Check to see if a surface is destroyed..
 *
 * Returns: %TRUE if the surface is destroyed
 **/
gboolean
gdk_surface_is_destroyed (GdkSurface *surface)
{
  return GDK_SURFACE_DESTROYED (surface);
}

/**
 * gdk_surface_get_mapped:
 * @surface: a #GdkSurface
 *
 * Checks whether the surface has been mapped (with gdk_surface_show() or
 * gdk_surface_show_unraised()).
 *
 * Returns: %TRUE if the surface is mapped
 **/
gboolean
gdk_surface_get_mapped (GdkSurface *surface)
{
  g_return_val_if_fail (GDK_IS_SURFACE (surface), FALSE);

  return GDK_SURFACE_IS_MAPPED (surface);
}

GdkGLContext *
gdk_surface_get_shared_data_gl_context (GdkSurface *surface)
{
  static int in_shared_data_creation;
  GdkDisplay *display;
  GdkGLContext *context;

  if (in_shared_data_creation)
    return NULL;

  in_shared_data_creation = 1;

  display = gdk_surface_get_display (surface);
  context = (GdkGLContext *)g_object_get_data (G_OBJECT (display), "gdk-gl-shared-data-context");
  if (context == NULL)
    {
      GError *error = NULL;
      context = GDK_SURFACE_GET_CLASS (surface)->create_gl_context (surface, FALSE, NULL, &error);
      if (context == NULL)
        {
          g_warning ("Failed to create shared context: %s", error->message);
          g_clear_error (&error);
        }

      gdk_gl_context_realize (context, &error);
      if (context == NULL)
        {
          g_warning ("Failed to realize shared context: %s", error->message);
          g_clear_error (&error);
        }


      g_object_set_data (G_OBJECT (display), "gdk-gl-shared-data-context", context);
    }

  in_shared_data_creation = 0;

  return context;
}

GdkGLContext *
gdk_surface_get_paint_gl_context (GdkSurface  *surface,
                                  GError    **error)
{
  GError *internal_error = NULL;

  if (GDK_DISPLAY_DEBUG_CHECK (surface->display, GL_DISABLE))
    {
      g_set_error_literal (error, GDK_GL_ERROR,
                           GDK_GL_ERROR_NOT_AVAILABLE,
                           _("GL support disabled via GDK_DEBUG"));
      return NULL;
    }

  if (surface->gl_paint_context == NULL)
    {
      GdkSurfaceClass *class = GDK_SURFACE_GET_CLASS (surface);

      if (class->create_gl_context == NULL)
        {
          g_set_error_literal (error, GDK_GL_ERROR, GDK_GL_ERROR_NOT_AVAILABLE,
                               _("The current backend does not support OpenGL"));
          return NULL;
        }

      surface->gl_paint_context =
        class->create_gl_context (surface, TRUE, NULL, &internal_error);
    }

  if (internal_error != NULL)
    {
      g_propagate_error (error, internal_error);
      g_clear_object (&(surface->gl_paint_context));
      return NULL;
    }

  gdk_gl_context_realize (surface->gl_paint_context, &internal_error);
  if (internal_error != NULL)
    {
      g_propagate_error (error, internal_error);
      g_clear_object (&(surface->gl_paint_context));
      return NULL;
    }

  return surface->gl_paint_context;
}

/**
 * gdk_surface_create_gl_context:
 * @surface: a #GdkSurface
 * @error: return location for an error
 *
 * Creates a new #GdkGLContext matching the
 * framebuffer format to the visual of the #GdkSurface. The context
 * is disconnected from any particular surface or surface.
 *
 * If the creation of the #GdkGLContext failed, @error will be set.
 *
 * Before using the returned #GdkGLContext, you will need to
 * call gdk_gl_context_make_current() or gdk_gl_context_realize().
 *
 * Returns: (transfer full): the newly created #GdkGLContext, or
 * %NULL on error
 **/
GdkGLContext *
gdk_surface_create_gl_context (GdkSurface   *surface,
                               GError      **error)
{
  GdkGLContext *paint_context;

  g_return_val_if_fail (GDK_IS_SURFACE (surface), NULL);
  g_return_val_if_fail (error == NULL || *error == NULL, NULL);

  paint_context = gdk_surface_get_paint_gl_context (surface, error);
  if (paint_context == NULL)
    return NULL;

  return GDK_SURFACE_GET_CLASS (surface)->create_gl_context (surface,
                                                             FALSE,
                                                             paint_context,
                                                             error);
}

/**
 * gdk_surface_create_cairo_context:
 * @surface: a #GdkSurface
 *
 * Creates a new #GdkCairoContext for rendering on @surface.
 *
 * Returns: (transfer full): the newly created #GdkCairoContext
 **/
GdkCairoContext *
gdk_surface_create_cairo_context (GdkSurface *surface)
{
  GdkDisplay *display;

  g_return_val_if_fail (GDK_IS_SURFACE (surface), NULL);

  display = surface->display;

  return g_object_new (GDK_DISPLAY_GET_CLASS (display)->cairo_context_type,
                       "surface", surface,
                       NULL);
}

/**
 * gdk_surface_create_vulkan_context:
 * @surface: a #GdkSurface
 * @error: return location for an error
 *
 * Creates a new #GdkVulkanContext for rendering on @surface.
 *
 * If the creation of the #GdkVulkanContext failed, @error will be set.
 *
 * Returns: (transfer full): the newly created #GdkVulkanContext, or
 * %NULL on error
 **/
GdkVulkanContext *
gdk_surface_create_vulkan_context (GdkSurface  *surface,
                                   GError    **error)
{
  GdkDisplay *display;

  g_return_val_if_fail (GDK_IS_SURFACE (surface), NULL);
  g_return_val_if_fail (error == NULL || *error == NULL, NULL);

  if (GDK_DISPLAY_DEBUG_CHECK (surface->display, VULKAN_DISABLE))
    {
      g_set_error_literal (error, GDK_VULKAN_ERROR, GDK_VULKAN_ERROR_NOT_AVAILABLE,
                           _("Vulkan support disabled via GDK_DEBUG"));
      return NULL;
    }

  display = surface->display;

  if (GDK_DISPLAY_GET_CLASS (display)->vk_extension_name == NULL)
    {
      g_set_error (error, GDK_VULKAN_ERROR, GDK_VULKAN_ERROR_UNSUPPORTED,
                   "The %s backend has no Vulkan support.", G_OBJECT_TYPE_NAME (display));
      return FALSE;
    }

  return g_initable_new (GDK_DISPLAY_GET_CLASS (display)->vk_context_type,
                         NULL,
                         error,
                         "surface", surface,
                         NULL);
}

/* Code for dirty-region queueing
 */
static GSList *update_surfaces = NULL;

static void
gdk_surface_add_update_surface (GdkSurface *surface)
{
  GSList *tmp;

  /*  Check whether "surface" is already in "update_surfaces" list.
   *  It could be added during execution of gtk_widget_destroy() when
   *  setting focus widget to NULL and redrawing old focus widget.
   *  See bug 711552.
   */
  tmp = g_slist_find (update_surfaces, surface);
  if (tmp != NULL)
    return;

  update_surfaces = g_slist_prepend (update_surfaces, g_object_ref (surface));
}

static void
gdk_surface_remove_update_surface (GdkSurface *surface)
{
  GSList *link;

  link = g_slist_find (update_surfaces, surface);
  if (link != NULL)
    {
      update_surfaces = g_slist_delete_link (update_surfaces, link);
      g_object_unref (surface);
    }
}

static gboolean
gdk_surface_is_toplevel_frozen (GdkSurface *surface)
{
  return surface->update_and_descendants_freeze_count > 0;
}

static void
gdk_surface_schedule_update (GdkSurface *surface)
{
  GdkFrameClock *frame_clock;

  g_return_if_fail (surface);

  if (surface->update_freeze_count ||
      gdk_surface_is_toplevel_frozen (surface))
    {
      surface->pending_schedule_update = TRUE;
      return;
    }

