Add lists

2 files changed, 93 insertions, 5 deletions

diff --git a/list.h b/list.h
new file mode 100644
index 0000000..c78e1c3
--- /dev/null
+++ b/list.h
@@ -0,0 +1,65 @@
+#ifndef LIST_H
+#define LIST_H
+
+/* Doubly linked lists */
+typedef struct link_t link_t;
+struct link_t
+{
+    link_t *next;
+    link_t *prev;
+};
+
+typedef struct list_t list_t;
+struct list_t
+{
+    link_t *head;
+    link_t *tail;
+};
+
+static inline void
+list_init (list_t *list)
+{
+    list->head = (link_t *)list;
+    list->tail = (link_t *)list;
+}
+
+static inline void
+list_prepend (list_t *list, link_t *link)
+{
+    link->next = list->head;
+    link->prev = (link_t *)list;
+    list->head->prev = link;
+    list->head = link;
+}
+
+static inline void
+list_unlink (link_t *link)
+{
+    link->prev->next = link->next;
+    link->next->prev = link->prev;
+}
+
+static inline void
+list_move_to_front (list_t *list, link_t *link)
+{
+    list_unlink (link);
+    list_prepend (list, link);
+}
+
+#define LIST_FOREACH(list, link)					\
+    for ((link) = (list)->head;						\
+	 (link) != (link_t *)(list);				\
+	 (link) = (link)->next)
+
+#if defined(__GNUC__) && __GNUC__ >= 4
+#   define OFFSET_OF(type, member)					\
+    ((unsigned long)__builtin_offsetof(type, member))
+#else
+#   define OFFSET_OF(type, member)					\
+    ((unsigned long)(&(((type *)0)->member))
+#endif
+
+#define CONTAINER_OF(type, member, data)				\
+    ((type *)(((uint8_t *)data) - OFFSET_OF(type, member)))
+
+#endif
diff --git a/window.c b/window.c
index e3f42b7..ea6ad7e 100644
--- a/window.c
+++ b/window.c
@@ -3,6 +3,7 @@
 #include <X11/Xutil.h>
 #include <assert.h>
 #include "window.h"
+#include "list.h"
 
 struct ws_t
 {
@@ -12,15 +13,18 @@ struct ws_t
     pixman_bool_t		composited;
     pixman_bool_t		has_alpha;
     int				byte_order;
+
+    list_t			windows;
 };
 
 struct window_t
 {
-    ws_t *ws;
-    XID xid;
-    int ref_count;
-    pixman_image_t *backing_store;
-    int x, y;
+    link_t		link;
+    ws_t *		ws;
+    XID			xid;
+    int			ref_count;
+    pixman_image_t *	backing_store;
+    int			x, y;
 };
 
 static pixman_bool_t
@@ -185,6 +189,22 @@ ws_open (void)
     return ws;
 }
 
+static window_t *
+find_window (ws_t *ws, XID xid)
+{
+    link_t *link;
+
+    LIST_FOREACH (&ws->windows, link)
+    {
+	window_t *window = CONTAINER_OF (window_t, link, link);
+
+	if (window->xid == xid)
+	    return window;
+    }
+
+    return NULL;
+}
+
 /* Window */
 window_t *
 ws_create_window (ws_t           *ws,
@@ -210,6 +230,9 @@ ws_create_window (ws_t           *ws,
     window->ws = ws;
     window->x = x;
     window->y = y;
+
+    list_prepend (&ws->windows, &window->link);
+
     return window;
 }