Physical Length of Text in RichEdit Control

[Gary Beene]

I would like to know how long a string would be if it were displayed in a richedit control - not how many characters, but physical width.

I'm trying to create a text string of length X, rather than measure a string that already exists in the control. Font selection needs to be taken into account.

I can get text physical size using XPrint and Graphic commands, but I'm not finding an equivalent one for a richedit control. I can attach a printer and use XPrint commands, or create a hidden graphic control and attach to it. Their length information can applied to text in a richedit control, but I wanted to avoid both alternatives - just use code specific to a richedit control (or any generic control that displays text).

For my purposes, the text would be on a single line (no multi-line issues).

[Edwin Knoppert]

paint the re to a very width emf and when done explore the objects by enumming.

[Edwin Knoppert]

Oh btw, you can measure the h-scrollbars range.

[Michael Mattias]

Call GetTextExtentPoint32 using hDC and text string. That will give you width and height in pixels.

Divide Length in pixels by GetDeviceCaps (hDC, HORZRES) and that gives you logical inches.

Soemthing like that, anyway.

MCM

[Dominic Mitchell]

GetTextExtentPoint32 is not of any use when dealing with rich edit text.
You will need to use COM for this if you do not want to create a window.
Do a search on windowless rich edit controls, the CreateTextServices function
and the ITextServices interface.

[Gary Beene]

MCM,
I did a search on GetTextExtentPoint32 and found a variety of versions. I built this function based on what I read. It seems to work.

Function GetTextWidth(buf$, hWnd as Dword) as Single
      Local hDC as Dword, R as SizeL
      hDC = GetDC(hWnd)
      hFont = SendMessage (hWnd, %WM_GETFONT, 0, 0)
      SelectObject hDc, hFont
      GetTextExtentPoint32 (hDc, ByVal StrPTR(buf$), Len(buf$), R)
      Function = R.cx/GetDeviceCaps(hdc, %LOGPIXELSX)
      ReleaseDC hWnd, hDC
End Function

The compilable version is below.

Dominic, your statement suggests there's a problem with using GetTextExtentPoint32 with a richedit control. In my situation, I have a richedit control but wanted to build text of a certain size before putting it in the control. Also, I'm working with the RE plain text, not the RE RTF text - perhaps that was your concern?

In this example I load text into the RE control so I can physically measure it with a ruler. But the text that I use to calculate the answer is simply programmatically assigned.

'Compilable Example:
#Compile Exe
#Dim All
#Include "Win32API.inc"
#Include "RichEdit.inc"
#Include "CommCtrl.inc"
Global hDlg as Dword, hRichEdit as Dword, hFont as Dword
%ID_RichEdit = 500
Function PBMain() As Long
   Local style&, buf$
   buf$ =  "This" + $Tab + "text" + $Tab + "rocks!" + $crlf + String$(6,"x") +$crlf + String$(12,"x")
   style& = %WS_Child Or %WS_Visible Or %ES_MultiLine Or %WS_VScroll Or %ES_AutoHScroll _
             Or %WS_HScroll Or %ES_AutoVScroll Or %ES_WantReturn Or %ES_NoHideSel Or %WS_TabStop
   Dialog New Pixels, 0, "Test Code",300,300,200,150, %WS_OverlappedWindow To hDlg
   Control Add Button, hDlg, 100,"Push", 30,10,140,20
   LoadLibrary("riched32.dll") : InitCommonControls
   Control Add "RichEdit", hDlg, %ID_RichEdit, buf$,20,40,160,100, style&, %WS_EX_ClientEdge
   Control Handle hDlg, %ID_RichEdit To hRichEdit
   Font New "Comic Sans MS", 10,1 To hFont
   Control Set Font hDlg, %ID_RichEdit, hFont
   Dialog Show Modal hDlg Call DlgProc
End Function

CallBack Function DlgProc() As Long
   If CB.Msg = %WM_Command AND CB.Ctl = 100 AND CB.Ctlmsg = %BN_Clicked Then
      Local buf$
      buf$ = String$(6,"x")
      MsgBox Str$( GetTextWidth(buf$, hRichEdit) )
      buf$ = String$(12,"x")
      MsgBox Str$( GetTextWidth(buf$, hRichEdit) )
   End If
End Function

Function GetTextWidth(buf$, hWnd as Dword) as Single
      Local hDC as Dword, R as SizeL
      hDC = GetDC(hWnd)
      hFont = SendMessage (hWnd, %WM_GETFONT, 0, 0)
      SelectObject hDc, hFont
      GetTextExtentPoint32 (hDc, ByVal StrPTR(buf$), Len(buf$), R)
      Function = R.cx/GetDeviceCaps(hdc, %LOGPIXELSX)
      ReleaseDC hWnd, hDC
End Function

[Dominic Mitchell]

GetTextExtentPoint32 as you used it will work if the text does not contain a mixture of
fonts, has no kerning, tabs, or overhang.
Compare the values returned by your GetTextWidth function for the first and third lines
of text in your sample.

Some of the other functions you might wish to consider are GetTabbedTextExtent and
DrawTextEx(with the DT_CALCRECT and DT_EXPANDTABS flags).

Also, restore the device context to its original state.

      hFontOld = SelectObject(hDc, hFont)
      ...
      SelectObject hDc, hFontOld

[Gary Beene]

Dominic,

Thanks for the clarifying comments and information.

In the following code, I reposition tab'd text using GetTextExtentPoint32 and can visually see that the text shifts slightly (from its original tab'd position) when my code is used. There shouldn't be any shift.

I'll write an equivalent code using DrawTextEx and post the results here later.

#Compile Exe
#Dim All
#Include "Win32API.inc"
#Include "RichEdit.inc"
#Include "CommCtrl.inc"
Global hDlg As Dword, hRichEdit As Dword, TabLoc() As Single, hFont As Dword, hDC As Dword
%ID_RichEdit = 500
Function PBMain() As Long
   Local style&, buf$
   buf$ = "This is" + $Tab + $Tab + "an example" + $Tab + "of a string with an embedded tab character."
   buf$ = buf$ + $CrLf + "2This is" + $Tab + "2an example" + $Tab + "2of a string with an embedded tab character."
   style& = %WS_Child Or %WS_Visible Or %ES_MultiLine Or %WS_VScroll Or %ES_AutoHScroll _
             Or %WS_HScroll Or %ES_AutoVScroll Or %ES_WantReturn Or %ES_NoHideSel Or %WS_TabStop
   Dialog New Pixels, 0, "Test Code",300,300,550,150, %WS_OverlappedWindow To hDlg
   Control Add Button, hDlg, 100,"Print", 30,10,140,20
   LoadLibrary("riched32.dll") : InitCommonControls
   Control Add "RichEdit", hDlg, %ID_RichEdit, buf$,20,40,510,100, style&, %WS_Ex_ClientEdge
      Control Handle hDlg, %ID_RichEdit To hRichEdit
      Font New "Comic Sans MS", 10, 0 To hFont
      Control Set Font hDlg, %ID_RichEdit, hFont
      hDC = GetDC(hRichEdit)
      hFont = SendMessage (hRichEdit, %WM_GETFONT, 0, 0)
      SelectObject hDc, hFont
   Dialog Show Modal hDlg Call DlgProc
      ReleaseDC hRichEdit, hDC
End Function

CallBack Function DlgProc() As Long
   If Cb.Msg = %WM_Command And Cb.Ctl = 100 And Cb.CtlMsg = %BN_Clicked Then
      Local temp$, w As Single, h As Single, i As Long
      ReDim TabLoc(50)  'tab locations
      For i = 0 To 50 : TAbLoc(i) = i * 0.5 : Next i   '0.5" tab locations
      Control Get Text hDlg, %ID_RichEdit To temp$
      temp$ = ConvertTABtoSpace (temp$)    'converted TABs to spaces
      Control Set Text hDlg, %ID_RichEdit, temp$
   End If
End Function

Function ConvertTABtoSpace(ByVal text$) As String
   'build string with variable # of spaces to reach TAB stops
   Local i As Long, j As Long, temp$, iSpaces&, iSpaceWidth!, result$, tempWidth!, ncWidth!, ncHeight!
   Dim D(ParseCount(text$,$CrLf)-1) As String, iTab&, R As SizeL

   'split text into lines, put in array D()
   Parse text$, D(), $CrLf

   'get/save width of space for current font
   temp$ = " "
   GetTextExtentPoint32 (hDc, ByVal StrPtr(temp$), Len(temp$), R)
   iSpaceWidth! = R.cx/GetDeviceCaps(hdc, %LOGPIXELSX)

   'build replacement string, substituting tabs with variable # of spaces (to reach tab locations)
   For j = 0 To UBound(D)
      temp$ = ""
      For i = 1 To ParseCount(D(j), $Tab)
         temp$ = temp$ + Parse$(D(j),$Tab, i)
         GetTextExtentPoint32 (hDc, ByVal StrPtr(temp$), Len(temp$), R)
         tempWidth! = R.cx/GetDeviceCaps(hdc, %LOGPIXELSX)
         iTab& = Fix(tempWidth!/0.5)+1              'next tab location after current endpoint
         iSpaces& = (TabLoc(iTab&)-tempWidth!) / iSpaceWidth!   '#spaces to widen to next tab location
         temp$ = temp$ + Space$(iSpaces&)
           'add extra single space as needed to ensure current tab position is crossed
            GetTextExtentPoint32 (hDc, ByVal StrPtr(temp$), Len(temp$), R)
            tempWidth! = R.cx/GetDeviceCaps(hdc, %LOGPIXELSX)
            If tempWidth! < TabLoc(iTab&) Then temp$ = temp$ + " "
      Next i
      result$ = result$ + $CrLf + temp$
   Next J
   Function = Mid$(result$,3)
End Function

[Gary Beene]

Well now, this is interesting.

I updated the code to use DrawTextEx and it, too, causes a shift (to the left) in the position of tab'd text. It looks to be about the same shift as I saw with GetTextExtentPoint32.

Perhaps there are some left edge values (borders?) that I am not taking correctly into account? I'll have to look further.

'Compilable Example:
'In this example, the Function above is broken apart so that some
'items do not have to be recalculated.
#Compile Exe
#Dim All
#Include "Win32API.inc"
#Include "RichEdit.inc"
#Include "CommCtrl.inc"
Global hDlg As Dword, hRichEdit As Dword, TabLoc() As Single, hFont As Dword, hDC As Dword
%ID_RichEdit = 500
Function PBMain() As Long
   Local style&, buf$
   buf$ = "This is" + $Tab + $Tab + "an example" + $Tab + "of a string with an embedded tab character."
   buf$ = buf$ + $CrLf + "2This is" + $Tab + "2an example" + $Tab + "2of a string with an embedded tab character."
   style& = %WS_Child Or %WS_Visible Or %ES_MultiLine Or %WS_VScroll Or %ES_AutoHScroll _
             Or %WS_HScroll Or %ES_AutoVScroll Or %ES_WantReturn Or %ES_NoHideSel Or %WS_TabStop
   Dialog New Pixels, 0, "Test Code",300,300,550,150, %WS_OverlappedWindow To hDlg
   Control Add Button, hDlg, 100,"Print", 30,10,140,20
   LoadLibrary("riched32.dll") : InitCommonControls
   Control Add "RichEdit", hDlg, %ID_RichEdit, buf$,20,40,510,100, style&, %WS_Ex_ClientEdge
      Control Handle hDlg, %ID_RichEdit To hRichEdit
      Font New "Comic Sans MS", 10, 0 To hFont
      Control Set Font hDlg, %ID_RichEdit, hFont
      hDC = GetDC(hRichEdit)
      hFont = SendMessage (hRichEdit, %WM_GETFONT, 0, 0)
      SelectObject hDc, hFont
   Dialog Show Modal hDlg Call DlgProc
      ReleaseDC hRichEdit, hDC
End Function

CallBack Function DlgProc() As Long
   If Cb.Msg = %WM_Command And Cb.Ctl = 100 And Cb.CtlMsg = %BN_Clicked Then
      Local temp$, w As Single, h As Single, i As Long
      ReDim TabLoc(50)  'tab locations
      For i = 0 To 50 : TAbLoc(i) = i * 0.5 : Next i   '0.5" tab locations
      Control Get Text hDlg, %ID_RichEdit To temp$
      temp$ = ConvertTABtoSpace (temp$)    'converted TABs to spaces
      Control Set Text hDlg, %ID_RichEdit, temp$
   End If
End Function

Function ConvertTABtoSpace(ByVal text$) As String
   'build string with variable # of spaces to reach TAB stops
   Local i As Long, j As Long, temp$, iSpaces&, iSpaceWidth!, result$, tempWidth!, ncWidth!, ncHeight!
   Dim D(ParseCount(text$,$CrLf)-1) As String, iTab&, R As Rect

   'split text into lines, put in array D()
   Parse text$, D(), $CrLf

   'get/save width of space for current font
   temp$ = " "
'   GetTextExtentPoint32 (hDc, ByVal StrPTR(temp$), Len(temp$), R)
   DrawTextEx hDC, ByVal StrPtr(temp$), Len(temp$), R, %DT_CalcRect, ByVal 0
   iSpaceWidth! = (R.nright - R.nleft)/GetDeviceCaps(hdc, %LOGPIXELSX)

   'build replacement string, substituting tabs with variable # of spaces (to reach tab locations)
   For j = 0 To UBound(D)
      temp$ = ""
      For i = 1 To ParseCount(D(j), $Tab)
         temp$ = temp$ + Parse$(D(j),$Tab, i)
'         GetTextExtentPoint32 (hDc, ByVal StrPTR(temp$), Len(temp$), R)
         DrawTextEx hDC, ByVal StrPtr(temp$), Len(temp$), R, %DT_CalcRect, ByVal 0
         tempWidth! = (R.nright - R.nleft)/GetDeviceCaps(hdc, %LOGPIXELSX)
         iTab& = Fix(tempWidth!/0.5)+1              'next tab location after current endpoint
         iSpaces& = (TabLoc(iTab&)-tempWidth!) / iSpaceWidth!   '#spaces to widen to next tab location
         temp$ = temp$ + Space$(iSpaces&)
           'add extra single space as needed to ensure current tab position is crossed
'            GetTextExtentPoint32 (hDc, ByVal StrPTR(temp$), Len(temp$), R)
            DrawTextEx hDC, ByVal StrPtr(temp$), Len(temp$), R, %DT_CalcRect, ByVal 0
            tempWidth! = (R.nright - R.nleft)/GetDeviceCaps(hdc, %LOGPIXELSX)
            If tempWidth! < TabLoc(iTab&) Then temp$ = temp$ + " "
      Next i
      result$ = result$ + $CrLf + temp$
   Next J
   Function = Mid$(result$,3)
End Function

[Michael Mattias]

If you want to print all your text with tabstops, why bother with a richedit control, or any edit control?

Just use a static control with SS_OWNERDRAW style and draw the text on the WM_OWNERDRAW notfication using any of the "Draw" functions you want.

If you need multiple lines with scrolling, take a look at a listbox control with LBS_OWNERDRAW{FIXED|VARIABLE} style and ditto. (There's a demo of this here somewhere).

Or, use a listview control in report mode, where subitems=columns ..... that will handle it, too. There's lots of demos of this here, including at least one where different columns are drawn in different colors. (and if it does different colors, it can do different fonts, too).

Basically I cannot reconcile in my mind the concept of using an edit or richedit control to accept tabbed or columnar user input. I think that's why "grid" controls are a popular offering.

MCM

[Gary Beene]

MCM,

If you want to print all your text with tabstops, why bother with a richedit control, or any edit control?

I don't (want to print all text with tabstops). The information I'm using has some content tab'd for alignment and some not.

As for needing the text length, there are lots of reasons why it might be needed. For example, the XPrint command does not handle tab characters, so if the original variable width font content has them I have to work around XPrint's limitations. Another example is converting content to HTML. Browsers don't handle tabs, so I have to work around it by converting to appropriate variable-width-font spaces (another utility I use converts the text to HTML).

Your comments about all-columnar data are appropriate, but that's the type of content I'm working with.

As for this broad stroke:

Basically I cannot reconcile in my mind the concept of using an edit or richedit control to accept tabbed or columnar user input.

What about a letter, where the address is placed in a tab position on the right side of the page? You'd want a user to space over to the position, instead of allowing the use of tabs?

[Michael Mattias]

I saw your XPRINT code in the source code forum and while I didn't run it, it looks nicely thought out (that means it's usable and easily adaptable).

First of all, if you are working with a printer, that's an OUTPUT device.... edit controls are INPUT devices.

Second, re your letter example

What about a letter, where the address is placed in a tab position on the right side of the page? You'd want a user to space over to the position, instead of allowing the use of tabs?

No, but I would force the user to put in the correct number of tabs or spaces. I give him separate controls for each field....

Return Address  [                       ]                 ' line one
                [                       ]                 ' line 2 
                [                       ]  [ ] [     ]   ' city, state zip

.. and tabs? If your screen is done correctly, the <TAB> key goes to the next field. Sounds pretty straightforward to me.

It's kind of like database design: you never design one field to hold multiple pieces of information; one field holds exactly one piece of information.

Bottom line for me is, input is not output, and one should use controls designed for input or controls designed for output as appropriate. Edit controls are input devices.


MCM

[Dominic Mitchell]

Your code does not mimic the behaviour of both the edit and rich edit controls.
A hint for what could be happening is provided by the documentation for the GetTabbedTextExtent
and TabbedTextOut functions and the EM_SETTABSTOPS message.

The docs for GetTabbedTextExtent and TabbedTextOut says the following:

If the nTabPositions parameter is zero and the lpnTabStopPositions parameter is NULL,
tabs are expanded to eight times the average character width.

The doc for EM_SETTABSTOPS says the same thing in a different way.

Specifies the number of tab stops contained in the array. If this parameter is zero, the lParam
parameter is ignored and default tab stops are set at every 32 dialog template units.

To calculate average character width, use the function below.
Do not use the tmAveCharWidth member of the TEXTMETRIC structure.

SUB phnxGetAverageCharDim _
  ( _
  BYVAL hFont   AS DWORD, _  ' handle of font
        cxChar  AS LONG, _   ' average character width of font
        cyChar  AS LONG _    ' height of characters in the font
  )

  LOCAL ttm            AS TEXTMETRIC
  LOCAL tsize          AS SIZEL
  LOCAL hDC            AS DWORD
  LOCAL hFontOld       AS DWORD
  LOCAL lMapModeOld    AS LONG

  ' Get the device context for the screen
  hDC         = GetDC(%NULL)
  lMapModeOld = SetMapMode(hDC, %MM_TEXT)
  hFontOld    = SelectObject(hDC, hFont)
  ' Average metrics for dialog font
  GetTextExtentPoint hDC,"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz", 52, tsize
  GetTextMetrics hDC, ttm
  ' This is the wacky formula used by Microsoft
  cxChar = (tsize.cx / 26)
  ' Round up the average character width
  cxChar = (cxChar + 1) / 2
  cyChar = ttm.tmHeight
  SelectObject hDC, hFontOld
  SetMapMode hDC, lMapModeOld
  ReleaseDC %NULL, hDC

END SUB

[Michael Mattias]

I had an idea to handle various fonts and stuff...

1. Make a guess or estimate how wide, using GetTextExtentPoint32 or something.

2. Starting with that guess as the formatting rectangle in the CHARRANGE structure, do some kind of loop sending the EM_FORMATRANGE message to the control, adjusting the formatting rectangle until the message returns exactly the number of characters in the string. At that point your formatting rectangle will be the size of the text.

That could be a tad frustrating, as you will have to convert back and forth between twips and pixels, but I'm sure it could be done.

MCM