  /* If there's no frame clock (a foreign surface), then the invalid
   * region will just stick around unless gdk_surface_process_updates()
   * is called. */
  frame_clock = gdk_surface_get_frame_clock (surface);
  if (frame_clock)
    gdk_frame_clock_request_phase (gdk_surface_get_frame_clock (surface),
                                   GDK_FRAME_CLOCK_PHASE_PAINT);
}

static void
gdk_surface_process_updates_internal (GdkSurface *surface)
{
  /* Ensure the surface lives while updating it */
  g_object_ref (surface);

  surface->in_update = TRUE;

  /* If an update got queued during update processing, we can get a
   * surface in the update queue that has an empty update_area.
   * just ignore it.
   */
  if (surface->update_area)
    {
      g_assert (surface->active_update_area == NULL); /* No reentrancy */

      surface->active_update_area = surface->update_area;
      surface->update_area = NULL;

      if (GDK_SURFACE_IS_MAPPED (surface))
        {
          cairo_region_t *expose_region;
          gboolean handled;

          expose_region = cairo_region_copy (surface->active_update_area);

          g_signal_emit (surface, signals[RENDER], 0, expose_region, &handled);

          cairo_region_destroy (expose_region);
        }

      cairo_region_destroy (surface->active_update_area);
      surface->active_update_area = NULL;
    }

  surface->in_update = FALSE;

  g_object_unref (surface);
}

static void
gdk_surface_paint_on_clock (GdkFrameClock *clock,
                            void          *data)
{
  GdkSurface *surface = GDK_SURFACE (data);

  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (GDK_SURFACE_DESTROYED (surface))
    return;

  g_object_ref (surface);

  if (surface->update_area &&
      !surface->update_freeze_count &&
      !gdk_surface_is_toplevel_frozen (surface) &&

      /* Don't recurse into process_updates_internal, we'll
       * do the update later when idle instead. */
      !surface->in_update)
    {
      gdk_surface_process_updates_internal (surface);
      gdk_surface_remove_update_surface (surface);
    }

  g_object_unref (surface);
}

/**
 * gdk_surface_invalidate_rect:
 * @surface: a #GdkSurface
 * @rect: (allow-none): rectangle to invalidate or %NULL to invalidate the whole
 *      surface
 *
 * A convenience wrapper around gdk_surface_invalidate_region() which
 * invalidates a rectangular region. See
 * gdk_surface_invalidate_region() for details.
 **/
void
gdk_surface_invalidate_rect (GdkSurface        *surface,
                             const GdkRectangle *rect)
{
  GdkRectangle surface_rect;
  cairo_region_t *region;

  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (!GDK_SURFACE_IS_MAPPED (surface))
    return;

  if (!rect)
    {
      surface_rect.x = 0;
      surface_rect.y = 0;
      surface_rect.width = surface->width;
      surface_rect.height = surface->height;
      rect = &surface_rect;
    }

  region = cairo_region_create_rectangle (rect);
  gdk_surface_invalidate_region (surface, region);
  cairo_region_destroy (region);
}

static void
impl_surface_add_update_area (GdkSurface     *impl_surface,
                              cairo_region_t *region)
{
  if (impl_surface->update_area)
    cairo_region_union (impl_surface->update_area, region);
  else
    {
      gdk_surface_add_update_surface (impl_surface);
      impl_surface->update_area = cairo_region_copy (region);
      gdk_surface_schedule_update (impl_surface);
    }
}

/**
 * gdk_surface_queue_expose:
 * @surface: a #GdkSurface
 *
 * Forces an expose event for @surface to be scheduled.
 *
 * If the invalid area of @surface is empty, an expose event will
 * still be emitted. Its invalid region will be empty.
 *
 * This function is useful for implementations that track invalid
 * regions on their own.
 **/
void
gdk_surface_queue_expose (GdkSurface *surface)
{
  cairo_region_t *region;

  g_return_if_fail (GDK_IS_SURFACE (surface));

  region = cairo_region_create ();
  impl_surface_add_update_area (surface, region);
  cairo_region_destroy (region);
}

/**
 * gdk_surface_invalidate_region:
 * @surface: a #GdkSurface
 * @region: a #cairo_region_t
 *
 * Adds @region to the update area for @surface. The update area is the
 * region that needs to be redrawn, or “dirty region.”
 *
 * GDK will process all updates whenever the frame clock schedules a redraw,
 * so there’s no need to do forces redraws manually, you just need to
 * invalidate regions that you know should be redrawn.
 **/
void
gdk_surface_invalidate_region (GdkSurface          *surface,
                               const cairo_region_t *region)
{
  cairo_region_t *visible_region;
  cairo_rectangle_int_t r;

  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (!GDK_SURFACE_IS_MAPPED (surface))
    return;

  if (cairo_region_is_empty (region))
    return;

  r.x = 0;
  r.y = 0;
  r.width = surface->width;
  r.height = surface->height;

  visible_region = cairo_region_copy (region);

  cairo_region_intersect_rectangle (visible_region, &r);
  impl_surface_add_update_area (surface, visible_region);

  cairo_region_destroy (visible_region);
}

/**
 * _gdk_surface_clear_update_area:
 * @surface: a #GdkSurface.
 *
 * Internal function to clear the update area for a surface. This
 * is called when the surface is hidden or destroyed.
 **/
void
_gdk_surface_clear_update_area (GdkSurface *surface)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (surface->update_area)
    {
      gdk_surface_remove_update_surface (surface);

      cairo_region_destroy (surface->update_area);
      surface->update_area = NULL;
    }
}

/**
 * gdk_surface_freeze_updates:
 * @surface: a #GdkSurface
 *
 * Temporarily freezes a surface such that it won’t receive expose
 * events.  The surface will begin receiving expose events again when
 * gdk_surface_thaw_updates() is called. If gdk_surface_freeze_updates()
 * has been called more than once, gdk_surface_thaw_updates() must be called
 * an equal number of times to begin processing exposes.
 **/
void
gdk_surface_freeze_updates (GdkSurface *surface)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  surface->update_freeze_count++;
  if (surface->update_freeze_count == 1)
    _gdk_frame_clock_uninhibit_freeze (surface->frame_clock);
}

/**
 * gdk_surface_thaw_updates:
 * @surface: a #GdkSurface
 *
 * Thaws a surface frozen with gdk_surface_freeze_updates(). Note that this
 * will not necessarily schedule updates if the surface freeze count reaches
 * zero.
 **/
void
gdk_surface_thaw_updates (GdkSurface *surface)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  g_return_if_fail (surface->update_freeze_count > 0);

  if (--surface->update_freeze_count == 0)
    {
      _gdk_frame_clock_inhibit_freeze (surface->frame_clock);

      if (surface->pending_schedule_update)
        {
          surface->pending_schedule_update = FALSE;
          gdk_surface_schedule_update (surface);
        }
    }
}

void
gdk_surface_freeze_toplevel_updates (GdkSurface *surface)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  surface->update_and_descendants_freeze_count++;
  gdk_surface_freeze_updates (surface);
}

void
gdk_surface_thaw_toplevel_updates (GdkSurface *surface)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));
  g_return_if_fail (surface->update_and_descendants_freeze_count > 0);

  surface->update_and_descendants_freeze_count--;
  gdk_surface_schedule_update (surface);
  gdk_surface_thaw_updates (surface);

