home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
OS/2 Shareware BBS: 10 Tools
/
10-Tools.zip
/
HOOKKBS.ZIP
/
hook_kbs.doc
< prev
next >
Wrap
Text File
|
1992-10-17
|
23KB
|
455 lines
Document File for hook_kbs program
From : Morton F. Kaplon CIS : 73457,437
1047 Johnston Drive
Bethlehem PA 18017
(215)758-9686
Revised and Updated : Sat 10-17-1992
Subject : Hooking the Keyboard in OS/2 2.0 and Assigning HotKeys
INTRODUCTION
HOOK_KBS is an OS/2 equivalent of a DOS TRS program. HotKeys are defined in
a user created data file that assigns to a HotKey a command to execute; the
data file is read by the program when loaded. Once loaded it intercepts the
message stream and inspects all WM_CHAR messages, the equivalent in DOS of
hooking the Keyboard Interrupt. When a key stroke meeting a HotKey
definition is detected, it takes appropriate action otherwise it passes
things along. The action taken is that of executing the assigned command
which may be a COM, EXE, CMD, or BAT file or loading an instance of the
command processor for either OS/2 or DOS. Thus you may activate a program or
load an instance of the command processor at the flick of a HotKey without
having to access an ICON.
HOOK_KBS works in conjunction with HOOK_DLS, a dynamic link module. HOOK_KBS
loads HOOK_DLS which captures Key Strokes (via sampling the systen nessage
queue) from all Windows BUT Full Screen OS/2 or DOS. The KeyStrokes
assignments are USER DEFINED in a data file named HOOK_KBS.DAT and the
program recognizes keystrokes assigned to Shift-Alt-X and Shift-Ctrl-X
where X is 0.....9 and A...Z independent of case (The restriction on X is
mine and is changeable of course). There are two combinations Shift-Alt-Del
and Shift-Alt-Ins (both white keys) that are hard coded into the program.
Shift-Alt-Del unloads the program and Shift-Alt-Ins pops up a small OS/2
window in the center of the screen. These, as is true for the other key
stroke combinations, may be called from anywhere, except for the Full Screen
sessions noted above.
To capture from Full Screen OS/2 or DOS would require an additional program
but since my principal purpose was to create a program that would allow me
to capture keystrokes independent of where I was working and since not using
Full Screen has advantages in flexibility, I decided to go without it. For
DOS windows you may in fact readily switch back and forth from Full Screen
to Windowed via the Alt-Home combination so nothing is really lost there.
The reason for requiring the triplet combination of Shift-Alt-X or
Shift-Ctrl-X is that besides the large number of pre-assigned keys in OS/2,
many programs use keystroke combinations for accessing specific features and
if the Hot Key is to be useful, it should not conflict. I can only remember
one program that I have seen over the years which used a Shift-Alt-X or
Shift-Ctrl-X combination and so it seems to be a fairly safe one, and one
that should not lead to conflicts. In filtering KeyStrokes the program
rejects all but the combinations Shift-Alt-X and Shift-Ctrl-X so that the
usual run of keystroke assignments of Alt-X or Ctrl-X and all Function key
combinations will be unaffected. Keystrokes are recognized on the down
stroke. I would note that the Shift-Alt or Shift-Ctrl combination is
particularly easy to access on those keyboards where the Shift Key sits
vertically between the Ctrl and Alt keys.
As presently configured, once a key stroke combination has activated a
program, using that combination a second time will not open an additional
instance of the program but will switch back to the original. HOWEVER, IF
the opened window was used to load another program (such as a command
processor window might), then that window loses its unique identity and
using the same HotKey will activate another copy. The reason for this is
that the Identity of each window is determined by its Window title which is
defined as "Alt-X" or "Ctl-X" where X is the key used. The window popped up
with Shift-Alt-Ins has the letter ID "Ω". If another program is started from
an open window, its program title is noted as "prgname.ext Alt-X" or
"prgname.ext Ctl-X", where ext is the program's extension, and is thus not
recognized as an already existing window title.
The program is written in 32 bit Assembler.
