MagSetWindowFilterList function not remove specified window of screenshot

[Fukiszo]

if it is allowed, upload the 80kb source, i dont have access on your link to look at.
edit: forget it, i just scrolled down and what i read is pretty simple,
when you translated the callback part you automatic have imported BMP format from where you can create hundrets of copies.

Code:

LONG lineSize = bmif.biWidth * bmif.biBitCount / 8;
BYTE* pLineData = new BYTE[lineSize];
BYTE* pStart;
BYTE* pEnd;
LONG lineStart = 0;
LONG lineEnd = bmif.biHeight - 1;
while (lineStart < lineEnd)
{
   // Get the address of the swap line
   pStart = pData + (lineStart * lineSize);
   pEnd = pData + (lineEnd * lineSize);
   // Swap the top with the bottom
   memcpy(pLineData, pStart, lineSize);
   memcpy(pStart, pEnd, lineSize);
   memcpy(pEnd, pLineData, lineSize);
   // Adjust the line index
   lineStart++;
   lineEnd--;
} 
delete pLineData;

at that point the image is ready

[flashcoder]

Zitat:

Zitat von Fukiszo (Beitrag 1392274)

if it is allowed, upload the 80kb source, i dont have access on your link to look at.
edit: forget it, i just scrolled down and what i read is pretty simple,
when you translated the callback part you automatic have imported BMP format from where you can create hundrets of copies.

Code:

LONG lineSize = bmif.biWidth * bmif.biBitCount / 8;
BYTE* pLineData = new BYTE[lineSize];
BYTE* pStart;
BYTE* pEnd;
LONG lineStart = 0;
LONG lineEnd = bmif.biHeight - 1;
while (lineStart < lineEnd)
{
   // Get the address of the swap line
   pStart = pData + (lineStart * lineSize);
   pEnd = pData + (lineEnd * lineSize);
   // Swap the top with the bottom
   memcpy(pLineData, pStart, lineSize);
   memcpy(pStart, pEnd, lineSize);
   memcpy(pEnd, pLineData, lineSize);
   // Adjust the line index
   lineStart++;
   lineEnd--;
} 
delete pLineData;

at that point the image is ready

I attached the source file of C++ example on question :-D
Look to the MagCaptureDlg.cpp file

[flashcoder]

Here is my complete code updated, i tried translate callback function (was a combine of these 2 links: LNK1 and LNK2), seems right but not is executing when MagSetImageScalingCallback api is called.

Delphi-Quellcode:

var
  Form1: TForm1;

implementation

uses
  Unit3, Magnification;

{$R *.dfm}

function ImageScaling(hwnd: hwnd; srcdata: Pointer; srcheader: MAGIMAGEHEADER;
  destdata: Pointer; destheader: MAGIMAGEHEADER; unclipped: TRect;
  clipped: TRect; dirty: HRGN): Boolean;
var
  lpbmih: TBitmapInfoHeader;
  lpbmi: TBitmapInfo;
  aBitmap: HBITMAP;
  aDC: HDC;
  bmp: TBitmap;
begin
  Fillchar(lpbmih, SizeOf(lpbmih), 0);
  lpbmih.biSize := SizeOf(lpbmih);
  lpbmih.biWidth := srcheader.width;
  lpbmih.biHeight := srcheader.height;
  lpbmih.biPlanes := 1;
  lpbmih.biBitCount := Floor(lpbmih.biSizeImage / lpbmih.biHeight /
    lpbmih.biWidth * 8);
  lpbmih.biCompression := BI_RGB;

  Fillchar(lpbmi, SizeOf(lpbmi), 0);
  lpbmi.bmiHeader.biSize := SizeOf(lpbmi.bmiHeader);
  lpbmi.bmiHeader.biWidth := srcheader.width;
  lpbmi.bmiHeader.biHeight := srcheader.height;
  lpbmi.bmiHeader.biPlanes := 1;
  lpbmi.bmiHeader.biBitCount :=
    Floor(lpbmi.bmiHeader.biSizeImage / lpbmi.bmiHeader.biHeight /
    lpbmi.bmiHeader.biWidth * 8);
  lpbmi.bmiHeader.biCompression := BI_RGB;

