Graphic Get Bitmap

[Gary Beene]

Does anyone know why I would get a compile error 426 "Variable Expected" with this PBWin9 code:

Local hImage as DWord, iResult&
keybd_event(%VK_SnapShot, 1, 0, 0)  'active dialog to clipboard 
Clipboard Get Bitmap To hImage, iResult&

The keybd_event appears to put a bitmap on the clipboard - I can paste it into other programs.

Help says 426 might be from using a reserved variable name. I used several names, but still get the error.

I dropped the "TO" (which Help says is optional) and the compile error goes away, but then iResult& gets a 0 during execution, indicating the operation was unsuccessful.

[colin glenn]

Uh, hmm. "Quote" keybd_event(%VK_SnapShot, 1, 0, 0)
Well, it works, but not quite THAT fast, I got it to work by inserting a Sleep 100 right after sending the virtual keystroke.
Am not seeing how to get it to work on the active window however.

#PBFORMS CREATED V1.51
'------------------------------------------------------------------------------
' The first line in this file is a PB/Forms metastatement.
' yadayada
'------------------------------------------------------------------------------

#COMPILE EXE
#DIM ALL

'------------------------------------------------------------------------------
'   ** Includes **
'------------------------------------------------------------------------------
#PBFORMS BEGIN INCLUDES
%USEMACROS = 1
#IF NOT %DEF(%WINAPI)
    #INCLUDE "WIN32API.INC"
#ENDIF
#IF NOT %DEF(%COMMCTRL_INC)
    #INCLUDE "COMMCTRL.INC"
#ENDIF
#INCLUDE "PBForms.INC"
#PBFORMS END INCLUDES
'------------------------------------------------------------------------------

'------------------------------------------------------------------------------
'   ** Constants **
'------------------------------------------------------------------------------
#PBFORMS BEGIN CONSTANTS
%IDC_GRAPHIC1     = 1001
%IDD_DIALOG1      =  101
%IDM_EDIT_PASTE   = 1003
%IDM_FILE_EXIT    = 1002
%IDR_ACCELERATOR1 =  103
%IDR_MENU1        =  102
#PBFORMS END CONSTANTS
'------------------------------------------------------------------------------

'------------------------------------------------------------------------------
'   ** Declarations **
'------------------------------------------------------------------------------
DECLARE CALLBACK FUNCTION ShowDIALOG1Proc()
DECLARE FUNCTION ShowDIALOG1(BYVAL hParent AS DWORD) AS LONG
DECLARE FUNCTION AttachMENU1(BYVAL hDlg AS DWORD) AS DWORD
DECLARE FUNCTION AttachACCELERATOR1(BYVAL hDlg AS DWORD) AS DWORD
DECLARE FUNCTION ASSIGNACCEL(tAccel AS ACCELAPI, BYVAL wKey AS WORD, BYVAL _
    wCmd AS WORD, BYVAL byFVirt AS BYTE) AS LONG
#PBFORMS DECLARATIONS
'------------------------------------------------------------------------------

'------------------------------------------------------------------------------
'   ** Main Application Entry Point **
'------------------------------------------------------------------------------
FUNCTION PBMAIN()
    PBFormsInitComCtls (%ICC_WIN95_CLASSES OR %ICC_DATE_CLASSES OR _
        %ICC_INTERNET_CLASSES)

    ShowDIALOG1 %HWND_DESKTOP
END FUNCTION
'------------------------------------------------------------------------------

'------------------------------------------------------------------------------
'   ** CallBacks **
'------------------------------------------------------------------------------
CALLBACK FUNCTION ShowDIALOG1Proc()
LOCAL hImage    AS DWORD
LOCAL Result    AS LONG

    SELECT CASE AS LONG CBMSG
        CASE %WM_INITDIALOG
            ' Initialization handler

        CASE %WM_NCACTIVATE
            STATIC hWndSaveFocus AS DWORD
            IF ISFALSE CBWPARAM THEN
                ' Save control focus
                hWndSaveFocus = GetFocus()
            ELSEIF hWndSaveFocus THEN
                ' Restore control focus
                SetFocus(hWndSaveFocus)
                hWndSaveFocus = 0
            END IF

