...

src/display.h

@@ -30,6 +30,7 @@
 typedef struct _MetaDisplay   MetaDisplay;
 typedef struct _MetaFrame     MetaFrame;
 typedef struct _MetaScreen    MetaScreen;
+typedef struct _MetaStack     MetaStack;
 typedef struct _MetaUISlave   MetaUISlave;
 typedef struct _MetaWindow    MetaWindow;
 typedef struct _MetaWorkspace MetaWorkspace;

src/stack.c

@@ -0,0 +1,471 @@
+/* Metacity Window Stack */
+
+/* 
+ * Copyright (C) 2001 Havoc Pennington
+ * 
+ * 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 "stack.h"
+
+struct _MetaStackOp
+{
+  guint raised : 1;
+  guint lowered : 1;
+  guint update_transient : 1;
+  guint update_layer : 1;
+  guint removed : 1;
+  MetaWindow *window;
+  Window xwindow; /* needed for remove, since window will be NULL */
+  int add_order;  /* sequence number of add since last sync */
+};
+
+static void meta_stack_sync_to_server (MetaStack *stack);
+
+
+MetaStack*
+meta_stack_new (MetaScreen *screen)
+{
+  MetaStack *stack;
+  int i;
+  
+  stack = g_new (MetaStack, 1);
+
+  stack->screen = screen;
+  stack->windows = g_array_new (FALSE, FALSE, sizeof (Window));
+
+  i = 0;
+  while (i < META_LAYER_LAST)
+    {
+      stack->layers[i] = NULL;
+      ++i;
+    }
+  stack->pending = NULL;
+  stack->freeze_count = 0;
+
+  return stack;
+}
+
+void
+meta_stack_free (MetaStack *stack)
+{
+  GList *tmp;
+  
+  g_array_free (stack->windows, TRUE);
+
+  i = 0;
+  while (i < META_LAYER_LAST)
+    {
+      g_list_free (stack->layers[i]);
+      ++i;
+    }
+  
+  tmp = stack->pending;
+  while (tmp != NULL)
+    {
+      MetaStackOp *op;
+
+      op = tmp->data;
+      if (op->window)
+        op->window->stack_op = NULL;
+      g_free (op);
+      
+      tmp = tmp->next;
+    }
+
+  g_list_free (stack->pending);
+}
+
+static MetaStackOp*
+ensure_op (MetaStack  *stack,
+           MetaWindow *window)
+{
+  if (window->stack_op == NULL)
+    {
+      /* init all flags to 0 */
+      window->stack_op = g_new0 (MetaStackOp, 1);
+      window->stack_op->window = window;
+      window->stack_op->xwindow = window->xwindow;
+      window->stack_op->add_order = -1; /* indicates never added */
+    }
+  else
+    {
+      /* Need to move to front of list */
+      stack->pending = g_list_remove (stack->pending, window->stack_op);
+    }
+
+  stack->pending = g_list_prepend (stack->pending, window->stack_op);
+  
+  return window->stack_op;
+}
+
+void
+meta_stack_add (MetaStack  *stack,
+                MetaWindow *window)
+{
+  MetaStackOp *op;
+
+  op = ensure_op (stack, window);
+
+  if (op->add_order >= 0)
+    meta_bug ("Window %s added to stack twice\n", window->desc);
+  
+  op->add_order = stack->n_added;
+  stack->n_added += 1;
+
+  if (op->removed)
+    meta_bug ("Remove op was left associated with window %s\n",
+              window->desc);
+  
+  /* We automatically need to update all new windows */
+  op->update_layer = TRUE;
+  op->update_transient = TRUE;
+  
+  meta_stack_sync_to_server (stack);
+}
+
+void
+meta_stack_remove (MetaStack  *stack,
+                   MetaWindow *window)
+{
+  MetaStackOp *op;
+  
+  op = ensure_op (stack, window);
+
+  if (op->add_order >= 0)
+    {
+      /* All we have to do is cancel the add */
+      stack->pending = g_list_remove (stack->pending, op);
+      window->stack_op = NULL;
+      g_free (op);
+      return;
+    }
+
+  /* op was other than an add, save a remove op */
+  
+  op->window = NULL;       /* can't touch this anymore. */
+  op->removed = TRUE;
+  op->add_order = -1;
+
+  /* Need to immediately remove from layer lists */
+  stack->layers[window->layer] =
+    g_list_remove (stack->layers[window->layer], window);
+  
+  meta_stack_sync_to_server (stack);
+}
+
+void
+meta_stack_update_layer (MetaStack  *stack,
+                         MetaWindow *window)
+{
+  MetaStackOp *op;
+
+  op = ensure_op (stack, window);