  aDC := GetWindowDC(hwnd);
  bmp := TBitmap.Create;
  aBitmap := 0;
  try
    aBitmap := CreateDIBitmap(aDC, lpbmih, 0, nil, lpbmi, DIB_RGB_COLORS);
    bmp.handle := aBitmap;
  finally
    DeleteObject(aBitmap);
    DeleteDC(aDC);
    bmp.Free;
  end;
  Result := True;
end;

procedure MagScreenShot;
var
  desktop, hwndMag: hwnd;
  desktoprect, sourceRect: TRect;
  filterList: THWNDArray;
  m_ScreenX, m_ScreenY, m_ScreenT, m_ScreenL: Integer;
begin

  if not Form3.Showing then
    Form3.Show;

  desktop := GetDesktopWindow;
  GetWindowRect(desktop, desktoprect);

  m_ScreenT := desktoprect.Top;
  m_ScreenL := desktoprect.Left;
  m_ScreenX := desktoprect.right;
  m_ScreenY := desktoprect.bottom;

  if (not MagInitialize) then
  begin
    Application.MessageBox('Init magnification failed', 'Error',
      mb_Ok + mb_IconError);
    Exit;
  end;

  hwndMag := CreateWindow(WC_MAGNIFIER, 'MagnifierWindow',
    WS_CHILD or MS_SHOWMAGNIFIEDCURSOR or WS_VISIBLE, 0, 0, m_ScreenX,
    m_ScreenY, Form1.handle, 0, hInstance, nil);

  if (hwndMag = 0) then
  begin
    Application.MessageBox('MagnifierWindow creation failed', 'Error',
      mb_Ok + mb_IconError);
    Exit;
  end;

  if (not MagSetImageScalingCallback(hwndMag, TMagImageScalingCallback(@ImageScaling))) then
  begin
    Application.MessageBox('Cannot set callback', 'Error',
      mb_Ok + mb_IconError);
    Exit;
  end;

  try
    filterList[0] := Form3.handle;
  except
  end;

  if (not MagSetWindowFilterList(hwndMag, MW_FILTERMODE_EXCLUDE, 1,
    @filterList[0])) then
  begin
    Application.MessageBox('Cannot exclude main window', 'Error',
      mb_Ok + mb_IconError);
    Exit;
  end;

  sourceRect.Top := m_ScreenT;
  sourceRect.Left := m_ScreenL;
  sourceRect.right := m_ScreenX;
  sourceRect.bottom := m_ScreenY;

  if (not MagSetWindowSource(hwndMag, sourceRect)) then
  begin
    Application.MessageBox('Cannot set source to MagnifierWindow', 'Error',
      mb_Ok + mb_IconError);
    Exit;
  end;

  { if (not MagUninitialize) then
    begin
    Application.MessageBox('Finalize magnification failed', 'Error',
    mb_Ok + mb_IconError);
    Exit;
    end; }
end;

procedure TForm1.tmr1Timer(Sender: TObject);
begin
  MagScreenShot;
end;

Timer is be to 10000ms

[Zacherl]

The calling convention of the callback should be

Delphi-Quellcode:

stdcall

. But besides that MSDN says:

Zitat:

Note The MagSetImageScalingCallback function is deprecated in Windows 7 and later, and should not be used in new applications. There is no alternate functionality.

and

Zitat:

This function works only when Desktop Window Manager (DWM) is off.

I guess the "magnifier window" uses a DirectX surface to display the desktop screenshot. It might be possible to obtain its handle (e.g. by hooking the corresponding DirectX interface(s), if there is no other way to do it).

[flashcoder]

Zitat:

Zitat von Zacherl

This function works only when Desktop Window Manager (DWM) is off.

