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VioRegister
Bindings: C, MASM
This call registers an alternate video subsystem within a session.
VioRegister (ModuleName, EntryPoint, FunctionMask1, FunctionMask2)
ModuleName (PSZ) - input
Address of the ASCIIZ string containing the 1-8 character file name of
the subsystem. The maximum length of the ASCIIZ string is 9 bytes
including the terminating byte of zero. The module must be a dynamic
link library but the name supplied must not include the .DLL
extension.
EntryPoint (PSZ) - input
Address of the ASCIIZ name string containing the dynamic link entry
point name of the routine in the subsystem to receive control when any
of the registered functions is called. The maximum length of the
ASCIIZ string is 33 bytes including the terminating byte of zero.
FunctionMask1 (ULONG) - input
A bit mask where each bit identifies a video function being
registered. The bit definitions are shown below. The first word
pushed onto the stack contains the high-order 16 bits of the function
mask, and the second word contains the low-order
16 bits.
BIT REGISTERED FUNCTION BIT REGISTERED FUNCTION
------------------------------------------------------------------
31 VioPrtScToggle 15 VioWrtCharStr
30 VioEndPopUp 14 VioWrtTTY
29 VioPopUp 13 VioWrtNCell
28 VioSavRedrawUndo 12 VioWrtNAttr
27 VioSavRedrawWait 11 VioWrtNChar
26 VioScrUnLock 10 VioReadCellStr
25 VioScrLock 9 VioReadCharStr
24 VioPrtSc 8 VioShowBuf
23 VioGetAnsi 7 VioSetMode
22 VioSetAnsi 6 VioSetCurType
21 VioScrollRt 5 VioSetCurPos
20 VioScrollLf 4 VioGetPhysBuf
19 VioScrollDn 3 VioGetBuf
18 VioScrollUp 2 VioGetMode
17 VioWrtCellStr 1 VioGetCurType
16 VioWrtCharStrAtt 0 VioGetCurPos
FunctionMask2 (ULONG) - input
A bit mask where each bit identifies a video function being
registered. The bit mask has the format shown below. The first word
pushed onto the stack contains the high order 16 bits of the function
mask, and the second word contains the low order 16 bits. Unused bits
are reserved and must be set to zero.
Bit Description
31-9 Reserved, set to zero
8 VioSetState
7 VioGetState
6 VioSetFont
5 VioGetCp
4 VioSetCp
3 VioGetConfig
2 VioGetFont
1 VioModeUndo
0 VioModeWait
rc (USHORT) - return
Return code descriptions are:
0 NO_ERROR
349 ERROR_VIO_INVALID_MASK
403 ERROR_VIO_INVALID_ASCIIZ
426 ERROR_VIO_REGISTER
430 ERROR_VIO_ILLEGAL_DURING_POPUP
465 ERROR_VIO_DETACHED
494 ERROR_VIO_EXTENDED_SG
Remarks
An alternate video subsystem must register which video calls it handles.
The default OS/2 video subsystem is the Base Video Subsystem.
When any of the registered functions are called, control is routed to
EntryPoint. When this routine is entered, four additional values (5
words) are pushed onto the stack.
The first value is the index number (Word) of the routine being called.
The second value is a near pointer (Word). The third value is the
caller's DS register (Word). The fourth value is the return address
(DWord) to the VIO router.
For example, if VioSetCurPos were a registered function, the stack would
appear as if the following instruction sequence were executed if
VioSetCurPos were called and control routed to EntryPoint:
+-------------------------------------------------------+
| PUSH WORD Row |
| PUSH WORD Column |
| PUSH WORD VioHandle |
| CALL FAR VioSetCurPos |
| PUSH WORD Index |
| CALL NEAR Entry point in Vio router |
| PUSH WORD Caller's DS |
| CALL FAR Dynamic link entry point |
+-------------------------------------------------------+
The index numbers that correspond to the registered functions are listed
below:
0 VioGetPhysBuf 22 VioSetAnsi
1 VioGetBuf 23 VioGetAnsi
2 VioShowBuf 24 VioPrtSc
3 VioGetCurPos 25 VioScrLock
4 VioGetCurType 26 VioScrUnLock
5 VioGetMode 27 VioSavRedrawWait
6 VioSetCurPos 28 VioSavRedrawUndo
7 VioSetCurType 29 VioPopUp
8 VioSetMode 30 VioEndPopUp
9 VioReadCharStr 31 VioPrtScToggle
10 VioReadCellStr 32 VioModeWait
11 VioWrtNChar 33 VioModeUndo
12 VioWrtNAttr 34 VioGetFont
13 VioWrtNCell 35 VioGetConfig
14 VioWrtCharStr 36 VioSetCp
15 VioWrtCharStrAtt 37 VioGetCp
16 VioWrtCellStr 38 VioSetFont
17 VioWrtTTY 39 VioGetState
18 VioScrollUp 40 VioSetState
19 VioScrollDn
20 VioScrollLf
21 VioScrollRt
When a registered function returns to the video router, the return code
is interpreted as follows:
Return code = 0
No error. Do not invoke the corresponding Base Video Subsystem
routine. Return to caller with Return code = 0.
Return code = -1
No error. Invoke the corresponding Base Video Subsystem
routine. Return to caller with Return code = return code from
Base Video Subsystem.
Return code = error (not 0 or -1)
Do not invoke the corresponding Base Video Subsystem routine.
Return to caller with Return code = error.
When an application registers a replacement for VioPopUp within a
session, the registered routine is only invoked when that session is in
the foreground. If VioPopUp is issued when that session is in the
background, the OS/2 default routine is invoked.
An alternate video subsystem should be designed so the routines
registered do not cause any hard errors when they are invoked. Otherwise,
a system lockout occurs. Code and data segments of registered routines,
that might be loaded from diskette, must be preloaded.
All VIO functions within a session are serialized on a thread basis.
That is, when an alternate video subsystem receives control, it can
safely assume that it is not called again from the same session until the
current call has completed.
Created using Inf-PHP v.2 (c) 2003 Yuri Prokushev
Created using Inf-HTML v.0.9b (c) 1995 Peter Childs