+  op->update_layer = TRUE;
+
+  meta_stack_sync_to_server (stack);
+}
+
+void
+meta_stack_update_transient (MetaStack  *stack,
+                             MetaWindow *window)
+{
+  MetaStackOp *op;
+
+  op = ensure_op (stack, window);
+  op->update_transient = TRUE;
+
+  meta_stack_sync_to_server (stack);
+}
+
+/* raise/lower within a layer */
+void
+meta_stack_raise (MetaStack  *stack,
+                  MetaWindow *window)
+{
+  MetaStackOp *op;
+
+  op = ensure_op (stack, window);
+  op->raised = TRUE;
+  op->lowered = FALSE;
+  
+  meta_stack_sync_to_server (stack);
+}
+
+void
+meta_stack_lower (MetaStack  *stack,
+                  MetaWindow *window)
+{
+  MetaStackOp *op;
+
+  op = ensure_op (stack, window);
+  op->raised = FALSE;
+  op->lowered = TRUE;
+  
+  meta_stack_sync_to_server (stack);
+}
+
+/* Prevent syncing to server until thaw */
+void
+meta_stack_freeze (MetaStack *stack)
+{
+  stack->freeze_count += 1;
+}
+
+void
+meta_stack_thaw (MetaStack *stack)
+{
+  g_return_if_fail (stack->freeze_count > 0);
+  
+  stack->freeze_count -= 1;
+  meta_stack_sync_to_server (stack);
+}
+
+static void
+compute_layer (MetaWindow *window)
+{
+  switch (window->type)
+    {
+    case META_WINDOW_DESKTOP:
+      window->layer = META_LAYER_DESKTOP;
+      break;
+
+    case META_WINDOW_DOCK:
+      window->layer = META_WINDOW_DOCK;
+      break;
+
+    default:
+      window->layer = META_LAYER_NORMAL;
+      break;
+    }
+}
+
+static void
+meta_stack_sync_to_server (MetaStack *stack)
+{
+  gboolean needs_sort[META_LAYER_LAST] = {
+    FALSE, FALSE, FALSE, FALSE, FALSE
+  };
+  GList *tmp;
+  Window *added;
+  Window *scratch;
+  int n_actually_added;
+  int i, j;
+  int old_size;
+  
+  /* Bail out if frozen */
+  if (stack->freeze_count > 0)
+    return;
+
+  /* Here comes the fun - figure out all the stacking.
+   * We make no pretense of efficiency.
+   *   a) replay all the pending operations
+   *   b) do a stable sort within each layer with a comparison
+   *      function that uses our constraints such as TRANSIENT_FOR
+   *   c) sync to server
+   */
+
+  /* n_added is the number of meta_stack_add() calls, not the number
+   * of windows that eventually get added here. meta_stack_remove()
+   * may have cancelled some add operations.
+   */
+  if (stack->n_added > 0)
+    added = g_new0 (Window, stack->n_added);
+  else
+    added = NULL;
+
+  n_actually_added = 0;
+  tmp = stack->pending;
+  while (tmp != NULL)
+    {
+      MetaStackOp *op;
+
+      op = tmp->data;
+
+      if (op->add_order >= 0)
+        {
+          added[op->add_order] = op->window->xwindow;
+          ++n_actually_added;
+        }
+
+      tmp = tmp->next;
+    }
+
+  old_size = stack->window->len;
+  g_array_set_size (stack->windows,
+                    old_size + n_actually_added);
+  
+  scratch = &g_array_index (stack->windows, Window, old_size);
+
+  i = 0;
+  j = 0;
+  while (i < stack->n_added)
+    {
+      if (added[i] != None)
+        {
+          scratch[j] = added[i];
+          ++j;
+        }
+      
+      ++i;
+    }
+  
+  g_assert (j == n_actually_added);
+  g_assert (i == stack->n_added);
+
+  g_free (added);
+
+  /* Now remove windows that need removing;
+   * they were already removed from the layer lists
+   * in meta_stack_remove()
+   */
+  tmp = stack->pending;
+  while (tmp != NULL)
+    {
+      MetaStackOp *op;
+
+      op = tmp->data;
+
+      if (op->removed)
+        {
+          /* Go from the end, on the principle that more recent
+           * windows are more likely to be removed, and also that we
+           * can remove without changing what we're iterating over.
+           */
+          i = stack->windows->len;
+          while (i > 0)
+            {
+              --i;
+
+              /* there's no guarantee we'll actually find windows to
