Capturing mouse and keyboard messages from a graphic control or window in PBWin 8.04

[Steve Rossell]

In PBWin 8.03 and previous versions of PBWin 8, you could subclass the graphic window and capture these messages, there was a change in PBWin 8.04, where you must subclass the static control on the graphic window to capture these messages. A graphic window is a dialog box with one static control on it, the static control is what you actually do the drawing on. All you need to do is get the handle of this static control with hStatic = GetWindow(hGraphicWindow, %GW_CHILD) and subclass hStatic instead of hGraphicWindow. The following example illustrates how to capture mouse and keyboard messages from both a graphic control and a graphic window in PBWin 8.04:

#COMPILE EXE
#DIM ALL

#INCLUDE "WIN32API.INC"

%IDC_LISTBOX1 = 1001
%IDC_GRAPHIC1 = 1002

GLOBAL GraphicWindowOldProc  AS LONG  
GLOBAL GraphicControlOldProc AS LONG
GLOBAL hDlg                  AS LONG

' Add a string to the list box and ensure that the last added string is visible
MACRO AddListBoxString(s)
    CONTROL SEND hDlg, %IDC_LISTBOX1, %LB_ADDSTRING, 0, VARPTR(s) TO i
    CONTROL SEND hDlg, %IDC_LISTBOX1, %LB_SETTOPINDEX, i, 0
END MACRO

' Callback routine to capture messages sent to the graphic window
FUNCTION GraphicWindowNewProc(BYVAL hWnd AS DWORD, BYVAL wMsg AS DWORD, BYVAL wParam AS DWORD, BYVAL lParam AS LONG) AS LONG
  LOCAL i AS LONG
  LOCAL s AS ASCIIZ * 256

  SELECT CASE wMsg
    CASE %WM_MOUSEMOVE
      s = "GRAPHIC WINDOW: %WM_MOUSEMOUSE ("+FORMAT$(LO(WORD, lParam))+","+FORMAT$(HI(WORD, lParam))+")"

    CASE %WM_LBUTTONDOWN
      s = "GRAPHIC WINDOW: %WM_LBUTTONDOWN ("+FORMAT$(LO(WORD, lParam))+","+FORMAT$(HI(WORD, lParam))+")"

    CASE %WM_RBUTTONDOWN
      s = "GRAPHIC WINDOW: %WM_RBUTTONDOWN ("+FORMAT$(LO(WORD, lParam))+","+FORMAT$(HI(WORD, lParam))+")"

    CASE %WM_KEYDOWN
      s = "GRAPHIC WINDOW: %WM_KEYDOWN key = "+CHR$(wParam)
      
  END SELECT
  
  IF LEN(s) THEN
    AddListBoxString(s)
  END IF
  
  ' Call the default callback routine to process any message we did not
  FUNCTION = CallWindowProc(GraphicWindowOldProc, hWnd, wMsg, wParam, lParam)

END FUNCTION

' Callback routine to capture messages sent to the graphic control
FUNCTION GraphicControlNewProc(BYVAL hWnd AS DWORD, BYVAL wMsg AS DWORD, BYVAL wParam AS DWORD, BYVAL lParam AS LONG) AS LONG
  LOCAL i AS LONG
  LOCAL s AS ASCIIZ * 256

  SELECT CASE wMsg
    CASE %WM_MOUSEMOVE
      s = "GRAPHIC CONTROL: %WM_MOUSEMOUSE ("+FORMAT$(LO(WORD, lParam))+","+FORMAT$(HI(WORD, lParam))+")"

    CASE %WM_LBUTTONDOWN
      s =  "GRAPHIC CONTROL: %WM_LBUTTONDOWN ("+FORMAT$(LO(WORD, lParam))+","+FORMAT$(HI(WORD, lParam))+")"

    CASE %WM_RBUTTONDOWN
     s = "GRAPHIC CONTROL: %WM_RBUTTONDOWN ("+FORMAT$(LO(WORD, lParam))+","+FORMAT$(HI(WORD, lParam))+")"

    CASE %WM_KEYDOWN
      s = "GRAPHIC CONTROL: %WM_KEYDOWN key = "+CHR$(wParam)

  END SELECT

  IF LEN(s) THEN
    AddListBoxString(s)
  END IF

  ' Call the default callback routine to process any message we did not
  FUNCTION = CallWindowProc(GraphicControlOldProc, hWnd, wMsg, wParam, lParam)

END FUNCTION

' Callback routine to process messages sent to the dialog box
CALLBACK FUNCTION DlgProc
  STATIC hGrWin AS LONG

  SELECT CASE AS LONG CBMSG
    CASE %WM_INITDIALOG
      ' Setup the graphic window
      GRAPHIC WINDOW "Graphic Window SubClass Example", 0, 0, 320, 240 TO hGrWin
      GRAPHIC ATTACH hGrWin, 0, REDRAW
      GRAPHIC CLEAR %BLACK
      GRAPHIC COLOR %YELLOW, %BLACK
      GRAPHIC PRINT "Move the mouse over the graphic window"
      GRAPHIC PRINT "or click the mouse on the graphic window"
      GRAPHIC PRINT "or press a key, the window must have focus"
      GRAPHIC PRINT "before a keypress can be captured."
      GRAPHIC REDRAW
      
      ' Setup the graphic control
      GRAPHIC ATTACH CBHNDL, %IDC_GRAPHIC1
      GRAPHIC CLEAR %BLACK
      GRAPHIC COLOR %YELLOW, %BLACK
      GRAPHIC PRINT "Move the mouse over the graphic window"
      GRAPHIC PRINT "or click the mouse on the graphic window"
      GRAPHIC PRINT "or press a key, the window must have focus"
      GRAPHIC PRINT "before a keypress can be captured."
      GRAPHIC REDRAW
      
      ' Get the handle of the static control on the graphic window
      hGrWin = GetWindow(hGrWin, %GW_CHILD)
      
      ' Subclass the static control on the graphic window
      GraphicWindowOldProc  = SetWindowLong(hGrWin, %GWL_WNDPROC, CODEPTR(GraphicWindowNewProc))
      
      ' Subclass the graphic control
      GraphicControlOldProc = SetWindowLong(GetDlgItem(CBHNDL, %IDC_GRAPHIC1), %GWL_WNDPROC, CODEPTR(GraphicControlNewProc))

    CASE %WM_DESTROY
      ' Set the graphic window to use it's original callback routine
      SetWindowLong(GetDlgItem(CBHNDL, %IDC_GRAPHIC1), %GWL_WNDPROC, GraphicControlOldProc)
      
      ' Set the graphic control to use it's original callback routine
      SetWindowLong(hGrWin, %GWL_WNDPROC, GraphicWindowOldProc)

  END SELECT
END FUNCTION

FUNCTION PBMAIN () AS LONG
  DIALOG NEW 0, "Graphic Subclass Example", 100, 170, 451, 205, %WS_POPUP OR %WS_BORDER OR %WS_DLGFRAME OR _
    %WS_SYSMENU OR %WS_CLIPSIBLINGS OR %WS_VISIBLE OR %DS_MODALFRAME OR %DS_3DLOOK OR %DS_NOFAILCREATE OR _
    %DS_SETFONT, %WS_EX_CONTROLPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING OR %WS_EX_RIGHTSCROLLBAR, TO hDlg
  CONTROL ADD LISTBOX, hDlg, %IDC_LISTBOX1, , 5, 5, 280, 195, %WS_CHILD OR %WS_VISIBLE OR %WS_TABSTOP OR %WS_VSCROLL _
    OR %LBS_NOSEL OR %LBS_NOINTEGRALHEIGHT, %WS_EX_CLIENTEDGE OR %WS_EX_LEFT OR %WS_EX_LTRREADING OR _
    %WS_EX_RIGHTSCROLLBAR
  CONTROL ADD GRAPHIC, hDlg, %IDC_GRAPHIC1, "", 290, 5, 155, 195, %WS_CHILD OR %WS_VISIBLE OR %WS_TABSTOP OR _
    %SS_NOTIFY, %WS_EX_CLIENTEDGE

  DIALOG SHOW MODAL hDlg, CALL DlgProc
END FUNCTION