OVERVIEW
FILES REQUIRED TO CREATE HOOK_KBS.EXE AND HOOK_DLS.DLL
DOSWIN32.MAC Macros and Equates used by Programs
HOOK_KBS.ASM Source for Executable, Assembled and Linked by MLC-W386.CMD
HOOK_DLS.DEF Define file needed by IMPLIB and linker for HOOK_DLS.ASM
HOOK_DLS.ASM Source for HOOK_DLS.DLL, Assembled and linked by DLL-W386.CMD
DLL-W386.CMD IMPLIB and HOOK_DLS.DEF create C:\TOOLKT20\OS2LIB\HOOK_DLS.LIB
MASM then assembles HOOK_DLS.ASM, LINK386 produces HOOK_DLS.DLL
and HOOK_DLS.DLL is copied to C:\OS2\DLL directory.
MLC-W386.CMD MASM assembles HOOK_KBS.ASM and LINK386 produces HOOK_KBS.EXE
To ASSEMBLE and LINK use the directory holding the above files as the
default and the two commands below to produce the necessary files.
DLL-W386 HOOK_DLS
MLC-W386 HOOK_KBS
FILES REQUIRED TO EXECUTE HOOK_KBS.EXE
HOOK_KBS.DAT Text File assigning programs to key strokes-read by HOOK_KBS.
The user creates this file according to the structure outlined
in the sample. MUST BE LOCATED IN C:\OS2. Edit the sample to
fit your needs. Note that my assignment to C0 (Shift-Ctrl-0)
displays a file which I have configured to list the Hot Key
assignments. It serves as a useful reminder and I would
recommend each user to make such an assignment. The one I
use is a reasonable template and is included as HOT-KEY.MNU.
All assignments fit on one screen in the default window size.
HOOK_KBS.EXE Exec file created above
HOOK_DLS.DLL Dynamic Load File Created Above - must be in C:\OS2\DLL
DO NOT RENAME HOOK_DLS.* or HOOK_KBS.DAT as those names are coded into
HOOK_KBS.ASM .
The assembler used is MASM 6.0 including its built in MACROS for control
structures and segment definitions.
The 32 bit linker (LINK386) and the 32 bit library, along with the necessary
INC files require the user to have the OS/2 TOOLKIT as well as MASM 6.0 to
assemble the program.
PROGRAM METHOD
The system message queue is hooked using the HK_INPUT parameter. The
function which samples the message queue is in HOOK_DLS.DLL. In the section
"Input Hook", p. 30-2 in the Programming Guide, Vol. II, it states : "The
system calls an input_hook function whenever the WinGetMsg or WinPeekMsg
functions is about to return a message."
The installed procedure, InputHook, in HOOK_DLS.DLL tests for WM_CHAR and
when detected it further tests to see if the key combination Shift-Alt-X or
Shift-Ctrl-X was struck, with X (as defined above) on the down stroke. If
that criteria is met its POSTS to HOOK_KBS, via the API function WinPostMsg,
the message WM_USER+300h. The mp1 parameter of that message holds a flag
indicating whether Alt or Ctl was down and the mp2 parameter has the scan
code for the key X that was struck.
HOOK_KBS determines if the Key actually struck was assigned in the file
HOOK_KBS.DAT and if so reads its parameters into the appropriate data
structure required to execute the program. The Shift-Alt-Del key-stroke is
assigned to removing the DLL from memory and closing the program, equivalent
to unloading a TSR in DOS.
The main program, HOOK_KBS.EXE, a PM program, sets up the hook, receives the
message indicated above and takes the appropriate action depending on the
Key Stroke. The program is established as Invisible and Not listed in the
Window List. The program should be launched from an OS/2 window with the
START command, i.e. "START HOOK_KBS". That command can be placed in a
STARTUP.CMD for automatic loading. If you modify the file HOOK_KBS.DAT, you
must unload HOOK_KBS by Shift-Alt-Del(white key) and then reload it to
activate the new set of key assignments.
The program automatically sets DPMI_DOS_API=ENABLED for programs whose
session type (DOS full or windowed) is defined as 4 or 7 in hook_kbs.dat.
