/*
 * Copyright © 2020 Red Hat, Inc.
 *
 * 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/>.
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */

#include "config.h"

#import "GdkMacosWindow.h"

#include "gdkmacostoplevelsurface-private.h"

#include "gdkframeclockidleprivate.h"
#include "gdkseatprivate.h"
#include "gdktoplevelprivate.h"

#include "gdkmacosdevice-private.h"
#include "gdkmacosdisplay-private.h"
#include "gdkmacosmonitor-private.h"
#include "gdkmacosutils-private.h"

static void
_gdk_macos_toplevel_surface_fullscreen (GdkMacosToplevelSurface *self)
{
  GdkMacosWindow *window;

  g_assert (GDK_IS_MACOS_TOPLEVEL_SURFACE (self));

  window = (GdkMacosWindow *)_gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));

  if (![window inFullscreenTransition] && ([window styleMask] & NSWindowStyleMaskFullScreen) == 0)
    [window toggleFullScreen:window];
}

static void
_gdk_macos_toplevel_surface_unfullscreen (GdkMacosToplevelSurface *self)
{
  GdkMacosWindow *window;

  g_assert (GDK_IS_MACOS_TOPLEVEL_SURFACE (self));

  window = (GdkMacosWindow *)_gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));

  if (![window inFullscreenTransition] && ([window styleMask] & NSWindowStyleMaskFullScreen) != 0)
    [window toggleFullScreen:window];
}

static void
_gdk_macos_toplevel_surface_maximize (GdkMacosToplevelSurface *self)
{
  NSWindow *window;

  g_assert (GDK_IS_MACOS_TOPLEVEL_SURFACE (self));

  window = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));

  if (![window isZoomed])
    [window zoom:window];
}

static void
_gdk_macos_toplevel_surface_unmaximize (GdkMacosToplevelSurface *self)
{
  NSWindow *window;

  g_assert (GDK_IS_MACOS_TOPLEVEL_SURFACE (self));

  window = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));

  if ([window isZoomed])
    [window zoom:window];
}

static void
_gdk_macos_toplevel_surface_unminimize (GdkMacosToplevelSurface *self)
{
  NSWindow *window;

  g_assert (GDK_IS_MACOS_TOPLEVEL_SURFACE (self));

  window = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));

  if ([window isMiniaturized])
    [window deminiaturize:window];
}

static gboolean
_gdk_macos_toplevel_surface_compute_size (GdkSurface *surface)
{
  GdkMacosToplevelSurface *self = (GdkMacosToplevelSurface *)surface;
  GdkMacosSurface *macos_surface = (GdkMacosSurface *)surface;
  GdkToplevelSize size;
  GdkDisplay *display;
  GdkMonitor *monitor;
  int bounds_width, bounds_height;
  GdkGeometry geometry;
  GdkSurfaceHints mask;

  g_assert (GDK_IS_MACOS_TOPLEVEL_SURFACE (self));

  if (!GDK_MACOS_SURFACE (surface)->geometry_dirty)
    return FALSE;

  GDK_MACOS_SURFACE (surface)->geometry_dirty = FALSE;

  display = gdk_surface_get_display (surface);
  monitor = gdk_display_get_monitor_at_surface (display, surface);

  if (monitor)
    {
      GdkRectangle workarea;

      gdk_macos_monitor_get_workarea (monitor, &workarea);
      bounds_width = workarea.width;
      bounds_height = workarea.height;
    }
  else
    {
      bounds_width = G_MAXINT;
      bounds_height = G_MAXINT;
    }

  gdk_toplevel_size_init (&size, bounds_width, bounds_height);
  gdk_toplevel_notify_compute_size (GDK_TOPLEVEL (surface), &size);

  g_warn_if_fail (size.width > 0);
  g_warn_if_fail (size.height > 0);

  if (self->layout != NULL &&
      gdk_toplevel_layout_get_resizable (self->layout))
    {
      geometry.min_width = size.min_width;
      geometry.min_height = size.min_height;
      mask = GDK_HINT_MIN_SIZE;
    }
  else
    {
      geometry.max_width = geometry.min_width = size.width;
      geometry.max_height = geometry.min_height = size.height;
      mask = GDK_HINT_MIN_SIZE | GDK_HINT_MAX_SIZE;
    }

