dlls/user32/painting.c

   1 /*
   2  * Window painting functions
   3  *
   4  * Copyright 1993, 1994, 1995, 2001, 2004, 2005, 2008 Alexandre Julliard
   5  * Copyright 1996, 1997, 1999 Alex Korobka
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  20  */
  21
  22 #include "config.h"
  23 #include "wine/port.h"
  24
  25 #include <assert.h>
  26 #include <stdarg.h>
  27 #include <string.h>
  28
  29 #include "ntstatus.h"
  30 #define WIN32_NO_STATUS
  31 #include "windef.h"
  32 #include "winbase.h"
  33 #include "wingdi.h"
  34 #include "winuser.h"
  35 #include "wine/server.h"
  36 #include "win.h"
  37 #include "user_private.h"
  38 #include "controls.h"
  39 #include "wine/list.h"
  40 #include "wine/debug.h"
  41
  42 WINE_DEFAULT_DEBUG_CHANNEL(win);
  43
  44
  45 struct dce
  46 {
  47     struct list entry;         /* entry in global DCE list */
  48     HDC         hdc;
  49     HWND        hwnd;
  50     HRGN        clip_rgn;
  51     DWORD       flags;
  52     LONG        count;         /* usage count; 0 or 1 for cache DCEs, always 1 for window DCEs,
  53                                   always >= 1 for class DCEs */
  54 };
  55
  56 static struct list dce_list = LIST_INIT(dce_list);
  57
  58 static BOOL CALLBACK dc_hook( HDC hDC, WORD code, DWORD_PTR data, LPARAM lParam );
  59
  60 static const WCHAR displayW[] = { 'D','I','S','P','L','A','Y',0 };
  61
  62
  63 /***********************************************************************
  64  *           dump_rdw_flags
  65  */
  66 static void dump_rdw_flags(UINT flags)
  67 {
  68     TRACE("flags:");
  69     if (flags & RDW_INVALIDATE) TRACE(" RDW_INVALIDATE");
  70     if (flags & RDW_INTERNALPAINT) TRACE(" RDW_INTERNALPAINT");
  71     if (flags & RDW_ERASE) TRACE(" RDW_ERASE");
  72     if (flags & RDW_VALIDATE) TRACE(" RDW_VALIDATE");
  73     if (flags & RDW_NOINTERNALPAINT) TRACE(" RDW_NOINTERNALPAINT");
  74     if (flags & RDW_NOERASE) TRACE(" RDW_NOERASE");
  75     if (flags & RDW_NOCHILDREN) TRACE(" RDW_NOCHILDREN");
  76     if (flags & RDW_ALLCHILDREN) TRACE(" RDW_ALLCHILDREN");
  77     if (flags & RDW_UPDATENOW) TRACE(" RDW_UPDATENOW");
  78     if (flags & RDW_ERASENOW) TRACE(" RDW_ERASENOW");
  79     if (flags & RDW_FRAME) TRACE(" RDW_FRAME");
  80     if (flags & RDW_NOFRAME) TRACE(" RDW_NOFRAME");
  81
  82 #define RDW_FLAGS \
  83     (RDW_INVALIDATE | \
  84     RDW_INTERNALPAINT | \
  85     RDW_ERASE | \
  86     RDW_VALIDATE | \
  87     RDW_NOINTERNALPAINT | \
  88     RDW_NOERASE | \
  89     RDW_NOCHILDREN | \
  90     RDW_ALLCHILDREN | \
  91     RDW_UPDATENOW | \
  92     RDW_ERASENOW | \
  93     RDW_FRAME | \
  94     RDW_NOFRAME)
  95
  96     if (flags & ~RDW_FLAGS) TRACE(" %04x", flags & ~RDW_FLAGS);
  97     TRACE("\n");
  98 #undef RDW_FLAGS
  99 }
 100
 101
 102 /***********************************************************************
 103  *              update_visible_region
 104  *
 105  * Set the visible region and X11 drawable for the DC associated to
 106  * a given window.
 107  */
 108 static void update_visible_region( struct dce *dce )
 109 {
 110     NTSTATUS status;
 111     HRGN vis_rgn = 0;
 112     HWND top_win = 0;
 113     DWORD flags = dce->flags;
 114     size_t size = 256;
 115     RECT win_rect, top_rect;
 116
 117     /* don't clip siblings if using parent clip region */
 118     if (flags & DCX_PARENTCLIP) flags &= ~DCX_CLIPSIBLINGS;
 119
 120     /* fetch the visible region from the server */
 121     do
 122     {
 123         RGNDATA *data = HeapAlloc( GetProcessHeap(), 0, sizeof(*data) + size - 1 );
 124         if (!data) return;
 125
 126         SERVER_START_REQ( get_visible_region )
 127         {
 128             req->window  = wine_server_user_handle( dce->hwnd );
 129             req->flags   = flags;
 130             wine_server_set_reply( req, data->Buffer, size );
 131             if (!(status = wine_server_call( req )))
 132             {
 133                 size_t reply_size = wine_server_reply_size( reply );
 134                 data->rdh.dwSize   = sizeof(data->rdh);
 135                 data->rdh.iType    = RDH_RECTANGLES;
 136                 data->rdh.nCount   = reply_size / sizeof(RECT);
 137                 data->rdh.nRgnSize = reply_size;
 138                 vis_rgn = ExtCreateRegion( NULL, size, data );
 139
 140                 top_win         = wine_server_ptr_handle( reply->top_win );
 141                 win_rect.left   = reply->win_rect.left;
 142                 win_rect.top    = reply->win_rect.top;
 143                 win_rect.right  = reply->win_rect.right;
 144                 win_rect.bottom = reply->win_rect.bottom;
 145                 top_rect.left   = reply->top_rect.left;
 146                 top_rect.top    = reply->top_rect.top;
 147                 top_rect.right  = reply->top_rect.right;
 148                 top_rect.bottom = reply->top_rect.bottom;
 149             }
 150             else size = reply->total_size;
 151         }
 152         SERVER_END_REQ;
 153         HeapFree( GetProcessHeap(), 0, data );
 154     } while (status == STATUS_BUFFER_OVERFLOW);
 155
 156     if (status || !vis_rgn) return;
 157
 158     USER_Driver->pGetDC( dce->hdc, dce->hwnd, top_win, &win_rect, &top_rect, flags );
 159
 160     if (dce->clip_rgn) CombineRgn( vis_rgn, vis_rgn, dce->clip_rgn,
 161                                    (flags & DCX_INTERSECTRGN) ? RGN_AND : RGN_DIFF );
 162
 163     /* map region to DC coordinates */
 164     OffsetRgn( vis_rgn, -win_rect.left, -win_rect.top );
 165     SelectVisRgn( dce->hdc, vis_rgn );
 166     DeleteObject( vis_rgn );
 167 }
 168
 169
 170 /***********************************************************************
 171  *              release_dce
 172  */
 173 static void release_dce( struct dce *dce )
 174 {
 175     if (!dce->hwnd) return;  /* already released */
 176
 177     USER_Driver->pReleaseDC( dce->hwnd, dce->hdc );
 178
 179     if (dce->clip_rgn) DeleteObject( dce->clip_rgn );
 180     dce->clip_rgn = 0;
 181     dce->hwnd     = 0;
 182     dce->flags   &= DCX_CACHE;
 183 }
 184
 185
 186 /***********************************************************************
 187  *   delete_clip_rgn
 188  */
 189 static void delete_clip_rgn( struct dce *dce )
 190 {
 191     if (!dce->clip_rgn) return;  /* nothing to do */
 192
 193     dce->flags &= ~(DCX_EXCLUDERGN | DCX_INTERSECTRGN);
 194     DeleteObject( dce->clip_rgn );
 195     dce->clip_rgn = 0;
 196
 197     /* make it dirty so that the vis rgn gets recomputed next time */
 198     SetHookFlags( dce->hdc, DCHF_INVALIDATEVISRGN );
 199 }
 200
 201
 202 /***********************************************************************
 203  *           alloc_dce
 204  *
 205  * Allocate a new DCE.