@Zacherl,

The C++ example works fine with DWM enable :).
And i followed your suggestion below, thank you:

Zitat:

Zitat von Zacherl

The calling convention of the callback should be

Delphi-Quellcode:

stdcall

Delphi-Quellcode:

TMagImageScalingCallback = function (hwnd: HWND; srcdata: Pointer;
    srcheader: MAGIMAGEHEADER; destdata: Pointer; destheader: MAGIMAGEHEADER;
    unclipped: TRect; clipped: TRect; dirty: HRGN): BOOL; stdcall; // definition found in Magnification.pas posted on question 

function ImageScaling(hwnd: hwnd; srcdata: Pointer; srcheader: MAGIMAGEHEADER;
  destdata: Pointer; destheader: MAGIMAGEHEADER; unclipped: TRect;
  clipped: TRect; dirty: HRGN): BOOL; stdcall;
var
  lpbmih: TBitmapInfoHeader;
  lpbmi: TBitmapInfo;
  aBitmap: HBITMAP;
  aDC: HDC;
  bmp: TBitmap;
begin
  Fillchar(lpbmih, SizeOf(lpbmih), 0);
  lpbmih.biSize := SizeOf(lpbmih);
  lpbmih.biWidth := srcheader.width;
  lpbmih.biHeight := srcheader.height;

//...
end;

//...

// calling in MagSetImageScalingCallback api

if (not MagSetImageScalingCallback(hwndMag, TMagImageScalingCallback(@ImageScaling))) then

So, like already said, when i put breakpoint inside my ImageScaling function, debug not go to function, then i noted that this callback function not is executed.

Here is how be is C++ code:

Code:

typedef BOOL (CALLBACK* MagImageScalingCallback)(HWND hwnd, void * srcdata, MAGIMAGEHEADER srcheader, void * destdata, MAGIMAGEHEADER destheader, RECT unclipped, RECT clipped, HRGN dirty );

//...

BOOL MagImageScaling(HWND hwnd, void *srcdata, MAGIMAGEHEADER srcheader, 
                void *destdata, MAGIMAGEHEADER destheader, 
                RECT unclipped, RECT clipped, HRGN dirty)
{
   // Setup the bitmap info header
      bmif.biSize = sizeof(BITMAPINFOHEADER);
      bmif.biHeight = srcheader.height;
      bmif.biWidth = srcheader.width;

//...
}

if (!MagSetImageScalingCallback(hwndMag, (MagImageScalingCallback)MagImageScaling))

[Zacherl]

Thats strange :? If

Delphi-Quellcode:

MagSetImageScalingCallback

returns

Delphi-Quellcode:

true

, the callback should at least get invoked. I'm trying out the C++ example now. Could you upload your complete Delphi project files as well?

Edit:
C++ example does not work for me (Windows 10 64-bit Build 1709).

Delphi-Quellcode:

MagSetWindowSource

raises an access violation in `Magnification.dll`. It does not crash, if I remove the call to

Delphi-Quellcode:

MagSetImageScalingCallback

, tho. I guess MSDN is correct about the deprecation :wink: Never mind, the callback is getting invoked, but something inside the callback crashes the example for some reason.

Edit2:
Wow, the author of the C++ example forgot about the

Delphi-Quellcode:

stdcall

as well :wall: :-D It seems to work now.

[flashcoder]

Zitat:

Zitat von Zacherl

Could you upload your complete Delphi project files as well?

My Delphi project is attach below.

[EWeiss]

Zitat:

Zitat von flashcoder (Beitrag 1392312)

Zitat:

Zitat von Zacherl

Could you upload your complete Delphi project files as well?

My Delphi project is attach below.

Here is your fix..
but which works only in the IDE.
Changed with D2010

for the future your should initialize a new Form if is NIL. ;)
callback works..

greets

[flashcoder]

Zitat:

Zitat von EWeiss

Here is your fix..
but which works only in the IDE.
Changed with D2010

Sorry, but this is the same project and with the same trouble, callback not is executed.
The diference here was only that you created the Form3 in runtime.

[EWeiss]

Zitat:

Zitat von flashcoder (Beitrag 1392317)

Zitat:

Zitat von EWeiss

Here is your fix..
but which works only in the IDE.
Changed with D2010

Sorry, but this is the same project and with the same trouble, callback not is executed.
The diference here was only that you created the Form3 in runtime.

execute always by me..
Win7 64 Bit as you can see on my Screenshot!
MagScreenShot is no longer Global is a part of Form1 now.

and i get the Shot from any Window where the mouse hover.

Delphi-Quellcode:

  GetCursorPos(Point);
  desktop := WindowFromPoint(Point);
  Caption := IntToStr(desktop);

as say works always by me.
I'm out ;)

shot removed..

greets