  _gdk_macos_surface_set_geometry_hints (macos_surface, &geometry, mask);

  if (surface->state & (GDK_TOPLEVEL_STATE_FULLSCREEN |
                        GDK_TOPLEVEL_STATE_MAXIMIZED |
                        GDK_TOPLEVEL_STATE_TILED |
                        GDK_TOPLEVEL_STATE_TOP_TILED |
                        GDK_TOPLEVEL_STATE_RIGHT_TILED |
                        GDK_TOPLEVEL_STATE_BOTTOM_TILED |
                        GDK_TOPLEVEL_STATE_LEFT_TILED |
                        GDK_TOPLEVEL_STATE_MINIMIZED) ||
      [macos_surface->window inLiveResize])
    return FALSE;

  /* If we delayed a user resize until the beginning of the frame,
   * apply it now so we can start processing updates for it.
   */
  if (macos_surface->next_layout.width > 0 &&
      macos_surface->next_layout.height > 0)
    {
      int root_x = macos_surface->next_layout.root_x;
      int root_y = macos_surface->next_layout.root_y;
      int width = macos_surface->next_layout.width;
      int height = macos_surface->next_layout.height;

      gdk_surface_constrain_size (&geometry, mask,
                                  width, height,
                                  &width, &height);

      macos_surface->next_layout.width = 0;
      macos_surface->next_layout.height = 0;

      _gdk_macos_surface_move_resize (macos_surface,
                                      root_x, root_y,
                                      width, height);

      return FALSE;
    }

  gdk_surface_constrain_size (&geometry, mask,
                              size.width, size.height,
                              &size.width, &size.height);

  if ((size.width != self->last_computed_width ||
       size.height != self->last_computed_height) &&
      (size.width != surface->width ||
       size.height != surface->height))
    {
      self->last_computed_width = size.width;
      self->last_computed_height = size.height;

      _gdk_macos_surface_resize (macos_surface, size.width, size.height);
    }

  return FALSE;
}

static void
_gdk_macos_toplevel_surface_present (GdkToplevel       *toplevel,
                                     GdkToplevelLayout *layout)
{
  GdkSurface *surface = GDK_SURFACE (toplevel);
  GdkMacosToplevelSurface *self = (GdkMacosToplevelSurface *)toplevel;
  NSWindow *nswindow = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));
  GdkDisplay *display = gdk_surface_get_display (surface);
  NSWindowStyleMask style_mask;
  gboolean maximize;
  gboolean fullscreen;

  g_assert (GDK_IS_MACOS_TOPLEVEL_SURFACE (self));
  g_assert (GDK_IS_MACOS_WINDOW (nswindow));

  if (layout != self->layout)
    {
      g_clear_pointer (&self->layout, gdk_toplevel_layout_unref);
      self->layout = gdk_toplevel_layout_copy (layout);
    }

  _gdk_macos_toplevel_surface_attach_to_parent (self);
  _gdk_macos_toplevel_surface_compute_size (surface);

  /* Only set 'Resizable' mask to get native resize zones if the window is
   * titled, otherwise we do this internally for CSD and do not need
   * NSWindow to do it for us. Additionally, it can mess things up when
   * doing a window resize since it can cause mouseDown to get passed
   * through to the next window.
   */
  style_mask = [nswindow styleMask];
  if (gdk_toplevel_layout_get_resizable (layout) &&
      (style_mask & NSWindowStyleMaskTitled) != 0)
    style_mask |= NSWindowStyleMaskResizable;
  else
    style_mask &= ~NSWindowStyleMaskResizable;

  if (style_mask != [nswindow styleMask])
    [nswindow setStyleMask:style_mask];

  /* Maximized state */
  if (gdk_toplevel_layout_get_maximized (layout, &maximize))
    {
      if (maximize)
        _gdk_macos_toplevel_surface_maximize (self);
      else
        _gdk_macos_toplevel_surface_unmaximize (self);
    }

  /* Fullscreen state */
  if (gdk_toplevel_layout_get_fullscreen (layout, &fullscreen))
    {
      if (fullscreen)
        {
          GdkMonitor *fullscreen_monitor =
            gdk_toplevel_layout_get_fullscreen_monitor (layout);

          if (fullscreen_monitor)
            {
              int x = 0, y = 0;

              _gdk_macos_display_position_surface (GDK_MACOS_DISPLAY (display),
                                                   GDK_MACOS_SURFACE (self),
                                                   fullscreen_monitor,
                                                   &x, &y);

              GDK_DEBUG (MISC, "Moving toplevel \"%s\" to %d,%d",
                         GDK_MACOS_SURFACE (self)->title ?
                         GDK_MACOS_SURFACE (self)->title :
                         "untitled",
                         x, y);

              _gdk_macos_surface_move (GDK_MACOS_SURFACE (self), x, y);
            }

          _gdk_macos_toplevel_surface_fullscreen (self);
        }
      else
        _gdk_macos_toplevel_surface_unfullscreen (self);
    }

  _gdk_macos_toplevel_surface_unminimize (self);

  if (!GDK_MACOS_SURFACE (self)->did_initial_present)
    {
      int x = 0, y = 0;

      _gdk_macos_display_position_surface (GDK_MACOS_DISPLAY (display),
                                           GDK_MACOS_SURFACE (self),
                                           gdk_toplevel_layout_get_fullscreen_monitor (layout),
                                           &x, &y);

      GDK_DEBUG (MISC, "Placing new toplevel \"%s\" at %d,%d",
                       GDK_MACOS_SURFACE (self)->title ?
                       GDK_MACOS_SURFACE (self)->title :
                       "untitled",
                       x, y);

      _gdk_macos_surface_move (GDK_MACOS_SURFACE (self), x, y);
    }

  _gdk_macos_surface_show (GDK_MACOS_SURFACE (self));

  GDK_MACOS_SURFACE (self)->did_initial_present = TRUE;
}

static gboolean
_gdk_macos_toplevel_surface_minimize (GdkToplevel *toplevel)
{
  GdkMacosToplevelSurface *self = (GdkMacosToplevelSurface *)toplevel;
  NSWindow *window = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));
  [window miniaturize:window];
  return TRUE;
}

static gboolean
_gdk_macos_toplevel_surface_lower (GdkToplevel *toplevel)
{
  GdkMacosToplevelSurface *self = (GdkMacosToplevelSurface *)toplevel;
  NSWindow *window = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));
  [window orderBack:window];
  return TRUE;
}

static void
_gdk_macos_toplevel_surface_focus (GdkToplevel *toplevel,
                                   guint32      timestamp)
{
  GdkMacosToplevelSurface *self = (GdkMacosToplevelSurface *)toplevel;
  NSWindow *nswindow;

  if (GDK_SURFACE_DESTROYED (self))
    return;

  nswindow = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));
  [nswindow makeKeyAndOrderFront:nswindow];
}

static void
_gdk_macos_toplevel_surface_begin_resize (GdkToplevel    *toplevel,
                                          GdkSurfaceEdge  edge,
                                          GdkDevice      *device,
                                          int             button,
                                          double          root_x,
                                          double          root_y,
                                          guint32         timestamp)
{
  NSWindow *nswindow;

  g_assert (GDK_IS_MACOS_SURFACE (toplevel));

  if (GDK_SURFACE_DESTROYED (toplevel))
    return;

  /* Release passive grab */
  if (button != 0)
    gdk_macos_device_set_implicit_grab (device, NULL);

  if ((nswindow = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (toplevel))))
    [(GdkMacosWindow *)nswindow beginManualResize:edge];
}

static void
_gdk_macos_toplevel_surface_begin_move (GdkToplevel *toplevel,
                                        GdkDevice   *device,
                                        int          button,
                                        double       root_x,
                                        double       root_y,
                                        guint32      timestamp)
{
  NSWindow *nswindow;

  g_assert (GDK_IS_MACOS_SURFACE (toplevel));

  if (GDK_SURFACE_DESTROYED (toplevel))
    return;

  /* Release passive grab */
  if (button != 0)
    gdk_macos_device_set_implicit_grab (device, NULL);

  if ((nswindow = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (toplevel))))
    [(GdkMacosWindow *)nswindow beginManualMove];
}


static void
toplevel_iface_init (GdkToplevelInterface *iface)
{
  iface->present = _gdk_macos_toplevel_surface_present;
  iface->minimize = _gdk_macos_toplevel_surface_minimize;
  iface->lower = _gdk_macos_toplevel_surface_lower;
  iface->focus = _gdk_macos_toplevel_surface_focus;
  iface->begin_resize = _gdk_macos_toplevel_surface_begin_resize;
  iface->begin_move = _gdk_macos_toplevel_surface_begin_move;
}

G_DEFINE_TYPE_WITH_CODE (GdkMacosToplevelSurface, _gdk_macos_toplevel_surface, GDK_TYPE_MACOS_SURFACE,
                         G_IMPLEMENT_INTERFACE (GDK_TYPE_TOPLEVEL, toplevel_iface_init))

enum {
  PROP_0,
  LAST_PROP
};

static void
_gdk_macos_toplevel_surface_set_transient_for (GdkMacosToplevelSurface *self,
                                               GdkMacosSurface         *parent)
{
  g_assert (GDK_IS_MACOS_TOPLEVEL_SURFACE (self));
  g_assert (!parent || GDK_IS_MACOS_SURFACE (parent));

  _gdk_macos_toplevel_surface_detach_from_parent (self);
  g_clear_object (&GDK_SURFACE (self)->transient_for);

  if (g_set_object (&GDK_SURFACE (self)->transient_for, GDK_SURFACE (parent)))
    _gdk_macos_toplevel_surface_attach_to_parent (self);
}

static void
_gdk_macos_toplevel_surface_set_decorated (GdkMacosToplevelSurface *self,
                                           gboolean                 decorated)
{
  g_assert (GDK_IS_MACOS_TOPLEVEL_SURFACE (self));

  decorated = !!decorated;

  if (decorated != self->decorated)
    {
      NSWindow *window = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));
      self->decorated = decorated;
      [(GdkMacosWindow *)window setDecorated:(BOOL)decorated];
    }
}

static void
_gdk_macos_toplevel_surface_hide (GdkSurface *surface)
{
  GdkMacosToplevelSurface *self = (GdkMacosToplevelSurface *)surface;

  _gdk_macos_toplevel_surface_detach_from_parent (self);

  GDK_SURFACE_CLASS (_gdk_macos_toplevel_surface_parent_class)->hide (surface);
}

static void
_gdk_macos_toplevel_surface_request_layout (GdkSurface *surface)
{
  GDK_MACOS_SURFACE (surface)->geometry_dirty = TRUE;
}

static void
_gdk_macos_toplevel_surface_destroy (GdkSurface *surface,
                                     gboolean    foreign_destroy)
{
  GdkMacosToplevelSurface *self = (GdkMacosToplevelSurface *)surface;

  g_clear_object (&GDK_SURFACE (self)->transient_for);
  g_clear_pointer (&self->layout, gdk_toplevel_layout_unref);

  GDK_SURFACE_CLASS (_gdk_macos_toplevel_surface_parent_class)->destroy (surface, foreign_destroy);
}

static void
_gdk_macos_toplevel_surface_get_property (GObject    *object,
                                          guint       prop_id,
                                          GValue     *value,
                                          GParamSpec *pspec)
{
  GdkSurface *surface = GDK_SURFACE (object);
  GdkMacosSurface *base = GDK_MACOS_SURFACE (surface);
  GdkMacosToplevelSurface *toplevel = GDK_MACOS_TOPLEVEL_SURFACE (base);

