rom/intuition/screenclass.c

   1 /*
   2     Copyright © 2013-2014, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <aros/debug.h>
   7 #include <cybergraphx/cybergraphics.h>
   8 #include <hidd/graphics.h>
   9 #include <hidd/hidd.h>
  10 #include <graphics/driver.h>
  11 #include <graphics/sprite.h>
  12 #include <intuition/intuition.h>
  13 #include <intuition/intuitionbase.h>
  14 #include <intuition/classes.h>
  15 #include <intuition/classusr.h>
  16 #include <intuition/monitorclass.h>
  17 #include <proto/alib.h>
  18 #include <proto/exec.h>
  19 #include <proto/intuition.h>
  20 #include <proto/oop.h>
  21 #include <proto/utility.h>
  22
  23 #include "intuition_intern.h"
  24 #include "intuition_customize.h"
  25 #include "monitorclass_private.h"
  26
  27 /*i***************************************************************************
  28
  29     NAME
  30         --background_screenclass--
  31
  32     LOCATION
  33         screenclass
  34
  35     NOTES
  36         In AROS screens are BOOPSI objects. It is possible to modify certain
  37         properties of the screen by using the SetAttrs() and GetAttr()
  38         functions. screenclass by itself is private to the system and does not
  39         have a public ID. The user can't create objects of this class
  40         manually. Screens are created and destroyed as usual, using
  41         the OpenScreen() and CloseScreen() functions.
  42
  43         This class is fully compatible with MorphOS starting from v2.x.
  44
  45 *****************************************************************************/
  46
  47 IPTR ScreenClass__OM_DISPOSE(Class *cl, Object *o, Msg msg)
  48 {
  49     struct IntuitionBase *IntuitionBase = (struct IntuitionBase *)cl->cl_UserData;
  50     struct IntScreen *screen = INST_DATA(cl, o);
  51
  52     /* Free decoration objects */
  53     DisposeObject(screen->WinDecorObj);
  54     DisposeObject(screen->MenuDecorObj);
  55     DisposeObject(screen->ScrDecorObj);
  56
  57     /* Free decoration buffer */
  58     FreeMem((APTR)screen->DecorUserBuffer, screen->DecorUserBufferSize);
  59
  60     if ((screen->Decorator != ((struct IntIntuitionBase *)(IntuitionBase))->Decorator) &&
  61         (screen->Decorator != NULL))
  62     {
  63         struct NewDecorator *nd = screen->Decorator;
  64
  65         ObtainSemaphore(&((struct IntIntuitionBase *)(IntuitionBase))->ScrDecorSem);
  66
  67         nd->nd_cnt--;
  68         if (nd->nd_IntPattern == NULL)
  69         {
  70             /*
  71              * If no pattern is defined, we assume it was old default decorator
  72              * which fell out of use. Unload it.
  73              */
  74             int_UnloadDecorator(nd, IntuitionBase);
  75         }
  76
  77         ReleaseSemaphore(&((struct IntIntuitionBase *)(IntuitionBase))->ScrDecorSem);
  78     }
  79
  80     return DoSuperMethodA(cl, o, msg);
  81 }
  82
  83 static IPTR GetScreen(ULONG attrID, struct IntScreen *screen, struct IntuitionBase *IntuitionBase)
  84 {
  85     Object *mon;
  86
  87     GetAttr(attrID, screen->IMonitorNode, (IPTR *)&mon);
  88
  89     if (mon)
  90     {
  91         ULONG lock = LockIBase(0);
  92         struct Screen *ret = FindFirstScreen(mon, IntuitionBase);
  93
  94         if (ret && ((ret->Flags & SCREENTYPE) == CUSTOMSCREEN))
  95         {
  96             /* We want only public screens */
  97             ret = NULL;
  98         }
  99
 100         UnlockIBase(lock);
 101
 102         return (IPTR)ret;
 103     }
 104
 105     return 0;
 106 }
 107
 108 /*i***************************************************************************
 109
 110     NAME
 111         SA_Left
 112
 113     SYNOPSIS
 114         [ISG], LONG
 115
 116     LOCATION
 117         screenclass
 118
 119     FUNCTION
 120         Position of left edge of the screen relative to top-left physical
 121         display corner.
 122
 123     NOTES
 124
 125     EXAMPLE
 126
 127     BUGS
 128
 129     SEE ALSO
 130
 131     INTERNALS
 132
 133 *****************************************************************************/
 134
 135 /*i***************************************************************************
 136
 137     NAME
 138         SA_Top
 139
 140     SYNOPSIS
 141         [ISG], LONG
 142
 143     LOCATION
 144         screenclass
 145
 146     FUNCTION
 147         Position of top edge of the screen relative to top-left physical
 148         display corner.
 149
 150     NOTES
 151
 152     EXAMPLE
 153
 154     BUGS
 155
 156     SEE ALSO
 157
 158     INTERNALS
 159
 160 *****************************************************************************/
 161 /*i***************************************************************************
 162
 163     NAME
 164         SA_Width
 165
 166     SYNOPSIS
 167         [I.G], LONG
 168
 169     LOCATION
 170         screenclass
 171
 172     FUNCTION
 173         Width of the screen (not display) in pixels.
 174
 175     NOTES
 176
 177     EXAMPLE
 178
 179     BUGS
 180
 181     SEE ALSO
 182
 183     INTERNALS
 184
 185 *****************************************************************************/
 186
 187 /*i***************************************************************************
 188
 189     NAME
 190         SA_Height
 191
 192     SYNOPSIS
 193         [I.G], LONG
 194
 195     LOCATION
 196         screenclass
 197
 198     FUNCTION
 199         Height of the screen (not display) in pixels.
 200
 201     NOTES
 202
 203     EXAMPLE
 204
 205     BUGS
 206
 207     SEE ALSO
 208
 209     INTERNALS
 210
 211 *****************************************************************************/
 212
 213 /*i***************************************************************************
 214
 215     NAME
 216         SA_Depth
 217
 218     SYNOPSIS
 219         [I.G], LONG
 220
 221     LOCATION
 222         screenclass
 223
 224     FUNCTION
 225         Depth of the screen.
 226
 227     NOTES
 228         This attribute returns the real depth; however, old structure fields,
 229         for example screen->RastPort.BitMap->bm_Depth, in case of direct-color
 230         screens will contain 8 for purposes of backwards compatibility.
 231
 232     EXAMPLE
 233
 234     BUGS
 235
 236     SEE ALSO
 237
 238     INTERNALS
 239
 240 *****************************************************************************/
 241
 242 /*i***************************************************************************
 243
 244     NAME
 245         SA_PubName
 246
 247     SYNOPSIS
 248         [I.G], STRPTR
 249
 250     LOCATION
 251         screenclass
 252
 253     FUNCTION
 254         Public screen name (system name, not human-readable title).
 255
 256     NOTES
 257
 258     EXAMPLE
 259
 260     BUGS
 261
 262     SEE ALSO
 263
 264     INTERNALS
 265
 266 *****************************************************************************/
 267
 268 /*i***************************************************************************
 269
 270     NAME
 271         SA_DisplayID
 272
 273     SYNOPSIS
 274         [I.G], LONG
 275
 276     LOCATION
 277         screenclass
 278
 279     FUNCTION
 280         Display mode ID of the screen.
 281
 282     NOTES
 283
 284     EXAMPLE
 285
 286     BUGS
 287
 288     SEE ALSO
 289
 290     INTERNALS
 291
 292 *****************************************************************************/
 293
 294 /*i***************************************************************************
 295
 296     NAME
 297         SA_Behind
 298
 299     SYNOPSIS
 300         [I.G], LONG
 301
 302     LOCATION
 303         screenclass
 304
 305     FUNCTION
 306         Supplying this attribute during screen creation (to OpenScreen() or
 307         OpenScreenTagList() functions) causes this screen to be created and
 308         opened behind all other screens.
