Repeated Question (Treeview Macros)

Greg,

thanks for the link. Although I'm not quite certain we are addressing the same issue - it might be so.

I was already starting to think that I have finally lost my mind and chasing ghosts getting ready to head to a funny farm. I had tried to write a small program to demonstrate the matter and could not reproduce the problem. Everything seemed to work like expected.

Then reading thru the thread you mentioned, it hit me: earlier I used GLOBAL variables and in my demostration program LOCALs. Back to PB/DLL and yes - there seems to be a difference between these two scopes. Globals do what I have tried to describe earlier, locals don't.

I have attached a small program which demonstrates my point.

Lasse Rantanen
[email protected]

#COMPILE EXE
$INCLUDE "WIN32API.INC"
 
%IDL_CONSTANT   = 1000
%IDL_LONG       = 1001
%IDL_DWORD      = 1002
%IDL_DWORDLONG  = 1003
%IDL_LONG1      = 1004
%IDL_DWORD1     = 1005
%IDL_DWORDLONG1 = 1006
 
%TVI_ROOT_DW1   = &HFFFF0000???
%TVI_ROOT_DW2   = &H0FFFF0000
%TVI_ROOT_L1    = &HFFFF0000
%TVI_ROOT_L2    = &HFFFF0000&
 
GLOBAL hDlg     AS LONG
GLOBAL dwTest1  AS DWORD
GLOBAL lTest1   AS LONG
 
'------------------------------------------------------------------------------
SUB SetLabels(iConst AS INTEGER)
 
    LOCAL dwTest   AS DWORD
    LOCAL lTest    AS LONG
    LOCAL sBits    AS STRING
    LOCAL i        AS INTEGER
 
    SELECT CASE iConst
        CASE 1
            dwTest = %TVI_ROOT_DW1
            lTest = %TVI_ROOT_DW1
            dwTest1 = %TVI_ROOT_DW1
            lTest1 = %TVI_ROOT_DW1
            CONTROL SET TEXT hDlg,%IDL_CONSTANT, "Define %TVI_ROOT = &HFFFF0000??? "
        CASE 2
            dwTest = %TVI_ROOT_DW2
            lTest = %TVI_ROOT_DW2
            dwTest1 = %TVI_ROOT_DW2
            lTest1 = %TVI_ROOT_DW2
            CONTROL SET TEXT hDlg,%IDL_CONSTANT, "Define %TVI_ROOT = &H0FFFF0000 "
        CASE 3
            dwTest = %TVI_ROOT_L1
            lTest = %TVI_ROOT_L1
            dwTest1 = %TVI_ROOT_L1
            lTest1 = %TVI_ROOT_L1
            CONTROL SET TEXT hDlg,%IDL_CONSTANT, "Define %TVI_ROOT = &HFFFF0000 "
        CASE 4
            dwTest = %TVI_ROOT_L2
            lTest = %TVI_ROOT_L2
            dwTest1 = %TVI_ROOT_L2
            lTest1 = %TVI_ROOT_L2
            CONTROL SET TEXT hDlg,%IDL_CONSTANT, "Define %TVI_ROOT = &HFFFF0000& "
    END SELECT
 
    sBits = ""
    FOR i= 31 TO 0 STEP -1
        sBits = sBits + TRIM$(STR$(BIT(lTest,i)))
    NEXT
    CONTROL SET TEXT hDlg, %IDL_LONG, sBits
 
    sBits = ""
    FOR i= 31 TO 0 STEP -1
        sBits = sBits + TRIM$(STR$(BIT(dwTest,i)))
    NEXT
    CONTROL SET TEXT hDlg, %IDL_DWORD, sBits
  
    lTest = dwTest
    sBits = ""
    FOR i= 31 TO 0 STEP -1
        sBits = sBits + TRIM$(STR$(BIT(lTest,i)))
    NEXT
    CONTROL SET TEXT hDlg, %IDL_DWORDLONG, sBits
 
    sBits = ""
    FOR i= 31 TO 0 STEP -1
        sBits = sBits + TRIM$(STR$(BIT(lTest1,i)))
    NEXT
    CONTROL SET TEXT hDlg, %IDL_LONG1, sBits
  
    sBits = ""
    FOR i= 31 TO 0 STEP -1
        sBits = sBits + TRIM$(STR$(BIT(dwTest1,i)))
    NEXT
    CONTROL SET TEXT hDlg, %IDL_DWORD1, sBits
 
    lTest1 = dwTest1
    sBits = ""
    FOR i= 31 TO 0 STEP -1
        sBits = sBits + TRIM$(STR$(BIT(lTest1,i)))
    NEXT
    CONTROL SET TEXT hDlg, %IDL_DWORDLONG1, sBits
END SUB
 
