rom/intuition/lockpubscreen.c

   1 /*
   2     Copyright  1995-2007, The AROS Development Team. All rights reserved.
   3     Copyright  2001-2003, The MorphOS Development Team. All Rights Reserved.
   4     $Id$
   5 */
   6
   7 #include <string.h>
   8 #include "intuition_intern.h"
   9
  10 /*****************************************************************************
  11
  12     NAME */
  13 #include <proto/intuition.h>
  14
  15     AROS_LH1(struct Screen *, LockPubScreen,
  16
  17 /*  SYNOPSIS */
  18          AROS_LHA(CONST_STRPTR, name, A0),
  19
  20 /*  LOCATION */
  21          struct IntuitionBase *, IntuitionBase, 85, Intuition)
  22
  23 /*  FUNCTION
  24
  25     Locks a public screen, thus preventing it from closing.
  26     This is useful if you want to put up a visitor window on a public screen
  27     and need to check some of the public screen's field first -- not locking
  28     the screen may lead to the public screen not existing when your visitor
  29     window is ready.
  30
  31     If you try to lock the Workbench screen or the default public screen
  32     and there isn't any, the Workbench screen will be automatically opened
  33     and locked.
  34
  35     INPUTS
  36
  37     Name   --  Name of the public screen or NULL for the default public
  38                screen. The name "Workbench" refers to the Workbench screen.
  39
  40     RESULT
  41
  42     A pointer to the screen or NULL if something went wrong. Failure can
  43     happen for instance when the public screen is in private state or doesn't
  44     exist.
  45
  46     NOTES
  47
  48     You don't need to hold the lock when your visitor window is opened as
  49     the pubscreen cannot be closed as long as there are visitor windows
  50     on it.
  51
  52     EXAMPLE
  53
  54     To open a visitor window which needs information from the screen structure
  55     of the public screen to open on, do this:
  56
  57     if((pubscreen = LockPubScreen("PubScreentoOpenon")) != NULL)
  58     {
  59         ...check pubscreen's internal data...
  60     OpenWindow(VisitorWindow, pubscreen);
  61     UnlockPubScreen(NULL, pubscreen);
  62     ...use your visitor window...
  63     CloseWindow(VisitorWindow);
  64     }
  65
  66     BUGS
  67
  68     SEE ALSO
  69
  70     OpenWindow(), UnlockPubScreen(), GetScreenData()
  71
  72     INTERNALS
  73
  74     HISTORY
  75     29-10-95    digulla automatically created from
  76                 intuition_lib.fd and clib/intuition_protos.h
  77
  78 *****************************************************************************/
  79 {
  80     AROS_LIBFUNC_INIT
  81
  82     struct Screen *screen = NULL;
  83     struct List   *list;
  84
  85     DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: name <%s>\n",
  86                                 name ? name : (CONST_STRPTR)"NULL"));
  87     DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: task %p <%s>\n",
  88                                 SysBase->ThisTask,
  89                                 SysBase->ThisTask->tc_Node.ln_Name ? SysBase->ThisTask->tc_Node.ln_Name : "NULL"));
  90
  91     list = LockPubScreenList();
  92
  93     if( !name )
  94     {
  95
  96         screen = GetPrivIBase(IntuitionBase)->DefaultPubScreen;
  97
  98         /* If IntuitionBase->DefaultPubScreen is NULL, then Workbench screen
  99            is default public screen. But note that, Workbench screen might
 100            here not be open either. */
 101
 102         if (!screen) screen = GetPrivIBase(IntuitionBase)->WorkBench;
 103
 104         if (screen)
 105         {
 106             ASSERT_VALID_PTR(screen);
 107             GetPrivScreen(screen)->pubScrNode->psn_VisitorCount++;
 108             DEBUG_VISITOR(dprintf("LockPubScreen: 1 screen %p count %ld Task <%s>\n",
 109                                   screen, GetPrivScreen(screen)->pubScrNode->psn_VisitorCount,
 110                                   FindTask(NULL)->tc_Node.ln_Name));
 111             DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: screen %p count %d\n",
 112                                         screen, GetPrivScreen(screen)->pubScrNode->psn_VisitorCount));
 113         }
 114
 115     }
 116     else
 117     {
 118         struct PubScreenNode *psn;
 119
 120         ASSERT_VALID_PTR_ROMOK(name);
 121
 122         /* Browse the public screen list */
 123         if( (psn = (struct PubScreenNode *) FindName(list, (UBYTE *)name )) )
 124         {
 125             ASSERT_VALID_PTR(psn);
 126
 127             /* Don't lock screens in private state */
 128             if( (psn != NULL) && !(psn->psn_Flags & PSNF_PRIVATE) )
 129             {
 130                 /* Increment screen lock count */
 131                 psn->psn_VisitorCount++;
 132                 screen = psn->psn_Screen;
 133                 DEBUG_VISITOR(dprintf("LockPubScreen: 2 node %p screen %p count %ld <%s>\n",
 134                                       psn, screen, psn->psn_VisitorCount,
 135                                       FindTask(NULL)->tc_Node.ln_Name));
 136                 DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: node %p screen %p count %d\n",
 137                                             psn, screen, psn->psn_VisitorCount));
 138                 ASSERT_VALID_PTR(screen);
 139             }
 140         }
 141
 142     }
 143
 144     UnlockPubScreenList();
 145
 146     /* If no screen was found and the requested one was the Workbench screen or
 147      * the default public screen, open the Workbench screen and lock it. */
 148     if( (screen == NULL) && ((name == NULL) || (strcmp( name, "Workbench" ) == 0)) )
 149     {
 150         OpenWorkBench();
 151         DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: opened workbench\n"));
 152
 153         LockPubScreenList();
 154
 155         screen = GetPrivIBase(IntuitionBase)->WorkBench;
 156         if (!screen)
 157         {
 158             struct PubScreenNode *psn;
 159
 160             /* Maybe something patched OpenWorkbench, and there is a 'Workbench'
 161              * screen in the list. Our private pointer is just not set. */
 162             if( (psn = (struct PubScreenNode *) FindName(list, "Workbench" )) )
 163             {
 164                 /* Don't lock screens in private state */
 165                 if( (psn != NULL) && !(psn->psn_Flags & PSNF_PRIVATE) )
 166                     screen = psn->psn_Screen;
 167             }
 168         }
 169
 170         if( screen )
 171         {
 172             ASSERT_VALID_PTR(screen);
 173             GetPrivScreen(screen)->pubScrNode->psn_VisitorCount++;
 174             DEBUG_VISITOR(dprintf("LockPubScreen: 3 screen %p count %d <%s>\n",
 175                                   screen, GetPrivScreen(screen)->pubScrNode->psn_VisitorCount,
 176                                   FindTask(NULL)->tc_Node.ln_Name));
 177
 178             DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: screen %p count %d\n",
 179                                         screen, GetPrivScreen(screen)->pubScrNode->psn_VisitorCount));
 180         }
 181
 182         UnlockPubScreenList();
 183     }
 184
 185     FireScreenNotifyMessage((IPTR) screen, SNOTIFY_LOCKPUBSCREEN, IntuitionBase);
 186
 187     DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: return %p\n", screen));
 188
 189     return screen;
 190
 191     AROS_LIBFUNC_EXIT
 192 } /* LockPubScreen */