        CASE %WM_COMMAND
            ' Process control notifications
            SELECT CASE AS LONG CB.CTL
                CASE %IDM_EDIT_PASTE
                    keybd_event(%VK_SnapShot, 0, 0, 0)
                    SLEEP 100
                    CLIPBOARD GET BITMAP hImage, Result
                    #DEBUG PRINT "Result="& FORMAT$(Result) &" hImage="& HEX$(hImage, 8)
                    GRAPHIC ATTACH CB.HNDL, %IDC_GRAPHIC1
                    GRAPHIC COPY hImage, 0
                    GRAPHIC ATTACH hImage, 0
                    GRAPHIC BITMAP END
                CASE %IDM_FILE_EXIT
                    DIALOG END CB.HNDL

            END SELECT
    END SELECT
END FUNCTION
'------------------------------------------------------------------------------

'------------------------------------------------------------------------------
'   ** Dialogs **
'------------------------------------------------------------------------------
FUNCTION ShowDIALOG1(BYVAL hParent AS DWORD) AS LONG
    LOCAL lRslt AS LONG

#PBFORMS BEGIN DIALOG %IDD_DIALOG1->%IDR_MENU1->%IDR_ACCELERATOR1
    LOCAL hDlg  AS DWORD

    DIALOG NEW hParent, "Dialog1", 243, 164, 201, 133, %WS_POPUP OR _
        %WS_BORDER OR %WS_THICKFRAME OR %WS_CAPTION OR %WS_SYSMENU OR _
        %WS_MINIMIZEBOX OR %WS_MAXIMIZEBOX OR %WS_CLIPSIBLINGS OR _
        %WS_VISIBLE OR %DS_MODALFRAME OR %DS_3DLOOK OR %DS_NOFAILCREATE OR _
        %DS_SETFONT, %WS_EX_CONTROLPARENT OR %WS_EX_LEFT OR _
        %WS_EX_LTRREADING OR %WS_EX_RIGHTSCROLLBAR, TO hDlg
    CONTROL ADD GRAPHIC, hDlg, %IDC_GRAPHIC1, "", 0, 0, 200, 120, %WS_CHILD _
        OR %WS_VISIBLE, %WS_EX_STATICEDGE

    AttachMENU1 hDlg

    AttachACCELERATOR1 hDlg
#PBFORMS END DIALOG

    DIALOG SHOW MODAL hDlg, CALL ShowDIALOG1Proc TO lRslt

#PBFORMS BEGIN CLEANUP %IDD_DIALOG1
#PBFORMS END CLEANUP

    FUNCTION = lRslt
END FUNCTION
'------------------------------------------------------------------------------

'------------------------------------------------------------------------------
FUNCTION AttachMENU1(BYVAL hDlg AS DWORD) AS DWORD
#PBFORMS BEGIN MENU %IDR_MENU1->%IDD_DIALOG1
    LOCAL hMenu   AS DWORD
    LOCAL hPopUp1 AS DWORD

    MENU NEW BAR TO hMenu
    MENU NEW POPUP TO hPopUp1
    MENU ADD POPUP, hMenu, "File", hPopUp1, %MF_ENABLED
        MENU ADD STRING, hPopUp1, "Exit" + $TAB + "Alt+F4", %IDM_FILE_EXIT, _
            %MF_ENABLED
    MENU NEW POPUP TO hPopUp1
    MENU ADD POPUP, hMenu, "Edit", hPopUp1, %MF_ENABLED
        MENU ADD STRING, hPopUp1, "Paste" + $TAB + "Ctrl+V", %IDM_EDIT_PASTE, _
            %MF_ENABLED

    MENU ATTACH hMenu, hDlg
#PBFORMS END MENU
    FUNCTION = hMenu
END FUNCTION
'------------------------------------------------------------------------------

'------------------------------------------------------------------------------
FUNCTION AttachACCELERATOR1(BYVAL hDlg AS DWORD) AS DWORD
#PBFORMS BEGIN ACCEL %IDR_ACCELERATOR1->%IDD_DIALOG1
    LOCAL hAccel   AS DWORD
    LOCAL tAccel() AS ACCELAPI
    DIM   tAccel(1 TO 2) AS ACCELAPI

    ASSIGNACCEL tAccel(1), %VK_F4, %IDM_FILE_EXIT, %FVIRTKEY OR %FALT OR _
        %FNOINVERT
    ASSIGNACCEL tAccel(2), ASC("V"), %IDM_EDIT_PASTE, %FVIRTKEY OR %FCONTROL _
        OR %FNOINVERT

    ACCEL ATTACH hDlg, tAccel() TO hAccel
#PBFORMS END ACCEL
    FUNCTION = hAccel
END FUNCTION
'------------------------------------------------------------------------------