'------------------------------------------------------------------------------
 
CALLBACK FUNCTION AssignDlgProc
 
    STATIC iStep AS INTEGER
 
    SELECT CASE CBMSG
 
        CASE %WM_COMMAND
            SELECT CASE CBCTL
 
                CASE %IDOK
                    INCR iStep
                    IF iStep > 4 THEN iStep = 1
                    SetLabels iStep
 
                CASE %IDCANCEL
                    DIALOG END CBHNDL
 
            END SELECT
 
    END SELECT
 
END FUNCTION
'------------------------------------------------------------------------------
 
FUNCTION PBMAIN () AS LONG
 
    $REGISTER NONE
 
' ** Create a new dialog template
    DIALOG NEW 0, "Some Numeric Assigments", ,, 320, 190, 0, 0 TO hDlg
 
' ** Add controls to it
 
    CONTROL ADD LABEL,  hDlg, %IDL_CONSTANT, "",5,15,310,12, %SS_LEFT
    CONTROL ADD LABEL,  hDlg, -1, "Results with Local Variables",5,30,310,12, %SS_LEFT
 
    CONTROL ADD LABEL,  hDlg, -1, "lTest = %TVI_ROOT : BITS in lTest -> ",5,40,175,12, %SS_LEFT
    CONTROL ADD LABEL,  hDlg, %IDL_LONG, "",180,40,140,12, %SS_LEFT
 
    CONTROL ADD LABEL,  hDlg, -1, "dwTest = %TVI_ROOT : BITS in dwTest -> ",5,55,175,12, %SS_LEFT
    CONTROL ADD LABEL,  hDlg, %IDL_DWORD, "",180,55,140,12, %SS_LEFT
 
    CONTROL ADD LABEL,  hDlg, -1, "dwTest = %TVI_ROOT : lTest = dwTest : BITS in lTest -> ",5,70,175,12, %SS_LEFT
    CONTROL ADD LABEL,  hDlg, %IDL_DWORDLONG, "",180,70,140,12, %SS_LEFT
 
    ' Labels for global case
    CONTROL ADD LABEL,  hDlg, -1, "Results with Global Variables",5,105,310,12, %SS_LEFT
 
    CONTROL ADD LABEL,  hDlg, -1, "lTest = %TVI_ROOT : BITS in lTest -> ",5,115,175,12, %SS_LEFT
    CONTROL ADD LABEL,  hDlg, %IDL_LONG1, "",180,115,140,12, %SS_LEFT
 
    CONTROL ADD LABEL,  hDlg, -1, "dwTest = %TVI_ROOT : BITS in dwTest -> ",5,130,175,12, %SS_LEFT
    CONTROL ADD LABEL,  hDlg, %IDL_DWORD1, "",180,130,140,12, %SS_LEFT
 
    CONTROL ADD LABEL,  hDlg, -1, "dwTest = %TVI_ROOT : lTest = dwTest : BITS in lTest -> ",5,145,175,12, %SS_LEFT
    CONTROL ADD LABEL,  hDlg, %IDL_DWORDLONG1, "",180,145,140,12, %SS_LEFT
 
    CONTROL ADD BUTTON, hDlg, %IDOK, "Next", 115, 165, 40, 14, %BS_DEFAULT
    CONTROL ADD BUTTON, hDlg, %IDCANCEL, "Cancel", 165, 165, 40, 14
 
' ** Display the dialog
    DIALOG SHOW MODAL hDlg, CALL AssignDlgProc
 
END FUNCTION

[Greg Turgeon]

<font face="courier new, courier" size="3"><pre>lasse--
the following link details something that i learned about dwords (vs. longs)
and might be relevant:

[/CODE]


------------------
-- greg
[email protected]

Lance,

Ok, first you have to be careful as BIN$() only works with signed values in the LONG integer range... if you pass an large unsigned value it "overflows" and the result is "undefined".

