Textbox events?

[hal9k]

Here's another dumb question.  I have a window with 91 Textboxes that the user can change.  A Save button and a Cancel button determine whether I update my data file with the new values or just quit the program.

It would be great if there was a way for me to know WHICH Textboxes were changed.  I can't find a way to do that.  Does anybody have a way around this?

Failing that, I have another question.  I don't know how LB buffers Put commands.  Is it better to do 91 If commands with 1 or 2 of them triggering a Put statement or is it better to just do the 91 Put statements regardless of whether the Textboxes have changed?

Thanks yet again!

[Rod]

As you are learning once you expose your system to users anything that can go wrong will. I would go for the 91 put statements but with some validation on the contents. The traditional way is to trap the contents on opening to an array and to use that array against the closing contents to know if a change has been made. Validation is the key for me. Free text would be a nightmare, list box choice of a restricted text set is by far the safest.

[hal9k]

That's pretty much what I'm coding. I'm expecting numbers. If the new contents are not numeric or wildly out of range I'm resetting it to the original value. I assumed the Puts are buffered such that there's probably only a single disk write rather than 91 of them.

Thanks.

[Rod]

Windows OS takes care of the put statement. All file activity is buffered to ram for speed. But Windows makes a pretty good job of this buffering. It never gets out of sync.

[Walt Decker]

Here's another dumb question. I have a window with 91 Textboxes that the user can change. A Save button and a Cancel button determine whether I update my data file with the new values or just quit the program.

Mr. Pryor, there is a way; however, with a textbox you will have to use an API call to do it. To find if the edit control has changed use:

EM.GETMODIFY = HEXDEC("&H00B8")
Determine whether the content of an edit control has been modified.

wParam = 0 <--- not used; must be zero
lParam = 0 <--- not used; must be zero

RETURN: If the content of edit control has been modified, the return value is TRUE; otherwise, it is FALSE.

NOTES: Windows maintains an internal flag indicating whether the content of the edit control has been changed. This flag is cleared when the edit control is first created; alternatively, an application can send an EM.SETMODIFY message to the edit control to clear the flag.

CALLDLL #user32, "SendMessageA", EdtHndl AS ULONG, EM.GETMODIFY AS ULONG, 0 AS LONG, 0 AS LONG, Modifyed AS LONG

Failing that, I have another question. I don't know how LB buffers Put commands. Is it better to do 91 If commands with 1 or 2 of them triggering a Put statement or is it better to just do the 91 Put statements regardless of whether the Textboxes have changed?

Normally, the output is buffered, therefore writing 91 "PUTS" will write the data at one shot. However, depending of the programming system and whether you use API code to output and/or input data, than may not always be the case.

[hal9k]

Thanks Mr. Decker. Using the API call it looks like I would still need to do 91 IF statements to test all the Textboxes. So, I think I'll just plow ahead with the 91 Puts. It's in a loop, so it's just a couple of lines of code.

Thanks again!

[Walt Decker]

Thanks Mr. Decker. Using the API call it looks like I would still need to do 91 IF statements to test all the Textboxes. So, I think I'll just plow ahead with the 91 Puts. It's in a loop, so it's just a couple of lines of code.

No. Only one if:

Ctl$ = "mywin.txb"
Holder$ = ""
DIM CtlHndls(90)
Elm = -1
FOR I = 1 TO 91
 Elm = Elm + 1
 Holder$ = Ctl$ + STR$(I)
 CtlHndls(Elm) = HWND(#Holder$)
NEXT I

'<======== OTHER CODE =========>

SUB BUTTON.CLICK BtnHndl$

EM.GETMODIFY = HEXDEC("&H00B8")
FOR I = 0 TO 90
 EdtHndl = CtlHndls(I)
 CALLDLL #user32, "SendMessageA", EdtHndl AS ULONG, EM.GETMODIFIED AS ULONG, _
                  0 AS LONG, 0 AS LONG, Modified AS LONG
 IF Modified THEN
   '<==== Do Something =====>
 END IF
NEXT I
END SUB


[hal9k]

Very nice. Thanks!

[Walt Decker]

Mr. Pryor, here is something in which you may be interested:
'
Mask = HEXDEC("&H8000")     '<--- Mask value for GetAsyncKeyState()

VK.RETURN  = HEXDEC("&H0D") '<--- virtual key codes of interest
VK.TAB     = HEXDEC("&H09")

ES.WANTRETURN  = HEXDEC("&H1000") '<--- edit control styles
ES.MULTILINE   = HEXDEC("&H0004")
ES.NOHIDESEL   = HEXDEC("&H0100")

[DEF.GLOBALS]
GLOBAL EM.GETMODIFY, _  '<--- edit control messages
      EM.SETMODIFY

GLOBAL Ubnd             '<--- # of elements in TxbHndls$()

DIM TxbHndls$(2, 2)

[INIT.GLOBALS]
EM.GETMODIFY = HEXDEC("&H00B8")
EM.SETMODIFY = HEXDEC("&H00B9")

Ubnd = 2

OPEN "User32.dll" FOR DLL AS #USER  '<--- could use #user32 instead

[DEF.CONTROLS]  '<--- set edit control style
'###########################################################################
'  If the TIMER AND THE [CHECK.ENTER] block is not used do not change
'  the edit control style.
'###########################################################################