 206  */
 207 static struct dce *alloc_dce(void)
 208 {
 209     struct dce *dce;
 210
 211     if (!(dce = HeapAlloc( GetProcessHeap(), 0, sizeof(*dce) ))) return NULL;
 212     if (!(dce->hdc = CreateDCW( displayW, NULL, NULL, NULL )))
 213     {
 214         HeapFree( GetProcessHeap(), 0, dce );
 215         return 0;
 216     }
 217     SaveDC( dce->hdc );
 218
 219     dce->hwnd      = 0;
 220     dce->clip_rgn  = 0;
 221     dce->flags     = 0;
 222     dce->count     = 1;
 223
 224     /* store DCE handle in DC hook data field */
 225     SetDCHook( dce->hdc, dc_hook, (DWORD_PTR)dce );
 226     SetHookFlags( dce->hdc, DCHF_INVALIDATEVISRGN );
 227     return dce;
 228 }
 229
 230
 231 /***********************************************************************
 232  *              get_window_dce
 233  */
 234 static struct dce *get_window_dce( HWND hwnd )
 235 {
 236     struct dce *dce;
 237     WND *win = WIN_GetPtr( hwnd );
 238
 239     if (!win || win == WND_OTHER_PROCESS || win == WND_DESKTOP) return NULL;
 240
 241     dce = win->dce;
 242     if (!dce && (dce = get_class_dce( win->class )))
 243     {
 244         win->dce = dce;
 245         dce->count++;
 246     }
 247     WIN_ReleasePtr( win );
 248
 249     if (!dce)  /* try to allocate one */
 250     {
 251         struct dce *dce_to_free = NULL;
 252         LONG class_style = GetClassLongW( hwnd, GCL_STYLE );
 253
 254         if (class_style & CS_CLASSDC)
 255         {
 256             if (!(dce = alloc_dce())) return NULL;
 257
 258             win = WIN_GetPtr( hwnd );
 259             if (win && win != WND_OTHER_PROCESS && win != WND_DESKTOP)
 260             {
 261                 if (win->dce)  /* another thread beat us to it */
 262                 {
 263                     dce_to_free = dce;
 264                     dce = win->dce;
 265                 }
 266                 else if ((win->dce = set_class_dce( win->class, dce )) != dce)
 267                 {
 268                     dce_to_free = dce;
 269                     dce = win->dce;
 270                     dce->count++;
 271                 }
 272                 else
 273                 {
 274                     dce->count++;
 275                     list_add_tail( &dce_list, &dce->entry );
 276                 }
 277                 WIN_ReleasePtr( win );
 278             }
 279             else dce_to_free = dce;
 280         }
 281         else if (class_style & CS_OWNDC)
 282         {
 283             if (!(dce = alloc_dce())) return NULL;
 284
 285             win = WIN_GetPtr( hwnd );
 286             if (win && win != WND_OTHER_PROCESS && win != WND_DESKTOP)
 287             {
 288                 if (win->dwStyle & WS_CLIPCHILDREN) dce->flags |= DCX_CLIPCHILDREN;
 289                 if (win->dwStyle & WS_CLIPSIBLINGS) dce->flags |= DCX_CLIPSIBLINGS;
 290                 if (win->dce)  /* another thread beat us to it */
 291                 {
 292                     dce_to_free = dce;
 293                     dce = win->dce;
 294                 }
 295                 else
 296                 {
 297                     win->dce = dce;
 298                     dce->hwnd = hwnd;
 299                     dce->count++;
 300                     list_add_tail( &dce_list, &dce->entry );
 301                 }
 302                 WIN_ReleasePtr( win );
 303             }
 304             else dce_to_free = dce;
 305         }
 306
 307         if (dce_to_free)
 308         {
 309             SetDCHook( dce->hdc, NULL, 0 );
 310             DeleteDC( dce->hdc );
 311             HeapFree( GetProcessHeap(), 0, dce );
 312         }
 313     }
 314     return dce;
 315 }
 316
 317
 318 /***********************************************************************
 319  *           free_dce
 320  *
 321  * Free a class or window DCE.
 322  */
 323 void free_dce( struct dce *dce, HWND hwnd )
 324 {
 325     USER_Lock();
 326
 327     if (dce)
 328     {
 329         if (!--dce->count)
 330         {
 331             /* turn it into a cache entry */
 332             release_dce( dce );
 333             dce->flags |= DCX_CACHE;
 334         }
 335         else if (dce->hwnd == hwnd)
 336         {
 337             release_dce( dce );
 338         }
 339     }
 340
 341     /* now check for cache DCEs */
 342
 343     if (hwnd)
 344     {
 345         LIST_FOR_EACH_ENTRY( dce, &dce_list, struct dce, entry )
 346         {
 347             if (dce->hwnd != hwnd) continue;
 348             if (!(dce->flags & DCX_CACHE)) continue;
 349
 350             if (dce->count) WARN( "GetDC() without ReleaseDC() for window %p\n", hwnd );
 351             dce->count = 0;
 352             release_dce( dce );
 353         }
 354     }
 355
 356     USER_Unlock();
 357 }
 358
 359
 360 /***********************************************************************
 361  *           make_dc_dirty
 362  *
 363  * Mark the associated DC as dirty to force a refresh of the visible region
 364  */
 365 static void make_dc_dirty( struct dce *dce )
 366 {
 367     if (!dce->count)
 368     {
 369         /* Don't bother with visible regions of unused DCEs */
 370         TRACE("\tpurged %p dce [%p]\n", dce, dce->hwnd);
 371         release_dce( dce );
 372     }
 373     else
 374     {
 375         /* Set dirty bits in the hDC and DCE structs */
 376         TRACE("\tfixed up %p dce [%p]\n", dce, dce->hwnd);
 377         SetHookFlags( dce->hdc, DCHF_INVALIDATEVISRGN );
 378     }
 379 }
 380
 381
 382 /***********************************************************************
 383  *   invalidate_dce
 384  *
 385  * It is called from SetWindowPos() - we have to
 386  * mark as dirty all busy DCEs for windows that have pWnd->parent as
 387  * an ancestor and whose client rect intersects with specified update
 388  * rectangle. In addition, pWnd->parent DCEs may need to be updated if
 389  * DCX_CLIPCHILDREN flag is set.
 390  */
 391 void invalidate_dce( HWND hwnd, const RECT *rect )
 392 {
 393     RECT window_rect, extra_rect;
 394     struct dce *dce;
 395     HWND hwndScope = GetAncestor( hwnd, GA_PARENT );
 396
 397     if (!hwndScope) return;
 398
 399     GetWindowRect( hwnd, &window_rect );
 400     if (rect)
 401     {
 402         extra_rect = *rect;
 403         MapWindowPoints( hwndScope, 0, (POINT *)&extra_rect, 2 );
 404     }
 405
 406     TRACE("%p scope hwnd = %p %s (%s)\n",
 407           hwnd, hwndScope, wine_dbgstr_rect(&window_rect), wine_dbgstr_rect(rect) );
 408
 409     /* walk all DCEs and fixup non-empty entries */
 410
 411     USER_Lock();
 412     LIST_FOR_EACH_ENTRY( dce, &dce_list, struct dce, entry )
 413     {
 414         TRACE( "%p: hwnd %p dcx %08x %s %s\n", dce, dce->hwnd, dce->flags,
 415                (dce->flags & DCX_CACHE) ? "Cache" : "Owned", dce->count ? "InUse" : "" );
 416
 417         if (!dce->hwnd) continue;
 418         if ((dce->hwnd == hwndScope) && !(dce->flags & DCX_CLIPCHILDREN))
 419             continue;  /* child window positions don't bother us */
 420
 421         /* if DCE window is a child of hwnd, it has to be invalidated */
 422         if (dce->hwnd == hwnd || IsChild( hwnd, dce->hwnd ))
 423         {
 424             make_dc_dirty( dce );
 425         }
 426         else  /* otherwise check if the window rectangle intersects this DCE window */
 427         {
 428             if (hwndScope == GetDesktopWindow() ||
 429                 hwndScope == dce->hwnd || IsChild( hwndScope, dce->hwnd ))
 430             {
 431                 RECT dce_rect, tmp;
 432                 GetWindowRect( dce->hwnd, &dce_rect );
 433                 if (IntersectRect( &tmp, &dce_rect, &window_rect ) ||
 434                     (rect && IntersectRect( &tmp, &dce_rect, &extra_rect )))
 435                     make_dc_dirty( dce );
 436             }
 437         }
 438     }
 439     USER_Unlock();
 440 }
 441
 442 /***********************************************************************
 443  *              release_dc
 444  *
 445  * Implementation of ReleaseDC.