That I understand, but I did not use BIN$ to produce the binary representation. Instead I checked every bit with BIT and build the binary representation that way, so the overflow is not caused by BIN$ function.

It looks like an overflow to me, too. But still, why assigning a constant causes an overflow and assigning a variable does not, even if both have similar bit pattern as far as I can tell and defined to be same type.

Haven't developed my next problem yet so I keep coming back to this.

Lasse Rantanen
[email protected]

[Lance Edmonds]

I had the latest version of commctrl.inc file. In order to make sure I downloaded win32api.zip once more and it still reads %TVI_ROOT = &HFFFF0000??? etc. in commctrl.inc.

Hmmm... Thats interesting... I checked my copy and I have it as &HFFFF0000&... ahha! a couple of days ago I reinstalled PB/DLL 6.0 from scratch and I was looking at the old files... I ask R&D to update this in the WIN32API.ZIP files.

To see what happens when you assign different numeric constants to a long variable, I wrote following small code snippet which shows the bit pattern after the substitution.

Ok, first you have to be careful as BIN$() only works with signed values in the LONG integer range... if you pass an large unsigned value it "overflows" and the result is "undefined".

%DWTEST = &HFFFF0000????
10000000000000000000000000000000
-2147483648
%DWTEST = &H0FFFF0000
10000000000000000000000000000000
-2147483648

BIN$() overflow. Both of these are unsigned values beyond the LONG integer range.

%DWTEST = &HFFFF0000
11111111111111110000000000000000
-65536
%DWTEST = &HFFFF0000&
11111111111111110000000000000000
-65536

Signed values in the LONG integer range.

so lParam is expected to be an unsigned long integer.

Yes. However, the equate definition specified an unsigned value, so internally, PB tried to convert it to a signed value before passing it to the API, but becaue it overflows the LONG range, PB passed an "undefined" value... that is what you (the programmer) told it to do, and it obeyed!

My question still is: why does assigning a CONSTANT defined to be a DWORD to a LONG variable produce different result than assigning a VARIABLE defined to be a DWORD?

See above.



------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

Lance,

I had the latest version of commctrl.inc file. In order to make sure I downloaded win32api.zip once more and it still reads %TVI_ROOT = &HFFFF0000??? etc. in commctrl.inc.

OK, but to matter under discussion. I hope I'm not boring you all by continuing this, but I still don't quite understand what happens.

To see what happens when you assign different numeric constants to a long variable, I wrote following small code snippet which shows the bit pattern after the substitution.

	LOCAL BitArray AS STRING
	LOCAL lTest    AS LONG
	BitArray = ""
	%DWTEST = &HFFFF0000??? ' <<< This is changed
	lTest = %DWTEST
	FOR i = 31 TO 0 STEP -1
    	BitArray = BitArray + STR$(BIT(lTest,i))
	NEXT
	                    
	MSGBOX BitArray + $CrLf + STR$(lTest)

Different defines produce following results

	%DWTEST = &HFFFF0000????
	10000000000000000000000000000000
	-2147483648
	
	%DWTEST = &H0FFFF0000
	10000000000000000000000000000000
	-2147483648
	
	%DWTEST = &HFFFF0000
	11111111111111110000000000000000
	-65536
	
	%DWTEST = &HFFFF0000&
	11111111111111110000000000000000
	-65536

Now %TVM_DELETEITEM message expects SendMessage parameters be

	wParam = 0; 
	lParam = (LPARAM) (HTREEITEM) hitem;

In MS's header files these are defined to be

	typedef struct _TREEITEM FAR* HTREEITEM;
	typedef DWORD LPARAM;

so lParam is expected to be an unsigned long integer. This means that when trying to delete all items from a treeview control, Windows expects to see a bit pattern 11111111111111110000000000000000 (TVI_ROOT) as defined in header files.

In commctrl.inc Treeview_DeleteAllItems macro is defined to be

FUNCTION TreeView_DeleteAllItems (BYVAL hWnd AS DWORD) AS LONG
    FUNCTION = SendMessage(hWnd, %TVM_DELETEITEM, 0, %TVI_ROOT)
END FUNCTION

In win32api.inc SendMessage is declared as follows

DECLARE FUNCTION SendMessage LIB "USER32.DLL" ALIAS "SendMessageA" (BYVAL hwnd AS LONG, BYVAL wMsg AS LONG, BYVAL wParam AS LONG, BYVAL lParam AS LONG) AS LONG

so it's lParam is defined to be a long (signed integer).

