mutter/src/core/workspace.c

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */

/* Metacity Workspaces */

/* 
 * Copyright (C) 2001 Havoc Pennington
 * Copyright (C) 2003 Rob Adams
 * Copyright (C) 2004, 2005 Elijah Newren
 * 
 * This program 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 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#include <config.h>
#include "workspace.h"
#include "errors.h"
#include "prefs.h"
#include <X11/Xatom.h>
#include <string.h>

void meta_workspace_queue_calc_showing   (MetaWorkspace *workspace);
static void set_active_space_hint        (MetaScreen *screen);
static void focus_ancestor_or_mru_window (MetaWorkspace *workspace,
                                          MetaWindow    *not_this_one,
                                          guint32        timestamp);

static void
maybe_add_to_list (MetaScreen *screen, MetaWindow *window, gpointer data)
{
  GList **mru_list = data;

  if (window->on_all_workspaces)
    *mru_list = g_list_prepend (*mru_list, window);
}

MetaWorkspace*
meta_workspace_new (MetaScreen *screen)
{
  MetaWorkspace *workspace;

  workspace = g_new (MetaWorkspace, 1);

  workspace->screen = screen;
  workspace->screen->workspaces =
    g_list_append (workspace->screen->workspaces, workspace);
  workspace->windows = NULL;
  workspace->mru_list = NULL;
  meta_screen_foreach_window (screen, maybe_add_to_list, &workspace->mru_list);

  workspace->work_areas_invalid = TRUE;
  workspace->work_area_xinerama = NULL;
  workspace->work_area_screen.x = 0;
  workspace->work_area_screen.y = 0;
  workspace->work_area_screen.width = 0;
  workspace->work_area_screen.height = 0;

  workspace->screen_region = NULL;
  workspace->xinerama_region = NULL;
  workspace->screen_edges = NULL;
  workspace->xinerama_edges = NULL;
  workspace->list_containing_self = g_list_prepend (NULL, workspace);

  workspace->all_struts = NULL;

  workspace->showing_desktop = FALSE;
  
  return workspace;
}

void
meta_workspace_free (MetaWorkspace *workspace)
{
  GList *tmp;
  MetaScreen *screen;
  int i;

  g_return_if_fail (workspace != workspace->screen->active_workspace);

  /* Here we assume all the windows are already on another workspace
   * as well, so they won't be "orphaned"
   */
  
  tmp = workspace->windows;
  while (tmp != NULL)
    {
      GList *next;
      MetaWindow *window = tmp->data;
      next = tmp->next;

      /* pop front of list we're iterating over */
      meta_workspace_remove_window (workspace, window);
      g_assert (window->workspace != NULL);

      tmp = next;
    }

  g_assert (workspace->windows == NULL);

  screen = workspace->screen;
  
  workspace->screen->workspaces =
    g_list_remove (workspace->screen->workspaces, workspace);
  
  g_free (workspace->work_area_xinerama);

  g_list_free (workspace->mru_list);
  g_slist_free (workspace->all_struts);
  g_list_free (workspace->list_containing_self);

  for (i = 0; i < screen->n_xinerama_infos; i++)
    meta_rectangle_free_list_and_elements (workspace->xinerama_region[i]);
  g_free (workspace->xinerama_region);
  meta_rectangle_free_list_and_elements (workspace->screen_region);
  meta_rectangle_free_list_and_elements (workspace->screen_edges);
  meta_rectangle_free_list_and_elements (workspace->xinerama_edges);

  g_free (workspace);

  /* don't bother to reset names, pagers can just ignore
   * extra ones
   */
}

void
meta_workspace_add_window (MetaWorkspace *workspace,
                           MetaWindow    *window)
{
  g_return_if_fail (window->workspace == NULL);
  