 309
 310         Querying this attribute returns its initial value.
 311
 312     NOTES
 313
 314     EXAMPLE
 315
 316     BUGS
 317
 318     SEE ALSO
 319
 320     INTERNALS
 321
 322 *****************************************************************************/
 323
 324 /*i***************************************************************************
 325
 326     NAME
 327         SA_MonitorName
 328
 329     SYNOPSIS
 330         [I.G], LONG
 331
 332     LOCATION
 333         screenclass
 334
 335     FUNCTION
 336         Name of the monitorclass object (AKA display device name) to which
 337         this screen belongs.
 338
 339     NOTES
 340
 341     EXAMPLE
 342
 343     BUGS
 344
 345     SEE ALSO
 346         SA_MonitorObject
 347
 348     INTERNALS
 349
 350 *****************************************************************************/
 351
 352 /*i***************************************************************************
 353
 354     NAME
 355         SA_MonitorObject
 356
 357     SYNOPSIS
 358         [..G], Object *
 359
 360     LOCATION
 361         screenclass
 362
 363     FUNCTION
 364         Returns display device (monitorclass) object to which this screen
 365         belongs.
 366
 367     NOTES
 368
 369     EXAMPLE
 370
 371     BUGS
 372
 373     SEE ALSO
 374         SA_MonitorName
 375
 376     INTERNALS
 377
 378 *****************************************************************************/
 379
 380 /*i***************************************************************************
 381
 382     NAME
 383         SA_TopLeftScreen
 384
 385     SYNOPSIS
 386         [..G], struct Screen *
 387
 388     LOCATION
 389         screenclass
 390
 391     FUNCTION
 392         Get a pointer to a public screen displayed on a monitor placed in
 393         top-left diagonal direction relative to this screen's one. If the
 394         frontmost screen on the given monitor is not public, NULL will be
 395         returned.
 396
 397     NOTES
 398         AROS supports screen composition, so more than one screen is actually
 399         displayed at any given time. In order to match MorphOS semantics this
 400         attribute takes into account only the frontmost screen on the given
 401         monitor.
 402
 403     EXAMPLE
 404
 405     BUGS
 406
 407     SEE ALSO
 408         monitorclass/MA_TopLeftMonitor
 409
 410     INTERNALS
 411
 412 *****************************************************************************/
 413
 414 /*i***************************************************************************
 415
 416     NAME
 417         SA_TopMiddleScreen
 418
 419     SYNOPSIS
 420         [..G], struct Screen *
 421
 422     LOCATION
 423         screenclass
 424
 425     FUNCTION
 426         Get a pointer to a public screen displayed on a monitor placed in top
 427         direction relative to this screen's one. If the frontmost screen on
 428         the given monitor is not public, NULL will be returned.
 429
 430     NOTES
 431         AROS supports screen composition, so more than one screen is actually
 432         displayed at any given time. In order to match MorphOS semantics this
 433         attribute takes into account only the frontmost screen on the given
 434         monitor.
 435
 436     EXAMPLE
 437
 438     BUGS
 439
 440     SEE ALSO
 441         monitorclass/MA_TopMiddleMonitor
 442
 443     INTERNALS
 444
 445 *****************************************************************************/
 446
 447 /*i***************************************************************************
 448
 449     NAME
 450         SA_TopRightScreen
 451
 452     SYNOPSIS
 453         [..G], struct Screen *
 454
 455     LOCATION
 456         screenclass
 457
 458     FUNCTION
 459         Get a pointer to a screen displayed on a monitor placed in top-right
 460         diagonal direction relative to this screen's one. If the frontmost
 461         screen on the given monitor is not public, NULL will be returned.
 462
 463     NOTES
 464         AROS supports screen composition, so more than one screen is actually
 465         displayed at any given time. In order to match MorphOS semantics this
 466         attribute takes into account only the frontmost screen on the given
 467         monitor.
