12to11/xdg_surface.c

/* Wayland compositor running on top of an X server.

Copyright (C) 2022 to various contributors.

This file is part of 12to11.

12to11 is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.

12to11 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 General Public License
for more details.

You should have received a copy of the GNU General Public License
along with 12to11.  If not, see <https://www.gnu.org/licenses/>.  */

#include <string.h>

#include <stdlib.h>
#include <stdio.h>

#include "compositor.h"
#include "xdg-shell.h"

#include <X11/extensions/shape.h>

#define XdgRoleFromRole(role) ((XdgRole *) (role))

/* This is the default core event mask used by our windows.  */
#define DefaultEventMask					\
  (ExposureMask | StructureNotifyMask | PropertyChangeMask)

enum
  {
    StatePendingFrameCallback	= 1,
    StateLateFrame		= (1 << 1),
    StatePendingWindowGeometry	= (1 << 2),
    StateWaitingForAckConfigure = (1 << 3),
    StateWaitingForAckCommit	= (1 << 4),
    StateLateFrameAcked		= (1 << 5),
    StateMaybeConfigure		= (1 << 6),
    StateDirtyFrameExtents	= (1 << 7),
    StateTemporaryBounds	= (1 << 8),
    StateFrameStarted		= (1 << 9),
  };

typedef struct _XdgRole XdgRole;
typedef struct _XdgState XdgState;
typedef struct _ReleaseLaterRecord ReleaseLaterRecord;
typedef struct _ReconstrainCallback ReconstrainCallback;

/* Association between XIDs and surfaces.  */

static XLAssocTable *surfaces;

/* The default border color of a window.  Not actually used for
   anything other than preventing BadMatch errors during window
   creation.  */

unsigned long border_pixel;

struct _ReconstrainCallback
{
  /* Function called when a configure event is received.  */
  void (*configure) (void *, XEvent *);

  /* Function called when we are certain a frame moved or resized.  */
  void (*resized) (void *);

  /* Data the functions is called with.  */
  void *data;

  /* The next and last callbacks in this list.  */
  ReconstrainCallback *next, *last;
};

struct _XdgState
{
  int window_geometry_x;
  int window_geometry_y;
  int window_geometry_width;
  int window_geometry_height;
};

struct _XdgRole
{
  /* The role object.  */
  Role role;

  /* Number of references to this role.  Used when the client
     terminates and the Wayland library destroys objects out of
     order.  */
  int refcount;

  /* The window backing this role.  */
  Window window;

  /* The render target backing this role.  */
  RenderTarget target;

  /* The subcompositor backing this role.  */
  Subcompositor *subcompositor;

  /* The implementation of this role.  */
  XdgRoleImplementation *impl;

  /* The pending frame ID.  */
  uint64_t pending_frame;

  /* Various role state.  */
  int state;

  /* Queue of buffers to release later (when the X server is done with
     them).  */
  ReleaseLaterRecord *release_records;

  /* The frame clock.  */
  FrameClock *clock;

  /* The pending xdg_surface state.  */
  XdgState pending_state;

  /* The current xdg_surface state.  */
  XdgState current_state;

  /* Configure event serial.  */
  uint32_t conf_serial, last_specified_serial;

  /* The current bounds of the subcompositor.  */
  int min_x, min_y, max_x, max_y;

  /* The bounds width and bounds height of the subcompositor.  */
  int bounds_width, bounds_height;

  /* The pending root window position of the subcompositor.  */
  int pending_root_x, pending_root_y;

  /* How many synthetic (in the case of toplevels) ConfigureNotify
     events to wait for before ignoring those coordinates.  */
  int pending_synth_configure;

  /* The type of the attached role.  */
  XdgRoleImplementationType type;

  /* The input region of the attached subsurface.  */
  pixman_region32_t input_region;

  /* List of callbacks run upon a ConfigureNotify event.  */
  ReconstrainCallback reconstrain_callbacks;

  /* The number of desynchronous children of this toplevel.  */
  int n_desync_children;
};

struct _ReleaseLaterRecord
{
  /* A monotonically (overflow aside) increasing identifier.  */
  uint64_t id;

  /* The buffer that should be released upon receiving this
     message.  */
  ExtBuffer *buffer;

  /* The idle callback.  */
  IdleCallbackKey key;

  /* The XdgRole.  */
  XdgRole *role;

  /* The next and last records.  */
  ReleaseLaterRecord *next, *last;
};

/* Event base of the XShape extension.  */
int shape_base;

static void
DeleteRecord (ReleaseLaterRecord *record)
{
  /* Removing the sentinel record is invalid.  */
  XLAssert (record->buffer != NULL);

  /* First, make the rest of the list skip RECORD.  */
  record->last->next = record->next;
  record->next->last = record->last;

  /* Finally, free RECORD.  */
  XLFree (record);
}

static void
FreeRecords (ReleaseLaterRecord *records)
{
  ReleaseLaterRecord *last, *tem;

  tem = records->next;

  while (tem != records)
    {
      last = tem;
      tem = tem->next;

      /* Release the buffer now.  */
      XLReleaseBuffer (last->buffer);

      /* Before freeing the record itself.  */
      XLFree (last);
    }

  XLFree (records);
}

static ReleaseLaterRecord *
AddRecordAfter (ReleaseLaterRecord *start)
{
  ReleaseLaterRecord *record;

  record = XLMalloc (sizeof *record);
  record->next = start->next;
  record->last = start;

  start->next->last = record;
  start->next = record;

  return record;
}

static ReconstrainCallback *
AddCallbackAfter (ReconstrainCallback *start)
{
  ReconstrainCallback *callback;

  callback = XLMalloc (sizeof *callback);
  callback->next = start->next;
  callback->last = start;

  start->next->last = callback;
  start->next = callback;

  return callback;
}

static void
UnlinkReconstrainCallback (ReconstrainCallback *callback)
{
  callback->last->next = callback->next;
  callback->next->last = callback->last;

  XLFree (callback);
}

static void
RunReconstrainCallbacksForXEvent (XdgRole *role, XEvent *event)
{
  ReconstrainCallback *callback;

  callback = role->reconstrain_callbacks.next;

  while (callback != &role->reconstrain_callbacks)
    {
      callback->configure (callback->data, event);
      callback = callback->next;
    }
}

static void
RunReconstrainCallbacks (XdgRole *role)
{
  ReconstrainCallback *callback;

  callback = role->reconstrain_callbacks.next;

  while (callback != &role->reconstrain_callbacks)
    {
      callback->resized (callback->data);
      callback = callback->next;
    }
}

static void
FreeReconstrainCallbacks (XdgRole *role)
{
  ReconstrainCallback *callback, *last;

  callback = role->reconstrain_callbacks.next;

  while (callback != &role->reconstrain_callbacks)
    {
      last = callback;
      callback = callback->next;