}

/**
 * gdk_surface_constrain_size:
 * @geometry: a #GdkGeometry structure
 * @flags: a mask indicating what portions of @geometry are set
 * @width: desired width of surface
 * @height: desired height of the surface
 * @new_width: (out): location to store resulting width
 * @new_height: (out): location to store resulting height
 *
 * Constrains a desired width and height according to a
 * set of geometry hints (such as minimum and maximum size).
 */
void
gdk_surface_constrain_size (GdkGeometry    *geometry,
                            GdkSurfaceHints  flags,
                            gint            width,
                            gint            height,
                            gint           *new_width,
                            gint           *new_height)
{
  /* This routine is partially borrowed from fvwm.
   *
   * Copyright 1993, Robert Nation
   *     You may use this code for any purpose, as long as the original
   *     copyright remains in the source code and all documentation
   *
   * which in turn borrows parts of the algorithm from uwm
   */
  gint min_width = 0;
  gint min_height = 0;
  gint base_width = 0;
  gint base_height = 0;
  gint xinc = 1;
  gint yinc = 1;
  gint max_width = G_MAXINT;
  gint max_height = G_MAXINT;

#define FLOOR(value, base)      ( ((gint) ((value) / (base))) * (base) )

  if ((flags & GDK_HINT_BASE_SIZE) && (flags & GDK_HINT_MIN_SIZE))
    {
      base_width = geometry->base_width;
      base_height = geometry->base_height;
      min_width = geometry->min_width;
      min_height = geometry->min_height;
    }
  else if (flags & GDK_HINT_BASE_SIZE)
    {
      base_width = geometry->base_width;
      base_height = geometry->base_height;
      min_width = geometry->base_width;
      min_height = geometry->base_height;
    }
  else if (flags & GDK_HINT_MIN_SIZE)
    {
      base_width = geometry->min_width;
      base_height = geometry->min_height;
      min_width = geometry->min_width;
      min_height = geometry->min_height;
    }

  if (flags & GDK_HINT_MAX_SIZE)
    {
      max_width = geometry->max_width ;
      max_height = geometry->max_height;
    }

  if (flags & GDK_HINT_RESIZE_INC)
    {
      xinc = MAX (xinc, geometry->width_inc);
      yinc = MAX (yinc, geometry->height_inc);
    }

  /* clamp width and height to min and max values
   */
  width = CLAMP (width, min_width, max_width);
  height = CLAMP (height, min_height, max_height);

  /* shrink to base + N * inc
   */
  width = base_width + FLOOR (width - base_width, xinc);
  height = base_height + FLOOR (height - base_height, yinc);

  /* constrain aspect ratio, according to:
   *
   *                width
   * min_aspect <= -------- <= max_aspect
   *                height
   */

  if (flags & GDK_HINT_ASPECT &&
      geometry->min_aspect > 0 &&
      geometry->max_aspect > 0)
    {
      gint delta;

      if (flags & GDK_HINT_BASE_SIZE)
        {
          width -= base_width;
          height -= base_height;
          min_width -= base_width;
          min_height -= base_height;
          max_width -= base_width;
          max_height -= base_height;
        }

      if (geometry->min_aspect * height > width)
        {
          delta = FLOOR (height - width / geometry->min_aspect, yinc);
          if (height - delta >= min_height)
            height -= delta;
          else
            {
              delta = FLOOR (height * geometry->min_aspect - width, xinc);
              if (width + delta <= max_width)
                width += delta;
            }
        }

      if (geometry->max_aspect * height < width)
        {
          delta = FLOOR (width - height * geometry->max_aspect, xinc);
          if (width - delta >= min_width)
            width -= delta;
          else
            {
              delta = FLOOR (width / geometry->max_aspect - height, yinc);
              if (height + delta <= max_height)
                height += delta;
            }
        }

      if (flags & GDK_HINT_BASE_SIZE)
        {
          width += base_width;
          height += base_height;
        }
    }

#undef FLOOR

  *new_width = width;
  *new_height = height;
}

/**
 * gdk_surface_get_device_position:
 * @surface: a #GdkSurface.
 * @device: pointer #GdkDevice to query to.
 * @x: (out) (allow-none): return location for the X coordinate of @device, or %NULL.
 * @y: (out) (allow-none): return location for the Y coordinate of @device, or %NULL.
 * @mask: (out) (allow-none): return location for the modifier mask, or %NULL.
 *
 * Obtains the current device position in doubles and modifier state.
 * The position is given in coordinates relative to the upper left
 * corner of @surface.
 **/
void
gdk_surface_get_device_position (GdkSurface       *surface,
                                 GdkDevice       *device,
                                 double          *x,
                                 double          *y,
                                 GdkModifierType *mask)
{
  gdouble tmp_x, tmp_y;
  GdkModifierType tmp_mask;

  g_return_if_fail (GDK_IS_SURFACE (surface));
  g_return_if_fail (GDK_IS_DEVICE (device));
  g_return_if_fail (gdk_device_get_source (device) != GDK_SOURCE_KEYBOARD);

  tmp_x = tmp_y = 0;
  tmp_mask = 0;
  GDK_SURFACE_GET_CLASS (surface)->get_device_state (surface,
                                                     device,
                                                     &tmp_x, &tmp_y,
                                                     &tmp_mask);

  if (x)
    *x = tmp_x;
  if (y)
    *y = tmp_y;
  if (mask)
    *mask = tmp_mask;
}

/**
 * gdk_surface_hide:
 * @surface: a #GdkSurface
 *
 * For toplevel surfaces, withdraws them, so they will no longer be
 * known to the window manager; for all surfaces, unmaps them, so
 * they won’t be displayed. Normally done automatically as
 * part of gtk_widget_hide().
 */
void
gdk_surface_hide (GdkSurface *surface)
{
  gboolean was_mapped;

  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (surface->destroyed)
    return;

  was_mapped = GDK_SURFACE_IS_MAPPED (surface);

  if (GDK_SURFACE_IS_MAPPED (surface))
    gdk_synthesize_surface_state (surface, 0, GDK_SURFACE_STATE_WITHDRAWN);

  if (was_mapped)
    {
      GdkDisplay *display;
      GdkSeat *seat;
      GList *devices, *d;

      /* May need to break grabs on children */
      display = surface->display;
      seat = gdk_display_get_default_seat (display);
      if (seat)
        {
          devices = gdk_seat_get_slaves (seat, GDK_SEAT_CAPABILITY_ALL);
          devices = g_list_prepend (devices, gdk_seat_get_keyboard (seat));
          devices = g_list_prepend (devices, gdk_seat_get_pointer (seat));
        }
      else
        devices = NULL;

      for (d = devices; d; d = d->next)
        {
          GdkDevice *device = d->data;

          if (_gdk_display_end_device_grab (display,
                                            device,
                                            _gdk_display_get_next_serial (display),
                                            surface,
                                            TRUE))
            {
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
              gdk_device_ungrab (device, GDK_CURRENT_TIME);
G_GNUC_END_IGNORE_DEPRECATIONS
            }
        }

      g_list_free (devices);
    }

  GDK_SURFACE_GET_CLASS (surface)->hide (surface);

  surface->popup.rect_anchor = 0;
  surface->popup.surface_anchor = 0;
  surface->x = 0;
  surface->y = 0;
}

static void
gdk_surface_set_cursor_internal (GdkSurface *surface,
                                 GdkDevice *device,
                                 GdkCursor *cursor)
{
  GdkPointerSurfaceInfo *pointer_info;

  if (GDK_SURFACE_DESTROYED (surface))
    return;

  g_assert (surface->display == gdk_device_get_display (device));

  pointer_info = _gdk_display_get_pointer_info (surface->display, device);

  if (surface == pointer_info->surface_under_pointer)
    update_cursor (surface->display, device);
}

