| Navigation: Language Reference > App C - PROP: Runtime Properties > Complete Property List >====== PROP:WndProc ====== |    |
Sets or gets the window's (not the client area) or a specific control's messaging procedure for use with low-level Windows API calls that require it. Generally used in sub-classing to track all Windows messages.
Example:
PROGRAM
MAP
Main PROCEDURE
SubClassFunc1 PROCEDURE(UNSIGNED,UNSIGNED,UNSIGNED,LONG),LONG,PASCAL
SubClassFunc2 PROCEDURE(UNSIGNED,UNSIGNED,UNSIGNED,LONG),LONG,PASCAL
MODULE('') !SoftVelocity Win Library
CallWindowProc PROCEDURE(LONG,UNSIGNED,SIGNED,UNSIGNED,LONG),LONG,PASCAL,NAME('CallWindowProcA')
END
END
SavedProc1 LONG
SavedProc2 LONG
WM_MOUSEMOVE EQUATE(0200H)
PT GROUP
X SIGNED
Y SIGNED
END
CODE
Main
Main PROCEDURE
WinView WINDOW('View'),AT(0,0,320,200),HVSCROLL,MAX,TIMER(1),STATUS
STRING('X Pos'),AT(1,1,,),USE(?String1)
STRING(@n3),AT(24,1,,),USE(PT:X)
STRING('Y Pos'),AT(44,1,,),USE(?String2)
STRING(@n3),AT(68,1,,),USE(PT:Y)
BUTTON('Close'),AT(240,180,60,20),USE(?Close)
END
CODE
OPEN(WinView)
SavedProc1 = WinView{PROP:WndProc} !Save this procedure
WinView{PROP:WndProc} = ADDRESS(SubClassFunc1) !Name subclass procedure
SavedProc2 = WinView{PROP:ClientWndProc} !Save this procedure
WinView{PROP:ClientWndProc} = ADDRESS(SubClassFunc2) !Name subclass procedure
ACCEPT
CASE ACCEPTED()
OF ?Close
BREAK
END
END
SubClassFunc1 PROCEDURE(hWnd,wMsg,wParam,lParam) !Sub class procedure
CODE ! to track mouse movement in
IF wMsg = WM_MOUSEMOVE ! window's status bar (only)
PT.X = MOUSEX() ; PT.Y = MOUSEY() !Assign mouse position
END
RETURN(CallWindowProc(SavedProc1,hWnd,wMsg,wParam,lParam))!Pass control to SavedProc1
SubClassFunc2 PROCEDURE(hWnd,wMsg,wParam,lParam) !Sub class procedure
CODE ! to track mouse movement in
IF wMsg = WM_MOUSEMOVE ! window's client area
PT.X = MOUSEX() ; PT.Y = MOUSEY() !Assign mouse position
END
RETURN(CallWindowProc(SavedProc2,hWnd,wMsg,wParam,lParam))!Pass control to SavedProc2