      XLFree (last);
    }
}

static void
RunFrameCallbacks (Surface *surface, XdgRole *role)
{
  struct timespec time;
  uint64_t last_drawn_time;

  /* Surface can be NULL for various reasons, especially events
     arriving after the shell surface is detached.  */
  if (!surface)
    return;

  last_drawn_time = XLFrameClockGetFrameTime (role->clock);

  if (!last_drawn_time)
    {
      clock_gettime (CLOCK_MONOTONIC, &time);
      XLSurfaceRunFrameCallbacks (surface, time);
    }
  else
    XLSurfaceRunFrameCallbacksMs (surface, last_drawn_time / 1000);
}

static void
RunFrameCallbacksConditionally (XdgRole *role)
{
  if (role->release_records->last == role->release_records
      && role->role.surface)
    RunFrameCallbacks (role->role.surface, role);
  else if (role->role.surface)
    /* weston-simple-shm seems to assume that a frame callback can
       only arrive after all buffers have been released.  */
    role->state |= StatePendingFrameCallback;
}

static void
BufferIdleCallback (RenderBuffer buffer, void *data)
{
  ReleaseLaterRecord *record;
  XdgRole *role;
  Surface *surface;

  record = data;
  role = record->role;


  XLReleaseBuffer (record->buffer);
  DeleteRecord (record);

  surface = role->role.surface;

  /* Run frame callbacks now, if no more buffers are waiting to be
     released.  */
  if (surface && role->state & StatePendingFrameCallback
      && role->release_records->next == role->release_records)
    {
      RunFrameCallbacks (surface, role);

      role->state &= ~StatePendingFrameCallback;
    }
}

Bool
XLHandleXEventForXdgSurfaces (XEvent *event)
{
  XdgRole *role;
  Window window;

  if (event->type == ClientMessage
      && ((event->xclient.message_type == _NET_WM_FRAME_DRAWN
	   || event->xclient.message_type == _NET_WM_FRAME_TIMINGS)
	  || (event->xclient.message_type == WM_PROTOCOLS
	      && event->xclient.data.l[0] == _NET_WM_SYNC_REQUEST)))
    {
      role = XLLookUpAssoc (surfaces, event->xclient.window);

      if (role)
	{
	  XLFrameClockHandleFrameEvent (role->clock, event);
	  return True;
	}

      return False;
    }

  if (event->type == Expose)
    {
      role = XLLookUpAssoc (surfaces, event->xexpose.window);

      if (role)
	{
	  /* If resizing is in progress with WM synchronization, don't
	     handle exposure events, since that causes updates outside
	     a frame.  */
	  if (!XLFrameClockNeedConfigure (role->clock))
	    SubcompositorExpose (role->subcompositor, event);

	  return True;
	}

      return False;
    }

  if (event->type == KeyPress || event->type == KeyRelease)
    {
      /* These events are actually sent by the input method library
	 upon receiving XIM_COMMIT messages.  */

      role = XLLookUpAssoc (surfaces, event->xkey.window);

      if (role && role->role.surface)
	{
	  XLTextInputDispatchCoreEvent (role->role.surface, event);
	  return True;
	}

      return False;
    }

  window = XLGetGEWindowForSeats (event);

  if (window != None)
    {
      role = XLLookUpAssoc (surfaces, window);

      if (role && role->role.surface)
	{
	  XLDispatchGEForSeats (event, role->role.surface,
				role->subcompositor);
	  return True;
	}

      return False;
    }

  return False;
}

static void
Destroy (struct wl_client *client, struct wl_resource *resource)
{
  XdgRole *role;

  role = wl_resource_get_user_data (resource);

  if (role->impl)
    {
      wl_resource_post_error (resource, XDG_WM_BASE_ERROR_ROLE,
			      "trying to destroy xdg surface with role");
      return;
    }

  wl_resource_destroy (resource);
}

static void
GetToplevel (struct wl_client *client, struct wl_resource *resource,
	     uint32_t id)
{
  XdgRole *role;

  role = wl_resource_get_user_data (resource);

  if (!role->role.surface)
    /* This object is inert.  */
    return;

  if (role->type == TypePopup)
    {
      wl_resource_post_error (resource, XDG_WM_BASE_ERROR_ROLE,
			      "surface was previously a popup");
      return;
    }

  role->type = TypeToplevel;

  XLGetXdgToplevel (client, resource, id);
}

static void
GetPopup (struct wl_client *client, struct wl_resource *resource,
	  uint32_t id, struct wl_resource *parent_resource,
	  struct wl_resource *positioner_resource)
{
  XdgRole *role;

  role = wl_resource_get_user_data (resource);

  if (!role->role.surface)
    /* This object is inert.  */
    return;

  if (role->type == TypeToplevel)
    {
      wl_resource_post_error (resource, XDG_WM_BASE_ERROR_ROLE,
			      "surface was previously a toplevel");
      return;
    }

  role->type = TypePopup;

  XLGetXdgPopup (client, resource, id, parent_resource,
		 positioner_resource);
}

static void
SetWindowGeometry (struct wl_client *client, struct wl_resource *resource,
		   int32_t x, int32_t y, int32_t width, int32_t height)
{
  XdgRole *role;

  role = wl_resource_get_user_data (resource);

  if (x == role->current_state.window_geometry_x
      && y == role->pending_state.window_geometry_y
      && width == role->pending_state.window_geometry_width
      && height == role->pending_state.window_geometry_height)
    return;

  role->state |= StatePendingWindowGeometry;

  role->pending_state.window_geometry_x = x;
  role->pending_state.window_geometry_y = y;
  role->pending_state.window_geometry_width = width;
  role->pending_state.window_geometry_height = height;
}

static void
AckConfigure (struct wl_client *client, struct wl_resource *resource,
	      uint32_t serial)
{
  XdgRole *xdg_role;

  xdg_role = wl_resource_get_user_data (resource);

  if (!xdg_role->role.surface)
    return;

