server/window.c

   1 /*
   2  * Server-side window handling
   3  *
   4  * Copyright (C) 2001 Alexandre Julliard
   5  */
   6
   7 #include <assert.h>
   8
   9 #include "object.h"
  10 #include "request.h"
  11 #include "thread.h"
  12 #include "process.h"
  13 #include "user.h"
  14
  15 struct window
  16 {
  17     struct window   *parent;      /* parent window */
  18     struct window   *owner;       /* owner of this window */
  19     struct window   *first_child; /* first child window */
  20     struct window   *last_child;  /* last child window */
  21     struct window   *next;        /* next window in Z-order */
  22     struct window   *prev;        /* prev window in Z-order */
  23     user_handle_t    handle;      /* full handle for this window */
  24     struct thread   *thread;      /* thread owning the window */
  25 };
  26
  27 static struct window *top_window;  /* top-level (desktop) window */
  28
  29
  30 /* retrieve a pointer to a window from its handle */
  31 inline static struct window *get_window( user_handle_t handle )
  32 {
  33     struct window *ret = get_user_object( handle, USER_WINDOW );
  34     if (!ret) set_error( STATUS_INVALID_HANDLE );
  35     return ret;
  36 }
  37
  38 /* link a window into the tree (or unlink it if the new parent is NULL)  */
  39 static void link_window( struct window *win, struct window *parent, struct window *previous )
  40 {
  41     if (win->parent)  /* unlink it from the previous location */
  42     {
  43         if (win->next) win->next->prev = win->prev;
  44         else if (win->parent->last_child == win) win->parent->last_child = win->prev;
  45         if (win->prev) win->prev->next = win->next;
  46         else if (win->parent->first_child == win) win->parent->first_child = win->next;
  47     }
  48     if (parent)
  49     {
  50         win->parent = parent;
  51         if ((win->prev = previous))
  52         {
  53             if ((win->next = previous->next)) win->next->prev = win;
  54             else if (win->parent->last_child == previous) win->parent->last_child = win;
  55             win->prev->next = win;
  56         }
  57         else
  58         {
  59             if ((win->next = parent->first_child)) win->next->prev = win;
  60             else win->parent->last_child = win;
  61             parent->first_child = win;
  62         }
  63     }
  64     else
  65     {
  66         /* don't touch parent; an unlinked window still has a valid parent pointer */
  67         win->next = win->prev = NULL;
  68     }
  69 }
  70
  71 /* destroy a window */
  72 static void destroy_window( struct window *win )
  73 {
  74     assert( win != top_window );
  75
  76     /* destroy all children */
  77     while (win->first_child) destroy_window( win->first_child );
  78
  79     /* reset siblings owner */
  80     if (win->parent)
  81     {
  82         struct window *ptr;
  83         for (ptr = win->parent->first_child; ptr; ptr = ptr->next)
  84             if (ptr->owner == win) ptr->owner = NULL;
  85     }
  86
  87     if (win->thread->queue) queue_cleanup_window( win->thread, win->handle );
  88     free_user_handle( win->handle );
  89     link_window( win, NULL, NULL );
  90     memset( win, 0x55, sizeof(*win) );
  91     free( win );
  92 }
  93
  94 /* create a new window structure (note: the window is not linked in the window tree) */
  95 static struct window *create_window( struct window *parent, struct window *owner )
  96 {
  97     struct window *win = mem_alloc( sizeof(*win) );
  98     if (!win) return NULL;
  99
 100     if (!(win->handle = alloc_user_handle( win, USER_WINDOW )))
 101     {
 102         free( win );
 103         return NULL;
 104     }
 105     win->parent      = parent;
 106     win->owner       = owner;
 107     win->first_child = NULL;
 108     win->last_child  = NULL;
 109     win->next        = NULL;
 110     win->prev        = NULL;
 111     win->thread      = current;
 112     return win;
 113 }
 114
 115 /* destroy all windows belonging to a given thread */
 116 void destroy_thread_windows( struct thread *thread )
 117 {
 118     user_handle_t handle = 0;
 119     struct window *win;
 120
 121     while ((win = next_user_handle( &handle, USER_WINDOW )))
 122     {
 123         if (win->thread != thread) continue;
 124         destroy_window( win );
 125     }
 126 }
 127
 128 /* check whether child is a descendant of parent */
 129 int is_child_window( user_handle_t parent, user_handle_t child )
 130 {
 131     struct window *child_ptr = get_user_object( child, USER_WINDOW );
 132     struct window *parent_ptr = get_user_object( parent, USER_WINDOW );
 133
 134     if (!child_ptr || !parent_ptr) return 0;
 135     while (child_ptr->parent)
 136     {
 137         if (child_ptr->parent == parent_ptr) return 1;
 138         child_ptr = child_ptr->parent;
 139     }
 140     return 0;
 141 }
 142
 143 /* create a window */
 144 DECL_HANDLER(create_window)
 145 {
 146     req->handle = 0;
