How to calculate text in pixels or dialog units in advance?

[Alexander Holzer]

Hello,
I want for definition of the size of the message to calculate text in pixels or dialog units before make the dialog/message.
How does it work? :shhh:

For example:

variable
txt$ = "the text string ..." will be in font "Tahoma", 9, normal

How is the text width in pixels or dialog units?

Thanks

[Kev Peel]

Use the API functions GetExtentPoint32 and GetDialogBaseUnits

Example:

' [You must create a device context (hDC) first and select your required font]
Local szl as SIZEL
GetExtentPoint32 hDC, "test", 4, szl
dialogunitX = (szl.cx * 4) / LOWRD(GetDialogBaseUnits)
dialogunitY = (szl.cy * 8) / HIWRD(GetDialogBaseUnits)

[Alexander Holzer]

I need text size before make the dialog/message !!!

[Kev Peel]

GetDC(%HWND_DESKTOP)

[Alexander Holzer]

How to be with FONT changing?

one "Tahoma", 9 , 0
In other case "Courier", 10, 1

Thanks

[John Petty]

Pardon poor understanding of your request but Windows need to know where you are putting the text before calculating the sizes, then all information about the font is given with GetTextMetrics

[John Petty]

Kev
Seems to be an interesting omission from PB that it provides standard Text Size functions for printers (XPrint) and Graphics but not Dialogs or Controls
John

[Tonny Bjorn]

Maybe?

Something to work from?

FUNCTION GetTextWidthInPixels(BYVAL hWnd AS LONG, BYVAL txt AS STRING) AS LONG
  LOCAL hDc AS LONG, hFont AS LONG, lpSize AS SIZEL
  hDc = GetDc(hWnd)                               'get handle for proper device context
    hFont = SendMessage(hWnd, %WM_GETFONT, 0, 0)  'must select hWnd's font into DC,
    hFont = SelectObject(hDC, hFont)              'otherwise System font is used..
    CALL GetTextExtentPoint32(hDc, BYVAL STRPTR(txt), LEN(txt), lpSize)
    SelectObject hDC, hFont                       'select original font back
  ReleaseDC hWnd, hDc                             'and release DC
  'FUNCTION = lpSize.cy                           '<- for textheight..
  FUNCTION = lpSize.cx                            '<- function returns the textwidth
END FUNCTION

[Egbert Zijlema]

Be sure it will fit: set pixel mode prior to call

SUB GetTextDimensions(BYVAL hWnd AS DWORD, BYVAL sText AS STRING, cx AS LONG, cy AS LONG)
  LOCAL hDC AS DWORD, hFnt AS DWORD, hOldFt AS DWORD
  LOCAL siz AS SIZEL

  sText = sText & "W"                            '  extra width to be sure text will fit
  hDC = GetDC(hWnd)
  hFnt   = SendMessage (hWnd, %WM_GETFONT, 0, 0)
  hOldFt = SelectObject(hDC, hFnt)
  IF SetMapMode (hDC, %MM_TEXT) THEN                   '  set pixelmode
    GetTextExtentPoint32 hDC, BYVAL STRPTR(sText), LEN(sText), siz
  END IF
  SelectObject hDC, hOldFt
  ReleaseDC hWnd, hDC
  cx = siz.cx
  cy = siz.cy
END SUB

[Alexander Holzer]

Thanks Tonny and Egbert,
but it is necessary to correct code..., I make so:

...
lResult = SendMessage (GetDlgItem(hDlg, %IDC_LABEL_TEXT), %WM_GETFONT, 0, 0) 
...

then all works

and

DIALOG PIXELS hDlg, sz.cx, sz.cy TO UNITS xx, yy

[Egbert Zijlema]

...
lResult = SendMessage (GetDlgItem(hDlg, %IDC_LABEL_TEXT), %WM_GETFONT, 0, 0) 
...

OK, no problem if you do it this way!
It works because you want the size of a control. In my (humble) opinion, though, it's more straight to retrieve the control's handle before calling the function. Like this:

hCtrl =  GetDlgItem(hDlg, %IDC_LABEL_TEXT)
GetTextDimensions hCtrl, sText, cx, cy

' In case you prefer DDT to retrieve the handle, you may replace 
' GetDlgItem() with: 
CONTROL HANDLE hDlg, %IDC_LABEL_TEXT TO hCtrl

[Michael Mattias]

Seems to be an interesting omission from PB that it provides standard Text Size functions for printers (XPrint) and Graphics but not Dialogs or Controls

So send in a New Feature Suggestion to [email protected]

Or, you could pray and hope your request is forwarded to Florida with a recommendation..

[John Petty]

Thanks Michael, I do that on improvements that are important to me. this was just interesting, don't want to distract them from more important improvements

[Egbert Zijlema]

Sample Code

Here follows a sample of how to calculate control sizes in advance.
Also try this without adding the extra "W" to the text (see: SUB GetTextDimensions) and see what happens.