#ifdef DEBUG_GEOMETRY_CALCULATION
  fprintf (stderr, "ack_configure: %"PRIu32"\n", serial);
#endif

  if (serial < xdg_role->conf_serial)
    {
      /* The client specified an outdated serial.  */
      wl_resource_post_error (resource, XDG_SURFACE_ERROR_INVALID_SERIAL,
			      "serial specified not monotonic");
      return;
    }

  if (serial && serial == xdg_role->last_specified_serial)
    {
      /* The client specified the same serial twice.  */
      wl_resource_post_error (resource, XDG_SURFACE_ERROR_INVALID_SERIAL,
			      "same serial specified twice");
      return;
    }

  if (serial == xdg_role->conf_serial)
    {
      xdg_role->last_specified_serial = serial;
      xdg_role->state &= ~StateWaitingForAckConfigure;

      /* Garbage the subcompositor too, since contents could be
	 exposed due to changes in bounds.  */
      SubcompositorGarbage (xdg_role->subcompositor);

      /* Also run frame callbacks if the frame clock is frozen.  */
      if (XLFrameClockIsFrozen (xdg_role->clock)
	  && xdg_role->role.surface)
	RunFrameCallbacksConditionally (xdg_role);

#ifdef DEBUG_GEOMETRY_CALCULATION
      fprintf (stderr, "Client acknowledged configuration\n");
#endif
    }

  if (xdg_role->impl)
    xdg_role->impl->funcs.ack_configure (&xdg_role->role,
					 xdg_role->impl,
					 serial);
}

static const struct xdg_surface_interface xdg_surface_impl =
  {
    .get_toplevel = GetToplevel,
    .get_popup = GetPopup,
    .destroy = Destroy,
    .set_window_geometry = SetWindowGeometry,
    .ack_configure = AckConfigure,
  };

static void
Unfreeze (XdgRole *role)
{
  XLFrameClockUnfreeze (role->clock);
}

static Bool
IsRoleMapped (XdgRole *role)
{
  if (!role->impl)
    /* This can happen when destroying subsurfaces as part of client
       cleanup.  */
    return False;

  return role->impl->funcs.is_window_mapped (&role->role,
					     role->impl);
}

static void
Commit (Surface *surface, Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  if (!xdg_role->impl)
    return;

  if (xdg_role->state & StatePendingWindowGeometry)
    {
      xdg_role->current_state.window_geometry_x
	= xdg_role->pending_state.window_geometry_x;
      xdg_role->current_state.window_geometry_y
	= xdg_role->pending_state.window_geometry_y;
      xdg_role->current_state.window_geometry_width
	= xdg_role->pending_state.window_geometry_width;
      xdg_role->current_state.window_geometry_height
	= xdg_role->pending_state.window_geometry_height;

#ifdef DEBUG_GEOMETRY_CALCULATION
      fprintf (stderr, "Client set window geometry to: [%d %d %d %d]\n",
	       xdg_role->current_state.window_geometry_x,
	       xdg_role->current_state.window_geometry_y,
	       xdg_role->current_state.window_geometry_width,
	       xdg_role->current_state.window_geometry_height);
#endif

      /* Now, clear the "pending window geometry" flag.  */
      xdg_role->state &= ~StatePendingWindowGeometry;

      /* Next, set the "dirty frame extents" flag; this is then used
	 to update the window geometry the next time the window is
	 resized.  */
      xdg_role->state |= StateDirtyFrameExtents;
    }

  xdg_role->impl->funcs.commit (role, surface,
				xdg_role->impl);

  /* This flag means no commit has happened after an
     ack_configure.  */
  if (!(xdg_role->state & StateWaitingForAckConfigure)
      && xdg_role->state & StateWaitingForAckCommit)
    {
#ifdef DEBUG_GEOMETRY_CALCULATION
      fprintf (stderr, "Client aknowledged commit\n");
#endif
      xdg_role->state &= ~StateWaitingForAckCommit;
    }

  /* If the window is unmapped, skip all of this code!  Once the
     window is mapped again, the compositor will send _NET_FRAME_DRAWN
     should a frame still be in progress.  */
  if (!IsRoleMapped (xdg_role))
    goto start_drawing;

  /* If the frame clock is frozen but we are no longer waiting for the
     configure event to be acknowledged by the client, unfreeze the
     frame clock.  */
  if (!(xdg_role->state & StateWaitingForAckConfigure))
    Unfreeze (xdg_role);

  /* A frame is already in progress, so instead say that an urgent
     update is needed immediately after the frame completes.  In any
     case, don't run frame callbacks upon buffer release anymore.  */
  if (XLFrameClockFrameInProgress (xdg_role->clock))
    {
      if (XLFrameClockCanBatch (xdg_role->clock))
	/* But if we can squeeze the frame inside the vertical
	   blanking period, or a frame is in progress but EndFrame has
	   not yet been called, go ahead.  */
	goto start_drawing;

      xdg_role->state |= StateLateFrame;
      xdg_role->state &= ~StatePendingFrameCallback;

      if (xdg_role->state & StateWaitingForAckConfigure)
	xdg_role->state &= ~StateLateFrameAcked;
      else
	xdg_role->state |= StateLateFrameAcked;

      return;
    }

 start_drawing:

  SubcompositorUpdate (xdg_role->subcompositor);

  /* Do not end frames explicitly.  Instead, wait for the
     NoteFrameCallback to end the frame.  */

  return;
}

static Bool
Setup (Surface *surface, Role *role)
{
  XdgRole *xdg_role;

  /* Set role->surface here, since this is where the refcounting is
     done as well.  */
  role->surface = surface;

  /* Prevent the surface from ever holding another kind of role.  */
  surface->role_type = XdgType;

  xdg_role = XdgRoleFromRole (role);
  ViewSetSubcompositor (surface->view,
		        xdg_role->subcompositor);
  ViewSetSubcompositor (surface->under,
		        xdg_role->subcompositor);

  /* Make sure the under view ends up beneath surface->view.  */
  SubcompositorInsert (xdg_role->subcompositor,
		       surface->under);
  SubcompositorInsert (xdg_role->subcompositor,
		       surface->view);

  /* Count the number of desynchronous children attached to this
     surface, directly or indirectly.  This number is then updated as
     surfaces are attached, made desynchronous and/or removed in
     NoteChildSynced and NoteDesyncChild.  */
  XLUpdateDesynchronousChildren (surface, &xdg_role->n_desync_children);

  /* If there are desynchronous children, enable frame refresh
     prediction in the frame clock, which batches subframes from
     multiple subsurfaces together if they arrive in time.  */
  if (xdg_role->n_desync_children)
    XLFrameClockSetPredictRefresh (xdg_role->clock);

  /* Retain the backing data.  */
  xdg_role->refcount++;

  return True;
}

static void
ReleaseBacking (XdgRole *role)
{
  if (--role->refcount)
    return;

  /* Sync, and then release all buffers pending release.  The sync is
     necessary because the X server does not perform operations
     immediately after the Xlib function is called.  */
  XSync (compositor.display, False);
  FreeRecords (role->release_records);

  /* Now release the reference to any toplevel implementation that
     might be attached.  */
  if (role->impl)
    XLXdgRoleDetachImplementation (&role->role, role->impl);

  /* Release all allocated resources.  */
  RenderDestroyRenderTarget (role->target);
  XDestroyWindow (compositor.display, role->window);

  /* And the association.  */
  XLDeleteAssoc (surfaces, role->window);

  /* There shouldn't be any children of the subcompositor at this
     point.  */
  SubcompositorFree (role->subcompositor);

  /* The frame clock is no longer useful.  */
  XLFreeFrameClock (role->clock);

  /* Free the input region.  */
  pixman_region32_fini (&role->input_region);

  /* Free reconstrain callbacks.  */
  FreeReconstrainCallbacks (role);

  /* And since there are no C level references to the role anymore, it
     can be freed.  */
  XLFree (role);
}

static void
Teardown (Surface *surface, Role *role)
{
  XdgRole *xdg_role;

  /* Clear role->surface here, since this is where the refcounting is
     done as well.  */
  role->surface = NULL;

  xdg_role = XdgRoleFromRole (role);

  /* Unparent the surface's views as well.  */
  ViewUnparent (surface->view);
  ViewUnparent (surface->under);

  /* Detach the surface's views from the subcompositor.  */
  ViewSetSubcompositor (surface->view, NULL);
  ViewSetSubcompositor (surface->under, NULL);

  /* Release the backing data.  */
  ReleaseBacking (xdg_role);
}

static void
ReleaseBuffer (Surface *surface, Role *role, ExtBuffer *buffer)
{
  RenderBuffer render_buffer;
  ReleaseLaterRecord *record;
  XdgRole *xdg_role;

  render_buffer = XLRenderBufferFromBuffer (buffer);
  xdg_role = XdgRoleFromRole (role);

  if (RenderIsBufferIdle (render_buffer, xdg_role->target))
    /* If the buffer is already idle, release it now.  */
    XLReleaseBuffer (buffer);
  else
    {
      /* Release the buffer once it is destroyed or becomes idle.  */
      record = AddRecordAfter (xdg_role->release_records);
      record->buffer = buffer;
      record->key = RenderAddIdleCallback (render_buffer,
					   xdg_role->target,
					   BufferIdleCallback,
					   record);
      record->role = xdg_role;
    }
}

static Bool
Subframe (Surface *surface, Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  /* If the frame clock is frozen, return False.  */
  if (XLFrameClockIsFrozen (xdg_role->clock))
    {
      /* However, run frame callbacks.  */
      RunFrameCallbacksConditionally (xdg_role);
      return False;
    }

  /* Similarly, return False if the role is unmapped.  */
  if (!IsRoleMapped (xdg_role))
    return False;

  /* If a frame is already in progress, return False.  Then, require a
     late frame.  */
  if (XLFrameClockFrameInProgress (xdg_role->clock))
    {
      if (XLFrameClockCanBatch (xdg_role->clock))
	/* But if we can squeeze the frame inside the vertical
	   blanking period, or a frame is in progress but EndFrame has
	   not yet been called, go ahead.  */
	return True;

      xdg_role->state |= StateLateFrame;
      xdg_role->state &= ~StatePendingFrameCallback;

      if (xdg_role->state & StateWaitingForAckConfigure)
	xdg_role->state &= ~StateLateFrameAcked;

      return False;
    }

  return True;
}

static void
EndSubframe (Surface *surface, Role *role)
{
  /* Don't end the frame here; instead, wait for the frame callback to
     note that drawing the frame has finished.  */
}

static Window
GetWindow (Surface *surface, Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);
  return xdg_role->window;
}

static void
HandleResourceDestroy (struct wl_resource *resource)
{
  XdgRole *role;

  role = wl_resource_get_user_data (resource);
  role->role.resource = NULL;

  /* Release the backing data.  */
  ReleaseBacking (role);
}

static void
AfterFrame (FrameClock *clock, void *data)
{
  XdgRole *role;

  role = data;

  /* If all pending frames have been drawn, run frame callbacks.
     Unless some buffers have not yet been released, in which case the
     callbacks will be run when they are.  */

  RunFrameCallbacksConditionally (role);
}

static void
OpaqueRegionChanged (Subcompositor *subcompositor,
		     void *client_data,
		     pixman_region32_t *opaque_region)
{
  XdgRole *role;
  long *data;
  int nrects, i;
  pixman_box32_t *boxes;

  boxes = pixman_region32_rectangles (opaque_region, &nrects);
  role = client_data;

  if (nrects < 64)
    data = alloca (4 * sizeof *data * nrects);
  else
    data = XLMalloc (4 * sizeof *data * nrects);

  for (i = 0; i < nrects; ++i)
    {
      data[i * 4 + 0] = BoxStartX (boxes[i]);
      data[i * 4 + 1] = BoxStartY (boxes[i]);
      data[i * 4 + 2] = BoxWidth (boxes[i]);
      data[i * 4 + 3] = BoxHeight (boxes[i]);
    }

  XChangeProperty (compositor.display, role->window,
		   _NET_WM_OPAQUE_REGION, XA_CARDINAL,
		   32, PropModeReplace,
		   (unsigned char *) data, nrects * 4);

  if (nrects >= 64)
    XLFree (data);
}

static void
InputRegionChanged (Subcompositor *subcompositor,
		    void *data,
		    pixman_region32_t *input_region)
{
  XdgRole *role;
  int nrects, i;
  pixman_box32_t *boxes;
  XRectangle *rects;

  role = data;
  boxes = pixman_region32_rectangles (input_region, &nrects);

  /* If the number of rectangles is small (<= 256), allocate them on
     the stack.  Otherwise, use the heap instead.  */

  if (nrects < 256)
    rects = alloca (sizeof *rects * nrects);
  else
    rects = XLMalloc (sizeof *rects * nrects);

  /* Convert the boxes into proper XRectangles and make them the input
     region of the window.  */

  for (i = 0; i < nrects; ++i)
    {
      rects[i].x = BoxStartX (boxes[i]);
      rects[i].y = BoxStartY (boxes[i]);
      rects[i].width = BoxWidth (boxes[i]);
      rects[i].height = BoxHeight (boxes[i]);
    }

  XShapeCombineRectangles (compositor.display,
			   role->window, ShapeInput,
			   0, 0, rects, nrects,
			   /* pixman uses the same region
			      representation as the X server, which is
			      YXBanded.  */
			   ShapeSet, YXBanded);

  if (nrects >= 256)
    XLFree (rects);