 147     if (!req->parent)  /* return desktop window */
 148     {
 149         if (!top_window)
 150         {
 151             if (!(top_window = create_window( NULL, NULL ))) return;
 152             top_window->thread = NULL;  /* no thread owns the desktop */
 153         }
 154         req->handle = top_window->handle;
 155     }
 156     else
 157     {
 158         struct window *win, *parent, *owner = NULL;
 159
 160         if (!(parent = get_window( req->parent ))) return;
 161         if (req->owner && !(owner = get_window( req->owner ))) return;
 162         if (!(win = create_window( parent, owner ))) return;
 163         req->handle = win->handle;
 164     }
 165 }
 166
 167
 168 /* link a window into the tree */
 169 DECL_HANDLER(link_window)
 170 {
 171     struct window *win, *parent = NULL, *previous = NULL;
 172
 173     if (!(win = get_window( req->handle ))) return;
 174     if (req->parent && !(parent = get_window( req->parent ))) return;
 175     if (parent && req->previous)
 176     {
 177         if (req->previous == (user_handle_t)1)  /* special case: HWND_BOTTOM */
 178         {
 179             previous = parent->last_child;
 180             if (previous == win) return;  /* nothing to do */
 181         }
 182         else
 183         {
 184             if (!(previous = get_window( req->previous ))) return;
 185             /* previous must be a child of parent, and not win itself */
 186             if (previous->parent != parent || previous == win)
 187             {
 188                 set_error( STATUS_INVALID_PARAMETER );
 189                 return;
 190             }
 191         }
 192     }
 193     link_window( win, parent, previous );
 194 }
 195
 196
 197 /* destroy a window */
 198 DECL_HANDLER(destroy_window)
 199 {
 200     struct window *win = get_window( req->handle );
 201     if (win)
 202     {
 203         if (win != top_window) destroy_window( win );
 204         else set_error( STATUS_ACCESS_DENIED );
 205     }
 206 }
 207
 208
 209 /* get information from a window handle */
 210 DECL_HANDLER(get_window_info)
 211 {
 212     struct window *win = get_window( req->handle );
 213
 214     req->full_handle = 0;
 215     req->tid = req->pid = 0;
 216     if (win)
 217     {
 218         req->full_handle = win->handle;
 219         if (win->thread)
 220         {
 221             req->tid = get_thread_id( win->thread );
 222             req->pid = get_process_id( win->thread->process );
 223         }
 224     }
 225 }
 226
 227
 228 /* get a list of the window parents, up to the root of the tree */
 229 DECL_HANDLER(get_window_parents)
 230 {
 231     struct window *ptr, *win = get_window( req->handle );
 232     int total = 0;
 233     size_t len;
 234
 235     if (win) for (ptr = win->parent; ptr; ptr = ptr->parent) total++;
 236
 237     req->count = total;
 238     len = min( get_req_data_size(req), total * sizeof(user_handle_t) );
 239     set_req_data_size( req, len );
 240     if (len)
 241     {
 242         user_handle_t *data = get_req_data(req);
 243         for (ptr = win->parent; ptr && len; ptr = ptr->parent, len -= sizeof(*data))
 244             *data++ = ptr->handle;
 245     }
 246 }
 247
 248
 249 /* get a list of the window children */
 250 DECL_HANDLER(get_window_children)
 251 {
 252     struct window *ptr, *parent = get_window( req->parent );
 253     int total = 0;
 254     size_t len;
 255
 256     if (parent)
 257         for (ptr = parent->first_child, total = 0; ptr; ptr = ptr->next) total++;
 258
 259     req->count = total;
 260     len = min( get_req_data_size(req), total * sizeof(user_handle_t) );
 261     set_req_data_size( req, len );
 262     if (len)
 263     {
 264         user_handle_t *data = get_req_data(req);
 265         for (ptr = parent->first_child; ptr && len; ptr = ptr->next, len -= sizeof(*data))
 266             *data++ = ptr->handle;
 267     }
 268 }
 269
 270
 271 /* get window tree information from a window handle */
 272 DECL_HANDLER(get_window_tree)
 273 {
 274     struct window *win = get_window( req->handle );
 275
 276     if (!win) return;
 277
 278     if (win->parent)
 279     {
 280         struct window *parent = win->parent;
 281         req->parent        = parent->handle;
 282         req->owner         = win->owner ? win->owner->handle : 0;
 283         req->next_sibling  = win->next ? win->next->handle : 0;
 284         req->prev_sibling  = win->prev ? win->prev->handle : 0;
 285         req->first_sibling = parent->first_child ? parent->first_child->handle : 0;
 286         req->last_sibling  = parent->last_child ? parent->last_child->handle : 0;
 287     }
 288     else
 289     {
 290         req->parent        = 0;
 291         req->owner         = 0;
 292         req->next_sibling  = 0;
 293         req->prev_sibling  = 0;
 294         req->first_sibling = 0;
 295         req->last_sibling  = 0;
 296     }
 297     req->first_child = win->first_child ? win->first_child->handle : 0;
 298     req->last_child  = win->last_child ? win->last_child->handle : 0;
 299 }