/**
 * gdk_surface_get_cursor:
 * @surface: a #GdkSurface
 *
 * Retrieves a #GdkCursor pointer for the cursor currently set on the
 * specified #GdkSurface, or %NULL.  If the return value is %NULL then
 * there is no custom cursor set on the specified surface, and it is
 * using the cursor for its parent surface.
 *
 * Returns: (nullable) (transfer none): a #GdkCursor, or %NULL. The
 *   returned object is owned by the #GdkSurface and should not be
 *   unreferenced directly. Use gdk_surface_set_cursor() to unset the
 *   cursor of the surface
 */
GdkCursor *
gdk_surface_get_cursor (GdkSurface *surface)
{
  g_return_val_if_fail (GDK_IS_SURFACE (surface), NULL);

  return surface->cursor;
}

/**
 * gdk_surface_set_cursor:
 * @surface: a #GdkSurface
 * @cursor: (allow-none): a cursor
 *
 * Sets the default mouse pointer for a #GdkSurface.
 *
 * Note that @cursor must be for the same display as @surface.
 *
 * Use gdk_cursor_new_from_name() or gdk_cursor_new_from_texture() to
 * create the cursor. To make the cursor invisible, use %GDK_BLANK_CURSOR.
 * Passing %NULL for the @cursor argument to gdk_surface_set_cursor() means
 * that @surface will use the cursor of its parent surface. Most surfaces
 * should use this default.
 */
void
gdk_surface_set_cursor (GdkSurface *surface,
                        GdkCursor *cursor)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (surface->cursor)
    {
      g_object_unref (surface->cursor);
      surface->cursor = NULL;
    }

  if (!GDK_SURFACE_DESTROYED (surface))
    {
      GdkDevice *device;
      GList *seats, *s;

      if (cursor)
        surface->cursor = g_object_ref (cursor);

      seats = gdk_display_list_seats (surface->display);

      for (s = seats; s; s = s->next)
        {
          GList *devices, *d;

          device = gdk_seat_get_pointer (s->data);
          gdk_surface_set_cursor_internal (surface, device, surface->cursor);

          devices = gdk_seat_get_slaves (s->data, GDK_SEAT_CAPABILITY_TABLET_STYLUS);
          for (d = devices; d; d = d->next)
            {
              device = gdk_device_get_associated_device (d->data);
              gdk_surface_set_cursor_internal (surface, device, surface->cursor);
            }
          g_list_free (devices);
        }

      g_list_free (seats);
      g_object_notify_by_pspec (G_OBJECT (surface), properties[PROP_CURSOR]);
    }
}

/**
 * gdk_surface_get_device_cursor:
 * @surface: a #GdkSurface.
 * @device: a master, pointer #GdkDevice.
 *
 * Retrieves a #GdkCursor pointer for the @device currently set on the
 * specified #GdkSurface, or %NULL.  If the return value is %NULL then
 * there is no custom cursor set on the specified surface, and it is
 * using the cursor for its parent surface.
 *
 * Returns: (nullable) (transfer none): a #GdkCursor, or %NULL. The
 *   returned object is owned by the #GdkSurface and should not be
 *   unreferenced directly. Use gdk_surface_set_cursor() to unset the
 *   cursor of the surface
 **/
GdkCursor *
gdk_surface_get_device_cursor (GdkSurface *surface,
                               GdkDevice *device)
{
  g_return_val_if_fail (GDK_IS_SURFACE (surface), NULL);
  g_return_val_if_fail (GDK_IS_DEVICE (device), NULL);
  g_return_val_if_fail (gdk_device_get_source (device) != GDK_SOURCE_KEYBOARD, NULL);
  g_return_val_if_fail (gdk_device_get_device_type (device) == GDK_DEVICE_TYPE_MASTER, NULL);

  return g_hash_table_lookup (surface->device_cursor, device);
}

/**
 * gdk_surface_set_device_cursor:
 * @surface: a #GdkSurface
 * @device: a master, pointer #GdkDevice
 * @cursor: a #GdkCursor
 *
 * Sets a specific #GdkCursor for a given device when it gets inside @surface.
 * Use gdk_cursor_new_from_name() or gdk_cursor_new_from_texture() to create
 * the cursor. To make the cursor invisible, use %GDK_BLANK_CURSOR. Passing
 * %NULL for the @cursor argument to gdk_surface_set_cursor() means that
 * @surface will use the cursor of its parent surface. Most surfaces should
 * use this default.
 **/
void
gdk_surface_set_device_cursor (GdkSurface *surface,
                               GdkDevice *device,
                               GdkCursor *cursor)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));
  g_return_if_fail (GDK_IS_DEVICE (device));
  g_return_if_fail (gdk_device_get_source (device) != GDK_SOURCE_KEYBOARD);
  g_return_if_fail (gdk_device_get_device_type (device) == GDK_DEVICE_TYPE_MASTER);

  if (!cursor)
    g_hash_table_remove (surface->device_cursor, device);
  else
    g_hash_table_replace (surface->device_cursor, device, g_object_ref (cursor));

  gdk_surface_set_cursor_internal (surface, device, cursor);
}

/*
 * gdk_surface_get_geometry:
 * @surface: a #GdkSurface
 * @x: (out) (allow-none): return location for X coordinate of surface (relative to its parent)
 * @y: (out) (allow-none): return location for Y coordinate of surface (relative to its parent)
 * @width: (out) (allow-none): return location for width of surface
 * @height: (out) (allow-none): return location for height of surface
 *
 * Any of the return location arguments to this function may be %NULL,
 * if you aren’t interested in getting the value of that field.
 *
 * The X and Y coordinates returned are relative to the parent surface
 * of @surface, which for toplevels usually means relative to the
 * surface decorations (titlebar, etc.) rather than relative to the
 * root window (screen-size background window).
 *
 * On the X11 platform, the geometry is obtained from the X server,
 * so reflects the latest position of @surface; this may be out-of-sync
 * with the position of @surface delivered in the most-recently-processed
 * #GdkEventConfigure. gdk_surface_get_position() in contrast gets the
 * position from the most recent configure event.
 *
 * Note: If @surface is not a toplevel, it is much better
 * to call gdk_surface_get_position(), gdk_surface_get_width() and
 * gdk_surface_get_height() instead, because it avoids the roundtrip to
 * the X server and because these functions support the full 32-bit
 * coordinate space, whereas gdk_surface_get_geometry() is restricted to
 * the 16-bit coordinates of X11.
 */
void
gdk_surface_get_geometry (GdkSurface *surface,
                          gint      *x,
                          gint      *y,
                          gint      *width,
                          gint      *height)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (GDK_SURFACE_DESTROYED (surface))
    return;