  /* If the window is on all workspaces, we want to add it to all mru
   * lists, otherwise just add it to this workspaces mru list
   */
  if (window->on_all_workspaces) 
    {
      if (window->workspace == NULL)
        {
          GList* tmp = window->screen->workspaces;
          while (tmp)
            {
              MetaWorkspace* work = (MetaWorkspace*) tmp->data;
              if (!g_list_find (work->mru_list, window))
                work->mru_list = g_list_prepend (work->mru_list, window);

              tmp = tmp->next;
            }
        }
    }
  else
    {
      g_assert (g_list_find (workspace->mru_list, window) == NULL);
      workspace->mru_list = g_list_prepend (workspace->mru_list, window);
    }

  workspace->windows = g_list_prepend (workspace->windows, window);
  window->workspace = workspace;

  meta_window_set_current_workspace_hint (window);
  
  if (window->struts)
    {
      meta_topic (META_DEBUG_WORKAREA,
                  "Invalidating work area of workspace %d since we're adding window %s to it\n",
                  meta_workspace_index (workspace), window->desc);
      meta_workspace_invalidate_work_area (workspace);
    }

  /* queue a move_resize since changing workspaces may change
   * the relevant struts
   */
  meta_window_queue (window, META_QUEUE_CALC_SHOWING|META_QUEUE_MOVE_RESIZE);
}

void
meta_workspace_remove_window (MetaWorkspace *workspace,
                              MetaWindow    *window)
{
  g_return_if_fail (window->workspace == workspace);

  workspace->windows = g_list_remove (workspace->windows, window);
  window->workspace = NULL;

  /* If the window is on all workspaces, we don't want to remove it
   * from the MRU list unless this causes it to be removed from all 
   * workspaces
   */
  if (window->on_all_workspaces) 
    {
      GList* tmp = window->screen->workspaces;
      while (tmp)
        {
          MetaWorkspace* work = (MetaWorkspace*) tmp->data;
          work->mru_list = g_list_remove (work->mru_list, window);

          tmp = tmp->next;
        }
    }
  else
    {
      workspace->mru_list = g_list_remove (workspace->mru_list, window);
      g_assert (g_list_find (workspace->mru_list, window) == NULL);
    }

  meta_window_set_current_workspace_hint (window);
  
  if (window->struts)
    {
      meta_topic (META_DEBUG_WORKAREA,
                  "Invalidating work area of workspace %d since we're removing window %s from it\n",
                  meta_workspace_index (workspace), window->desc);
      meta_workspace_invalidate_work_area (workspace);
    }

  /* queue a move_resize since changing workspaces may change
   * the relevant struts
   */
  meta_window_queue (window, META_QUEUE_CALC_SHOWING|META_QUEUE_MOVE_RESIZE);
}

void
meta_workspace_relocate_windows (MetaWorkspace *workspace,
                                 MetaWorkspace *new_home)
{
  GList *tmp;
  GList *copy;
  
  g_return_if_fail (workspace != new_home);

  /* can't modify list we're iterating over */
  copy = g_list_copy (workspace->windows);
  
  tmp = copy;
  while (tmp != NULL)
    {
      MetaWindow *window = tmp->data;

      meta_workspace_remove_window (workspace, window);
      meta_workspace_add_window (new_home, window);
      
      tmp = tmp->next;
    }

  g_list_free (copy);
  
  g_assert (workspace->windows == NULL);
}

void
meta_workspace_queue_calc_showing  (MetaWorkspace *workspace)
{
  GList *tmp;

  tmp = workspace->windows;
  while (tmp != NULL)
    {
      meta_window_queue (tmp->data, META_QUEUE_CALC_SHOWING);

      tmp = tmp->next;
    }
}

void
meta_workspace_activate_with_focus (MetaWorkspace *workspace,
                                    MetaWindow    *focus_this,
                                    guint32        timestamp)
{
  MetaWorkspace *old;
  MetaWindow *move_window;
  
  meta_verbose ("Activating workspace %d\n",
                meta_workspace_index (workspace));
  
  if (workspace->screen->active_workspace == workspace)
    return;

  /* Note that old can be NULL; e.g. when starting up */
  old = workspace->screen->active_workspace;
  
  workspace->screen->active_workspace = workspace;

  set_active_space_hint (workspace->screen);