 446  */
 447 static INT release_dc( HWND hwnd, HDC hdc, BOOL end_paint )
 448 {
 449     struct dce *dce;
 450     BOOL ret = FALSE;
 451
 452     TRACE("%p %p\n", hwnd, hdc );
 453
 454     USER_Lock();
 455     dce = (struct dce *)GetDCHook( hdc, NULL );
 456     if (dce && dce->count)
 457     {
 458         if (end_paint || (dce->flags & DCX_CACHE)) delete_clip_rgn( dce );
 459         if (dce->flags & DCX_CACHE) dce->count = 0;
 460         ret = TRUE;
 461     }
 462     USER_Unlock();
 463     return ret;
 464 }
 465
 466
 467 /***********************************************************************
 468  *              dc_hook
 469  *
 470  * See "Undoc. Windows" for hints (DC, SetDCHook, SetHookFlags)..
 471  */
 472 static BOOL CALLBACK dc_hook( HDC hDC, WORD code, DWORD_PTR data, LPARAM lParam )
 473 {
 474     BOOL retv = TRUE;
 475     struct dce *dce = (struct dce *)data;
 476
 477     TRACE("hDC = %p, %u\n", hDC, code);
 478
 479     if (!dce) return 0;
 480     assert( dce->hdc == hDC );
 481
 482     switch( code )
 483     {
 484     case DCHC_INVALIDVISRGN:
 485         /* GDI code calls this when it detects that the
 486          * DC is dirty (usually after SetHookFlags()). This
 487          * means that we have to recompute the visible region.
 488          */
 489         if (dce->count) update_visible_region( dce );
 490         else /* non-fatal but shouldn't happen */
 491             WARN("DC is not in use!\n");
 492         break;
 493     case DCHC_DELETEDC:
 494         /*
 495          * Windows will not let you delete a DC that is busy
 496          * (between GetDC and ReleaseDC)
 497          */
 498         USER_Lock();
 499         if (dce->count > 1)
 500         {
 501             WARN("Application trying to delete a busy DC %p\n", dce->hdc);
 502             retv = FALSE;
 503         }
 504         else
 505         {
 506             list_remove( &dce->entry );
 507             if (dce->clip_rgn) DeleteObject( dce->clip_rgn );
 508             HeapFree( GetProcessHeap(), 0, dce );
 509         }
 510         USER_Unlock();
 511         break;
 512     }
 513     return retv;
 514 }
 515
 516
 517 /***********************************************************************
 518  *           get_update_region
 519  *
 520  * Return update region (in screen coordinates) for a window.
 521  */
 522 static HRGN get_update_region( HWND hwnd, UINT *flags, HWND *child )
 523 {
 524     HRGN hrgn = 0;
 525     NTSTATUS status;
 526     RGNDATA *data;
 527     size_t size = 256;
 528
 529     do
 530     {
 531         if (!(data = HeapAlloc( GetProcessHeap(), 0, sizeof(*data) + size - 1 )))
 532         {
 533             SetLastError( ERROR_OUTOFMEMORY );
 534             return 0;
 535         }
 536
 537         SERVER_START_REQ( get_update_region )
 538         {
 539             req->window     = wine_server_user_handle( hwnd );
 540             req->from_child = wine_server_user_handle( child ? *child : 0 );
 541             req->flags      = *flags;
 542             wine_server_set_reply( req, data->Buffer, size );
 543             if (!(status = wine_server_call( req )))
 544             {
 545                 size_t reply_size = wine_server_reply_size( reply );
 546                 data->rdh.dwSize   = sizeof(data->rdh);
 547                 data->rdh.iType    = RDH_RECTANGLES;
 548                 data->rdh.nCount   = reply_size / sizeof(RECT);
 549                 data->rdh.nRgnSize = reply_size;
 550                 hrgn = ExtCreateRegion( NULL, size, data );
 551                 if (child) *child = wine_server_ptr_handle( reply->child );
 552                 *flags = reply->flags;
 553             }
 554             else size = reply->total_size;
 555         }
 556         SERVER_END_REQ;
 557         HeapFree( GetProcessHeap(), 0, data );
 558     } while (status == STATUS_BUFFER_OVERFLOW);
 559
 560     if (status) SetLastError( RtlNtStatusToDosError(status) );
 561     return hrgn;
 562 }
 563
 564
 565 /***********************************************************************
 566  *           get_update_flags
 567  *
 568  * Get only the update flags, not the update region.
 569  */
 570 static BOOL get_update_flags( HWND hwnd, HWND *child, UINT *flags )
 571 {
 572     BOOL ret;
 573
 574     SERVER_START_REQ( get_update_region )
 575     {
 576         req->window     = wine_server_user_handle( hwnd );
 577         req->from_child = wine_server_user_handle( child ? *child : 0 );
 578         req->flags      = *flags | UPDATE_NOREGION;
 579         if ((ret = !wine_server_call_err( req )))
 580         {
 581             if (child) *child = wine_server_ptr_handle( reply->child );
 582             *flags = reply->flags;
 583         }
 584     }
 585     SERVER_END_REQ;
 586     return ret;
 587 }
 588
 589
 590 /***********************************************************************
 591  *           redraw_window_rects
 592  *
 593  * Redraw part of a window.
 594  */
 595 static BOOL redraw_window_rects( HWND hwnd, UINT flags, const RECT *rects, UINT count )
 596 {
 597     BOOL ret;
 598
 599     if (!(flags & (RDW_INVALIDATE|RDW_VALIDATE|RDW_INTERNALPAINT|RDW_NOINTERNALPAINT)))
 600         return TRUE;  /* nothing to do */
 601
 602     SERVER_START_REQ( redraw_window )
 603     {
 604         req->window = wine_server_user_handle( hwnd );
 605         req->flags  = flags;
 606         wine_server_add_data( req, rects, count * sizeof(RECT) );
 607         ret = !wine_server_call_err( req );
 608     }
 609     SERVER_END_REQ;
 610     return ret;
 611 }
 612
 613
 614 /***********************************************************************
 615  *           send_ncpaint
 616  *
 617  * Send a WM_NCPAINT message if needed, and return the resulting update region (in screen coords).
 618  * Helper for erase_now and BeginPaint.