It seems to me that when substituting a constant to the lParam, something like the substitutions described above takes place and as result, first two cases produce wrong result, last two work OK (when speaking of bit patterns).

To mess up things more (I know I'm probably not making my point very clear), making following change in the small program above, produces different results.

	LOCAL BitArray AS STRING
	LOCAL lTest    AS LONG
	LOCAL dwTemp   AS DWORD
                    
	BitArray = ""
	%DWTEST = &HFFFF0000??? <<< This is changed
	dwTemp = %DWTEST
	lTest = dwTemp
	' Rest like above

Every define for %DWTEST produces correct result - when speaking about bit patterns. This also makes the two macro definition - Treeview_DeleteItem ans Treeview_DeleteAllItems - to behave differently as described in earlier postings.

My question still is: why does assigning a CONSTANT defined to be a DWORD to a LONG variable produce different result than assigning a VARIABLE defined to be a DWORD?

PB/DLL is a great product, I just want to understand also this feature of it.

Lasse Rantanen
[email protected]

[Lance Edmonds]

It has to do with signed VS unsigned.

%A = &HFFFF0000??? ' unsigned DWORD value assigned to %A
%B = &H0FFFF0000   ' unsigned DWORD value assigned to %B
%C = &HFFFF0000    ' Signed LONG value
%D = &HFFFF0000&   ' Signed LONG value

BTW, the WIN32API.INC files have had this value defined as &HFFFF0000& for some time now... download the latest updates from ftp://ftp.powerbasic.com/pub/support/win32api.zip

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

Just one addition - when I said "have to doubt that statement" I meant in case of DWORD (???).

Lasse Rantanen
[email protected]

------------------

Borje,

yes it does make it work.

Still, at least for me the original question remains unanswered - why? PB/DLL documentation says

You can also force a constant to be stored with a given precision by following the constant with one of the variable type specifiers (%, &, &&, ?, ??, ???, !, #, ##, @, @@)

I have to doubt that statement because the only way to make the original declares/defines to work was to replace %TVI_ROOT with a variable which was declared to be DWORD. And now Borje's finding also supports this - by removing the postfix type specifier seems to make &HFFFF0000 a DWORD.

Lasse Rantanen
[email protected]

[Borje Hagsten]

If you change

%TVI_ROOT = &HFFFF0000???

to

%TVI_ROOT = &HFFFF0000

in commctrl.inc, it works fine. I haven't tested the others, but
my guess is the same goes for them all..


------------------

Lance,

these are copied from my version of COMMCTRL.INC dated Dec. 10, 1999.

Lasse Rantanen
[email protected]

TYPE TV_ITEM
    mask AS DWORD
    hItem AS DWORD
    STATE AS DWORD
    stateMask AS DWORD
    pszText AS ASCIIZ PTR
    cchTextMax AS LONG
    iImage AS LONG
    iSelectedImage AS LONG
    cChildren AS LONG
    lParam AS LONG
END TYPE
 
TYPE TVITEM
    mask AS DWORD
    hItem AS DWORD
    STATE AS DWORD
    stateMask AS DWORD
    pszText AS ASCIIZ PTR
    cchTextMax AS LONG
    iImage AS LONG
    iSelectedImage AS LONG
    cChildren AS LONG
    lParam AS LONG
END TYPE
 
' only used for Get and Set messages.  no notifies
 
TYPE TVITEMEX
    mask AS DWORD
    hItem AS DWORD
    STATE AS DWORD
    stateMask AS DWORD
    pszText AS ASCIIZ PTR
    cchTextMax AS LONG
    iImage AS LONG
    iSelectedImage AS LONG
    cChildren AS LONG
    lParam AS LONG
    iIntegral AS LONG
END TYPE
 
%TVI_ROOT               = &HFFFF0000???
%TVI_FIRST              = &HFFFF0001???
%TVI_LAST               = &HFFFF0002???
%TVI_SORT               = &HFFFF0003???
 
UNION TV_ITEM_UNION
    itemex AS TVITEMEX
    item AS TV_ITEM
END UNION
 
TYPE TV_INSERTSTRUCT
  hParent AS DWORD
  hInsertAfter AS DWORD
  item AS TV_ITEM_UNION
END TYPE
 
%TVM_INSERTITEM         = %TV_FIRST + 0
%TVM_INSERTITEMW        = %TV_FIRST + 50
 
FUNCTION TreeView_InsertItem (BYVAL hWnd AS LONG, lpis AS TV_INSERTSTRUCT) _
   AS DWORD
    FUNCTION = SendMessage(hWnd, %TVM_INSERTITEM, 0, VARPTR(lpis))
END FUNCTION
 
%TVM_DELETEITEM         = %TV_FIRST + 1
 
FUNCTION TreeView_DeleteItem (BYVAL hWnd AS DWORD, BYVAL hitem AS DWORD) _
   AS LONG
    FUNCTION = SendMessage(hWnd, %TVM_DELETEITEM, 0, hitem)
END FUNCTION
 
FUNCTION TreeView_DeleteAllItems (BYVAL hWnd AS DWORD) AS LONG
    FUNCTION = SendMessage(hWnd, %TVM_DELETEITEM, 0, %TVI_ROOT)
END FUNCTION

[Lance Edmonds]

Please post the structure for TV_ITEM_UNION and anything else that is necessaru to compile your code... Thanks!!!



------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

Lance,

here is an example. Right click on main window to call the code to clear the treeview.

As I said earlier, this is not a real problem as such, because the desired effect can be achieved easily. I just want to understand.

Lasse Rantanen
[email protected]

' Eliminate unnecessary macros
%NOANIMATE = 1
%NODRAGLIST = 1
%NOHEADER = 1
%NOIMAGELIST = 1
%NOLISTVIEW = 1
%NOTABCONTROL = 1
%NOTRACKBAR = 1
'%NOTREEVIEW = 1
%NOUPDOWN = 1

$DIM ALL
$COMPILE EXE
$OPTION VERSION4

$INCLUDE "WIN32API.INC"
$INCLUDE "COMMCTRL.INC"

'==========================================================
'//* Constants
%ID_TREEVIEW        = 1003
%MAX_CATEGORY       = 32

'//* structures
TYPE tagLISTINFO
    hInst           AS LONG
    hWndMain        AS LONG
    hWndTreeView    AS LONG
END TYPE

GLOBAL g_ListInfo   AS tagLISTINFO

GLOBAL hTRoot   AS DWORD
GLOBAL hTPrev   AS DWORD
GLOBAL hTParent AS DWORD

'//* Function prototypes
DECLARE FUNCTION InitInstance(BYVAL hInstance AS LONG, BYVAL iCmdShow AS LONG) AS INTEGER
DECLARE FUNCTION InitApplication(BYVAL hInstance AS LONG) AS INTEGER
DECLARE FUNCTION CreateControls(BYVAL hWndParent AS LONG) AS INTEGER
DECLARE FUNCTION TV_CreateTreeView ( hWndParent AS LONG, hInst AS LONG) AS LONG
DECLARE FUNCTION TV_AddOneItem( lpszText AS ASCIIZ PTR , BYVAL hwndTree AS LONG, index AS INTEGER) AS DWORD

'==========================================================
FUNCTION WINMAIN (BYVAL hInstance     AS LONG, _
                  BYVAL hPrevInstance AS LONG, _
                  lpCmdLine           AS ASCIIZ PTR, _
                  BYVAL iCmdShow      AS LONG) AS LONG

    LOCAL Msg   AS tagMSG

    InitApplication hInstance
    InitInstance hInstance, iCmdShow
    WHILE (GetMessage(Msg, %NULL, 0, 0) > 0)
        TranslateMessage Msg
        DispatchMessage Msg
    WEND
    FUNCTION = Msg.wParam
END FUNCTION

'==========================================================
FUNCTION InitApplication(BYVAL hInstance AS LONG) AS INTEGER

    LOCAL wcNetwork     AS WndClassEx
    LOCAL szMenuName    AS ASCIIZ * 80
    LOCAL szClassName   AS ASCIIZ * 80

    szMenuName  = "NetworkMenu"
    szClassName = "NetworkWClass"

    wcNetwork.cbSize           = SIZEOF(wcNetwork)
    wcNetwork.style            = %CS_HREDRAW OR %CS_VREDRAW
    wcNetwork.lpfnWndProc      = CODEPTR( WndProc )
    wcNetwork.cbClsExtra       = 0
    wcNetwork.cbWndExtra       = 0
    wcNetwork.hInstance        = hInstance
    wcNetwork.hIcon            = LoadIcon(hInstance, BYVAL %NULL)
    wcNetwork.hCursor          = LoadCursor(%NULL, BYVAL %IDC_ARROW)
    wcNetwork.hbrBackground    = GetStockObject(%LTGRAY_BRUSH )
    wcNetwork.lpszMenuName     = VARPTR( szMenuName )
    wcNetwork.lpszClassName    = VARPTR( szClassName )
    wcNetwork.hIconSm          = LoadIcon( hInstance, BYVAL %NULL)

    FUNCTION = RegisterClassEx(wcNetwork)

END FUNCTION

'==========================================================
FUNCTION InitInstance(BYVAL hInstance AS LONG, BYVAL iCmdShow AS LONG) AS INTEGER

    LOCAL hWnd AS LONG

    g_ListInfo.hInst = hInstance
    g_ListInfo.hWndMain = CreateWindow( "NetworkWClass", _
                                        "Treeview Test", _
                                        %WS_OVERLAPPEDWINDOW, _
                                        GetSystemMetrics ( %SM_CXSCREEN )/4, _
                                        GetSystemMetrics ( %SM_CYSCREEN )/4, _
                                        GetSystemMetrics ( %SM_CXSCREEN )/2, _
                                        GetSystemMetrics ( %SM_CYSCREEN )/2, _
                                        %NULL, _
                                        %NULL, _
                                        hInstance, _
                                        BYVAL %NULL)
    ShowWindow g_ListInfo.hWndMain, iCmdShow
    UpdateWindow g_ListInfo.hWndMain
    FUNCTION=%TRUE
END FUNCTION

'==========================================================
FUNCTION WndProc (BYVAL hWnd AS LONG, BYVAL wMsg AS LONG, _
                  BYVAL wParam AS LONG, BYVAL lParam AS LONG) AS LONG
    SELECT CASE wMsg
        CASE %WM_CREATE
            CreateControls hWnd
            FUNCTION = %NULL
            EXIT FUNCTION
        CASE %WM_RBUTTONUP
            ' This does not clear Treeview
            MSGBOX "About to call Treeview_DeleteAllItems"
            TreeView_DeleteAllItems g_ListInfo.hWndTreeview
            ' This does
            MSGBOX "About to call Treeview_DeleteItem"
            TreeView_DeleteItem g_ListInfo.hWndTreeview, %TVI_ROOT
        CASE %WM_DESTROY
            PostQuitMessage 0
            FUNCTION = %NULL
            EXIT FUNCTION
    END SELECT
    FUNCTION = DefWindowProc(hWnd, wMsg, wParam, lParam)
END FUNCTION

'==========================================================
FUNCTION CreateControls(BYVAL hWndParent AS LONG) AS INTEGER

    InitCommonControls
    g_ListInfo.hWndTreeview = TV_CreateTreeview(hWndParent, g_ListInfo.hInst)
    IF g_ListInfo.hWndTreeview = 0 THEN
        FUNCTION = %FALSE
        EXIT FUNCTION
    END IF
    FUNCTION = %TRUE
END FUNCTION

'==========================================================
FUNCTION TV_CreateTreeView ( hWndParent AS LONG, hInst AS LONG) AS LONG

    LOCAL hwndTree      AS LONG
    LOCAL rcl           AS RECT
    LOCAL iLeft         AS INTEGER
    LOCAL iTop          AS INTEGER
    LOCAL iWidth        AS INTEGER
    LOCAL iHeight       AS INTEGER