  /* If the "show desktop" mode is active for either the old workspace
   * or the new one *but not both*, then update the
   * _net_showing_desktop hint
   */
  if (old && (old->showing_desktop ^ workspace->showing_desktop))
    meta_screen_update_showing_desktop_hint (workspace->screen);

  if (old == NULL)
    return;

  move_window = NULL;
  if (workspace->screen->display->grab_op == META_GRAB_OP_MOVING ||
      workspace->screen->display->grab_op == META_GRAB_OP_KEYBOARD_MOVING)
    move_window = workspace->screen->display->grab_window;
      
  if (move_window != NULL)
    {
      if (move_window->on_all_workspaces)
        move_window = NULL; /* don't move it after all */

      /* We put the window on the new workspace, flip spaces,
       * then remove from old workspace, so the window
       * never gets unmapped and we maintain the button grab
       * on it.
       */
      if (move_window && (move_window->workspace != workspace))
        {
          meta_workspace_remove_window (workspace, move_window);
          meta_workspace_add_window (workspace, move_window);
        }
    }

  meta_workspace_queue_calc_showing (old);
  meta_workspace_queue_calc_showing (workspace);

  /* FIXME: Why do we need this?!?  Isn't it handled in the lines above? */
  if (move_window)
      /* Removes window from other spaces */
      meta_window_change_workspace (move_window, workspace);

  if (focus_this)
    {
      meta_window_focus (focus_this, timestamp);
      meta_window_raise (focus_this);
    }
  else if (move_window)
    {
      meta_window_raise (move_window);
    }
  else
    {
      meta_topic (META_DEBUG_FOCUS, "Focusing default window on new workspace\n");
      meta_workspace_focus_default_window (workspace, NULL, timestamp);
    }
}

void
meta_workspace_activate (MetaWorkspace *workspace,
                         guint32        timestamp)
{
  meta_workspace_activate_with_focus (workspace, NULL, timestamp);
}

int
meta_workspace_index (MetaWorkspace *workspace)
{
  int ret;

  ret = g_list_index (workspace->screen->workspaces, workspace);

  if (ret < 0)
    meta_bug ("Workspace does not exist to index!\n");

  return ret;
}

/* get windows contained on workspace, including workspace->windows
 * and also sticky windows.
 */
GList*
meta_workspace_list_windows (MetaWorkspace *workspace)
{
  GSList *display_windows;
  GSList *tmp;
  GList *workspace_windows;
  
  display_windows = meta_display_list_windows (workspace->screen->display);

  workspace_windows = NULL;
  tmp = display_windows;
  while (tmp != NULL)
    {
      MetaWindow *window = tmp->data;

      if (meta_window_located_on_workspace (window, workspace))
        workspace_windows = g_list_prepend (workspace_windows,
                                            window);

      tmp = tmp->next;
    }

  g_slist_free (display_windows);

  return workspace_windows;
}

static void
set_active_space_hint (MetaScreen *screen)
{
  unsigned long data[1];

  /* this is because we destroy the spaces in order,
   * so we always end up setting a current desktop of
   * 0 when closing a screen, so lose the current desktop
   * on restart. By doing this we keep the current
   * desktop on restart.
   */
  if (screen->closing > 0)
    return;
  
  data[0] = meta_workspace_index (screen->active_workspace);

  meta_verbose ("Setting _NET_CURRENT_DESKTOP to %lu\n", data[0]);
  
  meta_error_trap_push (screen->display);
  XChangeProperty (screen->display->xdisplay, screen->xroot,
                   screen->display->atom_net_current_desktop,
                   XA_CARDINAL,
                   32, PropModeReplace, (guchar*) data, 1);
  meta_error_trap_pop (screen->display, FALSE);
}

void
meta_workspace_invalidate_work_area (MetaWorkspace *workspace)
{
  GList *tmp;
  GList *windows;
  int i;
  
  if (workspace->work_areas_invalid)
    {
      meta_topic (META_DEBUG_WORKAREA,
                  "Work area for workspace %d is already invalid\n",
                  meta_workspace_index (workspace));
      return;
    }

  meta_topic (META_DEBUG_WORKAREA,
              "Invalidating work area for workspace %d\n",
              meta_workspace_index (workspace));

  g_free (workspace->work_area_xinerama);
  workspace->work_area_xinerama = NULL;
      
  g_slist_free (workspace->all_struts);
  workspace->all_struts = NULL;

  for (i = 0; i < workspace->screen->n_xinerama_infos; i++)
    meta_rectangle_free_list_and_elements (workspace->xinerama_region[i]);
  g_free (workspace->xinerama_region);
  meta_rectangle_free_list_and_elements (workspace->screen_region);
  meta_rectangle_free_list_and_elements (workspace->screen_edges);
  meta_rectangle_free_list_and_elements (workspace->xinerama_edges);
  workspace->xinerama_region = NULL;
  workspace->screen_region = NULL;
  workspace->screen_edges = NULL;
  workspace->xinerama_edges = NULL;
  
  workspace->work_areas_invalid = TRUE;

  /* redo the size/position constraints on all windows */
  windows = meta_workspace_list_windows (workspace);
  tmp = windows;
  while (tmp != NULL)
    {
      MetaWindow *w = tmp->data;

      meta_window_queue (w, META_QUEUE_MOVE_RESIZE);
      
      tmp = tmp->next;
    }

  g_list_free (windows);

  meta_screen_queue_workarea_recalc (workspace->screen);
}

static void
ensure_work_areas_validated (MetaWorkspace *workspace)
{
  GList         *windows;
  GList         *tmp;
  MetaRectangle  work_area;
  int            i;  /* C89 absolutely sucks... */

  if (!workspace->work_areas_invalid)
    return;

  g_assert (workspace->all_struts == NULL);
  g_assert (workspace->xinerama_region == NULL);
  g_assert (workspace->screen_region == NULL);
  g_assert (workspace->screen_edges == NULL);
  g_assert (workspace->xinerama_edges == NULL);

  /* STEP 1: Get the list of struts */  
  windows = meta_workspace_list_windows (workspace);
  for (tmp = windows; tmp != NULL; tmp = tmp->next)
    {
      MetaWindow *win = tmp->data;
      GSList *s_iter;

      for (s_iter = win->struts; s_iter != NULL; s_iter = s_iter->next)
        workspace->all_struts = g_slist_prepend (workspace->all_struts,
                                                 s_iter->data);
    }
  g_list_free (windows);

  /* STEP 2: Get the maximal/spanning rects for the onscreen and
   *         on-single-xinerama regions
   */  
  g_assert (workspace->xinerama_region == NULL);
  g_assert (workspace->screen_region   == NULL);

  workspace->xinerama_region = g_new (GList*,
                                      workspace->screen->n_xinerama_infos);
  for (i = 0; i < workspace->screen->n_xinerama_infos; i++)
    {
      workspace->xinerama_region[i] =
        meta_rectangle_get_minimal_spanning_set_for_region (
          &workspace->screen->xinerama_infos[i].rect,
          workspace->all_struts);
    }
  workspace->screen_region =
    meta_rectangle_get_minimal_spanning_set_for_region (
      &workspace->screen->rect,
      workspace->all_struts);

  /* STEP 3: Get the work areas (region-to-maximize-to) for the screen and
   *         xineramas.
   */
  work_area = workspace->screen->rect;  /* start with the screen */
  if (workspace->screen_region == NULL)
    work_area = meta_rect (0, 0, -1, -1);
  else
    meta_rectangle_clip_to_region (workspace->screen_region,
                                   FIXED_DIRECTION_NONE,
                                   &work_area);

  /* Lots of paranoia checks, forcing work_area_screen to be sane */
#define MIN_SANE_AREA 100
  if (work_area.width < MIN_SANE_AREA)
    {
      meta_warning ("struts occupy an unusually large percentage of the screen; "
                    "available remaining width = %d < %d",
                    work_area.width, MIN_SANE_AREA);
      if (work_area.width < 1)
        {
          work_area.x = (workspace->screen->rect.width - MIN_SANE_AREA)/2;
          work_area.width = MIN_SANE_AREA;
        }
      else
        {
          int amount = (MIN_SANE_AREA - work_area.width)/2;
          work_area.x     -=   amount;
          work_area.width += 2*amount;
        }
    }
  if (work_area.height < MIN_SANE_AREA)
    {
      meta_warning ("struts occupy an unusually large percentage of the screen; "
                    "available remaining height = %d < %d",
                    work_area.height, MIN_SANE_AREA);
      if (work_area.height < 1)
        {
          work_area.y = (workspace->screen->rect.height - MIN_SANE_AREA)/2;
          work_area.height = MIN_SANE_AREA;
        }
      else
        {
          int amount = (MIN_SANE_AREA - work_area.height)/2;
          work_area.y      -=   amount;
          work_area.height += 2*amount;
        }
    }
  workspace->work_area_screen = work_area;
  meta_topic (META_DEBUG_WORKAREA,
              "Computed work area for workspace %d: %d,%d %d x %d\n",
              meta_workspace_index (workspace),
              workspace->work_area_screen.x,
              workspace->work_area_screen.y,
              workspace->work_area_screen.width,
              workspace->work_area_screen.height);    

  /* Now find the work areas for each xinerama */
  g_free (workspace->work_area_xinerama);
  workspace->work_area_xinerama = g_new (MetaRectangle,
                                         workspace->screen->n_xinerama_infos);

  for (i = 0; i < workspace->screen->n_xinerama_infos; i++)
    {
      work_area = workspace->screen->xinerama_infos[i].rect;

      if (workspace->xinerama_region[i] == NULL)
        /* FIXME: constraints.c untested with this, but it might be nice for
         * a screen reader or magnifier.
         */
        work_area = meta_rect (work_area.x, work_area.y, -1, -1);
      else
        meta_rectangle_clip_to_region (workspace->xinerama_region[i],
                                       FIXED_DIRECTION_NONE,
                                       &work_area);

      workspace->work_area_xinerama[i] = work_area;
      meta_topic (META_DEBUG_WORKAREA,
                  "Computed work area for workspace %d "
                  "xinerama %d: %d,%d %d x %d\n",
                  meta_workspace_index (workspace),
                  i,
                  workspace->work_area_xinerama[i].x,
                  workspace->work_area_xinerama[i].y,
                  workspace->work_area_xinerama[i].width,
                  workspace->work_area_xinerama[i].height);
    }

  /* STEP 4: Make sure the screen_region is nonempty (separate from step 2
   *         since it relies on step 3).
   */  
  if (workspace->screen_region == NULL)
    {
      MetaRectangle *nonempty_region;
      nonempty_region = g_new (MetaRectangle, 1);
      *nonempty_region = workspace->work_area_screen;
      workspace->screen_region = g_list_prepend (NULL, nonempty_region);
    }

  /* STEP 5: Cache screen and xinerama edges for edge resistance and snapping */
  g_assert (workspace->screen_edges    == NULL);
  g_assert (workspace->xinerama_edges  == NULL);
  workspace->screen_edges =
    meta_rectangle_find_onscreen_edges (&workspace->screen->rect,
                                        workspace->all_struts);
  tmp = NULL;
  for (i = 0; i < workspace->screen->n_xinerama_infos; i++)
    tmp = g_list_prepend (tmp, &workspace->screen->xinerama_infos[i].rect);
  workspace->xinerama_edges =
    meta_rectangle_find_nonintersected_xinerama_edges (tmp,
                                                       workspace->all_struts);
  g_list_free (tmp);

  /* We're all done, YAAY!  Record that everything has been validated. */
  workspace->work_areas_invalid = FALSE;
}

void
meta_workspace_get_work_area_for_xinerama (MetaWorkspace *workspace,
                                           int            which_xinerama,
                                           MetaRectangle *area)
{
  g_assert (which_xinerama >= 0);

  ensure_work_areas_validated (workspace);
  g_assert (which_xinerama < workspace->screen->n_xinerama_infos);
  
  *area = workspace->work_area_xinerama[which_xinerama];
}

void
meta_workspace_get_work_area_all_xineramas (MetaWorkspace *workspace,
                                            MetaRectangle *area)
{
  ensure_work_areas_validated (workspace);
  
  *area = workspace->work_area_screen;
}

GList*
meta_workspace_get_onscreen_region (MetaWorkspace *workspace)
{
  ensure_work_areas_validated (workspace);

  return workspace->screen_region;
}

GList*
meta_workspace_get_onxinerama_region (MetaWorkspace *workspace,
                                      int            which_xinerama)
{
  ensure_work_areas_validated (workspace);

  return workspace->xinerama_region[which_xinerama];
}

#ifdef WITH_VERBOSE_MODE
static char *
meta_motion_direction_to_string (MetaMotionDirection direction)
{
  switch (direction)
    {
    case META_MOTION_UP:
      return "Up";
    case META_MOTION_DOWN:
      return "Down";
    case META_MOTION_LEFT:
      return "Left";
    case META_MOTION_RIGHT:
      return "Right";
    }

  return "Unknown";
}
#endif /* WITH_VERBOSE_MODE */

MetaWorkspace*
meta_workspace_get_neighbor (MetaWorkspace      *workspace,
                             MetaMotionDirection direction)
{
  MetaWorkspaceLayout layout;  
  int i, current_space, num_workspaces;
  gboolean ltr;

  current_space = meta_workspace_index (workspace);
  num_workspaces = meta_screen_get_n_workspaces (workspace->screen);
  meta_screen_calc_workspace_layout (workspace->screen, num_workspaces,
                                     current_space, &layout);

  meta_verbose ("Getting neighbor of %d in direction %s\n",
                current_space, meta_motion_direction_to_string (direction));
  
  ltr = meta_ui_get_direction() == META_UI_DIRECTION_LTR;

  switch (direction) 
    {
    case META_MOTION_LEFT:
      layout.current_col -= ltr ? 1 : -1;
      break;
    case META_MOTION_RIGHT:
      layout.current_col += ltr ? 1 : -1;
      break;
    case META_MOTION_UP:
      layout.current_row -= 1;
      break;
    case META_MOTION_DOWN:
      layout.current_row += 1;
      break;
    }

  if (layout.current_col < 0)
    layout.current_col = 0;
  if (layout.current_col >= layout.cols)
    layout.current_col = layout.cols - 1;
  if (layout.current_row < 0)
    layout.current_row = 0;
  if (layout.current_row >= layout.rows)
    layout.current_row = layout.rows - 1;

  i = layout.grid[layout.current_row * layout.cols + layout.current_col];

  if (i < 0)
    i = current_space;

  if (i >= num_workspaces)
    meta_bug ("calc_workspace_layout left an invalid (too-high) workspace number %d in the grid\n",
              i);
    
  meta_verbose ("Neighbor workspace is %d at row %d col %d\n",
                i, layout.current_row, layout.current_col);

  meta_screen_free_workspace_layout (&layout);
  
  return meta_screen_get_workspace_by_index (workspace->screen, i);
}

const char*
meta_workspace_get_name (MetaWorkspace *workspace)
{
  return meta_prefs_get_workspace_name (meta_workspace_index (workspace));
}

void
meta_workspace_focus_default_window (MetaWorkspace *workspace,
                                     MetaWindow    *not_this_one,
                                     guint32        timestamp)
{
  if (timestamp == CurrentTime)
    {
      meta_warning ("CurrentTime used to choose focus window; "
                    "focus window may not be correct.\n");
    }


  if (meta_prefs_get_focus_mode () == META_FOCUS_MODE_CLICK ||
      !workspace->screen->display->mouse_mode)
    focus_ancestor_or_mru_window (workspace, not_this_one, timestamp);
  else
    {
      MetaWindow * window;
      window = meta_screen_get_mouse_window (workspace->screen, not_this_one);
      if (window &&
          window->type != META_WINDOW_DOCK &&
          window->type != META_WINDOW_DESKTOP)
        {
          if (timestamp == CurrentTime)
            {

