MsgControlHook

This hook allows the call to determine the flow of messages to be intercepted.

Syntax

MsgControlHook(hab, idContext, hwnd, pszClassName, usMsgClass, idControl, fSuccess);

Parameters

hab (HAB) - input

Anchor-block handle.

idContext (LONG) - input

Origin of call to hook.

MCHK_CLASSMSGINTEREST

WinSetClassMsgInterest

MCHK_MSGINTEREST

WinSetMsgInterest

MCHK_MSGMODE

WinSetMsgMode

MCHK_SYNCHRONISATION

WinSetSynchroMode

hwnd (HWND) - input

Window handle.

This is the same as the window handle in the hwnd parameter of the WinSetMsgInterest function.

pszClassName (PSZ) - input

Window class name.

This is the same as the window class name in the pszClassName parameter of the WinSetClassMsgInterest function.

usMsgClass (ULONG) - input

Message class.

This is the same as the message class in the ulMsgClass parameter of the WinSetMsgInterest and the WinSetClassMsgInterest functions.

idControl (LONG) - input

Control setting.

The setting varies with the value of the idContext parameter.

For MCHK_CLASSMSGINTEREST

it can be SMI_INTEREST, or SMI_NOINTEREST, or SMI_AUTODISPATCH.

For MCHK_MSGINTEREST

it can be SMI_INTEREST, or SMI_NOINTEREST, or SMI_RESET, or SMI_AUTODISPATCH.

For MCHK_MSGMODE

it can be SMD_DELAYED or SMD_IMMEDIATE.

For MCHK_SYNCHRONISATION

it can be SSM_SYNCHRONOUS, or SSM_ASYNCHRONOUS, or SSM_MIXED.

fSuccess (PBOOL) - in/out

Success indicator.

TRUE

Mode or interest successfully set.

FALSE

Mode or interest not successfully set.

Returns

rc (BOOL) - returns

Processing indicator.

TRUE

Do not call next hook in chain

FALSE

Call next hook in chain.

Remarks

If the hook is unable to alter the message control state, then the hook must establish the relevant error information.

Example Code

#define INCL_WINHOOKS /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HAB      hab;           /*  Anchor-block handle. */
LONG     idContext;     /*  Origin of call to hook. */
HWND     hwnd;          /*  Window handle. */
PSZ      pszClassName;  /*  Window class name. */
ULONG    usMsgClass;    /*  Message class. */
LONG     idControl;     /*  Control setting. */
PBOOL    fSuccess;      /*  Success indicator. */
BOOL     rc;            /*  Processing indicator. */

rc = MsgControlHook(hab, idContext, hwnd,
       pszClassName, usMsgClass, idControl,
       fSuccess);