This enables the Dos Protected Mode Interface for the DOS session. If the
Session type value of 0 is used, DPMI is not enabled as above. It is
interesting to note that setting that parameter is done by passing the
DosStartSession data structure an address holding the text string above,
even though the manual states that the field for a DOS session is reserved
and must be ZERO. Unfortunately, there are quite a few errors in the OS/2
Technical Library, but fortunately a lot of people to inform you about them.
The flow of HOOK_KBS is delineated below. The same headings are listed in
the source code in HOOK_KBS.ASM.
PROGRAM FLOW : HOOK_KBS
PRELIMINARIES
Define Model and Calling Protocol
Equates for Using Macros in .DATA section
Equates for INC files
Include file listings
Prototype definitions for MASM
Structure definition for storing info on Program Assignment to Keys
.STACK defines an 8KB stack
.DATA contains variables,parameters and strings required for .CODE section
.CODE outlined below
ESTABLISH WINDOW
WinInitialize ;Initialize
WinCreateMessageQueue ;Create a Message Queue
WinRegisterClass ;Registers and identifies MainWinProc as name
;of Procedure for messages
WinCreateStdWindow ;Creates window - here it is made Invisible,etc.
IS HOOK_DLS.DLL LOADED ? ;If yes, display message and exit
ALLOCATE SHARED MEM AND STORE Handle Returned by WinCreateStdWindow
This is required in order to pass the Handle to HOOK_DLS
IS DATA FILE AVAILABLE AND VALID ?
Load C:\OS2\HOOK_KBS.DAT ;If it does not exist, exit with Error Message
Get HOOK_KBS.DAT FileSize ;Required by program for subsequent use
AllocateMemoryBuffer ;Buffer for User Key assignments from DataFile
Copy HOOK_KBS.DAT->Buffer ;Read File into Buffer
Close HOOK_KBS.DAT ;No longer needed
Process Data in Buffer ;If Format Not Correct, EXIT with Message
ALLOCATE MEMORY FOR SWITCH LIST STRUCTURE
Do once since size needed can change as programs loaded/unloaded.
ESTABLISH THE HOOK
DosLoadModule ;Loads HOOK_DLS.DLL
DosQueryProcAddr ;Get the address of the function in the DLL
WinSetHook ;Uses the Address above and HK_INPUT to set HOOK
CREATE MAIN MESSAGE LOOP ;Standard PM requirement but EXIT TEST is
;commented out - a WM_QUIT message has no
;impact here
EXIT ROUTINE ;Note this is commented out but is included
;to demonstrate the overall structure of
;setting up a PM program
PROCESS MESSAGE QUEUE ;The heart of a PM program
MainWinProc ;Processes message queue
GET PASSED PARAMETERS FROM STACK
RESTORE STACK POINTER AND STACK STATUS
TEST SYSTEM QUEUE FOR MESSAGES FROM
WM_CREATE
WM_PAINT
WM_CHAR
WM_USER+300h ;dispatched from hook_dls.dll
IF msg = WM_USER+300h
GET SCAN CODE AND ALT/CTRL FLAG
IF Alt-Del struck
Release DLL,Memory, Close Queues and Windows and Exit
ELSE TEST FOR ASSIGNED KEYS
SETUP DATA STRUCTURES FOR ACTIVATING HOT KEY
GO THRU SWITCH LIST TO SEE IF HOT KEY ACTIVE
IF ACTIVE SWITCH TO
ELSE ACTIVATE HOT KEY PROGRAM
ENDIF
ENDIF
END PROGRAM FLOW : HOOK_KBS
The flow of HOOK_DLS is delineated below. The same headings are listed in
HOOK_KBS.DLL.
PROGRAM FLOW : HOOK_DLS
PRELIMINARIES
Define Model and Calling Protocol
Equates for INC files
Include file listings
.STACK defines a 2KB stack
.DATA contains variables,parameters and strings required for .CODE section
.CODE delineated below
ESTABLISH InputHook
GET PARAMETERS FROM STACK
GET ADDRESS OF SHARED MEMORY
Get Handle Of Hook_kbs and Release Shared Memory
IF WM_CHAR MESSAGE DETECTED
Save mp1 and mp2 of WM_CHAR message
Test for Shift Key,Alt/Ctrl Down and Valid Scan Key
IF ScanCode & Shift & one of Alt or Ctrl down
Send original message nowhere via WM_USER+0cfffh
WinPostMessage to HOOK_KBS via WM_USER+300h ;with ALt/Ctrl Flag and
ENDIF ;ScanCode as parms
ENDIF
END PROGRAM FLOW : HOOK_DLS
DISCUSSION
DOSWIN32.MAC (Macros and Equates used by Program)
This file contains the equates, EXTRN declarations, MACROS and Procedures
used in the ASM files. The EXTRN declarations include many more than those
used in the program but represent the accrued list of those used so far in
my OS/2 assembler programming. (As I use a new one, I just add it).
Included are two defines used in the .DATA section of hook_kbs.asm. The
single most important MACRO is $CALL. This allows one to list parameters
after the function name in the same order as they are listed in the OS/2 2.0
Technical Manuals (and as called in C) . The macro pushes them on the stack
in the correct order and resets the stack pointer after the call. It could
clearly easily be extended to accomodate a longer parameter list. Following
that are several useful macros and three others defined via equates.
For displaying error messages and rudimentary inline debugging, there are
three macros named $DosErrMsg, $WinErrMsg and $WinDebugMessage . The first
two are meant to be called after an API function call to display the error
number for the function used. Information on the success of the call is
returned in EAX and this must be tested. Note EAX returns differently for
DOS than for WIN calls. The user passes the text string for the Function
used on the parameter line for the $XXXErrMsg. $DosErrMsg can only be used
in Text Windows while $WinErrMsg only in PM windows.
Finally there are several macros and procedures used for Binary <-> ASCII
conversion for both Decimal and Hex, and also for displaying numerical
results in Binary form. Not all of these are used but are included as a part
of the overall package. Note that in 32 bit mode, it is most convenient to
do all these conversion as DWORDS. These are required for numerical to ASCII
conversion for the error messages.
HOOK_DLS.DEF
This file is required by both IMPLIB and LINK386 in the creation of
HOOK_DLS.DLL. It identifies the function(s) exported from the DLL.
HOOK_DLS.ASM
This file represents the dynamic link code. It contains one function, named
InputHook whose syntax is defined by OS/2 on page 30-2 of the Programming
Guide, Vol II of the OS/2 Technical Library. This DLL monitors the system
message queue and looks for the message WM_CHAR.
Since I decided to use WinPostMsg to return information to hook_kbs, its
handle is required in this program. The simplest way seemed to be to pass it
in a shared memory region established by hook_kbs. Thus the first task done
by the function InputHook, after setting itself up, is to get the address of
the shared memory region and to obtain the handle of hook_kbs that was placed
there by hook_kbs. After that is done, the shared memory is released.
The program then waits for a message WM_CHAR and when that is detected the
Keyboard Parameters are tested to see if they meet the HotKey criteria. If
they do not, the message is passed on. If they do, a flag denoting whether
the Alt or Ctrl key was down is equated to the mp1 parameter and the scan
code value equated to the mp2 parameter of the message WM_USER+300h which is
posted to HOOK_KBS by WinPostMsg.
This DLL is released from memory when hook_kbs is closed.
HOOK_KBS
The first four WIN... function calls are a standard calling sequence in
setting up a PM program. Since a PM program cannot display text using DOS
write calls, error messages cannot be displayed with Window Message Calls
until the Window is initialized with the first call.
After the window is established a test is done to see if HOOK_DLS is loaded.
If it is a message is given and the program terminates. A Shared Memory area
is then established. Its sole use in this program is to furnish a method of
passing HOOK_KBS's handle to HOOK_DLS. This is done following the call to
DosAllocSharedMem. Note that eax is now tested for a non-zero value
indicating an error, as contrasted to Win calls where a 0 returned in eax
indicates an error.