              /* We would like for this to never happen.  However, if
               * it does happen then we kludge since using CurrentTime
               * can mean ugly race conditions--and we can avoid these
               * by allowing EnterNotify events (which come with
               * timestamps) to handle focus.
               */

              meta_topic (META_DEBUG_FOCUS,
                          "Not focusing mouse window %s because EnterNotify events should handle that\n", window->desc);
            }
          else
            {
              meta_topic (META_DEBUG_FOCUS,
                          "Focusing mouse window %s\n", window->desc);
              meta_window_focus (window, timestamp);
            }

          if (workspace->screen->display->autoraise_window != window &&
              meta_prefs_get_auto_raise ()) 
            {
              meta_display_queue_autoraise_callback (workspace->screen->display,
                                                     window);
            }
        }
      else if (meta_prefs_get_focus_mode () == META_FOCUS_MODE_SLOPPY)
        focus_ancestor_or_mru_window (workspace, not_this_one, timestamp);
      else if (meta_prefs_get_focus_mode () == META_FOCUS_MODE_MOUSE)
        {
          meta_topic (META_DEBUG_FOCUS,
                      "Setting focus to no_focus_window, since no valid "
                      "window to focus found.\n");
          meta_display_focus_the_no_focus_window (workspace->screen->display,
                                                  workspace->screen,
                                                  timestamp);
        }
    }
}

static gboolean
record_ancestor (MetaWindow *window,
                 void       *data)
{
  MetaWindow **result = data;

  *result = window;
  return FALSE; /* quit with the first ancestor we find */
}

/* Focus ancestor of not_this_one if there is one, otherwise focus the MRU
 * window on active workspace
 */
static void
focus_ancestor_or_mru_window (MetaWorkspace *workspace,
                              MetaWindow    *not_this_one,
                              guint32        timestamp)
{
  MetaWindow *window = NULL;
  MetaWindow *desktop_window = NULL;
  GList *tmp;

  if (not_this_one)
    meta_topic (META_DEBUG_FOCUS,
                "Focusing MRU window excluding %s\n", not_this_one->desc);
  else
    meta_topic (META_DEBUG_FOCUS,
                "Focusing MRU window\n");

  /* First, check to see if we need to focus an ancestor of a window */  
  if (not_this_one)
    {
      MetaWindow *ancestor;
      ancestor = NULL;
      meta_window_foreach_ancestor (not_this_one, record_ancestor, &ancestor);
      if (ancestor != NULL)
        {
          meta_topic (META_DEBUG_FOCUS,
                      "Focusing %s, ancestor of %s\n", 
                      ancestor->desc, not_this_one->desc);
      
          meta_window_focus (ancestor, timestamp);

          /* Also raise the window if in click-to-focus */
          if (meta_prefs_get_focus_mode () == META_FOCUS_MODE_CLICK)
            meta_window_raise (ancestor);

          return;
        }
    }

  /* No ancestor, look for the MRU window */
  tmp = workspace->mru_list;  

  while (tmp)
    {
      MetaWindow* tmp_window;
      tmp_window = ((MetaWindow*) tmp->data);
      if (tmp_window != not_this_one           &&
          meta_window_showing_on_its_workspace (tmp_window) &&
          tmp_window->type != META_WINDOW_DOCK &&
          tmp_window->type != META_WINDOW_DESKTOP)
        {
          window = tmp->data;
          break;
        }
      else if (tmp_window != not_this_one      &&
               desktop_window == NULL          &&
               meta_window_showing_on_its_workspace (tmp_window) &&
               tmp_window->type == META_WINDOW_DESKTOP)
        {
          /* Found the most recently used desktop window */
          desktop_window = tmp_window;
        }

      tmp = tmp->next;
    }

  /* If no window was found, default to the MRU desktop-window */
  if (window == NULL)
    window = desktop_window;

  if (window)
    {
      meta_topic (META_DEBUG_FOCUS,
                  "Focusing workspace MRU window %s\n", window->desc);
      
      meta_window_focus (window, timestamp);

      /* Also raise the window if in click-to-focus */
      if (meta_prefs_get_focus_mode () == META_FOCUS_MODE_CLICK)
        meta_window_raise (window);
    }
  else
    {
      meta_topic (META_DEBUG_FOCUS, "No MRU window to focus found; focusing no_focus_window.\n");
      meta_display_focus_the_no_focus_window (workspace->screen->display,
                                              workspace->screen,
                                              timestamp);
    }
}