  /* Also save the input region for future use.  */
  pixman_region32_copy (&role->input_region, input_region);
}

static void
NoteConfigure (XdgRole *role, XEvent *event)
{
  if (role->pending_synth_configure)
    role->pending_synth_configure--;

  /* Update the surface that the surface is inside.  */
  if (role->role.surface)
    XLUpdateSurfaceOutputs (role->role.surface,
			    event->xconfigure.x + role->min_x,
			    event->xconfigure.y + role->min_y,
			    -1, -1);

  RunReconstrainCallbacksForXEvent (role, event);
}

static void
CurrentRootPosition (XdgRole *role, int *root_x, int *root_y)
{
  Window child_return;

  if (role->pending_synth_configure)
    {
      *root_x = role->pending_root_x;
      *root_y = role->pending_root_y;

      return;
    }

  XTranslateCoordinates (compositor.display, role->window,
			 DefaultRootWindow (compositor.display),
			 0, 0, root_x, root_y, &child_return);
}

static void
NoteBounds (void *data, int min_x, int min_y,
	    int max_x, int max_y)
{
  XdgRole *role;
  int bounds_width, bounds_height, root_x, root_y;
  Bool run_reconstrain_callbacks;

  role = data;
  run_reconstrain_callbacks = False;

  if (XLFrameClockIsFrozen (role->clock))
    /* We are waiting for the acknowledgement of a configure event.
       Don't resize the window until it's acknowledged.  */
    return;

  if (role->state & StateWaitingForAckCommit)
    /* Don't resize the window until all configure events are
       acknowledged.  We wait for a commit on the xdg_toplevel to do
       this, because Firefox updates subsurfaces while the old size is
       still in effect.  */
    return;

  if (role->state & StateTemporaryBounds)
    return;

  /* Avoid resizing the window should its actual size not have
     changed.  */

  bounds_width = max_x - min_x + 1;
  bounds_height = max_y - min_y + 1;

  if (role->bounds_width != bounds_width
      || role->bounds_height != bounds_height)
    {
#ifdef DEBUG_GEOMETRY_CALCULATION
      fprintf (stderr, "Resizing to: %d %d (from: %d %d)\n",
	       bounds_width, bounds_height, role->bounds_width,
	       role->bounds_height);
#endif
      
      if (role->impl->funcs.note_window_pre_resize)
	role->impl->funcs.note_window_pre_resize (&role->role,
						  role->impl,
						  bounds_width,
						  bounds_height);

      if (role->state & StateDirtyFrameExtents)
	{
	  /* Only handle window geometry changes once a commit happens
	     and the window is really resized.  */

	  if (role->impl->funcs.handle_geometry_change)
	    role->impl->funcs.handle_geometry_change (&role->role,
						      role->impl);

	  role->state &= ~StateDirtyFrameExtents;
	}

      XResizeWindow (compositor.display, role->window,
		     bounds_width, bounds_height);
      run_reconstrain_callbacks = True;

      if (role->impl->funcs.note_window_resized)
	role->impl->funcs.note_window_resized (&role->role,
					       role->impl,
					       bounds_width,
					       bounds_height);
    }

  /* Now, make sure the window stays at the same position relative to
     the origin of the view.  */

  if (min_x != role->min_x || min_y != role->min_y)
    {
      /* Move the window by the opposite of the amount the min_x and
	 min_y changed.  */

      CurrentRootPosition (role, &root_x, &root_y);
      XMoveWindow (compositor.display, role->window,
		   root_x + min_x + role->min_x,
		   root_y + min_y + role->min_y);

      /* Set pending root window positions.  These positions will be
	 used until the movement really happens, to avoid outdated
	 positions being used after the minimum positions change in
	 quick succession.  */
      role->pending_root_x = root_x + min_x + role->min_x;
      role->pending_root_y = root_y + min_y + role->min_y;
      role->pending_synth_configure++;
    }

  /* Finally, record the current bounds.  */

  role->min_x = min_x;
  role->max_x = max_x;
  role->min_y = min_y;
  role->max_y = max_y;

  role->bounds_width = bounds_width;
  role->bounds_height = bounds_height;

  /* Tell the role implementation about the change in window size.  */

  if (role->impl && role->impl->funcs.note_size)
    role->impl->funcs.note_size (&role->role, role->impl,
				 max_x - min_x + 1,
				 max_y - min_y + 1);

  /* Run reconstrain callbacks if a resize happened.  */
  if (run_reconstrain_callbacks)
    RunReconstrainCallbacks (role);
}

static void
NoteFrame (FrameMode mode, uint64_t id, void *data)
{
  XdgRole *role;

  role = data;

  switch (mode)
    {
    case ModeStarted:
      /* Record this frame counter as the pending frame.  */
      role->pending_frame = id;

      if (!(role->state & StateFrameStarted))
	{
	  role->state |= StateFrameStarted;
	  XLFrameClockStartFrame (role->clock, False);
	}

      /* Also run role "commit inside frame" hook.  */
      if (role->impl && role->impl->funcs.commit_inside_frame)
	role->impl->funcs.commit_inside_frame (&role->role,
					       role->impl);

      break;

    case ModePresented:
    case ModeComplete:
      /* The frame was completed.  */
      if (id == role->pending_frame)
	{
	  /* End the frame.  */
	  XLFrameClockEndFrame (role->clock);

	  /* Clear the frame completed flag.  */
	  role->state &= ~StateFrameStarted;

	  /* Clients which commit when a configure event that has not
	     yet been acked still expect frame callbacks to be called;
	     however, frame callbacks are not provided by the frame
	     clock while it is frozen.

