How to hook command window keystrokes
A customer asked how to hook events for the command window.
The sample below uses BINDEVENT to hook the WM_KEYDOWN, WM_KEYUP and WM_CHAR messages. It changes all ‘a’ keystrokes to ‘b’.
* From C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\PlatformSDK\Include\winuser.h
#define GWL_WNDPROC (-4)
#define WM_KEYDOWN 0x0100
#define WM_KEYUP 0x0101
#define WM_CHAR 0x0102
PUBLIC oMyHook as MyHook
oMyHook=NEWOBJECT("MyHook")
DEFINE CLASS MyHook AS session
dwOrigWindProc=0
dwShNotify=0
PROCEDURE init
DECLARE integer GetWindowLong IN WIN32API ;
integer hWnd, ;
integer nIndex
DECLARE integer CallWindowProc IN WIN32API ;
integer lpPrevWndFunc, ;
integer hWnd,integer Msg,;
integer wParam,;
integer lParam
THIS.dwOrigWindProc =GetWindowLong(_VFP.HWnd,GWL_WNDPROC)
cWind="Command"
WDOCKABLE(cWind,.f.) && make Command window not dockable
DECLARE integer FindWindowEx IN WIN32API integer, integer,STRING,string
hwndCmd=FindWindowEx(_screen.HWnd,0,0,cWind)
BINDEVENT(hwndCmd, WM_KEYDOWN,this,"HandleMsg")
BINDEVENT(hwndCmd, WM_KEYUP,this,"HandleMsg")
BINDEVENT(hwndCmd, WM_CHAR,this,"HandleMsg")
PROCEDURE HandleMsg(hWnd as Integer, msg as Integer, wParam as Integer, lParam as Integer)
LOCAL nRetvalue
nRetvalue=0
* ?PROGRAM(),msg,TRANSFORM(wParam,"@0x"),TRANSFORM(lParam,"@0x")," "
IF wParam=ASC("a")
wParam=ASC("b")
ENDIF
DO case
CASE lParam=WM_KEYDOWN
CASE lParam=WM_KEYUP
CASE lParam=WM_CHAR
ENDCASE
nRetvalue=CallWindowProc(this.dwOrigWindProc,hWnd,msg,wParam,lParam)
RETURN nRetvalue
ENDDEFINE
