rom/intuition/lockpubscreen.c

   1 /*
   2     Copyright  1995-2003, 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'tany, 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     AROS_LIBBASE_EXT_DECL(struct IntuitionBase *,IntuitionBase)
  82
  83     struct Screen *screen = NULL;
  84     struct List   *list;
  85
  86     DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: name <%s>\n",
  87                                 name ? name : (CONST_STRPTR)"NULL"));
  88     DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: task %p <%s>\n",
  89                                 SysBase->ThisTask,
  90                                 SysBase->ThisTask->tc_Node.ln_Name ? SysBase->ThisTask->tc_Node.ln_Name : "NULL"));
  91
  92     list = LockPubScreenList();
  93
  94     if( !name )
  95     {
  96
  97         screen = GetPrivIBase(IntuitionBase)->DefaultPubScreen;
  98
  99         /* If IntuitionBase->DefaultPubScreen is NULL, then Workbench screen
 100            is default public screen. But note that, Workbench screen might
 101            here not be open either. */
 102
 103         if (!screen) screen = GetPrivIBase(IntuitionBase)->WorkBench;
 104
 105         if (screen)
 106         {
 107             ASSERT_VALID_PTR(screen);
 108             GetPrivScreen(screen)->pubScrNode->psn_VisitorCount++;
 109             DEBUG_VISITOR(dprintf("LockPubScreen: 1 screen %p count %ld Task <%s>\n",
 110                                   screen, GetPrivScreen(screen)->pubScrNode->psn_VisitorCount,
 111                                   FindTask(NULL)->tc_Node.ln_Name));
 112             DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: screen %p count %d\n",
 113                                         screen, GetPrivScreen(screen)->pubScrNode->psn_VisitorCount));
 114         }
 115
 116     }
 117     else
 118     {
 119         struct PubScreenNode *psn;
 120
 121         ASSERT_VALID_PTR_ROMOK(name);
 122
 123         /* Browse the public screen list */
 124         if( (psn = (struct PubScreenNode *) FindName(list, (UBYTE *)name )) )
 125         {
 126             ASSERT_VALID_PTR(psn);
 127
 128             /* Don't lock screens in private state */
 129             if( (psn != NULL) && !(psn->psn_Flags & PSNF_PRIVATE) )
 130             {
 131                 /* Increment screen lock count */
 132                 psn->psn_VisitorCount++;
 133                 screen = psn->psn_Screen;
 134                 DEBUG_VISITOR(dprintf("LockPubScreen: 2 node %p screen %p count %ld <%s>\n",
 135                                       psn, screen, psn->psn_VisitorCount,
 136                                       FindTask(NULL)->tc_Node.ln_Name));
 137                 DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: node %p screen %p count %d\n",
 138                                             psn, screen, psn->psn_VisitorCount));
 139                 ASSERT_VALID_PTR(screen);
 140             }
 141         }
 142
 143     }
 144
 145     UnlockPubScreenList();
 146
 147     /* If no screen was found and the requested one was the Workbench screen or
 148      * the default public screen, open the Workbench screen and lock it. */
 149     if( (screen == NULL) && ((name == NULL) || (strcmp( name, "Workbench" ) == 0)) )
 150     {
 151         OpenWorkBench();
 152         DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: opened workbench\n"));
 153
 154         LockPubScreenList();
 155
 156         screen = GetPrivIBase(IntuitionBase)->WorkBench;
 157         if (!screen)
 158         {
 159             struct PubScreenNode *psn;
 160
 161             /* Maybe something patched OpenWorkbench, and there is a 'Workbench'
 162              * screen in the list. Our private pointer is just not set. */
 163             if( (psn = (struct PubScreenNode *) FindName(list, "Workbench" )) )
 164             {
 165                 /* Don't lock screens in private state */
 166                 if( (psn != NULL) && !(psn->psn_Flags & PSNF_PRIVATE) )
 167                     screen = psn->psn_Screen;
 168             }
 169         }
 170
 171         if( screen )
 172         {
 173             ASSERT_VALID_PTR(screen);
 174             GetPrivScreen(screen)->pubScrNode->psn_VisitorCount++;
 175             DEBUG_VISITOR(dprintf("LockPubScreen: 3 screen %p count %d <%s>\n",
 176                                   screen, GetPrivScreen(screen)->pubScrNode->psn_VisitorCount,
 177                                   FindTask(NULL)->tc_Node.ln_Name));
 178
 179             DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: screen %p count %d\n",
 180                                         screen, GetPrivScreen(screen)->pubScrNode->psn_VisitorCount));
 181         }
 182
 183         UnlockPubScreenList();
 184     }
 185
 186     FireScreenNotifyMessage((IPTR) screen, SNOTIFY_LOCKPUBSCREEN, IntuitionBase);
 187
 188     DEBUG_LOCKPUBSCREEN(dprintf("LockPubScreen: return %p\n", screen));
 189
 190     return screen;
 191
 192     AROS_LIBFUNC_EXIT
 193 } /* LockPubScreen */