	     If that happens, just run the frame callback
	     immediately.  */
	  if (XLFrameClockIsFrozen (role->clock)
	      /* If the window is not mapped, then the native frame
		 clock will not draw frames.  Some clients do commit
		 before the initial configure event and wait for the
		 frame callback to be called after or before
		 ack_configure, leading to the mapping commit never
		 being performed.  */
	      || !IsRoleMapped (role))
	    RunFrameCallbacksConditionally (role);
	}
    }
}

static void
ResizeForMap (XdgRole *role)
{
  int min_x, min_y, max_x, max_y;

  SubcompositorBounds (role->subcompositor, &min_x,
		       &min_y, &max_x, &max_y);

  /* At this point, we are probably still waiting for ack_commit; as a
     result, NoteBounds will not really resize the window.  */
  NoteBounds (role, min_x, min_y, max_x, max_y);

#ifdef DEBUG_GEOMETRY_CALCULATION
  fprintf (stderr, "ResizeForMap: %d %d\n",
	   max_x - min_x + 1, max_y - min_y + 1);
#endif

  if (role->state & StateDirtyFrameExtents)
    {
      /* Only handle window geometry changes once a commit
	 happens.  */

      if (role->impl->funcs.handle_geometry_change)
	role->impl->funcs.handle_geometry_change (&role->role,
						  role->impl);

      role->state &= ~StateDirtyFrameExtents;
    }

  /* Resize the window pre-map.  This should generate a
     ConfigureNotify event once the resize completes.  */
  XResizeWindow (compositor.display, role->window,
		 max_x - min_x + 1, max_y - min_y + 1);

  if (role->impl->funcs.note_window_resized)
    role->impl->funcs.note_window_resized (&role->role,
					   role->impl,
					   max_x - min_x + 1,
					   max_y - min_y + 1);
}

static void
GetResizeDimensions (Surface *surface, Role *role, int *x_out,
		     int *y_out)
{
  XLXdgRoleGetCurrentGeometry (role, NULL, NULL, x_out, y_out);

  /* Scale these surface-local dimensions to window-local ones.  */
  TruncateSurfaceToWindow (surface, *x_out, *y_out, x_out, y_out);
}

static void
PostResize (Surface *surface, Role *role, int west_motion,
	    int north_motion, int new_width, int new_height)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  if (!xdg_role->impl || !xdg_role->impl->funcs.post_resize)
    return;

  xdg_role->impl->funcs.post_resize (role, xdg_role->impl,
				     west_motion, north_motion,
				     new_width, new_height);
}

static void
MoveBy (Surface *surface, Role *role, int west, int north)
{
  XLXdgRoleMoveBy (role, west, north);
}

static void
Rescale (Surface *surface, Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  /* The window geometry actually applied to the X window (in the form
     of frame extents, etc) heavily depends on the output scale.  */

  if (xdg_role->impl->funcs.handle_geometry_change)
    xdg_role->impl->funcs.handle_geometry_change (role, xdg_role->impl);
}

static void
NoteChildSynced (Surface *surface, Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  if (xdg_role->n_desync_children)
    xdg_role->n_desync_children--;

  if (!xdg_role->n_desync_children)
    XLFrameClockDisablePredictRefresh (xdg_role->clock);
}

static void
NoteDesyncChild (Surface *surface, Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  xdg_role->n_desync_children++;
  XLFrameClockSetPredictRefresh (xdg_role->clock);
}

static void
WriteRedirectProperty (XdgRole *role)
{
  unsigned long bypass_compositor;

  bypass_compositor = 2;
  XChangeProperty (compositor.display, role->window,
		   _NET_WM_BYPASS_COMPOSITOR, XA_CARDINAL,
		   32, PropModeReplace,
		   (unsigned char *) &bypass_compositor, 1);
}

static void
HandleFreeze (void *data)
{
  XdgRole *role;

  role = data;

  /* _NET_WM_SYNC_REQUEST events should be succeeded by a
     ConfigureNotify event.  */
  role->state |= StateWaitingForAckConfigure;
  role->state |= StateWaitingForAckCommit;

  /* This flag means the WaitingForAckConfigure was caused by a
     _NET_WM_SYNC_REQUEST, and the following ConfigureNotify event
     might not lead to a configure event being sent.  */
  role->state |= StateMaybeConfigure;
}

static void
SelectExtraEvents (Surface *surface, Role *role,
		   unsigned long event_mask)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  /* Select extra events for the input method.  */
  XSelectInput (compositor.display, xdg_role->window,
		DefaultEventMask | event_mask);

  /* Set the target standard event mask.  */
  RenderSetStandardEventMask (xdg_role->target,
			      DefaultEventMask | event_mask);
}

void
XLGetXdgSurface (struct wl_client *client, struct wl_resource *resource,
		 uint32_t id, struct wl_resource *surface_resource)
{
  XdgRole *role;
  XSetWindowAttributes attrs;
  unsigned int flags;
  Surface *surface;

  surface = wl_resource_get_user_data (surface_resource);

  if (surface->role || (surface->role_type != AnythingType
			&& surface->role_type != XdgType))
    {
      /* A role already exists on that surface.  */
      wl_resource_post_error (resource, XDG_WM_BASE_ERROR_ROLE,
			      "surface already has attached role");
      return;
    }

  role = XLSafeMalloc (sizeof *role);

  if (!role)
    {
      wl_client_post_no_memory (client);
      return;
    }

  memset (role, 0, sizeof *role);

  role->release_records
    = XLSafeMalloc (sizeof *role->release_records);

  if (!role->release_records)
    {
      XLFree (role);
      wl_client_post_no_memory (client);

      return;
    }

  role->role.resource = wl_resource_create (client, &xdg_surface_interface,
					    wl_resource_get_version (resource),
					    id);

  if (!role->role.resource)
    {
      XLFree (role->release_records);
      XLFree (role);
      wl_client_post_no_memory (client);

      return;
    }

  wl_resource_set_implementation (role->role.resource, &xdg_surface_impl,
				  role, HandleResourceDestroy);

  /* Add a reference to this role struct since a wl_resource now
     refers to it.  */
  role->refcount++;

  role->role.funcs.commit = Commit;
  role->role.funcs.teardown = Teardown;
  role->role.funcs.setup = Setup;
  role->role.funcs.release_buffer = ReleaseBuffer;
  role->role.funcs.subframe = Subframe;
  role->role.funcs.end_subframe = EndSubframe;
  role->role.funcs.get_window = GetWindow;
  role->role.funcs.get_resize_dimensions = GetResizeDimensions;
  role->role.funcs.post_resize = PostResize;
  role->role.funcs.move_by = MoveBy;
  role->role.funcs.rescale = Rescale;
  role->role.funcs.note_desync_child = NoteDesyncChild;
  role->role.funcs.note_child_synced = NoteChildSynced;
  role->role.funcs.select_extra_events = SelectExtraEvents;

  attrs.colormap = compositor.colormap;
  attrs.border_pixel = border_pixel;
  attrs.event_mask = DefaultEventMask;
  attrs.cursor = InitDefaultCursor ();
  flags = (CWColormap | CWBorderPixel | CWEventMask
	   | CWCursor);