STYLEBITS #DMO.TXB0, ES.MULTILINE OR ES.WANTRETURN OR ES.NOHIDESEL, 0, 0, 0
STYLEBITS #DMO.TXB1, ES.MULTILINE OR ES.WANTRETURN OR ES.NOHIDESEL, 0, 0, 0
STYLEBITS #DMO.TXB2, ES.MULTILINE OR ES.WANTRETURN OR ES.NOHIDESEL, 0, 0, 0
TEXTBOX #DMO.TXB0, 5, 5, 100, 25
TEXTBOX #DMO.TXB1, 110, 5, 100, 25
TEXTBOX #DMO.TXB2, 215, 5, 100, 25

BUTTON #DMO.APPLY, "APPLY", BTN.APPLY, UL, 120, 35, 60, 25

WindowWidth = 335
OPEN "TEXTBOX DEMO" FOR WINDOW AS #DMO

'<------- save the edit control handles and names for later use ------->
Ctl$ = "#DMO.TXB"
Tmp$ = ""

FOR I = 0 TO 2
 Tmp$ = Ctl$ + STR$(I)
 TxbHndls$(I, 0) = STR$(HWND(#Tmp$))
 TxbHndls$(I, 1) = Tmp$
NEXT I

PRINT #DMO.TXB0, "!SETFOCUS"
PRINT #DMO, "TRAPCLOSE END.DMO"

CurFocus = 0 '<--- set the current element of TxbHndls$()

[BEGIN.WAIT]
TIMER 150, [CHECK.ENTER] '<--- set up timer event
WAIT

[CHECK.ENTER]
TIMER 0

ReturnKey = 0 '<--- virtual key of interest

HasFocus = 0 '<--- edit control with focus
RetVal   = 0 '<--- return value from function calls

Tmp$ = ""    '<--- temporary string

CtlHndl = VAL(TxbHndls$(CurFocus, 0)) '<--- handle of edit control

'#############################################
'  The GetAsyncKeyState() function returns the state of the
'  virtual key of interest since the LAST TIME THE FUNCTION
'  WAS CALLED.  You should always mask out the return value
'  instead of just quering whether the return value is true of
'  or fales.
'#############################################

CALLDLL #USER, "GetAsyncKeyState", VK.RETURN AS LONG, ReturnKey AS SHORT
ReturnKey = ReturnKey AND Mask
CALLDLL #USER, "GetFocus", HasFocus AS ULONG

IF HasFocus <> CtlHndl THEN
 RetVal = FN.FindFocus(HasFocus, Ubnd, 0) '<--- which contol has the focus

 IF RetVal < 0 THEN GOTO [BEGIN.WAIT] '<--- something other than an edit
                                      'has the focus

 CurFocus = RetVal '<--- set the element of TxbHndls$()
END IF

IF ReturnKey THEN '<--- ENTER key was pressed
 CurFocus = CurFocus + 1 '<--- set the element of TxbHndls$()
 IF CurFocus > Ubnd THEN CurFocus = 0

 Tmp$ = TxbHndls$(CurFocus, 1)
 PRINT #Tmp$, "!SETFOCUS"     '<--- set the focus
END IF
GOTO [BEGIN.WAIT]
[END.CHECK.ENTER]

'--------------------------------------
'--------------------------------------

SUB BTN.APPLY BtnHndl$

Modified = 0
CtlHndl  = 0

'<--- parse the TxbHndls$() array and obtain the change --->
'<--- state of each edit control ---->
FOR I = 0 TO Ubnd
 CtlHndl = VAL(TxbHndls$(I, 0))
 CALLDLL #USER, "SendMessageA", CtlHndl AS ULONG, EM.GETMODIFY AS ULONG, _
                 0 AS LONG, 0 AS LONG, Modified AS LONG
 IF Modified THEN
   TxbHndls$(I, 2) = "M" '<--- perhaps do something else here
 END IF
NEXT I

CALL END.DMO "#DMO"
END SUB

'--------------------------------------
'--------------------------------------

SUB END.DMO  DmoHndl$

FOR I = 0 TO Ubnd
 PRINT TxbHndls$(I, 1); " ";TxbHndls$(I, 2)
NEXT I

CLOSE #USER
CLOSE #DmoHndl$
END

END SUB

'----------------------------------
'----------------------------------

FUNCTION FN.FindFocus(Focus, Ubnd, Elm)

Found = 0
FOR I = 0 TO Ubnd
 IF Focus = VAL(TxbHndls$(I, Elm)) THEN
   Found = I
   EXIT FOR
 END IF
NEXT I

IF Found THEN
 FN.FindFocus = Found
 EXIT FUNCTION
END IF

FN.FindFocus = -1

END FUNCTION
'[code]



[hal9k]

Thanks again. Sadly the project was cancelled, but I'll keep this code in mind as I may need it for a future project.

[Brandon Parker]

Also, you can also add the _ES_NUMBER StyleBit to a TextBox to allow only numbers to be typed into the TextBox. This would prevent the use of negative numbers as well as the decimal character. Also, note that this StyleBit does not prevent pasting other characters into the TextBox.

You could, using something like WMLiberty.dll, trap the WM_CHAR message and allow whatever you wanted through.

Just some things to think about for future projects...



{:0)

Brandon Parker