 468
 469     EXAMPLE
 470
 471     BUGS
 472
 473     SEE ALSO
 474         monitorclass/MA_TopRightMonitor
 475
 476     INTERNALS
 477
 478 *****************************************************************************/
 479
 480 /*i***************************************************************************
 481
 482     NAME
 483         SA_MiddleLeftScreen
 484
 485     SYNOPSIS
 486         [..G], struct Screen *
 487
 488     LOCATION
 489         screenclass
 490
 491     FUNCTION
 492         Get a pointer to a public screen displayed on a monitor placed in left
 493         direction relative to this screen's one. If the frontmost screen on
 494         the given monitor is not public, NULL will be returned.
 495
 496     NOTES
 497         AROS supports screen composition, so more than one screen is actually
 498         displayed at any given time. In order to match MorphOS semantics this
 499         attribute takes into account only the frontmost screen on the given
 500         monitor.
 501
 502     EXAMPLE
 503
 504     BUGS
 505
 506     SEE ALSO
 507         monitorclass/MA_MiddleLeftMonitor
 508
 509     INTERNALS
 510
 511 *****************************************************************************/
 512
 513 /*i***************************************************************************
 514
 515     NAME
 516         SA_MiddleRightScreen
 517
 518     SYNOPSIS
 519         [..G], struct Screen *
 520
 521     LOCATION
 522         screenclass
 523
 524     FUNCTION
 525         Get a pointer to a public screen displayed on a monitor placed in left
 526         direction relative to this screen's one. If the frontmost screen on
 527         the given monitor is not public, NULL will be returned.
 528
 529     NOTES
 530         AROS supports screen composition, so more than one screen is actually
 531         displayed at any given time. In order to match MorphOS semantics this
 532         attribute takes into account only the frontmost screen on the given
 533         monitor.
 534
 535     EXAMPLE
 536
 537     BUGS
 538
 539     SEE ALSO
 540         monitorclass/MA_MiddleRightMonitor
 541
 542     INTERNALS
 543
 544 *****************************************************************************/
 545
 546 /*i***************************************************************************
 547
 548     NAME
 549         SA_BottomLeftScreen
 550
 551     SYNOPSIS
 552         [..G], struct Screen *
 553
 554     LOCATION
 555         screenclass
 556
 557     FUNCTION
 558         Get a pointer to a public screen displayed on a monitor placed in
 559         bottom-left diagonal direction relative to this screen's one. If the
 560         frontmost screen on the given monitor is not public, NULL will be
 561         returned.
 562
 563     NOTES
 564         AROS supports screen composition, so more than one screen is actually
 565         displayed at any given time. In order to match MorphOS semantics this
 566         attribute takes into account only the frontmost screen on the given
 567         monitor.
 568
 569     EXAMPLE
 570
 571     BUGS
 572
 573     SEE ALSO
 574         monitorclass/MA_BottomLeftMonitor
 575
 576     INTERNALS
 577
 578 *****************************************************************************/
 579
 580 /*i***************************************************************************
 581
 582     NAME
 583         SA_BottomMiddleScreen
 584
 585     SYNOPSIS
 586         [..G], struct Screen *
 587
 588     LOCATION
 589         screenclass
 590
 591     FUNCTION
 592         Get a pointer to a public screen displayed on a monitor placed in
 593         bottom direction relative to this screen's one. If the frontmost
 594         screen on the given monitor is not public, NULL will be returned.
 595
 596     NOTES
 597         AROS supports screen composition, so more than one screen is actually
 598         displayed at any given time. In order to match MorphOS semantics this
 599         attribute takes into account only the frontmost screen on the given
 600         monitor.
 601
 602     EXAMPLE
 603
 604     BUGS
 605
 606     SEE ALSO
 607         monitorclass/MA_BottomMiddleMonitor
 608
 609     INTERNALS
 610
 611 *****************************************************************************/
 612
 613 /*i***************************************************************************
 614
 615     NAME
 616         SA_BottomRightScreen
 617
 618     SYNOPSIS
 619         [..G], struct Screen *
 620
 621     LOCATION
 622         screenclass
 623
 624     FUNCTION
 625         Get a pointer to a screen displayed on a monitor placed in
 626         bottom-right diagonal direction relative to this screen's one. If the
 627         frontmost screen on the given monitor is not public, NULL will be
 628         returned.