    GetClientRect hWndParent, BYVAL VARPTR(rcl)
    iLeft = 0
    iTop = 0
    iWidth = (rcl.nRight - rcl.nLeft)/4
    iHeight = rcl.nBottom - rcl.nTop
    hwndTree = CreateWindowEx(  %WS_EX_CLIENTEDGE, _
                                $WC_TREEVIEW , _
                                "",_
                                %WS_VISIBLE OR %WS_CHILD OR %WS_BORDER OR %TVS_HASLINES OR _
                                %TVS_HASBUTTONS OR %TVS_LINESATROOT , _
                                iLeft, iTop, iWidth, iHeight, _
                                hWndParent, _
                                %ID_TREEVIEW, _
                                hInst, _
                                BYVAL %NULL )
    CALL TV_InitTreeView(hInst, hwndTree)
    FUNCTION = hWndTree
END FUNCTION

'==========================================================
SUB TV_InitTreeView (hInst AS LONG, hWndTree AS LONG)

    LOCAL szText    AS ASCIIZ*%MAX_CATEGORY
    LOCAL hItem    AS DWORD
    LOCAL iIndex    AS INTEGER
    
    hTParent = %TVI_ROOT
    hTPrev = %TVI_SORT
    FOR iIndex = 0 TO 3
        szText = "Item " + STR$(iIndex + 1)
        hItem = TV_AddOneItem (BYVAL VARPTR(szText),BYVAL hwndTree, iIndex)
    NEXT

END SUB

'==========================================================
FUNCTION TV_AddOneItem( lpszText AS ASCIIZ PTR , BYVAL hwndTree AS LONG, index AS INTEGER) AS DWORD

    LOCAL hItem AS LONG
    LOCAL tvI AS TV_ITEM_UNION
    LOCAL tvIns AS TV_INSERTSTRUCT

    tvI.item.mask = %TVIF_CHILDREN OR %TVIF_HANDLE OR _
                      %TVIF_STATE OR %TVIF_TEXT
    tvI.item.pszText = lpszText
    tvIns.item = tvI
    tvIns.hInsertAfter = hTPrev
    tvIns.hParent = hTParent
    hItem = SendMessage(hwndTree, %TVM_INSERTITEM, 0, VARPTR(tvIns))
    FUNCTION = hItem
END FUNCTION

[Lance Edmonds]

Lasse, you must have something else wrong... there is no operational difference between the two functions.

Things can be confusing (for the programmer) when it comes to signed versus unsigned values, but as the bit pattern passed to the API is correct (in this case), the API executes correctly regardless of whether you pass &HFFFF0000??? or &HFFFF0000& to it.

The value of TVI_ROOT is correct too (according to my VC++ header files).

Post an compilable example fo the code that fails, and we'll see what we can spot.

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

I have to repeat this question, because I am really interested to learn to use all the aspects of PB/DLL and I'm seemingly having some teething problems. I hope I'm not offending anybody by repeating this question so soon. I have always got good answers from this forum, so I believe somebody can explain this to me, too.

In COMMCTRL.INC there is a define statement

%TVI_ROOT = &HFFFF0000???

I understand this so that TVI_ROOT is defined to be type DWORD (???).

So given two following macro definitions from COMMCTRL.INC, why does the first one work and the second one not?

FUNCTION TreeView_DeleteItem (BYVAL hWnd AS DWORD, BYVAL hitem AS DWORD) _
   AS LONG
    FUNCTION = SendMessage(hWnd, %TVM_DELETEITEM, 0, hitem)
END FUNCTION

FUNCTION TreeView_DeleteAllItems (BYVAL hWnd AS DWORD) AS LONG
    FUNCTION = SendMessage(hWnd, %TVM_DELETEITEM, 0, %TVI_ROOT)
END FUNCTION

To work means here that making a call

	TreeView_DeleteItem hWndTreeView, %TVI_ROOT

clears the Treeview and a call

	TreeView_DeleteAllItems hWndTreeView

does not.

Making the following modification makes macro TreeView_DeleteAllItems to do what I assume it to do.

FUNCTION TreeView_DeleteAllItems (BYVAL hWnd AS DWORD) AS LONG
    LOCAL dwItem AS DWORD
    dwItem = %TVI_ROOT
    FUNCTION = SendMessage(hWnd, %TVM_DELETEITEM, 0, dwItem)
END FUNCTION

Why?

1. Am I assuming here something which is not true?

2. Is there something wrong with typing of numeric constants in PB/DLL version 6.0 (and Win98)?

I really hope someone could comment on this.

TIA
Lasse Rantanen
[email protected]