  GDK_SURFACE_GET_CLASS (surface)->get_geometry (surface, x, y, width, height);
}

/**
 * gdk_surface_get_width:
 * @surface: a #GdkSurface
 *
 * Returns the width of the given @surface.
 *
 * Surface size is reported in ”application pixels”, not
 * ”device pixels” (see gdk_surface_get_scale_factor()).
 *
 * Returns: The width of @surface
 */
int
gdk_surface_get_width (GdkSurface *surface)
{
  g_return_val_if_fail (GDK_IS_SURFACE (surface), 0);

  return surface->width;
}

/**
 * gdk_surface_get_height:
 * @surface: a #GdkSurface
 *
 * Returns the height of the given @surface.
 *
 * Surface size is reported in ”application pixels”, not
 * ”device pixels” (see gdk_surface_get_scale_factor()).
 *
 * Returns: The height of @surface
 */
int
gdk_surface_get_height (GdkSurface *surface)
{
  g_return_val_if_fail (GDK_IS_SURFACE (surface), 0);

  return surface->height;
}

/*
 * gdk_surface_get_origin:
 * @surface: a #GdkSurface
 * @x: (out): return location for X coordinate
 * @y: (out): return location for Y coordinate
 *
 * Obtains the position of a surface in root window coordinates.
 * (Compare with gdk_surface_get_position() and
 * gdk_surface_get_geometry() which return the position
 * of a surface relative to its parent surface.)
 */
void
gdk_surface_get_origin (GdkSurface *surface,
                        gint       *x,
                        gint       *y)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  gdk_surface_get_root_coords (surface, 0, 0, x, y);
}

/*
 * gdk_surface_get_root_coords:
 * @surface: a #GdkSurface
 * @x: X coordinate in surface
 * @y: Y coordinate in surface
 * @root_x: (out): return location for X coordinate
 * @root_y: (out): return location for Y coordinate
 *
 * Obtains the position of a surface position in root
 * window coordinates. This is similar to
 * gdk_surface_get_origin() but allows you to pass
 * in any position in the surface, not just the origin.
 */
void
gdk_surface_get_root_coords (GdkSurface *surface,
                             gint       x,
                             gint       y,
                             gint      *root_x,
                             gint      *root_y)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (GDK_SURFACE_DESTROYED (surface))
    {
      *root_x = 0;
      *root_y = 0;
      return;
    }
  
  GDK_SURFACE_GET_CLASS (surface)->get_root_coords (surface, x, y, root_x, root_y);
}

/**
 * gdk_surface_set_input_region:
 * @surface: a #GdkSurface
 * @region: region of surface to be reactive
 *
 * Apply the region to the surface for the purpose of event
 * handling. Mouse events which happen while the pointer position
 * corresponds to an unset bit in the mask will be passed on the
 * surface below @surface.
 *
 * An input region is typically used with RGBA surfaces.
 * The alpha channel of the surface defines which pixels are
 * invisible and allows for nicely antialiased borders,
 * and the input region controls where the surface is
 * “clickable”.
 *
 * Use gdk_display_support_input_shapes() to find out if
 * a particular backend supports input regions.
 */
void
gdk_surface_set_input_region (GdkSurface     *surface,
                              cairo_region_t *region)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (GDK_SURFACE_DESTROYED (surface))
    return;

  if (cairo_region_equal (surface->input_region, region))
    return;

  if (surface->input_region)
    cairo_region_destroy (surface->input_region);

  if (region)
    surface->input_region = cairo_region_copy (region);
  else
    surface->input_region = NULL;

  GDK_SURFACE_GET_CLASS (surface)->set_input_region (surface, surface->input_region);
}

static void
update_cursor (GdkDisplay *display,
               GdkDevice  *device)
{
  GdkSurface *cursor_surface;
  GdkSurface *pointer_surface;
  GdkPointerSurfaceInfo *pointer_info;
  GdkDeviceGrabInfo *grab;
  GdkCursor *cursor;

  pointer_info = _gdk_display_get_pointer_info (display, device);
  pointer_surface = pointer_info->surface_under_pointer;

  /* We ignore the serials here and just pick the last grab
     we've sent, as that would shortly be used anyway. */
  grab = _gdk_display_get_last_device_grab (display, device);
  if (grab != NULL)
    {
      /* use the cursor from the grab surface */
      cursor_surface = grab->surface;
    }
  else
    {
      /* otherwise use the cursor from the pointer surface */
      cursor_surface = pointer_surface;
    }

  cursor = g_hash_table_lookup (cursor_surface->device_cursor, device);

  if (!cursor)
    cursor = cursor_surface->cursor;

  GDK_DEVICE_GET_CLASS (device)->set_surface_cursor (device, pointer_surface, cursor);
}

/**
 * gdk_surface_beep:
 * @surface: a toplevel #GdkSurface
 *
 * Emits a short beep associated to @surface in the appropriate
 * display, if supported. Otherwise, emits a short beep on
 * the display just as gdk_display_beep().
 **/
void
gdk_surface_beep (GdkSurface *surface)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (GDK_SURFACE_DESTROYED (surface))
    return;

  if (GDK_SURFACE_GET_CLASS (surface)->beep (surface))
    return;

  gdk_display_beep (surface->display);
}

/**
 * gdk_surface_set_support_multidevice:
 * @surface: a #GdkSurface.
 * @support_multidevice: %TRUE to enable multidevice support in @surface.
 *
 * This function will enable multidevice features in @surface.
 *
 * Multidevice aware surfaces will need to handle properly multiple,
 * per device enter/leave events, device grabs and grab ownerships.
 **/
void
gdk_surface_set_support_multidevice (GdkSurface *surface,
                                     gboolean   support_multidevice)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (GDK_SURFACE_DESTROYED (surface))
    return;

  if (surface->support_multidevice == support_multidevice)
    return;

  surface->support_multidevice = support_multidevice;

  /* FIXME: What to do if called when some pointers are inside the surface ? */
}

/**
 * gdk_surface_get_support_multidevice:
 * @surface: a #GdkSurface.
 *
 * Returns %TRUE if the surface is aware of the existence of multiple
 * devices.
 *
 * Returns: %TRUE if the surface handles multidevice features.
 **/
gboolean
gdk_surface_get_support_multidevice (GdkSurface *surface)
{
  g_return_val_if_fail (GDK_IS_SURFACE (surface), FALSE);

  if (GDK_SURFACE_DESTROYED (surface))
    return FALSE;

  return surface->support_multidevice;
}

void
_gdk_display_set_surface_under_pointer (GdkDisplay *display,
                                        GdkDevice  *device,
                                        GdkSurface  *surface)
{
  GdkPointerSurfaceInfo *device_info;

  device_info = _gdk_display_get_pointer_info (display, device);

  if (device_info->surface_under_pointer)
    g_object_unref (device_info->surface_under_pointer);
  device_info->surface_under_pointer = surface;

  if (surface)
    {
      g_object_ref (surface);
      update_cursor (display, device);
    }
}

#define GDK_ANY_BUTTON_MASK (GDK_BUTTON1_MASK | \
                             GDK_BUTTON2_MASK | \
                             GDK_BUTTON3_MASK | \
                             GDK_BUTTON4_MASK | \
                             GDK_BUTTON5_MASK)

void
_gdk_windowing_got_event (GdkDisplay *display,
                          GList      *event_link,
                          GdkEvent   *event,
                          gulong      serial)
{
  GdkSurface *event_surface;
  gboolean unlink_event = FALSE;
  GdkDeviceGrabInfo *button_release_grab;
  GdkPointerSurfaceInfo *pointer_info = NULL;
  GdkDevice *device, *source_device;
  GdkEventType type;

  _gdk_display_update_last_event (display, event);

  device = gdk_event_get_device (event);
  source_device = gdk_event_get_source_device (event);

  if (device)
    {
      if (gdk_device_get_source (device) != GDK_SOURCE_KEYBOARD &&
          gdk_device_get_source (device) != GDK_SOURCE_TABLET_PAD)
        {
          pointer_info = _gdk_display_get_pointer_info (display, device);

          if (source_device != pointer_info->last_slave &&
              gdk_device_get_device_type (source_device) == GDK_DEVICE_TYPE_SLAVE)
            pointer_info->last_slave = source_device;
          else if (pointer_info->last_slave)
            source_device = pointer_info->last_slave;
        }