 629
 630     NOTES
 631         AROS supports screen composition, so more than one screen is actually
 632         displayed at any given time. In order to match MorphOS semantics this
 633         attribute takes into account only the frontmost screen on the given
 634         monitor.
 635
 636     EXAMPLE
 637
 638     BUGS
 639
 640     SEE ALSO
 641         monitorclass/MA_BottomRightMonitor
 642
 643     INTERNALS
 644
 645 *****************************************************************************/
 646
 647 /*i***************************************************************************
 648
 649     NAME
 650         SA_StopBlanker
 651
 652     SYNOPSIS
 653         [S..], BOOL
 654
 655     LOCATION
 656         screenclass
 657
 658     FUNCTION
 659         This attribute is currently reserved and exists only for source
 660         compatibility with MorphOS.
 661
 662     NOTES
 663
 664     EXAMPLE
 665
 666     BUGS
 667
 668     SEE ALSO
 669
 670     INTERNALS
 671
 672 *****************************************************************************/
 673
 674 /*i***************************************************************************
 675
 676     NAME
 677         SA_ShowPointer
 678
 679     SYNOPSIS
 680         [ISG], BOOL
 681
 682     LOCATION
 683         screenclass
 684
 685     FUNCTION
 686         Setting this attribute to FALSE makes mouse pointer invisible on your
 687         custom screen. The default value is TRUE. Setting this attribute on
 688         public screens is ignored.
 689
 690     NOTES
 691
 692     EXAMPLE
 693
 694     BUGS
 695
 696     SEE ALSO
 697
 698     INTERNALS
 699
 700 *****************************************************************************/
 701
 702 /*i***************************************************************************
 703
 704     NAME
 705         SA_GammaControl
 706
 707     SYNOPSIS
 708         [I..], BOOL
 709
 710     LOCATION
 711         screenclass
 712
 713     FUNCTION
 714         Setting this attribute to TRUE enables use of the SA_GammaRed,
 715         SA_GammaBlue and SA_GammaGreen attributes to supply a custom gamma
 716         correction table for your screen.
 717
 718     NOTES
 719         Since in AROS more than one screen can be visible simultaneously, the
 720         current display gamma correction table is determined by the frontmost
 721         screen on that display.
 722
 723     EXAMPLE
 724
 725     BUGS
 726
 727     SEE ALSO
 728
 729     INTERNALS
 730
 731 *****************************************************************************/
 732
 733 IPTR ScreenClass__OM_GET(Class *cl, Object *o, struct opGet *msg)
 734 {
 735     struct IntuitionBase *IntuitionBase = (struct IntuitionBase *)cl->cl_UserData;
 736     struct Library *OOPBase = GetPrivIBase(IntuitionBase)->OOPBase;
 737     OOP_AttrBase HiddBitMapAttrBase = GetPrivIBase(IntuitionBase)->HiddAttrBase;
 738     OOP_AttrBase HiddPixFmtAttrBase = GetPrivIBase(IntuitionBase)->HiddPixFmtAttrBase;
 739     struct IntScreen *screen = INST_DATA(cl, o);
 740
 741     switch (msg->opg_AttrID)
 742     {
 743     case SA_Left:
 744         *msg->opg_Storage = screen->Screen.LeftEdge;
 745         break;
 746
 747     case SA_Top:
 748         *msg->opg_Storage = screen->Screen.TopEdge;
 749         break;
 750
 751     case SA_Width:
 752         *msg->opg_Storage = screen->Screen.Width;
 753         break;
 754
 755     case SA_Height:
 756         *msg->opg_Storage = screen->Screen.Height;
 757         break;
 758
 759     case SA_Depth:
 760         *msg->opg_Storage = screen->realdepth;
 761         break;