Next the program attempts to load the data file C:\OS2\HOOK_KBS.DAT. If it
does not exist, an error message is displayed and the program terminates. If
it loads, its size is obtained (note the calls are rather similar to what
you would do in DOS) and that value is used to create a buffer to hold the
file in memory. The file is read into the buffer and then closed. The big
.WHILE loop reads the buffer and assigns the Addresses of the Executable
program name and Command Line parameters and the Session type to the
appropriate member of the Structure ExecOnKb and places a 0 at the end of
strings in order that they meet the requirement of being ASCIIZ strings. If
the count of characters read in the buffer does not equal the file size or
if the data file was not properly formatted, an error message is displayed
and the program terminated; the error message displays the number of bytes
of the buffer processed when the program terminated.
If everything is in order, a large memory block is defined to hold the data
structure of the Switch List (which is used to determine if a program is
loaded or not) and then the HOOK is established with the next three calls to
DosLoadModule, DosQueryProcAddr and WinSetHook.
The Main Message Loop is next established. Normally this loop is exited when
WM_QUIT is received and the exit code is executed to gracefully terminate
the program. However, in this program, to ensure that it is terminated only
by the Key Combination Alt-Del, the Main Message Loop is not exitable (I
have commented out the normal tests) and I have included the Exit code only
for purposes of demonstration of what a more normal program would look like.
The procedure MainWinProc examines the message queue. It first sets up to
get the parameters passed on the stack and goes through a series of tests
for specific messages. In a C program this would usually be a Case
statement. There is no requirement for these tests to do anything in this
case since the window is invisible but they are required to respond to
certain system calls.
The heart of the program is the test for WM_USER+300h . WM_USER defines a
lower limit for message IDs that is (presumably) guaranteed not to conflict
with any system messages. I have arbitrarily used WM_USER + 300h. HOOK_DLS
uses this message ID in posting its information to this programs message
queue. First a test is done to see whether Alt-Del was struck and if so, the
system is closed and exited. If not, tests are done to see whether the Scan
Code of the key struck is in the list read from HOOK_KBS.DAT. A test is
first done to see if the (white)Insert key was struck, and if not, a test is
done for the rest of the possible assignments.
Depending on the key combination struck, the address of the program, address
of the command line parameters, the Session Type for the Key Combination
identified in the message and the Program Title ( based on the Key
combination ) are obtained and inserted into the StartData structure
required for the DosStartSession function. The Switch (Task) list is then
examined to see if the HotKey program is already loaded and its identity
unchanged. If it is, it is switched to, else DosStartSession is then called
with appropriate parameters.
Note that WinSetFocus is called before DosStartSession. The programs started
by DosStartSession will not be in the foreground unless the program calling
DosStartSession is in the foreground and it seems reasonable that programs
called with a "HotKey" want to be in the foreground.
The six procedures at the very end are just routines used by parts of the
code in the program.
I have found this program very useful, particularly with respect to programs
using COM ports. Since OS/2 will not allow you to have two programs open at
the same time that use the same COM port, this affords a rapid means of
serially accessing programs sharing a common COM port. Another use I have
found effective is to assign MENUS to some of the Hot Keys. In my sample
HOOK_KBS.DAT file, the assignment Aq (Alt-q) to loadq.cmd, is a CMD file
that displays a menu for editing a variety of different files and the
assignment Ar (Alt-r) to viewref.cmd displays a menu whose choices allow you
to View the various OnLine References of OS/2 and Toolkit20. You can readily
assign any program assigned to an ICON to a hot key, presuming the program
has an executable form or can be called as a parameter to another program.
But by far I have found it an efficient expediter for rapidly accessing
programs without changing anything on your DeskTop.
As it was with TSR's in DOS, you must be careful of your assignments so that
required keys in programs are not made unavailable. That stricture was
reflected in my choice of keys to assign and reflects my particular
concerns. A natural question to ask is - are there any problems with other
programs that may be sampling the system message queue ?
Included in OS/2 and the Toolkit are the following programs that I am aware
of which are "resident" in the above sense:
PULSE From Productivity Group - Samples Processor Activity
KWIKINF From OS/2 ToolKit20 - An OnLineReference Access
PMSPY From OS/2 ToolKit20 - A Message queue trace
I have not detected any problems with HOOK_KBS loaded with any or all of the
above programs active, independent of the order of loading.