  switch (prop_id)
    {
    case LAST_PROP + GDK_TOPLEVEL_PROP_STATE:
      g_value_set_flags (value, surface->state);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_TITLE:
      g_value_set_string (value, _gdk_macos_surface_get_title (base));
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_STARTUP_ID:
      g_value_set_static_string (value, "");
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_TRANSIENT_FOR:
      g_value_set_object (value, GDK_SURFACE (toplevel)->transient_for);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_MODAL:
      g_value_set_boolean (value, GDK_SURFACE (toplevel)->modal_hint);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_ICON_LIST:
      g_value_set_pointer (value, NULL);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_DECORATED:
      g_value_set_boolean (value, toplevel->decorated);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_DELETABLE:
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_FULLSCREEN_MODE:
      g_value_set_enum (value, surface->fullscreen_mode);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_SHORTCUTS_INHIBITED:
      g_value_set_boolean (value, surface->shortcuts_inhibited);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_CAPABILITIES:
      g_value_set_flags (value, GDK_TOPLEVEL_CAPABILITIES_MAXIMIZE |
                                GDK_TOPLEVEL_CAPABILITIES_FULLSCREEN |
                                GDK_TOPLEVEL_CAPABILITIES_MINIMIZE |
                                GDK_TOPLEVEL_CAPABILITIES_LOWER);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_GRAVITY:
      g_value_set_enum (value, GDK_GRAVITY_NORTH_EAST);
      break;

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

static void
_gdk_macos_toplevel_surface_set_property (GObject      *object,
                                          guint         prop_id,
                                          const GValue *value,
                                          GParamSpec   *pspec)
{
  GdkSurface *surface = GDK_SURFACE (object);
  GdkMacosSurface *base = GDK_MACOS_SURFACE (surface);
  GdkMacosToplevelSurface *toplevel = GDK_MACOS_TOPLEVEL_SURFACE (base);

  switch (prop_id)
    {
    case LAST_PROP + GDK_TOPLEVEL_PROP_TITLE:
      _gdk_macos_surface_set_title (base, g_value_get_string (value));
      g_object_notify_by_pspec (G_OBJECT (surface), pspec);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_STARTUP_ID:
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_TRANSIENT_FOR:
      _gdk_macos_toplevel_surface_set_transient_for (toplevel, g_value_get_object (value));
      g_object_notify_by_pspec (G_OBJECT (surface), pspec);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_MODAL:
      GDK_SURFACE (surface)->modal_hint = g_value_get_boolean (value);
      g_object_notify_by_pspec (G_OBJECT (surface), pspec);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_ICON_LIST:
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_DECORATED:
      _gdk_macos_toplevel_surface_set_decorated (toplevel, g_value_get_boolean (value));
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_DELETABLE:
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_FULLSCREEN_MODE:
      surface->fullscreen_mode = g_value_get_enum (value);
      g_object_notify_by_pspec (G_OBJECT (surface), pspec);
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_SHORTCUTS_INHIBITED:
      break;

    case LAST_PROP + GDK_TOPLEVEL_PROP_GRAVITY:
      break;

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

static void
_gdk_macos_toplevel_surface_constructed (GObject *object)
{
  GDK_BEGIN_MACOS_ALLOC_POOL;

  GdkMacosWindow *window;
  GdkMacosToplevelSurface *self = GDK_MACOS_TOPLEVEL_SURFACE (object);
  GdkSurface *surface = GDK_SURFACE (self);
  GdkMacosDisplay *display = GDK_MACOS_DISPLAY (gdk_surface_get_display (surface));
  GdkFrameClock *frame_clock;
  NSUInteger style_mask;
  NSRect content_rect;
  NSRect visible_frame;
  NSScreen *screen;
  int nx;
  int ny;

  style_mask = (NSWindowStyleMaskTitled |
                NSWindowStyleMaskClosable |
                NSWindowStyleMaskMiniaturizable |
                NSWindowStyleMaskResizable);

  _gdk_macos_display_to_display_coords (display, 0, 100, &nx, &ny);

  screen = _gdk_macos_display_get_screen_at_display_coords (display, nx, ny);
  visible_frame = [screen visibleFrame];
  content_rect = NSMakeRect (nx - visible_frame.origin.x, ny - visible_frame.origin.y, 100, 100);
  window = [[GdkMacosWindow alloc] initWithContentRect:content_rect
                                             styleMask:style_mask
                                               backing:NSBackingStoreBuffered
                                                 defer:NO
                                                screen:screen];