      _gdk_display_device_grab_update (display, device, source_device, serial);

      if (!_gdk_display_check_grab_ownership (display, device, serial))
        {
          /* Device events are blocked by another device grab */
          unlink_event = TRUE;
          goto out;
        }
    }

  event_surface = gdk_event_get_surface (event);
  if (!event_surface)
    goto out;

  type = gdk_event_get_event_type (event);
  if (type == GDK_ENTER_NOTIFY)
    _gdk_display_set_surface_under_pointer (display, device, event_surface);
  else if (type == GDK_LEAVE_NOTIFY)
    _gdk_display_set_surface_under_pointer (display, device, NULL);

  if (type == GDK_BUTTON_PRESS)
    {
      GdkSurface *grab_surface;
      gboolean owner_events;

      if (!gdk_device_grab_info (display, device, &grab_surface, &owner_events))
        {
          _gdk_display_add_device_grab (display,
                                        device,
                                        event_surface,
                                        GDK_OWNERSHIP_NONE,
                                        FALSE,
                                        GDK_ALL_EVENTS_MASK,
                                        serial,
                                        gdk_event_get_time (event),
                                        TRUE);
          _gdk_display_device_grab_update (display, device,
                                           source_device, serial);
        }
    }
  else if (type == GDK_BUTTON_RELEASE ||
           type == GDK_TOUCH_CANCEL ||
           type == GDK_TOUCH_END)
    {
      if (type == GDK_BUTTON_RELEASE ||
          gdk_event_get_pointer_emulated (event))
        {
          button_release_grab =
            _gdk_display_has_device_grab (display, device, serial);

          if (button_release_grab &&
              button_release_grab->implicit &&
              (gdk_event_get_modifier_state (event) & GDK_ANY_BUTTON_MASK & ~(GDK_BUTTON1_MASK << (gdk_button_event_get_button (event) - 1))) == 0)
            {
              button_release_grab->serial_end = serial;
              button_release_grab->implicit_ungrab = FALSE;
              _gdk_display_device_grab_update (display, device, source_device, serial);
            }
        }
    }

 out:
  if (unlink_event)
    {
      _gdk_event_queue_remove_link (display, event_link);
      g_list_free_1 (event_link);
      gdk_event_unref (event);
    }

  /* This does two things - first it sees if there are motions at the
   * end of the queue that can be compressed. Second, if there is just
   * a single motion that won't be dispatched because it is a compression
   * candidate it queues up flushing the event queue.
   */
  _gdk_event_queue_handle_motion_compression (display);
  gdk_event_queue_handle_scroll_compression (display);
}

/**
 * gdk_surface_create_similar_surface:
 * @surface: surface to make new surface similar to
 * @content: the content for the new surface
 * @width: width of the new surface
 * @height: height of the new surface
 *
 * Create a new surface that is as compatible as possible with the
 * given @surface. For example the new surface will have the same
 * fallback resolution and font options as @surface. Generally, the new
 * surface will also use the same backend as @surface, unless that is
 * not possible for some reason. The type of the returned surface may
 * be examined with cairo_surface_get_type().
 *
 * Initially the surface contents are all 0 (transparent if contents
 * have transparency, black otherwise.)
 *
 * Returns: a pointer to the newly allocated surface. The caller
 * owns the surface and should call cairo_surface_destroy() when done
 * with it.
 *
 * This function always returns a valid pointer, but it will return a
 * pointer to a “nil” surface if @other is already in an error state
 * or any other error occurs.
 **/
cairo_surface_t *
gdk_surface_create_similar_surface (GdkSurface *     surface,
                                    cairo_content_t content,
                                    int             width,
                                    int             height)
{
  cairo_surface_t *similar_surface;
  int scale;

  g_return_val_if_fail (GDK_IS_SURFACE (surface), NULL);

  scale = gdk_surface_get_scale_factor (surface);

  similar_surface = cairo_image_surface_create (content == CAIRO_CONTENT_COLOR ? CAIRO_FORMAT_RGB24 :
                                                content == CAIRO_CONTENT_ALPHA ? CAIRO_FORMAT_A8 : CAIRO_FORMAT_ARGB32,
                                                width * scale, height * scale);
  cairo_surface_set_device_scale (similar_surface, scale, scale);

  return similar_surface;
}

/* This function is called when the XWindow is really gone.
 */
void
gdk_surface_destroy_notify (GdkSurface *surface)
{
  GDK_SURFACE_GET_CLASS (surface)->destroy_notify (surface);
}

/**
 * gdk_drag_begin:
 * @surface: the source surface for this drag
 * @device: the device that controls this drag
 * @content: (transfer none): the offered content
 * @actions: the actions supported by this drag
 * @dx: the x offset to @device's position where the drag nominally started
 * @dy: the y offset to @device's position where the drag nominally started
 *
 * Starts a drag and creates a new drag context for it.
 *
 * This function is called by the drag source. After this call, you
 * probably want to set up the drag icon using the surface returned
 * by gdk_drag_get_drag_surface().
 *
 * This function returns a reference to the GdkDrag object, but GTK
 * keeps its own reference as well, as long as the DND operation is
 * going on.
 *
 * Note: if @actions include %GDK_ACTION_MOVE, you need to listen for
 * the #GdkDrag::dnd-finished signal and delete the data at the source
 * if gdk_drag_get_selected_action() returns %GDK_ACTION_MOVE.
 *
 * Returns: (transfer full) (nullable): a newly created #GdkDrag or
 *     %NULL on error.
 */
GdkDrag *
gdk_drag_begin (GdkSurface          *surface,
                GdkDevice          *device,
                GdkContentProvider *content,
                GdkDragAction       actions,
                double              dx,
                double              dy)
{
  g_return_val_if_fail (GDK_IS_SURFACE (surface), NULL);
  g_return_val_if_fail (GDK_IS_DEVICE (device), NULL);
  g_return_val_if_fail (surface->display == gdk_device_get_display (device), NULL);
  g_return_val_if_fail (GDK_IS_CONTENT_PROVIDER (content), NULL);

  return GDK_SURFACE_GET_CLASS (surface)->drag_begin (surface, device, content, actions, dx, dy);
}

static void
gdk_surface_flush_events (GdkFrameClock *clock,
                          void          *data)
{
  GdkSurface *surface = GDK_SURFACE (data);

  _gdk_event_queue_flush (surface->display);
  _gdk_display_pause_events (surface->display);

  gdk_frame_clock_request_phase (clock, GDK_FRAME_CLOCK_PHASE_RESUME_EVENTS);
  surface->frame_clock_events_paused = TRUE;
}

static void
gdk_surface_resume_events (GdkFrameClock *clock,
                           void          *data)
{
  GdkSurface *surface = GDK_SURFACE (data);

  if (surface->frame_clock_events_paused)
    {
      _gdk_display_unpause_events (surface->display);
      surface->frame_clock_events_paused = FALSE;
    }
}

static void
gdk_surface_set_frame_clock (GdkSurface     *surface,
                             GdkFrameClock *clock)
{
  g_return_if_fail (GDK_IS_SURFACE (surface));
  g_return_if_fail (clock == NULL || GDK_IS_FRAME_CLOCK (clock));

  if (clock == surface->frame_clock)
    return;

  if (clock)
    {
      g_object_ref (clock);

      g_signal_connect (G_OBJECT (clock),
                        "flush-events",
                        G_CALLBACK (gdk_surface_flush_events),
                        surface);
      g_signal_connect (G_OBJECT (clock),
                        "resume-events",
                        G_CALLBACK (gdk_surface_resume_events),
                        surface);
      g_signal_connect (G_OBJECT (clock),
                        "paint",
                        G_CALLBACK (gdk_surface_paint_on_clock),
                        surface);

