Date: 02-16-2022
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created by gbSnippets
'A hook is a point in the Microsoft� Windows� message-handling mechanism
'where an application can install a subroutine to monitor the message
'traffic in the system and process certain types of messages before
'they reach the target window procedure.
'Hooks tend to slow down the system because they increase the amount of
'processing the system must perform for each message. You should install
'a hook only when necessary, and remove it as soon as possible.
'Global hooks must be in a separate DLL. Thread-specific hooks do not.
'Hook Types:
'Each type of hook enables an application to monitor a different aspect
'of the system's message-handling mechanism.
'Most used:
WH_CBT (structres: CBT_CreateWnd, CBTActiveStruct)
'system calls a WH_CBT hook procedure before activating, creating, destroying,
'minimizing, maximizing, moving, or sizing a window; before completing a system
'command;
WH_KEYBOARD (structure: KBDLLHookStruct)
'monitor message traffic for WM_KEYDOWN and WM_KEYUP messages
WH_MOUSE (structures: MouseHookStruct, MouseHookStructEX
'monitor mouse messages
'Others
WH_CALLWNDPROC and WH_CALLWNDPROCRET
WH_DEBUG
WH_FOREGROUNDIDLE
WH_GETMESSAGE
WH_JOURNALPLAYBACK
WH_JOURNALRECORD
WH_KEYBOARD_LL
WH_MOUSE_LL
WH_MSGFILTER and WH_SYSMSGFILTER
WH_SHELL
'Hook Procedures:
SetWindowsHookEx - install hook at beginning of a hook chain
CallNextHookEx - pass event to the next procedure
'Note that the hook procedures for some types of hooks can only monitor
'messages. the system passes messages to each hook procedure, regardless
'of whether a particular procedure calls CallNextHookEx.
'Install a hook:
ghHook = SetWindowsHookEx(%WH_CBT, CodePtr(InputBoxProc), GetModuleHandle(""), GetCurrentThreadId)
'Remove a hook:
UnhookWindowsHookEx ghHook
Function HookProc(nCode,wParam,lParam)
'nCode
Function = CallNextHookEx(ByVal ghHook, ByVal nCode, ByVal wParam, ByVal lParam)
End Function
Function InputBoxProc(ByVal nCode As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
'do stuff here ...
Function = CallNextHookEx(ByVal ghHook, ByVal nCode, ByVal wParam, ByVal lParam)
End Function
'Structures
TYPE CBT_CREATEWND
lpcs AS CREATESTRUCT PTR
hWndInsertAfter AS DWord
END TYPE
TYPE CREATESTRUCT
lpCreateParams As Long
hInstance AS DWord
hMenu AS DWord
hwndParent AS DWord
cy As Long
cx As Long
y As Long
x As Long
STYLE As Long
lpszName As AsciiZ PTR
lpszClass As AsciiZ PTR
dwExStyle AS DWord
END TYPE
TYPE KBDLLHOOKSTRUCT
vkCode AS DWord
scanCode AS DWord
flags AS DWord
time AS DWord
dwExtraInfo AS DWord
END TYPE
TYPE MOUSEHOOKSTRUCT
pt AS POINTAPI
hWnd AS DWord
wHitTestCode AS DWord
dwExtraInfo AS DWord
END TYPE
TYPE MOUSEHOOKSTRUCTEX
pt AS POINTAPI
hWnd AS DWord
wHitTestCode AS DWord
dwExtraInfo AS DWord
mouseData AS DWord
END TYPE
'Compilable Example: (Jose Includes)
#Compiler PBWin 9, PBWin 10
#Compile EXE
#Dim All
%Unicode=1
#Include "win32api.inc"
%IDC_Ask = 500
Global ix, iy As Long, hDlg As Dword, ghHook As Dword
Function PBMain() As Long
ix = 300 : iy = 300
Dialog New Pixels, 0, "Toolbar Test",ix,iy,400,300, %WS_OverlappedWindow To hDlg
Control Add Button, hDlg, %IDC_Ask, "Ask", 10,10,50,25
Dialog Show Modal hDlg Call DlgProc
End Function
CallBack Function DlgProc() As Long
Local temp$
Select Case Cb.Msg
Case %WM_Command
Select Case Cb.Ctl
Case %IDC_Ask
ghHook = SetWindowsHookEx(%WH_CBT, CodePtr(InputBoxProc), GetModuleHandle(""), GetCurrentThreadId)
temp$ = InputBox$("Enter your name:", "InputBox Test", "Gary Beene",ix+50,iy+50)
End Select
End Select
End Function
Function InputBoxProc(ByVal nCode As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Local szTemp As Asciiz * %Max_Path, cw As CBT_CREATEWND Ptr, cst As CREATESTRUCT Ptr
Function = CallNextHookEx(ByVal ghHook, ByVal nCode, ByVal wParam, ByVal lParam)
If nCode < 0 Then Exit Function
If nCode = %HCBT_ACTIVATE Then UnhookWindowsHookEx ghHook
If nCode = %HCBT_CREATEWND Then
cw = lParam ' Get pointer to CBT_CREATEWND struct so we can... TT: Nick Melnick
cst = @cw.lpcs ' get a pointer to the CREATESTRUCT struct
GetClassName wParam, szTemp, %Max_Path ' for each window / control as it is created
If UCase$(szTemp) = "STATIC" Then @cst.cy = 20 'prompt
If UCase$(szTemp) = "EDIT" Then @cst.cx = 190 : @cst.y = @cst.y - 130 'textbox
If UCase$(szTemp) = "#32770" Then @cst.cy = @cst.cy - 130 'dialog
End If
End Function
'gbs_00830
'Date: 03-10-2012
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