#COMPILE EXE
#DIM ALL

%IDC_LABEL = 1001

#INCLUDE "WIN32API.INC"
  
SUB CenterMainDialog(BYVAL hDlg AS DWORD)
     ' centers a dialog on the desktop
  LOCAL xScr AS LONG, yScr AS LONG, xDlg AS LONG, yDlg AS LONG
  xScr = GetSystemMetrics(%SM_CXSCREEN)
  yScr = GetSystemMetrics(%SM_CYSCREEN)
  DIALOG GET SIZE hDlg TO xDlg, yDlg
  DIALOG SET LOC hDlg, (xScr - xDlg) / 2, (yScr - yDlg) / 2
END SUB

SUB GetTextDimensions(BYVAL hWnd AS DWORD, BYVAL sText AS STRING, cx AS LONG, cy AS LONG)
  LOCAL hDC AS DWORD, hFnt AS DWORD, hOldFt AS DWORD
  LOCAL siz AS SIZEL

  sText = sText & "W"
  hDC = GetDC(hWnd)
  hFnt   = SendMessage (hWnd, %WM_GETFONT, 0, 0)
  hOldFt = SelectObject(hDC, hFnt)
  IF SetMapMode (hDC, %MM_TEXT) THEN
    GetTextExtentPoint32 hDC, BYVAL STRPTR(sText), LEN(sText), siz
  END IF
  SelectObject hDC, hOldFt
  ReleaseDC hWnd, hDC
  cx = siz.cx
  cy = siz.cy
END SUB

FUNCTION MakeFont(fWeight AS LONG, fItalic AS BYTE, fUnderline AS BYTE, fStrikeOut AS BYTE, _
                                                  fFaceName AS STRING, fPtSize AS SINGLE) AS DWORD
  LOCAL lf  AS LOGFONT
  LOCAL hDC AS DWORD
  hDC = GetDC(%HWND_DESKTOP)
  lf.lfFaceName = fFaceName & CHR$(0)
  lf.lfWeight = fWeight
  lf.lfUnderline = fUnderline
  lf.lfItalic = fItalic
  lf.lfStrikeOut = fStrikeOut
  lf.lfHeight = -(fPtSize * GetDeviceCaps(hDC, %LOGPIXELSY)) \ 72
  FUNCTION = CreateFontIndirect(lf)
  ReleaseDC 0, hDC
END FUNCTION

CALLBACK FUNCTION MainDlgProc()
  STATIC hFnt AS DWORD
  LOCAL hCtrl AS DWORD
  
  SELECT CASE AS LONG CBMSG
    CASE %WM_INITDIALOG
      LOCAL sText AS STRING
      LOCAL xLbl AS LONG, yLbl AS LONG
      LOCAL xDlg AS LONG, yDlg AS LONG
      
      sText = " This is a test"
      
      ' initially set a font for the label:
      hFnt = MakeFont(%FW_BOLD, 0, 0, 0, "Arial", 14)
      CONTROL SEND CBHNDL, %IDC_LABEL, %WM_SETFONT, hFnt, 0
      
      ' now the font is set, calculate the control's dimensions 
      CONTROL HANDLE CBHNDL, %IDC_LABEL TO hCtrl
      GetTextDimensions hCtrl, sText, xLbl, yLbl
      CONTROL SET SIZE CBHNDL, %IDC_LABEL, xLbl, yLbl * 3   ' height = 3 lines
      CONTROL SET TEXT CBHNDL, %IDC_LABEL, $CRLF & sText
      CONTROL SET LOC CBHNDL, %IDC_LABEL, 10, 10            ' margins 10 pixels
      
      ' now the size of the control is known, calculate and set the dialog's size
      xDlg = xLbl + _                                       ' width of control
             (2 * 10) + _                                   ' left and right margin
             (GetSystemMetrics(%SM_CXDLGFRAME) * 2)         ' left and right frame
      yDlg = (3 * yLbl) + _
             (2 * 10) + _
             (GetSystemMetrics(%SM_CYDLGFRAME) * 2) + _
             GetSystemMetrics(%SM_CYCAPTION)
      DIALOG SET SIZE CBHNDL, xDlg, yDlg
      
      ' finally center the dialog
      CenterMainDialog CBHNDL
    
    CASE %WM_DESTROY
      DeleteObject hFnt                                     ' delete the font on exit
    
  END SELECT
END FUNCTION

FUNCTION PBMain () AS LONG
  LOCAL hDlg AS DWORD
  DIALOG NEW PIXELS, %HWND_DESKTOP, " Testing text dimensions...", , , 0, 0, _
                                    %WS_CAPTION OR %WS_MINIMIZEBOX OR %WS_SYSMENU TO hDlg
  ' ad a static control, unknown size and location, with a sunken border to see how the text fits in
  CONTROL ADD LABEL, hDlg, %IDC_LABEL, "", 0, 0, 0, 0, %SS_SUNKEN
  CONTROL SET COLOR hDlg, %IDC_LABEL, %BLUE, %WHITE
  DIALOG SHOW MODAL hDlg, CALL MainDlgProc
END FUNCTION

[BOB MECHLER]

Interesting code Egbert.