      if (surface->update_freeze_count == 0)
        _gdk_frame_clock_inhibit_freeze (clock);
    }

  if (surface->frame_clock)
    {
      if (surface->frame_clock_events_paused)
        gdk_surface_resume_events (surface->frame_clock, G_OBJECT (surface));

      g_signal_handlers_disconnect_by_func (G_OBJECT (surface->frame_clock),
                                            G_CALLBACK (gdk_surface_flush_events),
                                            surface);
      g_signal_handlers_disconnect_by_func (G_OBJECT (surface->frame_clock),
                                            G_CALLBACK (gdk_surface_resume_events),
                                            surface);
      g_signal_handlers_disconnect_by_func (G_OBJECT (surface->frame_clock),
                                            G_CALLBACK (gdk_surface_paint_on_clock),
                                            surface);

      if (surface->update_freeze_count == 0)
        _gdk_frame_clock_uninhibit_freeze (surface->frame_clock);

      g_object_unref (surface->frame_clock);
    }

  surface->frame_clock = clock;
}

/**
 * gdk_surface_get_frame_clock:
 * @surface: surface to get frame clock for
 *
 * Gets the frame clock for the surface. The frame clock for a surface
 * never changes unless the surface is reparented to a new toplevel
 * surface.
 *
 * Returns: (transfer none): the frame clock
 */
GdkFrameClock*
gdk_surface_get_frame_clock (GdkSurface *surface)
{
  g_return_val_if_fail (GDK_IS_SURFACE (surface), NULL);

  return surface->frame_clock;
}

/**
 * gdk_surface_get_scale_factor:
 * @surface: surface to get scale factor for
 *
 * Returns the internal scale factor that maps from surface coordinates
 * to the actual device pixels. On traditional systems this is 1, but
 * on very high density outputs this can be a higher value (often 2).
 *
 * A higher value means that drawing is automatically scaled up to
 * a higher resolution, so any code doing drawing will automatically look
 * nicer. However, if you are supplying pixel-based data the scale
 * value can be used to determine whether to use a pixel resource
 * with higher resolution data.
 *
 * The scale of a surface may change during runtime, if this happens
 * a configure event will be sent to the toplevel surface.
 *
 * Returns: the scale factor
 */
gint
gdk_surface_get_scale_factor (GdkSurface *surface)
{
  GdkSurfaceClass *class;

  g_return_val_if_fail (GDK_IS_SURFACE (surface), 1);

  if (GDK_SURFACE_DESTROYED (surface))
    return 1;

  class = GDK_SURFACE_GET_CLASS (surface);
  if (class->get_scale_factor)
    return class->get_scale_factor (surface);

  return 1;
}

/* Returns the *real* unscaled size, which may be a fractional size
   in surface scale coordinates. We need this to properly handle GL
   coordinates which are y-flipped in the real coordinates. */
void
gdk_surface_get_unscaled_size (GdkSurface *surface,
                               int *unscaled_width,
                               int *unscaled_height)
{
  GdkSurfaceClass *class;
  gint scale;

  g_return_if_fail (GDK_IS_SURFACE (surface));

  class = GDK_SURFACE_GET_CLASS (surface);

  if (class->get_unscaled_size)
    {
      class->get_unscaled_size (surface, unscaled_width, unscaled_height);
      return;
    }

  scale = gdk_surface_get_scale_factor (surface);

  if (unscaled_width)
    *unscaled_width = surface->width * scale;

  if (unscaled_height)
    *unscaled_height = surface->height * scale;
}


/**
 * gdk_surface_set_opaque_region:
 * @surface: a top-level or non-native #GdkSurface
 * @region: (allow-none):  a region, or %NULL
 *
 * For optimisation purposes, compositing window managers may
 * like to not draw obscured regions of surfaces, or turn off blending
 * during for these regions. With RGB windows with no transparency,
 * this is just the shape of the window, but with ARGB32 windows, the
 * compositor does not know what regions of the window are transparent
 * or not.
 *
 * This function only works for toplevel surfaces.
 *
 * GTK will update this property automatically if
 * the @surface background is opaque, as we know where the opaque regions
 * are. If your surface background is not opaque, please update this
 * property in your #GtkWidgetClass.css_changed() handler.
 */
void
gdk_surface_set_opaque_region (GdkSurface      *surface,
                               cairo_region_t *region)
{
  GdkSurfaceClass *class;

  g_return_if_fail (GDK_IS_SURFACE (surface));
  g_return_if_fail (!GDK_SURFACE_DESTROYED (surface));

  if (cairo_region_equal (surface->opaque_region, region))
    return;

  g_clear_pointer (&surface->opaque_region, cairo_region_destroy);

  if (region != NULL)
    surface->opaque_region = cairo_region_reference (region);

  class = GDK_SURFACE_GET_CLASS (surface);
  if (class->set_opaque_region)
    class->set_opaque_region (surface, region);
}

/**
 * gdk_surface_set_shadow_width:
 * @surface: a #GdkSurface
 * @left: The left extent
 * @right: The right extent
 * @top: The top extent
 * @bottom: The bottom extent
 *
 * Newer GTK windows using client-side decorations use extra geometry
 * around their frames for effects like shadows and invisible borders.
 * Window managers that want to maximize windows or snap to edges need
 * to know where the extents of the actual frame lie, so that users
 * don’t feel like windows are snapping against random invisible edges.
 *
 * Note that this property is automatically updated by GTK, so this
 * function should only be used by applications which do not use GTK
 * to create toplevel surfaces.
 */
void
gdk_surface_set_shadow_width (GdkSurface *surface,
                              gint       left,
                              gint       right,
                              gint       top,
                              gint       bottom)
{
  GdkSurfaceClass *class;

  g_return_if_fail (GDK_IS_SURFACE (surface));
  g_return_if_fail (!GDK_SURFACE_DESTROYED (surface));
  g_return_if_fail (left >= 0 && right >= 0 && top >= 0 && bottom >= 0);

  if (surface->shadow_left == left &&
      surface->shadow_right == right &&
      surface->shadow_top == top &&
      surface->shadow_bottom == bottom)
    return;

  surface->shadow_top = top;
  surface->shadow_left = left;
  surface->shadow_right = right;
  surface->shadow_bottom = bottom;

  class = GDK_SURFACE_GET_CLASS (surface);
  if (class->set_shadow_width)
    class->set_shadow_width (surface, left, right, top, bottom);
}

void
gdk_surface_set_state (GdkSurface      *surface,
                       GdkSurfaceState  new_state)
{
  gboolean was_mapped, mapped;
  gboolean was_sticky, sticky;
  g_return_if_fail (GDK_IS_SURFACE (surface));

  if (new_state == surface->state)
    return; /* No actual work to do, nothing changed. */