'------------------------------------------------------------------------------
#PBFORMS BEGIN ASSIGNACCEL
FUNCTION ASSIGNACCEL(tAccel AS ACCELAPI, BYVAL wKey AS WORD, BYVAL wCmd AS _
    WORD, BYVAL byFVirt AS BYTE) AS LONG
    tAccel.fVirt = byFVirt
    tAccel.key   = wKey
    tAccel.cmd   = wCmd
END FUNCTION
#PBFORMS END ASSIGNACCEL
'------------------------------------------------------------------------------

[Michael Mattias]

>I dropped the "TO" (which Help says is optional) and the compile error goes away

So "optional" means you get your choice of not using it - or not using it?

Cool. Keeps number of decisions to a minimum.

MCM

[Gary Beene]

Michael,

Yep, Help says optional, except that using it is when the compile error happens.

From Help, syntax:

CLIPBOARD GET BITMAP  [TO] ClipVar [, ClipResult]

Colin,

I use

keybd_event(%VK_SnapShot, 0, 0, 0) 'screen on clipboard

keybd_event(%VK_SnapShot, 1, 0, 0)  'active dialog on clipboard

for the two options (dialog or screen capture)

[Gary Beene]

Colin,

I used the 1,0,0 in your code - worked fine to capture dialog.

But when I put the TO back into your code, I get the same compile error message as I got with my code.

Neither puts the bitmap into the graphic control.

I also simply tried using another app to copy an image to the clipboard, thinking keyb... might somehow be incompatible? But same answer - Clipboard Get Bitmap gives a 0 (failure) return code.

[Gary Beene]

Michael,

Your droll comment made me realize that I didn't tell you that with or without the TO, the Clipboard Get Bitmap fails - one in compilation, the other in execution.

In the following code, the goal was to save an image of the dialog, but the file never gets saved. That's when I used the TO so I could get a result code, which is where I get the failure 0 result.

Sub SaveDialogImage
      Local hImage As Dword, iResult&
      temp$ = EXE.Path$ + "gbfind.bmp"
      'put dialog on clipboard
      Sleep 500
      keybd_event(%VK_SnapShot, 1, 0, 0)  'active dialog to clipboard
      'save clipboard to file
      Clipboard Get Bitmap hImage   'get handle to bitmap
      Graphic Attach hImage, 0       'attach to handle
      Graphic Save temp$
End Sub

One might guess I'm missing something trivial, but my Saturday mind hasn't found anything obvious so far.

[Gary Beene]

Colin,

I played with your code more.

The keyb... function works fine - it can capture either dialog or full screen.

But using Clipboard Get Bitmap works only when the full screen is captured. I can get the full screen to display in the graphic control in your code, but not the captured dialog image.

That's that same results you tried to tell me - I misunderstood your message on 1st reading.

I guess I'll have to think on it more. It's not obvious what's wrong.

[Michael Mattias]

Your droll comment made me realize that I didn't tell you that with or without the TO, the Clipboard Get Bitmap fails

How would you know WITH the 'TO?' That program never compiled!

FWIW, I don't understand your call parameters to keybd_event, especially param two, either one or zero.... my SDK doc shows...

Syntax

VOID keybd_event(  
    BYTE bVk,
    BYTE bScan,
    DWORD dwFlags,
    PTR dwExtraInfo
);

Parameters

bVk
[in] Specifies a virtual-key code. The code must be a value in the range 1 to 254. For a complete list, see Virtual-Key Codes.
bScan
This parameter is not used.
dwFlags
[in] Specifies various aspects of function operation. This parameter can be one or more of the following values.
KEYEVENTF_EXTENDEDKEY
If specified, the scan code was preceded by a prefix byte having the value 0xE0 (224).
KEYEVENTF_KEYUP
If specified, the key is being released. If not specified, the key is being depressed.
dwExtraInfo
[in] Specifies an additional value associated with the key stroke.

If I go by that, you could put your grandma in param two and it would not make any difference.

Also, not the pressed/released status (param three). Maybe you need to specify a RELASE to get the copy to happen. (KEYEVENTF_KEYUP)

Me, I'd call keybd_event twice, once for press, once for release. I think that's what happens when you use fingers instead of code.