+               * remove, e.g. the same xwindow could have been
+               * added/removed before we ever synced, or even
+               * added/removed/added/removed/added again, etc.
+               */
+              if (op->xwindow == g_array_index (stack->windows, Window, i))
+                {
+                  g_array_remove_index (stack->windows, i);
+                  goto next;
+                }
+            }
+        }
+
+    next:
+      tmp = tmp->next;
+    }
+  
+  /* With all the adding/removing sorted out, actually do our
+   * operations
+   */
+  
+  tmp = stack->pending;
+  while (tmp != NULL)
+    {
+      MetaStackOp *op;
+
+      op = tmp->data;
+
+      if (!op->removed)
+        {
+          MetaStackLayer old_layer;
+
+          old_layer = op->window->layer;
+
+          if (op->update_layer)
+            {
+              compute_layer (op->window);
+
+              if (op->window->layer != old_layer)
+                {
+                  /* don't resort old layer, it's
+                   * assumed that removing a window
+                   * makes no difference.
+                   */
+                  needs_sort[op->window->layer] = TRUE;
+
+                  stack->layers[old_layer] =
+                    g_list_remove (stack->layers[old_layer], op->window);
+                  stack->layers[op->window->layer] =
+                    g_list_prepend (stack->layers[op->window->layer], op->window);
+                }
+            }
+                    
+          if (op->update_transient)
+            {
+              /* need to resort our layer */
+              needs_sort[op->window->layer] = TRUE;
+            }
+
+          /* We assume that ordering between changing layers
+           * and raise/lower is irrelevant; if you raise, then
+           * the layer turns out to be different, you still
+           * raise inside the new layer
+           */
+          if (op->raised)
+            {
+              /* "top" is the front of the list */
+
+              stack->layers[op->window->layer] =
+                g_list_remove (stack->layers[op->window->layer],
+                               op->window);
+
+              stack->layers[op->window->layer] =
+                g_list_prepend (stack->layers[op->window->layer],
+                                op->window);
+            }
+          else if (op->lowered)
+            {
+              stack->layers[op->window->layer] =
+                g_list_remove (stack->layers[op->window->layer],
+                               op->window);
+
+              stack->layers[op->window->layer] =
+                g_list_append (stack->layers[op->window->layer],
+                               op->window);
+            }
+        }
+
+      g_free (op);
+      
+      tmp = tmp->next;
+    }  
+
+  g_list_free (stack->pending);
+  stack->pending = NULL;
+  stack->n_added = 0;
+
+
+  /* Sort the layer lists */
+  i = 0;  
+  while (i < META_LAYER_LAST)
+    {
+      if (needs_sort[i])
+        {
+          
+
+        }
+
+      ++i;
+    }
+
+  /* Create stacked xwindow array */
+  
+  /* Sync to server */
+  
+  /* Sync _NET_CLIENT_LIST and _NET_CLIENT_LIST_STACKING */
+  
+}
+

src/window.c

@@ -190,6 +190,9 @@ meta_window_new (MetaDisplay *display, Window xwindow)
   window->type = META_WINDOW_NORMAL;
   window->type_atom = None;
 
+  window->layer = META_LAYER_NORMAL;
+  window->stack_op = NULL;
+  
   meta_display_register_x_window (display, &window->xwindow, window);
 
   update_size_hints (window);

src/window.h

@@ -134,6 +134,10 @@ struct _MetaWindow
   int border_width;
   /* x/y/w/h here get filled with ConfigureRequest values */
   XSizeHints size_hints;
+
+  /* Managed by stack.c */
+  MetaStackLayer layer;
+  MetaStackOp *stack_op;
 };
 
 MetaWindow* meta_window_new                (MetaDisplay *display,