View source for 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==
<pre>
#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);
</pre>

[[Category:Hooks and Procedures]]