[colin glenn]

@MM: Nail on the head:

                    keybd_event(%VK_SnapShot, 1, 0, 0)
                    DIALOG DOEVENTS
                    SLEEP 100
                    keybd_event(%VK_SnapShot, 1, %KEYEVENTF_KEYUP, 0)
                    DIALOG DOEVENTS
                    SLEEP 500

[Gary Beene]

Colin,

Thanks for the updated code.

I put the new code in the original code you posted. It seems to work only in debug mode, and not in normal execution mode. In normal mode, the dialog image does not appear in the graphic control.

Is that what you saw?

[Gary Beene]

Michael,

The questions with my keyb_event code aside, the image of interest was on the clipboard - as demonstrated by the fact that after the PowerBASIC apps completed, the expected image was on the clipboard and could be manually pasted into other programs.

It was with the Clipboard Get Bitmap (either with-TO getting a compile error or without-TO returning a 0 result code) that things stalled.

Was your focus on the keyb_event function indicating a thought that if the keyb_event code was corrected, that the Clipboard Get Bitmap would then work? Or were you just starting at the top and working your way down?

I do appreciate the response!

[colin glenn]

Gary, mod:

keybd_event(%VK_SnapShot, 1, 0, 0)
DIALOG DOEVENTS
SLEEP 100
keybd_event(%VK_SnapShot, 1, %KEYEVENTF_KEYUP, 0)
DIALOG DOEVENTS
SLEEP 2000
CLIPBOARD GET BITMAP hImage, Result
MSGBOX "Result="& FORMAT$(Result) &" hImage="& HEX$(hImage, 8)

And the MsgBox comes up with -1, but the hImage comes up zero.
I have the ClipBook Viewer up as well, so I'm seeing the window appear in the clipboard, so it IS getting the snapshot.

[Dave Biggs]

This seems to work ok. (Sans TO - which looks like bug !)

STATIC hImage    AS DWORD
...
CASE %IDM_EDIT_PASTE
        KeyBd_Event %VK_SnapShot, 1, 0, 0       ' Capture active window
        Do Until Result
            Dialog DoEvents 
            CLIPBOARD GET BITMAP hImage, Result
        Loop
        #DEBUG PRINT "Result="& FORMAT$(Result) &" hImage="& HEX$(hImage, 8)
        GRAPHIC ATTACH CB.HNDL, %IDC_GRAPHIC1
        GRAPHIC COPY hImage, 0
        GRAPHIC ATTACH hImage, 0
        GRAPHIC BITMAP END

Other options for VK_SnapShot

 '          KeyBd_Event %VK_SnapShot, 1, 0, 0                 ' active window | - Version > 4 Win2k^
 '          KeyBd_Event %VK_SnapShot, 0, 0, 0                 ' whole screen  |
          keybd_event %VK_MENU, 0, 0, 0                     '+ active window  | - Version =< 4
          keybd_event %VK_SNAPSHOT, 0, 0, 0                 '  whole screen   |
          keybd_event %VK_SNAPSHOT, 0, %KEYEVENTF_KEYUP, 0  '  whole screen   |
          keybd_event %VK_MENU, 0, %KEYEVENTF_KEYUP, 0      '+ active window  |

[Gösta H. Lovgren-2]

I'm missing something here. Isn't this code supposed to create an image of the dialog and put it in the Clipboard? I tried all 3 versions above (2 Colin, 1 Dave) and none do that.(clicking Edit/Paste) What they do is pop up my screen capture program (CaptureWizPro.exe).

What am I missing? Or is that the point?

==================================
“If liberty means anything at all
it means the right to tell people
what they do not want to hear.”
George Orwell.
==================================

[Dave Biggs]

Gösta,

Sounds like CaptureWizPro.exe has installed a hook on your system. Does it pop up when you press the Print Scrn button on your keyboard?

Gary's program simulates a Print Scrn button press to load up the clipboard with a bitmap image then shows that image on a graphic control.

[Gösta H. Lovgren-2]

Gösta,

Sounds like CaptureWizPro.exe has installed a hook on your system. Does it pop up when you press the Print Scrn button on your keyboard?

That's what it does alright. Good observation Dave.

================================================
"Not everything that can be counted counts,
and not everything that counts can be counted."
Albert Einstein (1879-1955)
================================================

[colin glenn]

I expanded the core of the test program to include getting text off the clipboard, and putting a bitmap on the clipboard.

Needed a means to load a bitmap into the program, so added a DISPLAY function to call up a load bitmap.

CASE %IDM_FILE_OPEN
    Filter = "Bitmap Images"& CHR$(0) &"*.bmp"& CHR$(0) & CHR$(0)
    DISPLAY OPENFILE CB.HNDL, , , "Open Bitmap", EXE.PATH$, Filter, _
        "", "", %OFN_FILEMUSTEXIST TO FileName, Result
    IF Result > 0 THEN
        GRAPHIC BITMAP LOAD FileName, 0, 0, 0 TO hImage
        GRAPHIC ATTACH CB.HNDL, %IDC_GRAPHIC1
        GRAPHIC COPY hImage, 0
        GRAPHIC ATTACH hImage, 0
        GRAPHIC BITMAP END
    END IF

A means to copy this bitmap to the clipboard:

CASE %IDM_EDIT_COPY
    CLIPBOARD RESET
    CONTROL HANDLE CB.HNDL, %IDC_GRAPHIC1 TO hImage
    CLIPBOARD SET BITMAP hImage, Result
    MSGBOX "Result="& FORMAT$(Result) &" hImage="& HEX$(hImage, 8)

Debug Run: Result=0 hImage=001205D8
Compiled: Result=0 hImage=001B0430

As can be seen, according to the result, both modes fail to copy to the clipboard, and with the ClipBook Viewer open, I fail to see a bitmap appear there.

Text test was a simple "get it from the clipboard" action:

CASE %IDM_EDIT_GETTEXT
    CLIPBOARD GET TEXT cText, Result
    MSGBOX "Result="& FORMAT$(Result) &" cText="& cText

And the message box does display the text it gets from the clipboard, as verified when ClipBook is displaying text in the clipboard.

For the extra menu and accelerator elements, get the source from the attached Zip file.

But the observation is that currently, the CLIPBOARD function seems to be a bit broken.

[Michael Mattias]

CASE %IDM_EDIT_COPY
    CLIPBOARD RESET
    CONTROL HANDLE CB.HNDL, %IDC_GRAPHIC1 TO hImage
    CLIPBOARD SET BITMAP hImage, Result
    MSGBOX "Result="& FORMAT$(Result) &" hImage="& HEX$(hImage, 8)

As can be seen, according to the result, both modes fail to copy to the clipboard, and with the ClipBook Viewer open, I fail to see a bitmap appear there.

Darn, this syntax is confusing as hell, where "cliphndl" might be a handle to a bitmap, a handle to a control or a handle to a window....

CLIPBOARD SET BITMAP ClipHndl [, ClipResult]
..
A GRAPHIC BITMAP, specified by ClipHndl, is stored on the CLIPBOARD. The GRAPHIC BITMAP may be a GRAPHIC CONTROL, GRAPHIC WINDOW, or GRAPHIC BITMAP. When passing a GRAPHIC CONTROL to the Clipboard, use CONTROL GET HANDLE to obtain the handle to the GRAPHIC CONTROL

Maybe hImage (in this case a control handle) must be ATTACHed for CLIPBOARD SET BITMAP to work?

MCM

[colin glenn]

@MM, tried that, didn't make a difference.

BUT!

This did:

CASE %IDM_EDIT_COPY
    CLIPBOARD RESET
    ' CONTROL HANDLE CB.HNDL, %IDC_GRAPHIC1 TO hImage
    GRAPHIC BITMAP NEW 256, 256 TO hImage
    GRAPHIC ATTACH hImage, 0
    GRAPHIC COPY CB.HNDL, %IDC_GRAPHIC1
    CLIPBOARD SET BITMAP hImage, Result
    GRAPHIC BITMAP END
    MSGBOX "Result="& FORMAT$(Result) &" hImage="& HEX$(hImage, 8)

With issues, namely the ClipBook is NOT displaying the results, but the results can be pasted into Word. What ClipBook is reporting is:

"ClipBook Viewer cannot display the information in its current format or there is not enough memory to display it. Quit one or more applications to increase the available memory, and then try again."

Right, 2gig ram with a 100gig swap, ...

Let me think where I got a construct that retrieves raw data from the clipboard and I'll post the alleged headers, ClipBook is at least reporting that the information in the clipboard IS a bitmap.

[colin glenn]

That was interesting:

biSize=40
biWidth=96
biHeight=-96
biPlanes=1
biBitCount=32
biCompression=0
biSizeImage=36864
biXPelsPerMeter=0
biYPelsPerMeter=0
biClrUsed=0
biClrImportant=0

It's making a Top Down bitmap on the clipboard.