 762
 763     case SA_PubName:
 764         *msg->opg_Storage = (IPTR)screen->pubScrNode->psn_Node.ln_Name;
 765         break;
 766
 767     case SA_DisplayID:
 768         *msg->opg_Storage = screen->ModeID;
 769         break;
 770
 771     case SA_Behind:
 772         *msg->opg_Storage = (screen->Screen.Flags & SCREENBEHIND) ? TRUE : FALSE;
 773         break;
 774
 775     case SA_Displayed:
 776         *msg->opg_Storage = screen->GammaControl.Active;
 777         break;
 778
 779     case SA_MonitorName:
 780         return GetAttr(MA_MonitorName, screen->IMonitorNode, msg->opg_Storage);
 781
 782     case SA_MonitorObject:
 783         *msg->opg_Storage = (IPTR)screen->IMonitorNode;
 784         break;
 785
 786     case SA_TopLeftScreen:
 787         *msg->opg_Storage = GetScreen(MA_TopLeftMonitor, screen, IntuitionBase);
 788         break;
 789
 790     case SA_TopMiddleScreen:
 791         *msg->opg_Storage = GetScreen(MA_TopMiddleMonitor, screen, IntuitionBase);
 792         break;
 793
 794     case SA_TopRightScreen:
 795         *msg->opg_Storage = GetScreen(MA_TopRightMonitor, screen, IntuitionBase);
 796         break;
 797
 798     case SA_MiddleLeftScreen:
 799         *msg->opg_Storage = GetScreen(MA_MiddleLeftMonitor, screen, IntuitionBase);
 800         break;
 801
 802     case SA_MiddleRightScreen:
 803         *msg->opg_Storage = GetScreen(MA_MiddleRightMonitor, screen, IntuitionBase);
 804         break;
 805
 806     case SA_BottomLeftScreen:
 807         *msg->opg_Storage = GetScreen(MA_BottomLeftMonitor, screen, IntuitionBase);
 808         break;
 809
 810     case SA_BottomMiddleScreen:
 811         *msg->opg_Storage = GetScreen(MA_BottomMiddleMonitor, screen, IntuitionBase);
 812         break;
 813
 814     case SA_BottomRightScreen:
 815         *msg->opg_Storage = GetScreen(MA_BottomRightMonitor, screen, IntuitionBase);
 816         break;
 817
 818     case SA_ShowPointer:
 819         *msg->opg_Storage = screen->ShowPointer;
 820         break;
 821
 822     case SA_GammaRed:
 823         *msg->opg_Storage = (IPTR)screen->GammaControl.GammaTableR;
 824         break;
 825
 826     case SA_GammaBlue:
 827         *msg->opg_Storage = (IPTR)screen->GammaControl.GammaTableB;
 828         break;
 829
 830     case SA_GammaGreen:
 831         *msg->opg_Storage = (IPTR)screen->GammaControl.GammaTableG;
 832         break;
 833
 834     case SA_DisplayWidth:
 835         *msg->opg_Storage = screen->Screen.ViewPort.DWidth;
 836         break;
 837
 838     case SA_DisplayHeight:
 839         *msg->opg_Storage = screen->Screen.ViewPort.DHeight;
 840         break;
 841
 842     case SA_PixelFormat:
 843         if (IS_HIDD_BM(screen->Screen.RastPort.BitMap))
 844         {
 845             OOP_Object *pixfmt;
 846
 847             OOP_GetAttr(HIDD_BM_OBJ(screen->Screen.RastPort.BitMap), aHidd_BitMap_PixFmt, (IPTR *)&pixfmt);
 848             OOP_GetAttr(pixfmt, aHidd_PixFmt_CgxPixFmt, msg->opg_Storage);
 849         }
 850         else
 851         {
 852             *msg->opg_Storage = -1;
 853         }
 854         break;
 855
 856     case SA_ScreenbarTextYPos:
 857         *msg->opg_Storage = screen->Screen.BarVBorder + screen->Screen.BarLayer->rp->TxBaseline;
 858         break;
 859
 860     case SA_ScreenbarTextPen:
 861         *msg->opg_Storage = screen->Pens[BARDETAILPEN];
 862         break;
 863
 864     case SA_ScreenbarTextFont:
 865         *msg->opg_Storage = (IPTR)screen->Screen.BarLayer->rp->Font;
 866         break;
 867
 868     case SA_CompositingFlags:
 869         *msg->opg_Storage = (IPTR)(screen->SpecialFlags >> 8);