  /* Sentinel node.  */
  role->release_records->next = role->release_records;
  role->release_records->last = role->release_records;
  role->release_records->buffer = NULL;

  role->window = XCreateWindow (compositor.display,
				DefaultRootWindow (compositor.display),
				0, 0, 20, 20, 0, compositor.n_planes,
				InputOutput, compositor.visual, flags,
				&attrs);
  role->target = RenderTargetFromWindow (role->window, DefaultEventMask);

  role->subcompositor = MakeSubcompositor ();
  role->clock = XLMakeFrameClockForWindow (role->window);

  XLFrameClockSetFreezeCallback (role->clock, HandleFreeze, role);

  SubcompositorSetTarget (role->subcompositor, &role->target);
  SubcompositorSetInputCallback (role->subcompositor,
				 InputRegionChanged, role);
  SubcompositorSetOpaqueCallback (role->subcompositor,
				  OpaqueRegionChanged, role);
  SubcompositorSetBoundsCallback (role->subcompositor,
				  NoteBounds, role);
  SubcompositorSetNoteFrameCallback (role->subcompositor,
				     NoteFrame, role);
  XLSelectStandardEvents (role->window);
  XLMakeAssoc (surfaces, role->window, role);

  /* Tell the compositing manager to never un-redirect this window.
     If it does, frame synchronization will not work.  */
  WriteRedirectProperty (role);

  /* Initialize frame callbacks.  */
  XLFrameClockAfterFrame (role->clock, AfterFrame, role);

  if (!XLSurfaceAttachRole (surface, &role->role))
    abort ();

  /* Initialize the input region.  */
  pixman_region32_init (&role->input_region);

  /* Initialize the sentinel node of the reconstrain callbacks
     list.  */
  role->reconstrain_callbacks.next = &role->reconstrain_callbacks;
  role->reconstrain_callbacks.last = &role->reconstrain_callbacks;
}

Window
XLWindowFromXdgRole (Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);
  return xdg_role->window;
}

Subcompositor *
XLSubcompositorFromXdgRole (Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);
  return xdg_role->subcompositor;
}

void
XLXdgRoleAttachImplementation (Role *role, XdgRoleImplementation *impl)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  XLAssert (!xdg_role->impl && role->surface);
  impl->funcs.attach (role, impl);

  xdg_role->impl = impl;
}

void
XLXdgRoleDetachImplementation (Role *role, XdgRoleImplementation *impl)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  XLAssert (xdg_role->impl == impl);
  impl->funcs.detach (role, impl);

  xdg_role->impl = NULL;
}

void
XLXdgRoleSendConfigure (Role *role, uint32_t serial)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);
  xdg_role->conf_serial = serial;
  xdg_role->state |= StateWaitingForAckConfigure;
  xdg_role->state |= StateWaitingForAckCommit;

  /* See the comment under XLXdgRoleSetBoundsSize.  */
  xdg_role->state &= ~StateTemporaryBounds;

  /* We know know that the ConfigureNotify event following any
     _NET_WM_SYNC_REQUEST event was accepted, so clear the maybe
     configure flag.  */
  xdg_role->state &= ~StateMaybeConfigure;

#ifdef DEBUG_GEOMETRY_CALCULATION
  fprintf (stderr, "Waiting for ack_configure (%"PRIu32")...\n",
	   xdg_role->conf_serial);
#endif

  xdg_surface_send_configure (role->resource, serial);
}

void
XLXdgRoleCalcNewWindowSize (Role *role, int width, int height,
			    int *new_width, int *new_height)
{
  XdgRole *xdg_role;
  int temp, temp1, geometry_width, geometry_height;
  int current_width, current_height, min_x, min_y, max_x, max_y;

  xdg_role = XdgRoleFromRole (role);

  if (!xdg_role->current_state.window_geometry_width
      /* If no surface exists, we might as well return immediately,
	 since the scale factor will not be obtainable.  */
      || !role->surface)
    {
      *new_width = width;
      *new_height = height;

      return;
    }

  SubcompositorBounds (xdg_role->subcompositor,
		       &min_x, &min_y, &max_x, &max_y);

  /* Calculate the current width and height.  */
  current_width = (max_x - min_x + 1);
  current_height = (max_y - min_y + 1);

  /* Adjust the current_width and current_height by the scale
     factor.  */
  TruncateScaleToSurface (role->surface, current_width,
			  current_height, &current_width,
			  &current_height);

  XLXdgRoleGetCurrentGeometry (role, NULL, NULL, &geometry_width,
			       &geometry_height);

  /* Now, temp and temp1 become the difference between the current
     window geometry and the size of the surface (incl. subsurfaces)
     in both axes.  */

  temp = current_width - geometry_width;
  temp1 = current_height - geometry_height;

  *new_width = width - temp;
  *new_height = height - temp1;

#ifdef DEBUG_GEOMETRY_CALCULATION
  fprintf (stderr,
	   "Configure event width, height: %d %d\n"
	   "Generated width, height:       %d %d\n",
	   width, height, *new_width, *new_height);
#endif
}

int
XLXdgRoleGetWidth (Role *role)
{
  XdgRole *xdg_role;
  int x, y, x1, y1;

  xdg_role = XdgRoleFromRole (role);

  SubcompositorBounds (xdg_role->subcompositor,
		       &x, &y, &x1, &y1);

  return x1 - x + 1;
}

int
XLXdgRoleGetHeight (Role *role)
{
  XdgRole *xdg_role;
  int x, y, x1, y1;

  xdg_role = XdgRoleFromRole (role);

  SubcompositorBounds (xdg_role->subcompositor,
		       &x, &y, &x1, &y1);

  return y1 - y + 1;
}

void
XLXdgRoleSetBoundsSize (Role *role, int bounds_width, int bounds_height)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);
  xdg_role->bounds_width = bounds_width;
  xdg_role->bounds_height = bounds_height;

#ifdef DEBUG_GEOMETRY_CALCULATION
  fprintf (stderr, "Set new bounds size: %d %d\n", bounds_width,
	   bounds_height);
#endif

  /* Now, a temporary bounds_width and bounds_height has been
     recorded.  This means that if a configure event has not yet been
     delivered, then any subsequent SubcompositorUpdate will cause
     NoteBounds to resize back to the old width and height, confusing
     the window manager and possibly causing it to maximize us.