  /* Actually update the field in GdkSurface, this is sort of an odd
   * place to do it, but seems like the safest since it ensures we expose no
   * inconsistent state to the user.
   */

  was_mapped = GDK_SURFACE_IS_MAPPED (surface);
  was_sticky = GDK_SURFACE_IS_STICKY (surface);

  surface->state = new_state;

  mapped = GDK_SURFACE_IS_MAPPED (surface);
  sticky = GDK_SURFACE_IS_STICKY (surface);

  if (GDK_IS_TOPLEVEL (surface))
    g_object_notify (G_OBJECT (surface), "state");

  if (was_mapped != mapped)
    g_object_notify_by_pspec (G_OBJECT (surface), properties[PROP_MAPPED]);

  if (was_sticky != sticky)
    g_object_notify (G_OBJECT (surface), "sticky");
}

void
gdk_synthesize_surface_state (GdkSurface     *surface,
                              GdkSurfaceState unset_flags,
                              GdkSurfaceState set_flags)
{
  gdk_surface_set_state (surface, (surface->state | set_flags) & ~unset_flags);
}

static void
hide_popup_chain (GdkSurface *surface)
{
  GdkSurface *parent;

  gdk_surface_hide (surface);

  parent = surface->parent;
  if (parent->autohide)
    hide_popup_chain (parent);
}

static gboolean
check_autohide (GdkEvent *event)
{
  GdkDisplay *display;
  GdkDevice *device;
  GdkSurface *grab_surface;

 switch ((guint) gdk_event_get_event_type (event))
    {
    case GDK_BUTTON_PRESS:
#if 0
    // FIXME: we need to ignore the release that is paired
    // with the press starting the grab - due to implicit
    // grabs, it will be delivered to the same place as the
    // press, and will cause the auto dismissal to be triggered.
    case GDK_BUTTON_RELEASE:
#endif
    case GDK_TOUCH_BEGIN:
    case GDK_TOUCH_END:
    case GDK_TOUCH_CANCEL:
    case GDK_TOUCHPAD_SWIPE:
    case GDK_TOUCHPAD_PINCH:
      display = gdk_event_get_display (event);
      device = gdk_event_get_device (event);
      if (gdk_device_grab_info (display, device, &grab_surface, NULL))
        {
          if (grab_surface != gdk_event_get_surface (event) &&
              grab_surface->autohide)
            {
              hide_popup_chain (grab_surface);
              return TRUE;
            }
        }
      break;
    default:;
    }

  return FALSE;
}

static void
add_event_mark (GdkEvent *event,
                gint64    time,
                guint64   duration)
{
  gchar *message = NULL;
  const gchar *kind;
  GEnumClass *class;
  GEnumValue *value;
  GdkEventType event_type;

  event_type = gdk_event_get_event_type (event);
  class = g_type_class_ref (GDK_TYPE_EVENT_TYPE);
  value = g_enum_get_value (class, event_type);
  g_type_class_unref (class);
  kind = value ? value->value_nick : "event";

  switch ((int) event_type)
    {
    case GDK_MOTION_NOTIFY:
      {
        double x, y;
        gdk_event_get_position (event, &x, &y);
        message = g_strdup_printf ("%s {x=%lf, y=%lf, state=0x%x}",
                                   kind,
                                   x, y,
                                   gdk_event_get_modifier_state (event));
        break;
      }

    case GDK_BUTTON_PRESS:
    case GDK_BUTTON_RELEASE:
      {
        double x, y;
        gdk_event_get_position (event, &x, &y);
        message = g_strdup_printf ("%s {button=%u, x=%lf, y=%lf, state=0x%x}",
                                   kind,
                                   gdk_button_event_get_button (event),
                                   x, y,
                                   gdk_event_get_modifier_state (event));
        break;
      }

    case GDK_KEY_PRESS:
    case GDK_KEY_RELEASE:
      {
        message = g_strdup_printf ("%s {keyval=%u, state=0x%x, keycode=%u layout=%u level=%u is_modifier=%u}",
                                   kind,
                                   gdk_key_event_get_keyval (event),
                                   gdk_event_get_modifier_state (event),
                                   gdk_key_event_get_keycode (event),
                                   gdk_key_event_get_layout (event),
                                   gdk_key_event_get_level (event),
                                   gdk_key_event_is_modifier (event));
        break;
      }

    case GDK_CONFIGURE:
      {
        int width, height;
        gdk_configure_event_get_size (event, &width, &height);
        message = g_strdup_printf ("%s {width=%d, height=%d}", kind, width, height);
        break;
      }

    case GDK_ENTER_NOTIFY:
    case GDK_LEAVE_NOTIFY:
    case GDK_TOUCHPAD_SWIPE:
    case GDK_TOUCHPAD_PINCH:
    case GDK_SCROLL:
    case GDK_DRAG_ENTER:
    case GDK_DRAG_LEAVE:
    case GDK_DRAG_MOTION:
    case GDK_DROP_START:
    case GDK_TOUCH_BEGIN:
    case GDK_TOUCH_UPDATE:
    case GDK_TOUCH_END:
    case GDK_TOUCH_CANCEL:
    case GDK_PAD_BUTTON_PRESS:
    case GDK_PAD_BUTTON_RELEASE:
    case GDK_PAD_RING:
    case GDK_PAD_STRIP:
    case GDK_PAD_GROUP_MODE:
    case GDK_GRAB_BROKEN:
    case GDK_DELETE:
    case GDK_FOCUS_CHANGE:
    case GDK_PROXIMITY_IN:
    case GDK_PROXIMITY_OUT:
    case GDK_EVENT_LAST:
    default:
      break;
    }

  gdk_profiler_add_mark (time, duration, "event", message ? message : kind);

  g_free (message);
}

gboolean
gdk_surface_handle_event (GdkEvent *event)
{
  gint64 begin_time = g_get_monotonic_time ();
  gboolean handled = FALSE;

  if (check_autohide (event))
    return TRUE;

  if (gdk_event_get_event_type (event) == GDK_CONFIGURE)
    {
      int width, height;

      gdk_configure_event_get_size (event, &width, &height);
      g_signal_emit (gdk_event_get_surface (event), signals[SIZE_CHANGED], 0,
                     width, height);
      handled = TRUE;
    }
  else
    {
      g_signal_emit (gdk_event_get_surface (event), signals[EVENT], 0, event, &handled);
    }

  if (GDK_PROFILER_IS_RUNNING)
    add_event_mark (event, begin_time, g_get_monotonic_time () - begin_time);

  return handled;
}

/**
 * gdk_surface_translate_coordinates:
 * @from: the origin surface
 * @to: the target surface
 * @x: coordinates to translate
 * @y: coordinates to translate
 *
 * Translates the given coordinates from being
 * relative to the @from surface to being relative
 * to the @to surface.
 *
 * Note that this only works if @to and @from are
 * popups or transient-for to the same toplevel
 * (directly or indirectly).
 *
 * Returns: %TRUE if the coordinates were successfully
 *     translated
 */
gboolean
gdk_surface_translate_coordinates (GdkSurface *from,
                                   GdkSurface *to,
                                   double     *x,
                                   double     *y)
{
  int x1, y1, x2, y2;
  GdkSurface *f, *t;

  x1 = 0;
  y1 = 0;
  f = from;
  while (f->parent)
    {
      x1 += f->x;
      y1 += f->y;
      f = f->parent;
    }

  x2 = 0;
  y2 = 0;
  t = to;
  while (t->parent)
    {
      x2 += t->x;
      y2 += t->y;
      t = t->parent;
    }

  if (f != t)
    return FALSE;

  *x += x1 - x2;
  *y += y1 - y2;

  return TRUE;
}

GdkSeat *
gdk_surface_get_seat_from_event (GdkSurface *surface,
                                 GdkEvent   *event)
{
  if (event)
    {
      GdkDevice *device = gdk_event_get_device (event);
      GdkSeat *seat = NULL;

      if (device)
        seat = gdk_device_get_seat (device);

      if (seat)
        return seat;
    }
  return gdk_display_get_default_seat (surface->display);
}

void
gdk_surface_enter_monitor (GdkSurface *surface,
                           GdkMonitor *monitor)
{
  g_signal_emit (surface, signals[ENTER_MONITOR], 0, monitor);
}

void
gdk_surface_leave_monitor (GdkSurface *surface,
                           GdkMonitor *monitor)
{
  g_signal_emit (surface, signals[LEAVE_MONITOR], 0, monitor);
}