 870         break;
 871
 872     case SA_AlphaPreCompositingHook:
 873         *msg->opg_Storage = (IPTR)screen->preAlphaCompHook;
 874         break;
 875
 876     case SA_OpacitySupport:    /* These are reserved in AROS */
 877     case SA_SourceAlphaSupport:
 878     case SA_ScreenbarSignal:
 879     case SA_CompositingLayers:
 880         *msg->opg_Storage = 0;
 881         break;
 882
 883     default:
 884         return FALSE;
 885     }
 886
 887     return TRUE;
 888 }
 889
 890 IPTR ScreenClass__OM_SET(Class *cl, Object *o, struct opSet *msg)
 891 {
 892     struct IntuitionBase *IntuitionBase = (struct IntuitionBase *)cl->cl_UserData;
 893     struct Library *UtilityBase = GetPrivIBase(IntuitionBase)->UtilityBase;
 894     struct IntScreen *screen = INST_DATA(cl, o);
 895     struct TagItem *tstate = msg->ops_AttrList;
 896     struct TagItem *tag;
 897     BOOL showpointer = screen->ShowPointer;
 898     BOOL movescreen = FALSE;
 899     BOOL gammaset = FALSE;
 900
 901     while((tag = NextTagItem(&tstate)))
 902     {
 903         switch (tag->ti_Tag)
 904         {
 905         case SA_Left:
 906             if (screen->SpecialFlags & SF_Draggable)
 907             {
 908                 screen->Screen.LeftEdge = tag->ti_Data;
 909                 movescreen = TRUE;
 910             }
 911             break;
 912
 913         case SA_Top:
 914             if (screen->SpecialFlags & SF_Draggable)
 915             {
 916                 screen->Screen.TopEdge = tag->ti_Data;
 917                 movescreen = TRUE;
 918             }
 919             break;
 920
 921         case SA_ShowPointer:
 922             showpointer = tag->ti_Data;
 923             break;
 924
 925         case SA_GammaRed:
 926             if (screen->GammaControl.UseGammaControl)
 927             {
 928                 screen->GammaControl.GammaTableR = (UBYTE *)tag->ti_Data;
 929                 gammaset = TRUE;
 930             }
 931             break;
 932
 933         case SA_GammaBlue:
 934             if (screen->GammaControl.UseGammaControl)
 935             {
 936                 screen->GammaControl.GammaTableB = (UBYTE *)tag->ti_Data;
 937                 gammaset = TRUE;
 938             }
 939             break;
 940
 941         case SA_GammaGreen:
 942             if (screen->GammaControl.UseGammaControl)
 943             {
 944                 screen->GammaControl.GammaTableG = (UBYTE *)tag->ti_Data;
 945                 gammaset = TRUE;
 946             }
 947             break;
 948
 949         case SA_AlphaPreCompositingHook:
 950             {
 951                 screen->preAlphaCompHook = (struct Hook *)tag->ti_Data;
 952             }
 953             break;
 954         }
 955     }
 956
 957     if (movescreen)
 958     {
 959         /*
 960          * Move the screen to (0, 0) relative of current position.
 961          * LeftEdge/TopEdge have been already updated.
 962          */
 963         ScreenPosition(&screen->Screen, SPOS_RELATIVE, 0, 0, 0, 0);
 964     }
 965
 966     if (showpointer != screen->ShowPointer)
 967     {
 968         screen->ShowPointer = showpointer;
 969         /* TODO: Actually implement this */
 970     }
 971
 972     if (gammaset)
 973     {
 974         /*
 975          * Update gamma table on the monitor.
 976          * The monitorclass takes care itself about whether this screen
 977          * currently controlls gamma table.
 978          */
 979         DoMethod((Object *)screen->IMonitorNode, MM_SetScreenGamma, &GetPrivScreen(screen)->GammaControl, FALSE);
 980     }
 981
 982     return 0;
 983 }