     Set a flag that tells NoteBounds to abstain from resizing the
     window.  This flag is then cleared once a configure event is
     delivered, or the next time the role is mapped.  */
  xdg_role->state |= StateTemporaryBounds;
}

void
XLXdgRoleGetCurrentGeometry (Role *role, int *x_return, int *y_return,
			     int *width, int *height)
{
  XdgRole *xdg_role;
  int x, y, x1, y1, min_x, max_x, min_y, max_y;

  xdg_role = XdgRoleFromRole (role);

  SubcompositorBounds (xdg_role->subcompositor,
		       &min_x, &min_y, &max_x, &max_y);

  if (!xdg_role->current_state.window_geometry_width)
    {
      if (x_return)
	*x_return = min_x;
      if (y_return)
	*y_return = min_y;

      if (width)
	*width = max_x - min_x + 1;
      if (height)
	*height = max_y - min_y + 1;

      return;
    }

  x = xdg_role->current_state.window_geometry_x;
  y = xdg_role->current_state.window_geometry_y;
  x1 = (xdg_role->current_state.window_geometry_x
	+ xdg_role->current_state.window_geometry_width - 1);
  y1 = (xdg_role->current_state.window_geometry_y
	+ xdg_role->current_state.window_geometry_height - 1);

  x1 = MIN (x1, max_x);
  y1 = MIN (y1, max_y);
  x = MAX (min_x, x);
  y = MAX (min_y, y);

  if (x_return)
    *x_return = x;
  if (y_return)
    *y_return = y;

  if (width)
    *width = x1 - x + 1;
  if (height)
    *height = y1 - y + 1;
}

void
XLXdgRoleNoteConfigure (Role *role, XEvent *event)
{
  NoteConfigure (XdgRoleFromRole (role), event);
}

void
XLRetainXdgRole (Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);
  xdg_role->refcount++;
}

void
XLReleaseXdgRole (Role *role)
{
  ReleaseBacking (XdgRoleFromRole (role));
}

void
XLXdgRoleCurrentRootPosition (Role *role, int *root_x, int *root_y)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);
  CurrentRootPosition (xdg_role, root_x, root_y);
}

XdgRoleImplementationType
XLTypeOfXdgRole (Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);
  return xdg_role->type;
}

XdgRoleImplementation *
XLImplementationOfXdgRole (Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);
  return xdg_role->impl;
}

Bool
XLXdgRoleInputRegionContains (Role *role, int x, int y)
{
  XdgRole *xdg_role;
  pixman_box32_t dummy_box;

  xdg_role = XdgRoleFromRole (role);
  return pixman_region32_contains_point (&xdg_role->input_region,
					 x, y, &dummy_box);
}

void
XLXdgRoleResizeForMap (Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  /* Clear the StateTemporaryBounds flag; it should not persist after
     mapping, as a configure event is no longer guaranteed to be sent
     if the toplevel is unmapped immediately after
     XLXdgRoleSetBoundsSize.  */
  xdg_role->state &= ~StateTemporaryBounds;
  ResizeForMap (xdg_role);
}

void *
XLXdgRoleRunOnReconstrain (Role *role, void (*configure_func) (void *,
							       XEvent *),
			   void (*resize_func) (void *), void *data)
{
  ReconstrainCallback *callback;
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  callback = AddCallbackAfter (&xdg_role->reconstrain_callbacks);
  callback->configure = configure_func;
  callback->resized = resize_func;
  callback->data = data;

  return callback;
}

void
XLXdgRoleCancelReconstrainCallback (void *key)
{
  ReconstrainCallback *callback;

  callback = key;
  UnlinkReconstrainCallback (callback);
}

void
XLXdgRoleReconstrain (Role *role, XEvent *event)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);
  RunReconstrainCallbacksForXEvent (xdg_role, event);
}

void
XLXdgRoleMoveBy (Role *role, int west, int north)
{
  int root_x, root_y;
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  /* Move the window by the opposite of west and north.  */

  CurrentRootPosition (xdg_role, &root_x, &root_y);
  XMoveWindow (compositor.display, xdg_role->window,
	       root_x - west, root_y - north);

  /* Set pending root window positions.  These positions will be
     used until the movement really happens, to avoid outdated
     positions being used after the minimum positions change in
     quick succession.  */
  xdg_role->pending_root_x = root_x - west;
  xdg_role->pending_root_y = root_y - north;
  xdg_role->pending_synth_configure++;
}

FrameClock *
XLXdgRoleGetFrameClock (Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);
  return xdg_role->clock;
}

void
XLInitXdgSurfaces (void)
{
  XColor alloc;
  int shape_minor, shape_major, shape_error;

  surfaces = XLCreateAssocTable (1024);

  alloc.red = 0;
  alloc.green = 65535;
  alloc.blue = 0;

  if (!XAllocColor (compositor.display, compositor.colormap,
		    &alloc))
    {
      fprintf (stderr, "Failed to allocate green pixel\n");
      exit (1);
    }

  border_pixel = alloc.pixel;

  /* Now initialize the nonrectangular window shape extension.  We
     need a version that supports input shapes, which means 1.1 or
     later.  */

  if (!XShapeQueryExtension (compositor.display, &shape_base,
			     &shape_error))
    {
      fprintf (stderr, "The Nonrectangular Window Shape extension is not"
	       " present on the X server\n");
      exit (1);
    }

  if (!XShapeQueryVersion (compositor.display,
			   &shape_major, &shape_minor))
    {
      fprintf (stderr, "A supported version of the Nonrectangular Window"
	       " Shape extension is not present on the X server\n");
      exit (1);
    }

  if (shape_major < 1 || (shape_major == 1 && shape_minor < 1))
    {
      fprintf (stderr, "The version of the Nonrectangular Window Shape"
	       " extension is too old\n");
      exit (1);
    }
}

XdgRoleImplementation *
XLLookUpXdgToplevel (Window window)
{
  XdgRole *role;

  role = XLLookUpAssoc (surfaces, window);

  if (!role)
    return NULL;

  if (role->type != TypeToplevel)
    return NULL;

  return role->impl;
}

XdgRoleImplementation *
XLLookUpXdgPopup (Window window)
{
  XdgRole *role;

  role = XLLookUpAssoc (surfaces, window);

  if (!role)
    return NULL;

  if (role->type != TypePopup)
    return NULL;

  return role->impl;
}

void
XLXdgRoleNoteRejectedConfigure (Role *role)
{
  XdgRole *xdg_role;

  xdg_role = XdgRoleFromRole (role);

  if (xdg_role->state & StateMaybeConfigure)
    {
      /* A configure event immediately following _NET_WM_SYNC_REQUEST
	 was rejected, meaning that we do not have to change anything
	 before unfreezing the frame clock.  */
      xdg_role->state &= ~StateWaitingForAckConfigure;
      xdg_role->state &= ~StateWaitingForAckCommit;
      xdg_role->state &= ~StateMaybeConfigure;

      /* Unfreeze the frame clock now.  */
      XLFrameClockUnfreeze (xdg_role->clock);
    }
}