 619  */
 620 static HRGN send_ncpaint( HWND hwnd, HWND *child, UINT *flags )
 621 {
 622     HRGN whole_rgn = get_update_region( hwnd, flags, child );
 623     HRGN client_rgn = 0;
 624
 625     if (child) hwnd = *child;
 626
 627     if (hwnd == GetDesktopWindow()) return whole_rgn;
 628
 629     if (whole_rgn)
 630     {
 631         RECT client, update;
 632         INT type;
 633
 634         /* check if update rgn overlaps with nonclient area */
 635         type = GetRgnBox( whole_rgn, &update );
 636         GetClientRect( hwnd, &client );
 637         MapWindowPoints( hwnd, 0, (POINT *)&client, 2 );
 638
 639         if ((*flags & UPDATE_NONCLIENT) ||
 640             update.left < client.left || update.top < client.top ||
 641             update.right > client.right || update.bottom > client.bottom)
 642         {
 643             client_rgn = CreateRectRgnIndirect( &client );
 644             CombineRgn( client_rgn, client_rgn, whole_rgn, RGN_AND );
 645
 646             /* check if update rgn contains complete nonclient area */
 647             if (type == SIMPLEREGION)
 648             {
 649                 RECT window;
 650                 GetWindowRect( hwnd, &window );
 651                 if (EqualRect( &window, &update ))
 652                 {
 653                     DeleteObject( whole_rgn );
 654                     whole_rgn = (HRGN)1;
 655                 }
 656             }
 657         }
 658         else
 659         {
 660             client_rgn = whole_rgn;
 661             whole_rgn = 0;
 662         }
 663
 664         if (whole_rgn) /* NOTE: WM_NCPAINT allows wParam to be 1 */
 665         {
 666             if (*flags & UPDATE_NONCLIENT) SendMessageW( hwnd, WM_NCPAINT, (WPARAM)whole_rgn, 0 );
 667             if (whole_rgn > (HRGN)1) DeleteObject( whole_rgn );
 668         }
 669     }
 670     return client_rgn;
 671 }
 672
 673
 674 /***********************************************************************
 675  *           send_erase
 676  *
 677  * Send a WM_ERASEBKGND message if needed, and optionally return the DC for painting.
 678  * If a DC is requested, the region is selected into it. In all cases the region is deleted.
 679  * Helper for erase_now and BeginPaint.
 680  */
 681 static BOOL send_erase( HWND hwnd, UINT flags, HRGN client_rgn,
 682                         RECT *clip_rect, HDC *hdc_ret )
 683 {
 684     BOOL need_erase = (flags & UPDATE_DELAYED_ERASE) != 0;
 685     HDC hdc = 0;
 686     RECT dummy;
 687
 688     if (!clip_rect) clip_rect = &dummy;
 689     if (hdc_ret || (flags & UPDATE_ERASE))
 690     {
 691         UINT dcx_flags = DCX_INTERSECTRGN | DCX_USESTYLE;
 692         if (IsIconic(hwnd)) dcx_flags |= DCX_WINDOW;
 693
 694         if ((hdc = GetDCEx( hwnd, client_rgn, dcx_flags )))
 695         {
 696             INT type = GetClipBox( hdc, clip_rect );
 697
 698             if (flags & UPDATE_ERASE)
 699             {
 700                 /* don't erase if the clip box is empty */
 701                 if (type != NULLREGION)
 702                     need_erase = !SendMessageW( hwnd, WM_ERASEBKGND, (WPARAM)hdc, 0 );
 703             }
 704             if (!hdc_ret) release_dc( hwnd, hdc, TRUE );
 705         }
 706
 707         if (hdc_ret) *hdc_ret = hdc;
 708     }
 709     if (!hdc) DeleteObject( client_rgn );
 710     return need_erase;
 711 }
 712
 713
 714 /***********************************************************************
 715  *           erase_now
 716  *
 717  * Implementation of RDW_ERASENOW behavior.
 718  */
 719 void erase_now( HWND hwnd, UINT rdw_flags )
 720 {
 721     HWND child = 0;
 722     HRGN hrgn;
 723     BOOL need_erase = FALSE;
 724
 725     /* loop while we find a child to repaint */
 726     for (;;)
 727     {
 728         UINT flags = UPDATE_NONCLIENT | UPDATE_ERASE;
 729
 730         if (rdw_flags & RDW_NOCHILDREN) flags |= UPDATE_NOCHILDREN;
 731         else if (rdw_flags & RDW_ALLCHILDREN) flags |= UPDATE_ALLCHILDREN;
 732         if (need_erase) flags |= UPDATE_DELAYED_ERASE;
 733
 734         if (!(hrgn = send_ncpaint( hwnd, &child, &flags ))) break;
 735         need_erase = send_erase( child, flags, hrgn, NULL, NULL );
 736
 737         if (!flags) break;  /* nothing more to do */
 738         if ((rdw_flags & RDW_NOCHILDREN) && !need_erase) break;
 739     }
 740 }
 741
 742
 743 /***********************************************************************
 744  *           update_now
 745  *
 746  * Implementation of RDW_UPDATENOW behavior.
 747  *
 748  * FIXME: Windows uses WM_SYNCPAINT to cut down the number of intertask
 749  * SendMessage() calls. This is a comment inside DefWindowProc() source
 750  * from 16-bit SDK:
 751  *
 752  *   This message avoids lots of inter-app message traffic
 753  *   by switching to the other task and continuing the
 754  *   recursion there.
 755  *
 756  * wParam         = flags
 757  * LOWORD(lParam) = hrgnClip
 758  * HIWORD(lParam) = hwndSkip  (not used; always NULL)
 759  *
 760  */
 761 static void update_now( HWND hwnd, UINT rdw_flags )
 762 {
 763     HWND child = 0;
 764
 765     /* desktop window never gets WM_PAINT, only WM_ERASEBKGND */
 766     if (hwnd == GetDesktopWindow()) erase_now( hwnd, rdw_flags | RDW_NOCHILDREN );
 767
 768     /* loop while we find a child to repaint */
 769     for (;;)
 770     {
 771         UINT flags = UPDATE_PAINT | UPDATE_INTERNALPAINT;
 772
 773         if (rdw_flags & RDW_NOCHILDREN) flags |= UPDATE_NOCHILDREN;
 774         else if (rdw_flags & RDW_ALLCHILDREN) flags |= UPDATE_ALLCHILDREN;
 775
 776         if (!get_update_flags( hwnd, &child, &flags )) break;
 777         if (!flags) break;  /* nothing more to do */
 778
 779         SendMessageW( child, WM_PAINT, 0, 0 );
 780         if (rdw_flags & RDW_NOCHILDREN) break;
 781     }
 782 }
 783
 784
 785 /*************************************************************************
 786  *             fix_caret
 787  *
 788  * Helper for ScrollWindowEx:
 789  * If the return value is 0, no special caret handling is necessary.
 790  * Otherwise the return value is the handle of the window that owns the
 791  * caret. Its caret needs to be hidden during the scroll operation and
 792  * moved to new_caret_pos if move_caret is TRUE.