  _gdk_macos_surface_set_native (GDK_MACOS_SURFACE (self), window);

  [window setOpaque:NO];

  /* Workaround: if we use full transparency, window rendering becomes slow,
   * because macOS tries to dynamically calculate the shadow.
   * Instead provide a tiny bit of alpha, so shadows are drawn around the window.
   */
  [window setBackgroundColor:[[NSColor blackColor] colorWithAlphaComponent:0.00001]];

  /* Allow NSWindow to go fullscreen */
  [window setCollectionBehavior:NSWindowCollectionBehaviorFullScreenPrimary];

  frame_clock = _gdk_frame_clock_idle_new ();
  gdk_surface_set_frame_clock (surface, frame_clock);
  g_object_unref (frame_clock);

  GDK_END_MACOS_ALLOC_POOL;

  G_OBJECT_CLASS (_gdk_macos_toplevel_surface_parent_class)->constructed (object);
}

static void
_gdk_macos_toplevel_surface_class_init (GdkMacosToplevelSurfaceClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);
  GdkSurfaceClass *surface_class = GDK_SURFACE_CLASS (klass);

  object_class->constructed = _gdk_macos_toplevel_surface_constructed;
  object_class->get_property = _gdk_macos_toplevel_surface_get_property;
  object_class->set_property = _gdk_macos_toplevel_surface_set_property;

  surface_class->destroy = _gdk_macos_toplevel_surface_destroy;
  surface_class->hide = _gdk_macos_toplevel_surface_hide;
  surface_class->compute_size = _gdk_macos_toplevel_surface_compute_size;
  surface_class->request_layout = _gdk_macos_toplevel_surface_request_layout;

  gdk_toplevel_install_properties (object_class, LAST_PROP);
}

static void
_gdk_macos_toplevel_surface_init (GdkMacosToplevelSurface *self)
{
  self->decorated = TRUE;
}

void
_gdk_macos_toplevel_surface_attach_to_parent (GdkMacosToplevelSurface *self)
{
  GdkSurface *surface = (GdkSurface *)self;

  g_return_if_fail (GDK_IS_MACOS_TOPLEVEL_SURFACE (self));

  if (GDK_SURFACE_DESTROYED (surface))
    return;

  if (surface->transient_for != NULL &&
      !GDK_SURFACE_DESTROYED (surface->transient_for))
    {
      NSWindow *parent = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (surface->transient_for));
      NSWindow *window = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));
      int x, y;

      [parent addChildWindow:window ordered:NSWindowAbove];

      if (GDK_SURFACE (self)->modal_hint)
        [window setLevel:NSModalPanelWindowLevel];

      surface->x = 0;
      surface->y = 0;

      _gdk_macos_display_clear_sorting (GDK_MACOS_DISPLAY (surface->display));
      _gdk_macos_display_position_surface (GDK_MACOS_DISPLAY (surface->display),
                                           GDK_MACOS_SURFACE (surface),
                                           NULL,
                                           &x, &y);
      _gdk_macos_surface_move (GDK_MACOS_SURFACE (surface), x, y);
    }
}

void
_gdk_macos_toplevel_surface_detach_from_parent (GdkMacosToplevelSurface *self)
{
  GdkSurface *surface = (GdkSurface *)self;

  g_return_if_fail (GDK_IS_MACOS_TOPLEVEL_SURFACE (self));

  if (GDK_SURFACE_DESTROYED (surface))
    return;

  if (surface->transient_for != NULL &&
      !GDK_SURFACE_DESTROYED (surface->transient_for))
    {
      NSWindow *parent = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (surface->transient_for));
      NSWindow *window = _gdk_macos_surface_get_native (GDK_MACOS_SURFACE (self));

      [parent removeChildWindow:window];
      [window setLevel:NSNormalWindowLevel];

      _gdk_macos_display_clear_sorting (GDK_MACOS_DISPLAY (surface->display));
    }
}