I had asked in an earlier post about fractional fonts and your code showed me an example of how to do it. I'd always assumed they had to be integer because of sample code I've been using for a long time.

Pays to read every post, never know when you'll pick up good code. Thanks!

Bob Mechler

[Alexander Holzer]

I make this:

#COMPILE EXE

#INCLUDE "Win32Api.Inc"
#INCLUDE "PBForms.INC"

%IDC_LABEL_TEXT = 1000

FUNCTION PBMAIN()

  LOCAL hDlg, hDC     AS DWORD
  LOCAL Txt           AS STRING
  LOCAL sz            AS SIZEL
  LOCAL hFont         AS DWORD
  LOCAL x1,y1,xx1,yy1 AS LONG
  LOCAL dialogunitY   AS LONG
  LOCAL xx,yy         AS LONG
  LOCAL lResult       AS LONG
  LOCAL Rct           AS RECT

SystemParametersInfo %SPI_GETWORKAREA, 0, BYVAL VARPTR(Rct), 0

Txt   = "That is not long text"

hFont = PBFormsMakeFont("Tahoma", 9, 400, %FALSE, %FALSE, %FALSE, %ANSI_CHARSET) ' from PBForms, otherwise - CreateFont()
x1 = 20  ' offset x in pixel
y1 = 15  ' offset y in pixel
IF LEN(Txt) < 30 THEN x1 = 50 - LEN(Txt) 'if text is too short

DIALOG NEW 0, "TEST",,, 1, 1, %WS_SYSMENU, TO hDlg
CONTROL ADD LABEL, hDlg, %IDC_LABEL_TEXT, Txt,  0, 0, 0, 0
CONTROL SEND hDlg, %IDC_LABEL_TEXT, %WM_SETFONT, hFont, 0

  hDc = GetDc (hDlg)
  lResult = SendMessage (GetDlgItem(hDlg, %IDC_LABEL_TEXT), %WM_GETFONT, 0, 0)
  lResult = SelectObject(hDc, lResult)
  GetTextExtentPoint32 hDc, BYVAL STRPTR(Txt), LEN(Txt), sz
  lResult = SelectObject(hDc, lResult)
  ReleaseDC hDlg, hDc

DIALOG PIXELS hDlg, sz.cx, sz.cy TO UNITS xx, yy
DIALOG PIXELS hDlg, x1, y1 TO UNITS xx1, yy1

CONTROL SET SIZE  hDlg, %IDC_LABEL_TEXT, xx, yy
CONTROL SET COLOR hDlg, %IDC_LABEL_TEXT, RGB(10,20,120), RGB(230,230,230)
DIALOG SET COLOR hDlg, -1, RGB(230,230,230)
CONTROL SET LOC hDlg, %IDC_LABEL_TEXT, xx1, yy1

DIALOG  SET SIZE hDlg, xx + 2*xx1 + 4, yy + 2*yy1 + 20' x/y offsets, 4 - widh 2 x border lines, 20 - caption (?)

DIALOG PIXELS hDlg, Rct.nLeft,  Rct.nTop    TO UNITS Rct.nLeft,  Rct.nTop
DIALOG PIXELS hDlg, Rct.nRight, Rct.nBottom TO UNITS Rct.nRight, Rct.nBottom
DIALOG SET LOC hDlg, (Rct.nRight - Rct.nLeft - (xx + 2*xx1)) / 2, (Rct.nBottom - Rct.nTop - (yy + 2*yy1 + 20))/2

DIALOG SHOW MODAL hDlg

END FUNCTION

I always look for a short way of the decision and a small code.

All helped - many thanks.

[Alexander Holzer]

OK, no problem if you do it this way!
It works because you want the size of a control. In my (humble) opinion, though, it's more straight to retrieve the control's handle before calling the function. Like this:

hCtrl =  GetDlgItem(hDlg, %IDC_LABEL_TEXT)
GetTextDimensions hCtrl, sText, cx, cy

' In case you prefer DDT to retrieve the handle, you may replace 
' GetDlgItem() with: 
CONTROL HANDLE hDlg, %IDC_LABEL_TEXT TO hCtrl

GetTextDimensions - ?
What is the function?

[Egbert Zijlema]

Alexander asks: what is the function?

GetTextDimensions is a function written by myself. That's all.

[Alexander Holzer]

I apologize,
Nonsense has asked..

[Egbert Zijlema]

Extra W does not really satisfy

Although I'm using the here presented code (see previous page) for a couple of years now, I'm not really satisfied with the fact that I need to insert an extra character "W" in order to get a sufficient cx-value (= width) in return. If you omit that extra "W" a control in many cases will not be wide enough to accommodate the text string. In my opinion GetTextExtentPoint32 should return correct values, provided we use it correctly, but without the necessity to pass a "dirty trick". So what am I (are we) doing wrong here? :headache: