sdk transparent labels on gradient bkgrnd

[BOB MECHLER]

I can't figure out why the following code doesn't produce a transparent sdk label since I use the ws_ex_transparent style. I paint the background with a gradient.

First, am I doing the 'static' control correctly. Secondly, is it required to use a null_brush in the dialog call back to get it to go transparent?

I've started looking at ownerdrawn but don't see how I can remove the drawtext or textout output.

#DIM ALL
#REGISTER ALL
#INCLUDE "win32api.inc"

GLOBAL ghMain AS DWORD

CALLBACK FUNCTION dlgMain 
  SELECT CASE CBMSG
    CASE %WM_PAINT
      CALL PaintBg(CBHNDL,0,0,0)
  END SELECT    
END FUNCTION


FUNCTION PBMAIN
    %LBL_LABEL = 1001
    DIM hWndControl AS DWORD,szControlText AS STRING

    DIALOG NEW 0, "Transparent sdk style label ", 0,0,150,170, %WS_OVERLAPPEDWINDOW OR %DS_CENTER TO ghMain
    szControlText = "Sample Text"
    hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szControlText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 10, 150, 15, _
                                 ghMain, %LBL_LABEL, GetModuleHandle(BYVAL 0&), BYVAL %Null)
    DIALOG SHOW MODAL ghMain CALL dlgMain

END FUNCTION
FUNCTION SetColor (BYVAL tCOLOR AS BYTE) AS WORD
    ' the windows api GradientFill routine wants r/g/b colors to be
    ' 16 bit words with the 8 bit color values left shifted 8 bits.
    ' this takes care of that.
    LOCAL clr AS WORD
    clr = tCOLOR
    SHIFT LEFT clr, 8
    FUNCTION = clr
END FUNCTION
SUB PaintBg(BYVAL hDialog AS LONG, BYVAL r AS LONG, BYVAL g AS LONG, BYVAL b AS LONG)
     ' this is to paint the background of the dialog
     ' it's all straight out of the MSDN help file.  We can change the values
     ' if we like.
     LOCAL ps AS PAINTSTRUCT
     LOCAL rc AS Rect
     LOCAL hDc AS DWORD
     LOCAL Xin&
     LOCAL Yin&,Temp&,cRed&,cGreen&,cBlue&
     DIM vert(1) AS TRIVERTEX
     DIM gRect AS GRADIENT_RECT
     hDC = BeginPaint(hDialog, ps)
       ' Tile the background
     GetClientRect hdialog, rc
     Xin = rc.nRight - rc.nLeft
     Yin = rc.nBottom - rc.nTop
     Xin = rc.nRight - rc.nLeft
     Yin = rc.nBottom - rc.nTop
     Temp& = RGB(205,214,255)
     IF Temp& <> 0 THEN
       cRed&   = Temp& MOD 256
       cGreen& = (Temp& \ 256) MOD 256
       cBlue&  = ((Temp& \ 256) \ 256) MOD 256
     ELSE
       cRed&   = 192
       cGreen& = 224
       cBlue&  = 192
     END IF
     vert(0).x      = 0
     vert(0).y      = 0
     vert(0).Red    = SetColor(cRed& - 90)
     vert(0).Green  = SetColor(cGreen& - 90)
     vert(0).Blue   = SetColor(cBlue& - 90)
     vert(0).Alpha  = &h0000
     vert(1).x      = xin
     vert(1).y      = yin
     vert(1).Red    = SetColor(cRed&)
     vert(1).Green  = SetColor(cGreen&)
     vert(1).Blue   = SetColor(cBlue&)
     vert(1).Alpha  = &h0000
     gRect.UpperLeft  = 0
     gRect.LowerRight = 1
     GradientFill hDc, vert(0), 2, gRect, 1, %GRADIENT_FILL_RECT_v
     EndPaint hDialog, ps
END SUB

[Chris Boss]

Here is your code with the problem fixed. They key is handling the WM_CTLCOLORSTATIC message properly.

#DIM ALL
#REGISTER ALL
#INCLUDE "win32api.inc"
GLOBAL ghMain AS DWORD
CALLBACK FUNCTION dlgMain
  SELECT CASE CBMSG
    CASE %WM_ERASEBKGND
         FUNCTION=1
         EXIT FUNCTION
    CASE %WM_SIZE
         InvalidateRect CBHNDL, BYVAL %NULL,1
    CASE %WM_CTLCOLORSTATIC
         SetBKMode CBWPARAM, %TRANSPARENT
         FUNCTION=GetStockObject(%NULL_BRUSH)
         EXIT FUNCTION
    CASE %WM_PAINT
      CALL PaintBg(CBHNDL,0,0,0)
      FUNCTION=1    ' required for dialog procedure
      EXIT FUNCTION
  END SELECT
END FUNCTION
 
FUNCTION PBMAIN
    %LBL_LABEL = 1001
    DIM hWndControl AS DWORD,szControlText AS STRING
    DIALOG NEW 0, "Transparent sdk style label ", 0,0,150,170, %WS_OVERLAPPEDWINDOW OR %DS_CENTER OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN TO ghMain
    szControlText = "Sample Text"
    hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szControlText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 10, 150, 15, _
                                 ghMain, %LBL_LABEL, GetModuleHandle(BYVAL 0&), BYVAL %Null)
    DIALOG SHOW MODAL ghMain CALL dlgMain
END FUNCTION
FUNCTION SetColor (BYVAL tCOLOR AS BYTE) AS WORD
    ' the windows api GradientFill routine wants r/g/b colors to be
    ' 16 bit words with the 8 bit color values left shifted 8 bits.
    ' this takes care of that.
    LOCAL clr AS WORD
    clr = tCOLOR
    SHIFT LEFT clr, 8
    FUNCTION = clr
END FUNCTION
SUB PaintBg(BYVAL hDialog AS LONG, BYVAL r AS LONG, BYVAL g AS LONG, BYVAL b AS LONG)
     ' this is to paint the background of the dialog
     ' it's all straight out of the MSDN help file.  We can change the values
     ' if we like.
     LOCAL ps AS PAINTSTRUCT
     LOCAL rc AS Rect
     LOCAL hDc AS DWORD
     LOCAL Xin&
     LOCAL Yin&,Temp&,cRed&,cGreen&,cBlue&
     DIM vert(1) AS TRIVERTEX
     DIM gRect AS GRADIENT_RECT
     hDC = BeginPaint(hDialog, ps)
       ' Tile the background
     GetClientRect hdialog, rc
     Xin = rc.nRight - rc.nLeft
     Yin = rc.nBottom - rc.nTop
     Xin = rc.nRight - rc.nLeft
     Yin = rc.nBottom - rc.nTop
     Temp& = RGB(205,214,255)
     IF Temp& <> 0 THEN
       cRed&   = Temp& MOD 256
       cGreen& = (Temp& \ 256) MOD 256
       cBlue&  = ((Temp& \ 256) \ 256) MOD 256
     ELSE
       cRed&   = 192
       cGreen& = 224
       cBlue&  = 192
     END IF
     vert(0).x      = 0
     vert(0).y      = 0
     vert(0).Red    = SetColor(cRed& - 90)
     vert(0).Green  = SetColor(cGreen& - 90)
     vert(0).Blue   = SetColor(cBlue& - 90)
     vert(0).Alpha  = &h0000
     vert(1).x      = xin
     vert(1).y      = yin
     vert(1).Red    = SetColor(cRed&)
     vert(1).Green  = SetColor(cGreen&)
     vert(1).Blue   = SetColor(cBlue&)
     vert(1).Alpha  = &h0000
     gRect.UpperLeft  = 0
     gRect.LowerRight = 1
     GradientFill hDc, vert(0), 2, gRect, 1, %GRADIENT_FILL_RECT_v
     EndPaint hDialog, ps
END SUB

[Dominic Mitchell]

There is another problem you might have to deal with. If the window is resizeable, add the following code right after the DIALOG NEW statement.

 SetClassLong ghMain, %GCL_STYLE, GetClassLong(ghMain, %GCL_STYLE) OR %CS_HREDRAW OR %CS_VREDRAW

Click the maximize image(button) in the caption to see why.

[Chris Boss]

Another solution to the redrawing of the gradient background when resizing:

    CASE %WM_SIZE
         InvalidateRect CBHNDL, BYVAL %NULL,1

Forces the entire client area to be redrawn, when ever reiszed.

I fixed the code I posted above to reflect this fix.

[Frank Kestens]

Bitmap question

Somehow off topic here , but i wanted to rephrase my question here to EZGUI

http://www.powerbasic.com/support/pbforums/showthread.php?t=36318

[Michael Mattias]

CASE %WM_CTLCOLORSTATIC
         SetBKMode CBWPARAM, %TRANSPARENT
         FUNCTION=GetStockObject(%NULL_BRUSH)
         EXIT FUNCTION

Works here because only one control is sending WM_CTLCOLORSTATIC. In general you'd want to trap to which control the notification message applies...

CASE %WM_CTLCOLORSTATIC
[b]  IF GetDlgCtlId(CBLPARAM) = %LBL_LABEL THEN [/b]
         SetBKMode CBWPARAM, %TRANSPARENT
         FUNCTION=GetStockObject(%NULL_BRUSH)
         EXIT FUNCTION
[b]  END IF  [/b]

GetDlgCtlID(CBLPARAM) "might" equal CBCTL, but I'm not a DDT guy and don't feel like testing it myself.

[Chris Boss]

Michael is correct about the color message. I was in a hurry to demonstrate the key method to make it work, not to handle multiple controls.

Now to handle multiple controls it may be good to not test for control ID's but simply test for the WS_EX_TRANSPARENT extended window style of the control. This way multiple static controls could be used and the ones which are transparent would be handled correctly.

[Chris Boss]

Frank,

I would suggest that using a brush is not the best way to go there.

You need to be able to draw a Bitmap which has transparent pixels.
Your graphic tool should be able to do this, I would think.

Using the API, you can use ImageLists, since they can draw bitmaps with transparent pixels (one unique RGB color is used to define the trasnparent pixels)

Another technique is to BitBlt a Bitmap, but use a round cliiping region to draw only within the region. This can be done to draw a round image.

Another technique is to use something like PB's GETBITs commands to get the pixels of the background and an image and then pixel by pixel combine them and then copy the pixels back.

[BOB MECHLER]

Static sdk labels work DDT label has a little problem

The following code takes some of the suggestions and tests a DDT label (which is why I started to learn about the SDK version) against SDK ones. I set an SDK label before the Dialog Show Modeless. Then I add a DDT label and an SDK label after the Dialog Show Modeless but before the message loop. I then add 4 more labels based on a button click. I tried to make the DDT LABEL work with the same styles, but as you can see it doesn't turn transparent. (I know about the -1,-2 approach prior to the Dialog Show Modeless but in my testing, this doesn't work on labels placed after the Dialog Show Modeless. A separate InvalidateRect is required for the DDT labels. Only the SDK labels work the way I want them too.

#DIM ALL
#REGISTER ALL
#INCLUDE "win32api.inc"

GLOBAL ghMain AS DWORD,hFontCap AS LONG
    %LBL_LABEL = 1001
    %LBL_AFTER = 1002
    %LBL_DDT   = 1003
    %NEW_LBL1  = 1004
    %NEW_LBL2  = 1005
    %NEW_LBL3  = 1006
    %NEW_LBL4  = 1007
    %BUT_DDT   = 2001

FUNCTION MakeFont(BYVAL CFont AS STRING, BYVAL PointSize AS LONG) AS LONG

  LOCAL hDC      AS LONG
  LOCAL CyPixels AS LONG

  hDC = GetDC(%HWND_DESKTOP)
  CyPixels  = GetDeviceCaps(hDC, %LOGPIXELSY)
  ReleaseDC %HWND_DESKTOP, hDC

  PointSize = (PointSize * CyPixels) \ 72
  FUNCTION = CreateFont(0 - PointSize, 0, 0, 0, %FW_NORMAL, 0, 0, 0, _
            %ANSI_CHARSET, %OUT_TT_PRECIS, %CLIP_DEFAULT_PRECIS, _
            %DEFAULT_QUALITY, %FF_DONTCARE, BYCOPY CFONT)
END FUNCTION 

CALLBACK FUNCTION dlgMain
  LOCAL szNewStaticText AS STRING 
  DIM hWndControl AS DWORD
  SELECT CASE CBMSG
      hFontCap = MakeFont("Ms Sans Serif",10)   
    CASE %WM_CTLCOLORSTATIC
      SELECT CASE GetDlgCtrlId(CBLPARAM) 
        CASE %LBL_LABEL TO %NEW_LBL4      'in case other labels need different handling
          SelectObject CBWPARAM, hFontCap
          SetBkMode CBWPARAM,%Transparent
         FUNCTION = GetStockObject(%NULL_BRUSH)
      END SELECT    
    CASE %WM_PAINT
      CALL PaintBg(CBHNDL,0,0,0)
    CASE %WM_COMMAND
      SELECT CASE CBCTL
        CASE %BUT_DDT
          szNewStaticText = "New Label 1"
          hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szNewStaticText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 64, 150, 18, _
                                 ghMain, %NEW_LBL1, GetModuleHandle(BYVAL 0&), BYVAL %NULL)
          szNewStaticText = "New Label 2"
          hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szNewStaticText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 84, 150, 18, _
                                 ghMain, %NEW_LBL2, GetModuleHandle(BYVAL 0&), BYVAL %NULL)
          szNewStaticText = "New Label 3"
          hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szNewStaticText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 104, 150, 18, _
                                 ghMain, %NEW_LBL3, GetModuleHandle(BYVAL 0&), BYVAL %NULL)
          szNewStaticText = "New Label 4"
          hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szNewStaticText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 124, 150, 18, _
                                 ghMain, %NEW_LBL4, GetModuleHandle(BYVAL 0&), BYVAL %NULL)
          
      END SELECT  
  END SELECT    
END FUNCTION

FUNCTION PBMAIN
    DIM hWndControl AS DWORD,szControlText AS STRING,cnt AS LONG

    DIALOG NEW 0, "Transparent sdk style label ",,,200,170,%WS_SYSMENU TO ghMain

    szControlText = "Before Show ghMain"
    hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szControlText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 10, 150, 18, _
                                 ghMain, %LBL_LABEL, GetModuleHandle(BYVAL 0&), BYVAL %Null)
    DIALOG SHOW MODELESS ghMain CALL dlgMain
    
    szControlText = "After Show ghMain"
    hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szControlText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 30, 150, 18, _
                                 ghMain, %LBL_AFTER, GetModuleHandle(BYVAL 0&), BYVAL %NULL)

    CONTROL ADD LABEL, ghMain,%LBL_DDT,"After Show ghMain DDT",7,30,60,10,%SS_LEFT OR %WS_CHILD OR %WS_VISIBLE _
                                                               OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                                               %WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING
    CONTROL ADD BUTTON, ghMain,%BUT_DDT,"Add more labels",120,130,60,14                                                                                                                                 
    DO
      DIALOG DOEVENTS TO cnt      
    LOOP UNTIL cnt = 0
END FUNCTION

FUNCTION SetColor (BYVAL tCOLOR AS BYTE) AS WORD
    ' the windows api GradientFill routine wants r/g/b colors to be
    ' 16 bit words with the 8 bit color values left shifted 8 bits.
    ' this takes care of that.
    LOCAL clr AS WORD
    clr = tCOLOR
    SHIFT LEFT clr, 8
    FUNCTION = clr
END FUNCTION 

SUB PaintBg(BYVAL hDialog AS LONG, BYVAL r AS LONG, BYVAL g AS LONG, BYVAL b AS LONG)
     ' this is to paint the background of the dialog
     ' it's all straight out of the MSDN help file.  We can change the values
     ' if we like.
     LOCAL ps AS PAINTSTRUCT
     LOCAL rc AS Rect
     LOCAL hDc AS DWORD
     LOCAL Xin&
     LOCAL Yin&,Temp&,cRed&,cGreen&,cBlue&
     DIM vert(1) AS TRIVERTEX
     DIM gRect AS GRADIENT_RECT
     hDC = BeginPaint(hDialog, ps)
       ' Tile the background
     GetClientRect hdialog, rc
     Xin = rc.nRight - rc.nLeft
     Yin = rc.nBottom - rc.nTop
     Xin = rc.nRight - rc.nLeft
     Yin = rc.nBottom - rc.nTop
     Temp& = RGB(205,214,255)
     IF Temp& <> 0 THEN
       cRed&   = Temp& MOD 256
       cGreen& = (Temp& \ 256) MOD 256
       cBlue&  = ((Temp& \ 256) \ 256) MOD 256
     ELSE
       cRed&   = 192
       cGreen& = 224
       cBlue&  = 192
     END IF
     vert(0).x      = 0
     vert(0).y      = 0
     vert(0).Red    = SetColor(cRed& - 90)
     vert(0).Green  = SetColor(cGreen& - 90)
     vert(0).Blue   = SetColor(cBlue& - 90)
     vert(0).Alpha  = &h0000
     vert(1).x      = xin
     vert(1).y      = yin
     vert(1).Red    = SetColor(cRed&)
     vert(1).Green  = SetColor(cGreen&)
     vert(1).Blue   = SetColor(cBlue&)
     vert(1).Alpha  = &h0000
     gRect.UpperLeft  = 0
     gRect.LowerRight = 1
     GradientFill hDc, vert(0), 2, gRect, 1, %GRADIENT_FILL_RECT_v
     EndPaint hDialog, ps
END SUB

[Michael Mattias]

DDT has some quirks re returning values directly, as required by the handling of WM_CTLCOLORSTATIC, specifcially you can't return the value zero. If GetStockObject(%NULL_BRUSH) = 0 (which it might well be), that will never get thru... a zero return gets read by DDT as "do default stuff" which is exactly what you are trying to NOT do.

No, I don't know how to get around that other than using SDK-style coding syntax for the dialog.

[BOB MECHLER]

The following works if placed right after the CONTROL ADD LABEL statement if this statement is being executed after the Dialog Show Modeless.

    CONTROL SHOW STATE ghMain,%LBL_DDT,%SW_HIDE                                                               
    CONTROL SHOW STATE ghMain,%LBL_DDT,%SW_SHOW

[BOB MECHLER]

I think using a brush in this situation won't work. I put a little sleep 300 in between putting 23 new labels on the screen and this is how it proceeded. It started by putting rectangles with no text of the dialog's original color (before the gradient), After it created these empty rectangles, it placed the text and the transparent effect only when it hit a messagbox or a textbox.

I'm going now in the direction of transparent bits as Chris suggested. I need the ability to put the text on the screen with a transparent background without the intermediate steps. This particular program has 259 fields that come into view with information based on buttons I provide. The problem of course is not there if I abandon the gradient effect and make the labels have the same background color as the dialog.

I thought I had the problem licked with the SDK labels but in practice they acted very much like the DDT labels if I drew enough of them at one time.

BOB MECHLER

[Peter Jinks]

Hi Bob,

You mentioned in one of your posts the "-1, -2 method", but that it doesn't work for DDT controls placed after the SHOW MODELESS. I'm guessing that the method you are referring to is CONTROL SET COLOR ? If so, then that does appear to work after the SHOW statement, but you need to force a redraw. i.e. if you add these two lines:

CONTROL SET COLOR ghMain, %LBL_DDT, -1, -2
CONTROL REDRAW ghMain, %LBL_DDT

After the CONTROL ADD LABEL, then it appears to work fine.

Not sure if that helps any, and I get the sneaking feeling I'm missing something, but this appears to work...

Regards,

Pete.

[BOB MECHLER]

I tried that Peter but with as many labels as I draw at one time, going from screen to screen removing and then adding up 40 labels the redraw causes an unacceptable flicker. I'm playing with loading a bitmap and it seems to work just fine. What I want to do is create a gradient bitmap and load it as you would from a resource file to allow the user to choose their own starting color. I'm in the process of trying to find some code that will create the gradient bitmap and then how to transfer it to the dialog.

Bob Mechler

[Dominic Mitchell]

Try the modified version of your code shown below.
The old version had a serious memory leak because a new font was created with each invocation of dlgMain.
Also, your old code did not have the modification to WM_ERASEBKGND suggested by Chris.
Unfortunately, even with that modification you will still get streaks when a window is dragged across your dialog.

This modified version paints the background during WM_CTLCOLORDLG, adds an hDC parameter to the PaintBg procedure, and drops BeginPaint/EndPaint.
Also, the font is created and destroyed during WM_INITDIALOG and WM_DESTROY respectively.

#DIM ALL
#REGISTER ALL
#INCLUDE "win32api.inc"

GLOBAL ghMain AS DWORD,hFontCap AS LONG
    %LBL_LABEL = 1001
    %LBL_AFTER = 1002
    %LBL_DDT   = 1003
    %NEW_LBL1  = 1004
    %NEW_LBL2  = 1005
    %NEW_LBL3  = 1006
    %NEW_LBL4  = 1007
    %BUT_DDT   = 2001

FUNCTION MakeFont(BYVAL CFont AS STRING, BYVAL PointSize AS LONG) AS LONG

  LOCAL hDC      AS LONG
  LOCAL CyPixels AS LONG

  hDC = GetDC(%HWND_DESKTOP)
  CyPixels  = GetDeviceCaps(hDC, %LOGPIXELSY)
  ReleaseDC %HWND_DESKTOP, hDC

  PointSize = (PointSize * CyPixels) \ 72
  FUNCTION = CreateFont(0 - PointSize, 0, 0, 0, %FW_NORMAL, 0, 0, 0, _
            %ANSI_CHARSET, %OUT_TT_PRECIS, %CLIP_DEFAULT_PRECIS, _
            %DEFAULT_QUALITY, %FF_DONTCARE, BYCOPY CFONT)
END FUNCTION 

CALLBACK FUNCTION dlgMain
  LOCAL szNewStaticText AS STRING 
  DIM hWndControl AS DWORD
  SELECT CASE CBMSG 
    CASE %WM_INITDIALOG
      hFontCap = MakeFont("Ms Sans Serif",10) 

    CASE %WM_DESTROY
      DeleteObject hFontCap
      
    CASE %WM_CTLCOLORSTATIC
      SELECT CASE GetDlgCtrlID(CBLPARAM) 
        CASE %LBL_LABEL TO %NEW_LBL4      'in case other labels need different handling
          SelectObject CBWPARAM, hFontCap
          SetBkMode CBWPARAM,%TRANSPARENT
         FUNCTION = GetStockObject(%NULL_BRUSH)
      END SELECT 

    CASE %WM_CTLCOLORDLG
      CALL PaintBg(CBHNDL,CBWPARAM,0,0,0)      
      FUNCTION = GetStockObject(%NULL_BRUSH)

    CASE %WM_COMMAND
      SELECT CASE CBCTL
        CASE %BUT_DDT
          szNewStaticText = "New Label 1"
          hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szNewStaticText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 64, 150, 18, _
                                 ghMain, %NEW_LBL1, GetModuleHandle(BYVAL 0&), BYVAL %NULL)
          szNewStaticText = "New Label 2"
          hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szNewStaticText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 84, 150, 18, _
                                 ghMain, %NEW_LBL2, GetModuleHandle(BYVAL 0&), BYVAL %NULL)
          szNewStaticText = "New Label 3"
          hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szNewStaticText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 104, 150, 18, _
                                 ghMain, %NEW_LBL3, GetModuleHandle(BYVAL 0&), BYVAL %NULL)
          szNewStaticText = "New Label 4"
          hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szNewStaticText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 124, 150, 18, _
                                 ghMain, %NEW_LBL4, GetModuleHandle(BYVAL 0&), BYVAL %NULL)
          
      END SELECT  
  END SELECT    
END FUNCTION

FUNCTION PBMAIN
    DIM hWndControl AS DWORD,szControlText AS STRING,cnt AS LONG

    DIALOG NEW 0, "Transparent sdk style label ",,,200,170,%WS_SYSMENU TO ghMain

    szControlText = "Before Show ghMain"
    hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szControlText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 10, 150, 18, _
                                 ghMain, %LBL_LABEL, GetModuleHandle(BYVAL 0&), BYVAL %NULL)
    DIALOG SHOW MODELESS ghMain CALL dlgMain
    
    szControlText = "After Show ghMain"
    hWndControl = CreateWindowEx(%WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING , _
                                 "Static", _  ' window class name
                                 BYCOPY szControlText, _    ' window caption
                                 %SS_LEFT OR %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                 10, 30, 150, 18, _
                                 ghMain, %LBL_AFTER, GetModuleHandle(BYVAL 0&), BYVAL %NULL)

    CONTROL ADD LABEL, ghMain,%LBL_DDT,"After Show ghMain DDT",100,30,130,18,%SS_LEFT OR %WS_CHILD OR %WS_VISIBLE _
                                                               OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, _
                                                               %WS_EX_TRANSPARENT OR %WS_EX_LEFT OR %WS_EX_LTRREADING

    CONTROL ADD BUTTON, ghMain,%BUT_DDT,"Add more labels",120,130,60,14                                                                                                                                 
    DO
      DIALOG DOEVENTS TO cnt      
    LOOP UNTIL cnt = 0
END FUNCTION

FUNCTION SetColor (BYVAL tCOLOR AS BYTE) AS WORD
    ' the windows api GradientFill routine wants r/g/b colors to be
    ' 16 bit words with the 8 bit color values left shifted 8 bits.
    ' this takes care of that.
    LOCAL clr AS WORD
    clr = tCOLOR
    SHIFT LEFT clr, 8
    FUNCTION = clr
END FUNCTION 

SUB PaintBg(BYVAL hDialog AS LONG, BYVAL hDC AS DWORD, BYVAL r AS LONG, BYVAL g AS LONG, BYVAL b AS LONG)
     ' this is to paint the background of the dialog
     ' it's all straight out of the MSDN help file.  We can change the values
     ' if we like.
     LOCAL rc AS Rect

     LOCAL Xin&
     LOCAL Yin&,Temp&,cRed&,cGreen&,cBlue&
     DIM vert(1) AS TRIVERTEX
     DIM gRect AS GRADIENT_RECT

       ' Tile the background
     GetClientRect hdialog, rc
     Xin = rc.nRight - rc.nLeft
     Yin = rc.nBottom - rc.nTop
     Xin = rc.nRight - rc.nLeft
     Yin = rc.nBottom - rc.nTop
     Temp& = RGB(205,214,255)
     IF Temp& <> 0 THEN
       cRed&   = Temp& MOD 256
       cGreen& = (Temp& \ 256) MOD 256
       cBlue&  = ((Temp& \ 256) \ 256) MOD 256
     ELSE
       cRed&   = 192
       cGreen& = 224
       cBlue&  = 192
     END IF
     vert(0).x      = 0
     vert(0).y      = 0
     vert(0).Red    = SetColor(cRed& - 90)
     vert(0).Green  = SetColor(cGreen& - 90)
     vert(0).Blue   = SetColor(cBlue& - 90)
     vert(0).Alpha  = &H0000
     vert(1).x      = xin
     vert(1).y      = yin
     vert(1).Red    = SetColor(cRed&)
     vert(1).Green  = SetColor(cGreen&)
     vert(1).Blue   = SetColor(cBlue&)
     vert(1).Alpha  = &H0000
     gRect.UpperLeft  = 0
     gRect.LowerRight = 1
     GradientFill hDc, vert(0), 2, gRect, 1, %GRADIENT_FILL_RECT_V

END SUB

[BOB MECHLER]

I moved the relevant changes you proposed to my production code and it works absolutely great. I can now happily erase and/or replace all the controls on my gradient background dialog as much as I want and no flicker.

Thanks Dominic!! As a bonus I used Chris's suggestion of loading a bitmap into the dialog and that also works well too. Great,great,great!

Thanks,

Bob Mechler

[BOB MECHLER]

Forgot to mention that this approach allowed the CONTROL ADD LABEL statements to work fine. I didn't need to go to SDK.

Bob Mechler

[BRENT GARDNER]

Very interesting. Is there a way to convert the paint structure so that it
will paint background of textbox instead of dialog? I get too much flicker
when editing text in textbox over a bitmap, which is rendered on a
graphic control. Thought, maybe just paint a gradient background for
textbox control and do away with graphic control. Should not be any
flicker?

[BOB MECHLER]

Don't know myself but I've seen code where it works for a static label to draw a gradient on it's background. I felt the non-flickering transparent effect on the static label with a gradient dialog background was good enough for now. Interested to see the answer myself.

Bob Mechler

[BRENT GARDNER]

Using Dominic's code and getting the dimensions of my textbox, it will
paint gradient background for textbox and I can edit text with no flicker!
Problem is that the rest of the dialog is transparent and shows desktop?
I guess I need some help on how to just paint a region the size of textbox and not entire dialog?