 793  */
 794 static HWND fix_caret(HWND hWnd, const RECT *scroll_rect, INT dx, INT dy,
 795                      UINT flags, LPBOOL move_caret, LPPOINT new_caret_pos)
 796 {
 797     GUITHREADINFO info;
 798     RECT rect, mapped_rcCaret;
 799     BOOL hide_caret = FALSE;
 800
 801     if (!GetGUIThreadInfo( GetCurrentThreadId(), &info )) return 0;
 802     if (!info.hwndCaret) return 0;
 803
 804     if (info.hwndCaret == hWnd)
 805     {
 806         /* Move the caret if it's (partially) in the source rectangle */
 807         if (IntersectRect(&rect, scroll_rect, &info.rcCaret))
 808         {
 809             *move_caret = TRUE;
 810             hide_caret = TRUE;
 811             new_caret_pos->x = info.rcCaret.left + dx;
 812             new_caret_pos->y = info.rcCaret.top + dy;
 813         }
 814         else
 815         {
 816             *move_caret = FALSE;
 817
 818             /* Hide the caret if it's in the destination rectangle */
 819             rect = *scroll_rect;
 820             OffsetRect(&rect, dx, dy);
 821             hide_caret = IntersectRect(&rect, &rect, &info.rcCaret);
 822         }
 823     }
 824     else
 825     {
 826         if ((flags & SW_SCROLLCHILDREN) && IsChild(hWnd, info.hwndCaret))
 827         {
 828             *move_caret = FALSE;
 829
 830             /* Hide the caret if it's in the source or in the destination
 831                rectangle */
 832             mapped_rcCaret = info.rcCaret;
 833             MapWindowPoints(info.hwndCaret, hWnd, (LPPOINT)&mapped_rcCaret, 2);
 834
 835             if (IntersectRect(&rect, scroll_rect, &mapped_rcCaret))
 836             {
 837                 hide_caret = TRUE;
 838             }
 839             else
 840             {
 841                 rect = *scroll_rect;
 842                 OffsetRect(&rect, dx, dy);
 843                 hide_caret = IntersectRect(&rect, &rect, &mapped_rcCaret);
 844             }
 845         }
 846         else
 847             return 0;
 848     }
 849
 850     if (hide_caret)
 851     {
 852         HideCaret(info.hwndCaret);
 853         return info.hwndCaret;
 854     }
 855     else
 856         return 0;
 857 }
 858
 859
 860 /***********************************************************************
 861  *              BeginPaint (USER32.@)
 862  */
 863 HDC WINAPI BeginPaint( HWND hwnd, PAINTSTRUCT *lps )
 864 {
 865     HRGN hrgn;
 866     UINT flags = UPDATE_NONCLIENT | UPDATE_ERASE | UPDATE_PAINT | UPDATE_INTERNALPAINT | UPDATE_NOCHILDREN;
 867
 868     if (!lps) return 0;
 869
 870     HideCaret( hwnd );
 871
 872     if (!(hrgn = send_ncpaint( hwnd, NULL, &flags ))) return 0;
 873
 874     lps->fErase = send_erase( hwnd, flags, hrgn, &lps->rcPaint, &lps->hdc );
 875
 876     TRACE("hdc = %p box = (%s), fErase = %d\n",
 877           lps->hdc, wine_dbgstr_rect(&lps->rcPaint), lps->fErase);
 878
 879     return lps->hdc;
 880 }
 881
 882
 883 /***********************************************************************
 884  *              EndPaint (USER32.@)
 885  */
 886 BOOL WINAPI EndPaint( HWND hwnd, const PAINTSTRUCT *lps )
 887 {
 888     if (!lps) return FALSE;
 889     release_dc( hwnd, lps->hdc, TRUE );
 890     ShowCaret( hwnd );
 891     return TRUE;
 892 }
 893
 894
 895 /***********************************************************************
 896  *              GetDCEx (USER32.@)
 897  */
 898 HDC WINAPI GetDCEx( HWND hwnd, HRGN hrgnClip, DWORD flags )
 899 {
 900     static const DWORD clip_flags = DCX_PARENTCLIP | DCX_CLIPSIBLINGS | DCX_CLIPCHILDREN | DCX_WINDOW;
 901     struct dce *dce;
 902     BOOL bUpdateVisRgn = TRUE;
 903     HWND parent;
 904     LONG window_style = GetWindowLongW( hwnd, GWL_STYLE );
 905
 906     if (!hwnd) hwnd = GetDesktopWindow();
 907     else hwnd = WIN_GetFullHandle( hwnd );
 908
 909     TRACE("hwnd %p, hrgnClip %p, flags %08x\n", hwnd, hrgnClip, flags);
 910
 911     /* fixup flags */
 912
 913     if (flags & (DCX_WINDOW | DCX_PARENTCLIP)) flags |= DCX_CACHE;
 914
 915     if (flags & DCX_USESTYLE)
 916     {
 917         flags &= ~(DCX_CLIPCHILDREN | DCX_CLIPSIBLINGS | DCX_PARENTCLIP);
 918
 919         if (window_style & WS_CLIPSIBLINGS) flags |= DCX_CLIPSIBLINGS;
 920
 921         if (!(flags & DCX_WINDOW))
 922         {
 923             if (GetClassLongW( hwnd, GCL_STYLE ) & CS_PARENTDC) flags |= DCX_PARENTCLIP;
 924
 925             if (window_style & WS_CLIPCHILDREN && !(window_style & WS_MINIMIZE))
 926                 flags |= DCX_CLIPCHILDREN;
 927         }
 928     }
 929
 930     if (flags & DCX_WINDOW) flags &= ~DCX_CLIPCHILDREN;
 931
 932     parent = GetAncestor( hwnd, GA_PARENT );
 933     if (!parent || (parent == GetDesktopWindow()))
 934         flags = (flags & ~DCX_PARENTCLIP) | DCX_CLIPSIBLINGS;
 935
 936     /* it seems parent clip is ignored when clipping siblings or children */
 937     if (flags & (DCX_CLIPSIBLINGS | DCX_CLIPCHILDREN)) flags &= ~DCX_PARENTCLIP;
 938
 939     if( flags & DCX_PARENTCLIP )
 940     {
 941         LONG parent_style = GetWindowLongW( parent, GWL_STYLE );
 942         if( (window_style & WS_VISIBLE) && (parent_style & WS_VISIBLE) )
 943         {
 944             flags &= ~DCX_CLIPCHILDREN;
 945             if (parent_style & WS_CLIPSIBLINGS) flags |= DCX_CLIPSIBLINGS;
 946         }
 947     }
 948
 949     /* find a suitable DCE */
 950
 951     if ((flags & DCX_CACHE) || !(dce = get_window_dce( hwnd )))
 952     {
 953         struct dce *dceEmpty = NULL, *dceUnused = NULL;
 954
 955         /* Strategy: First, we attempt to find a non-empty but unused DCE with
 956          * compatible flags. Next, we look for an empty entry. If the cache is
 957          * full we have to purge one of the unused entries.
 958          */
 959         USER_Lock();
 960         LIST_FOR_EACH_ENTRY( dce, &dce_list, struct dce, entry )
 961         {
 962             if ((dce->flags & DCX_CACHE) && !dce->count)
 963             {
 964                 dceUnused = dce;
 965
 966                 if (!dce->hwnd) dceEmpty = dce;
 967                 else if ((dce->hwnd == hwnd) && !((dce->flags ^ flags) & clip_flags))
 968                 {
 969                     TRACE("\tfound valid %p dce [%p], flags %08x\n",
 970                           dce, hwnd, dce->flags );
 971                     bUpdateVisRgn = FALSE;
 972                     break;
 973                 }
 974             }
 975         }
 976
 977         if (&dce->entry == &dce_list)  /* nothing found */
 978             dce = dceEmpty ? dceEmpty : dceUnused;
 979
 980         if (dce) dce->count = 1;
 981
 982         USER_Unlock();
 983
 984         /* if there's no dce empty or unused, allocate a new one */
 985         if (!dce)
 986         {
 987             if (!(dce = alloc_dce())) return 0;
 988             dce->flags = DCX_CACHE;
 989             USER_Lock();
 990             list_add_head( &dce_list, &dce->entry );
 991             USER_Unlock();
 992         }
 993     }
 994     else
 995     {
 996         flags |= DCX_NORESETATTRS;
 997         if (dce->hwnd == hwnd)
 998         {
 999             TRACE("\tskipping hVisRgn update\n");
1000             bUpdateVisRgn = FALSE; /* updated automatically, via DCHook() */
1001         }
1002         else
1003         {
1004             /* we should free dce->clip_rgn here, but Windows apparently doesn't */
1005             dce->flags &= ~(DCX_EXCLUDERGN | DCX_INTERSECTRGN);
1006             dce->clip_rgn = 0;
1007         }
1008     }
1009
1010     if (flags & (DCX_INTERSECTRGN | DCX_EXCLUDERGN))
1011     {
1012         /* if the extra clip region has changed, get rid of the old one */
1013         if (dce->clip_rgn != hrgnClip || ((flags ^ dce->flags) & (DCX_INTERSECTRGN | DCX_EXCLUDERGN)))
1014             delete_clip_rgn( dce );
1015         dce->clip_rgn = hrgnClip;
1016         if (!dce->clip_rgn) dce->clip_rgn = CreateRectRgn( 0, 0, 0, 0 );
1017         dce->flags |= flags & (DCX_INTERSECTRGN | DCX_EXCLUDERGN);
1018         bUpdateVisRgn = TRUE;
1019     }
1020
1021     dce->hwnd = hwnd;
1022     dce->flags = (dce->flags & ~clip_flags) | (flags & clip_flags);
1023
1024     if (SetHookFlags( dce->hdc, DCHF_VALIDATEVISRGN )) bUpdateVisRgn = TRUE;  /* DC was dirty */
1025
1026     if (bUpdateVisRgn) update_visible_region( dce );
1027
1028     if (!(flags & DCX_NORESETATTRS))
1029     {
1030         RestoreDC( dce->hdc, 1 );  /* initial save level is always 1 */
1031         SaveDC( dce->hdc );  /* save the state again for next time */
1032     }
1033
1034     TRACE("(%p,%p,0x%x): returning %p\n", hwnd, hrgnClip, flags, dce->hdc);
1035     return dce->hdc;
1036 }
1037
1038
1039 /***********************************************************************
1040  *              GetDC (USER32.@)
1041  *
1042  * Get a device context.
1043  *
1044  * RETURNS
1045  *      Success: Handle to the device context
1046  *      Failure: NULL.
1047  */
1048 HDC WINAPI GetDC( HWND hwnd )
1049 {
1050     if (!hwnd) return GetDCEx( 0, 0, DCX_CACHE | DCX_WINDOW );
1051     return GetDCEx( hwnd, 0, DCX_USESTYLE );
1052 }
1053
1054
1055 /***********************************************************************
1056  *              GetWindowDC (USER32.@)
1057  */
1058 HDC WINAPI GetWindowDC( HWND hwnd )
1059 {
1060     return GetDCEx( hwnd, 0, DCX_USESTYLE | DCX_WINDOW );
1061 }
1062
1063
1064 /***********************************************************************
1065  *              ReleaseDC (USER32.@)
1066  *
1067  * Release a device context.
1068  *
1069  * RETURNS
1070  *      Success: Non-zero. Resources used by hdc are released.
1071  *      Failure: 0.
1072  */
1073 INT WINAPI ReleaseDC( HWND hwnd, HDC hdc )
1074 {
1075     return release_dc( hwnd, hdc, FALSE );
1076 }
1077
1078
1079 /**********************************************************************
1080  *              WindowFromDC (USER32.@)
1081  */
1082 HWND WINAPI WindowFromDC( HDC hdc )
1083 {
1084     struct dce *dce;
1085     HWND hwnd = 0;
1086
1087     USER_Lock();
1088     dce = (struct dce *)GetDCHook( hdc, NULL );
1089     if (dce) hwnd = dce->hwnd;
1090     USER_Unlock();
1091     return hwnd;
1092 }
1093
1094
1095 /***********************************************************************
1096  *              LockWindowUpdate (USER32.@)
1097  *
1098  * Enables or disables painting in the chosen window.
1099  *
1100  * PARAMS
1101  *  hwnd [I] handle to a window.
1102  *
1103  * RETURNS
1104  *  If successful, returns nonzero value. Otherwise,
1105  *  returns 0.
1106  *
1107  * NOTES
1108  *  You can lock only one window at a time.
1109  */
1110 BOOL WINAPI LockWindowUpdate( HWND hwnd )
1111 {
1112     static HWND lockedWnd;
1113
1114     FIXME("(%p), partial stub!\n",hwnd);
1115
1116     USER_Lock();
1117     if (lockedWnd)
1118     {
1119         if (!hwnd)
1120         {
1121             /* Unlock lockedWnd */
1122             /* FIXME: Do something */
1123         }
1124         else
1125         {
1126             /* Attempted to lock a second window */
1127             /* Return FALSE and do nothing */
1128             USER_Unlock();
1129             return FALSE;
1130         }
1131     }
1132     lockedWnd = hwnd;
1133     USER_Unlock();
1134     return TRUE;
1135 }
1136
1137
1138 /***********************************************************************
1139  *              RedrawWindow (USER32.@)
1140  */
1141 BOOL WINAPI RedrawWindow( HWND hwnd, const RECT *rect, HRGN hrgn, UINT flags )
1142 {
1143     static const RECT empty;
1144     BOOL ret;
1145
1146     if (!hwnd) hwnd = GetDesktopWindow();
1147
1148     if (TRACE_ON(win))
1149     {
1150         if (hrgn)
1151         {
1152             RECT r;
1153             GetRgnBox( hrgn, &r );
1154             TRACE( "%p region %p box %s ", hwnd, hrgn, wine_dbgstr_rect(&r) );
1155         }
1156         else if (rect)
1157             TRACE( "%p rect %s ", hwnd, wine_dbgstr_rect(rect) );
1158         else
1159             TRACE( "%p whole window ", hwnd );
1160
1161         dump_rdw_flags(flags);
1162     }
1163
1164     /* process pending expose events before painting */
1165     if (flags & RDW_UPDATENOW) USER_Driver->pMsgWaitForMultipleObjectsEx( 0, NULL, 0, QS_PAINT, 0 );
1166
1167     if (rect && !hrgn)
1168     {
1169         if (IsRectEmpty( rect )) rect = &empty;
1170         ret = redraw_window_rects( hwnd, flags, rect, 1 );
1171     }
1172     else if (!hrgn)
1173     {
1174         ret = redraw_window_rects( hwnd, flags, NULL, 0 );
1175     }
1176     else  /* need to build a list of the region rectangles */
1177     {
1178         DWORD size;
1179         RGNDATA *data = NULL;
1180
1181         if (!(size = GetRegionData( hrgn, 0, NULL ))) return FALSE;
1182         if (!(data = HeapAlloc( GetProcessHeap(), 0, size ))) return FALSE;
1183         GetRegionData( hrgn, size, data );
1184         if (!data->rdh.nCount)  /* empty region -> use a single all-zero rectangle */
1185             ret = redraw_window_rects( hwnd, flags, &empty, 1 );
1186         else
1187             ret = redraw_window_rects( hwnd, flags, (const RECT *)data->Buffer, data->rdh.nCount );
1188         HeapFree( GetProcessHeap(), 0, data );
1189     }
1190
1191     if (flags & RDW_UPDATENOW) update_now( hwnd, flags );
1192     else if (flags & RDW_ERASENOW) erase_now( hwnd, flags );
1193
1194     return ret;
1195 }
1196
1197
1198 /***********************************************************************
1199  *              UpdateWindow (USER32.@)
1200  */
1201 BOOL WINAPI UpdateWindow( HWND hwnd )
1202 {
1203     return RedrawWindow( hwnd, NULL, 0, RDW_UPDATENOW | RDW_ALLCHILDREN );
1204 }
1205
1206
1207 /***********************************************************************
1208  *              InvalidateRgn (USER32.@)
1209  */
1210 BOOL WINAPI InvalidateRgn( HWND hwnd, HRGN hrgn, BOOL erase )
1211 {
1212     if (!hwnd)
1213     {
1214         SetLastError( ERROR_INVALID_WINDOW_HANDLE );
1215         return FALSE;
1216     }
1217
1218     return RedrawWindow(hwnd, NULL, hrgn, RDW_INVALIDATE | (erase ? RDW_ERASE : 0) );
1219 }
1220
1221
1222 /***********************************************************************
1223  *              InvalidateRect (USER32.@)
1224  *
1225  * MSDN: if hwnd parameter is NULL, InvalidateRect invalidates and redraws
1226  * all windows and sends WM_ERASEBKGND and WM_NCPAINT.
1227  */
1228 BOOL WINAPI InvalidateRect( HWND hwnd, const RECT *rect, BOOL erase )
1229 {
1230     UINT flags = RDW_INVALIDATE | (erase ? RDW_ERASE : 0);
1231
1232     if (!hwnd)
1233     {
1234         flags = RDW_ALLCHILDREN | RDW_INVALIDATE | RDW_FRAME | RDW_ERASE | RDW_ERASENOW;
1235         rect = NULL;
1236     }
1237
1238     return RedrawWindow( hwnd, rect, 0, flags );
1239 }
1240
1241
1242 /***********************************************************************
1243  *              ValidateRgn (USER32.@)
1244  */
1245 BOOL WINAPI ValidateRgn( HWND hwnd, HRGN hrgn )
1246 {
1247     if (!hwnd)
1248     {
1249         SetLastError( ERROR_INVALID_WINDOW_HANDLE );
1250         return FALSE;
1251     }
1252
1253     return RedrawWindow( hwnd, NULL, hrgn, RDW_VALIDATE );
1254 }
1255
1256
1257 /***********************************************************************
1258  *              ValidateRect (USER32.@)
1259  *
1260  * MSDN: if hwnd parameter is NULL, ValidateRect invalidates and redraws
1261  * all windows and sends WM_ERASEBKGND and WM_NCPAINT.
1262  */
1263 BOOL WINAPI ValidateRect( HWND hwnd, const RECT *rect )
1264 {
1265     UINT flags = RDW_VALIDATE;
1266
1267     if (!hwnd)
1268     {
1269         flags = RDW_ALLCHILDREN | RDW_INVALIDATE | RDW_FRAME | RDW_ERASE | RDW_ERASENOW;
1270         rect = NULL;
1271     }
1272
1273     return RedrawWindow( hwnd, rect, 0, flags );
1274 }
1275
1276
1277 /***********************************************************************
1278  *              GetUpdateRgn (USER32.@)
1279  */
1280 INT WINAPI GetUpdateRgn( HWND hwnd, HRGN hrgn, BOOL erase )
1281 {
1282     INT retval = ERROR;
1283     UINT flags = UPDATE_NOCHILDREN;
1284     HRGN update_rgn;
1285
1286     if (erase) flags |= UPDATE_NONCLIENT | UPDATE_ERASE;
1287
1288     if ((update_rgn = send_ncpaint( hwnd, NULL, &flags )))
1289     {
1290         POINT offset;
1291
1292         retval = CombineRgn( hrgn, update_rgn, 0, RGN_COPY );
1293         if (send_erase( hwnd, flags, update_rgn, NULL, NULL ))
1294         {
1295             flags = UPDATE_DELAYED_ERASE;
1296             get_update_flags( hwnd, NULL, &flags );
1297         }
1298         /* map region to client coordinates */
1299         offset.x = offset.y = 0;
1300         ScreenToClient( hwnd, &offset );
1301         OffsetRgn( hrgn, offset.x, offset.y );
1302     }
1303     return retval;
1304 }
1305
1306
1307 /***********************************************************************
1308  *              GetUpdateRect (USER32.@)
1309  */
1310 BOOL WINAPI GetUpdateRect( HWND hwnd, LPRECT rect, BOOL erase )
1311 {
1312     UINT flags = UPDATE_NOCHILDREN;
1313     HRGN update_rgn;
1314     BOOL need_erase;
1315
1316     if (erase) flags |= UPDATE_NONCLIENT | UPDATE_ERASE;
1317
1318     if (!(update_rgn = send_ncpaint( hwnd, NULL, &flags ))) return FALSE;
1319
1320     if (rect)
1321     {
1322         if (GetRgnBox( update_rgn, rect ) != NULLREGION)
1323         {
1324             HDC hdc = GetDCEx( hwnd, 0, DCX_USESTYLE );
1325             MapWindowPoints( 0, hwnd, (LPPOINT)rect, 2 );
1326             DPtoLP( hdc, (LPPOINT)rect, 2 );
1327             ReleaseDC( hwnd, hdc );
1328         }
1329     }
1330     need_erase = send_erase( hwnd, flags, update_rgn, NULL, NULL );
1331
1332     /* check if we still have an update region */
1333     flags = UPDATE_PAINT | UPDATE_NOCHILDREN;
1334     if (need_erase) flags |= UPDATE_DELAYED_ERASE;
1335     return (get_update_flags( hwnd, NULL, &flags ) && (flags & UPDATE_PAINT));
1336 }
1337
1338
1339 /***********************************************************************
1340  *              ExcludeUpdateRgn (USER32.@)
1341  */
1342 INT WINAPI ExcludeUpdateRgn( HDC hdc, HWND hwnd )
1343 {
1344     HRGN update_rgn = CreateRectRgn( 0, 0, 0, 0 );
1345     INT ret = GetUpdateRgn( hwnd, update_rgn, FALSE );
1346
1347     if (ret != ERROR)
1348     {
1349         POINT pt;
1350
1351         GetDCOrgEx( hdc, &pt );
1352         MapWindowPoints( 0, hwnd, &pt, 1 );
1353         OffsetRgn( update_rgn, -pt.x, -pt.y );
1354         ret = ExtSelectClipRgn( hdc, update_rgn, RGN_DIFF );
1355         DeleteObject( update_rgn );
1356     }
1357     return ret;
1358 }
1359
1360
1361 /*************************************************************************
1362  *              ScrollWindowEx (USER32.@)
1363  *
1364  * Note: contrary to what the doc says, pixels that are scrolled from the
1365  *      outside of clipRect to the inside are NOT painted.
1366  *
1367  */
1368 INT WINAPI ScrollWindowEx( HWND hwnd, INT dx, INT dy,
1369                            const RECT *rect, const RECT *clipRect,
1370                            HRGN hrgnUpdate, LPRECT rcUpdate,
1371                            UINT flags )
1372 {
1373     INT   retVal = NULLREGION;
1374     BOOL  bOwnRgn = TRUE;
1375     BOOL  bUpdate = (rcUpdate || hrgnUpdate || flags & (SW_INVALIDATE | SW_ERASE));
1376     int rdw_flags;
1377     HRGN  hrgnTemp;
1378     HRGN  hrgnWinupd = 0;
1379     HDC   hDC;
1380     RECT  rc, cliprc;
1381     HWND hwndCaret = NULL;
1382     BOOL moveCaret = FALSE;
1383     POINT newCaretPos;
1384
1385     TRACE( "%p, %d,%d hrgnUpdate=%p rcUpdate = %p %s %04x\n",
1386            hwnd, dx, dy, hrgnUpdate, rcUpdate, wine_dbgstr_rect(rect), flags );
1387     TRACE( "clipRect = %s\n", wine_dbgstr_rect(clipRect));
1388     if( flags & ~( SW_SCROLLCHILDREN | SW_INVALIDATE | SW_ERASE))
1389         FIXME("some flags (%04x) are unhandled\n", flags);
1390
1391     rdw_flags = (flags & SW_ERASE) && (flags & SW_INVALIDATE) ?
1392                                 RDW_INVALIDATE | RDW_ERASE  : RDW_INVALIDATE ;
1393
1394     if (!WIN_IsWindowDrawable( hwnd, TRUE )) return ERROR;
1395     hwnd = WIN_GetFullHandle( hwnd );
1396
1397     GetClientRect(hwnd, &rc);
1398
1399     if (clipRect) IntersectRect(&cliprc,&rc,clipRect);
1400     else cliprc = rc;
1401
1402     if (rect) IntersectRect(&rc, &rc, rect);
1403
1404     if( hrgnUpdate ) bOwnRgn = FALSE;
1405     else if( bUpdate ) hrgnUpdate = CreateRectRgn( 0, 0, 0, 0 );
1406
1407     newCaretPos.x = newCaretPos.y = 0;
1408
1409     if( !IsRectEmpty(&cliprc) && (dx || dy)) {
1410         DWORD dcxflags = DCX_CACHE;
1411         DWORD style = GetWindowLongW( hwnd, GWL_STYLE );
1412
1413         hwndCaret = fix_caret(hwnd, &rc, dx, dy, flags, &moveCaret, &newCaretPos);
1414
1415         if( style & WS_CLIPSIBLINGS) dcxflags |= DCX_CLIPSIBLINGS;
1416         if( GetClassLongW( hwnd, GCL_STYLE ) & CS_PARENTDC)
1417             dcxflags |= DCX_PARENTCLIP;
1418         if( !(flags & SW_SCROLLCHILDREN) && (style & WS_CLIPCHILDREN))
1419             dcxflags |= DCX_CLIPCHILDREN;
1420         hDC = GetDCEx( hwnd, 0, dcxflags);
1421         if (hDC)
1422         {
1423             ScrollDC( hDC, dx, dy, &rc, &cliprc, hrgnUpdate, rcUpdate );
1424
1425             ReleaseDC( hwnd, hDC );
1426
1427             if (!bUpdate)
1428                 RedrawWindow( hwnd, NULL, hrgnUpdate, rdw_flags);
1429         }
1430
1431         /* If the windows has an update region, this must be
1432          * scrolled as well. Keep a copy in hrgnWinupd
1433          * to be added to hrngUpdate at the end. */
1434         hrgnTemp = CreateRectRgn( 0, 0, 0, 0 );
1435         retVal = GetUpdateRgn( hwnd, hrgnTemp, FALSE );
1436         if (retVal != NULLREGION)
1437         {
1438             HRGN hrgnClip = CreateRectRgnIndirect(&cliprc);
1439             if( !bOwnRgn) {
1440                 hrgnWinupd = CreateRectRgn( 0, 0, 0, 0);
1441                 CombineRgn( hrgnWinupd, hrgnTemp, 0, RGN_COPY);
1442             }
1443             OffsetRgn( hrgnTemp, dx, dy );
1444             CombineRgn( hrgnTemp, hrgnTemp, hrgnClip, RGN_AND );
1445             if( !bOwnRgn)
1446                 CombineRgn( hrgnWinupd, hrgnWinupd, hrgnTemp, RGN_OR );
1447             RedrawWindow( hwnd, NULL, hrgnTemp, rdw_flags);
1448
1449            /* Catch the case where the scrolling amount exceeds the size of the
1450             * original window. This generated a second update area that is the
1451             * location where the original scrolled content would end up.
1452             * This second region is not returned by the ScrollDC and sets
1453             * ScrollWindowEx apart from just a ScrollDC.
1454             *
1455             * This has been verified with testing on windows.
1456             */
1457             if (abs(dx) > abs(rc.right - rc.left) ||
1458                 abs(dy) > abs(rc.bottom - rc.top))
1459             {
1460                 SetRectRgn( hrgnTemp, rc.left + dx, rc.top + dy, rc.right+dx, rc.bottom + dy);
1461                 CombineRgn( hrgnTemp, hrgnTemp, hrgnClip, RGN_AND );
1462                 CombineRgn( hrgnUpdate, hrgnUpdate, hrgnTemp, RGN_OR );
1463
1464                 if( !bOwnRgn)
1465                     CombineRgn( hrgnWinupd, hrgnWinupd, hrgnTemp, RGN_OR );
1466             }
1467             DeleteObject( hrgnClip );
1468         }
1469         DeleteObject( hrgnTemp );
1470     } else {
1471         /* nothing was scrolled */
1472         if( !bOwnRgn)
1473             SetRectRgn( hrgnUpdate, 0, 0, 0, 0 );
1474         SetRectEmpty( rcUpdate);
1475     }
1476
1477     if( flags & SW_SCROLLCHILDREN )
1478     {
1479         HWND *list = WIN_ListChildren( hwnd );
1480         if (list)
1481         {
1482             int i;
1483             RECT r, dummy;
1484             for (i = 0; list[i]; i++)
1485             {
1486                 GetWindowRect( list[i], &r );
1487                 MapWindowPoints( 0, hwnd, (POINT *)&r, 2 );
1488                 if (!rect || IntersectRect(&dummy, &r, rect))
1489                     SetWindowPos( list[i], 0, r.left + dx, r.top  + dy, 0, 0,
1490                                   SWP_NOZORDER | SWP_NOSIZE | SWP_NOACTIVATE |
1491                                   SWP_NOREDRAW | SWP_DEFERERASE );
1492             }
1493             HeapFree( GetProcessHeap(), 0, list );
1494         }
1495     }
1496
1497     if( flags & (SW_INVALIDATE | SW_ERASE) )
1498         RedrawWindow( hwnd, NULL, hrgnUpdate, rdw_flags |
1499                       ((flags & SW_SCROLLCHILDREN) ? RDW_ALLCHILDREN : 0 ) );
1500
1501     if( hrgnWinupd) {
1502         CombineRgn( hrgnUpdate, hrgnUpdate, hrgnWinupd, RGN_OR);
1503         DeleteObject( hrgnWinupd);
1504     }
1505
1506     if( hwndCaret ) {
1507         if ( moveCaret ) SetCaretPos( newCaretPos.x, newCaretPos.y );
1508         ShowCaret(hwndCaret);
1509     }
1510
1511     if( bOwnRgn && hrgnUpdate ) DeleteObject( hrgnUpdate );
1512
1513     return retVal;
1514 }
1515
1516
1517 /*************************************************************************
1518  *              ScrollWindow (USER32.@)
1519  *
1520  */
1521 BOOL WINAPI ScrollWindow( HWND hwnd, INT dx, INT dy,
1522                           const RECT *rect, const RECT *clipRect )
1523 {
1524     return (ERROR != ScrollWindowEx( hwnd, dx, dy, rect, clipRect, 0, NULL,
1525                                      (rect ? 0 : SW_SCROLLCHILDREN) |
1526                                      SW_INVALIDATE | SW_ERASE ));
1527 }
1528
1529
1530 /*************************************************************************
1531  *              ScrollDC (USER32.@)
1532  *
1533  * dx, dy, lprcScroll and lprcClip are all in logical coordinates (msdn is
1534  * wrong) hrgnUpdate is returned in device coordinates with rcUpdate in
1535  * logical coordinates.
1536  */
1537 BOOL WINAPI ScrollDC( HDC hdc, INT dx, INT dy, const RECT *lprcScroll,
1538                       const RECT *lprcClip, HRGN hrgnUpdate, LPRECT lprcUpdate )
1539
1540 {
1541     return USER_Driver->pScrollDC( hdc, dx, dy, lprcScroll, lprcClip, hrgnUpdate, lprcUpdate );
1542 }
1543
1544 /************************************************************************
1545  *              PrintWindow (USER32.@)
1546  *
1547  */
1548 BOOL WINAPI PrintWindow(HWND hwnd, HDC hdcBlt, UINT nFlags)
1549 {
1550     UINT flags = PRF_CHILDREN | PRF_ERASEBKGND | PRF_OWNED | PRF_CLIENT;
1551     if(!(nFlags & PW_CLIENTONLY))
1552     {
1553         flags |= PRF_NONCLIENT;
1554     }
1555     SendMessageW(hwnd, WM_PRINT, (WPARAM)hdcBlt, flags);
1556     return TRUE;
1557 }