🚀 go-pugleaf

Fernando Alvarez wrote:
> It works with bmp pictures but it doesn�t work with gif/jpg pictures.
> How can I use gif/jpg pictures?

IMHO, 'Active Desktop' must be enbaled.

-- 
how to get rid of this damn sig

"Fernando Alvarez" <ferjat@lycos.es> wrote in message
news:3ea2c223$1@newsgroups.borland.com...

> It works with bmp pictures but it doesn�t work
> with gif/jpg pictures. How can I use gif/jpg pictures?

You don't.  Windows only supports bmps for wallpaper.  What you ask for will
require you to either:

1) simply convert the images to bmp first

2) use the IActiveDesktop interface instead (ActiveDesktop is a feature
introduced in InternetExplorer4).  Note that this requires IE4 to be
installed (all systems running Win98 or higher already have that - Win95 and
WinNT need a separate installation), and that ActiveDesktop needs to be
enabled by the user before it can be utilized.


Gambit

Thank you for the help. How can I convert gif/jpg to bmp?
Thank you.

"Remy Lebeau (TeamB)" <gambit47@yahoo.com> escribi� en el mensaje
news:3ea3164d$1@newsgroups.borland.com...
>
> "Fernando Alvarez" <ferjat@lycos.es> wrote in message
> news:3ea2c223$1@newsgroups.borland.com...
>
> > It works with bmp pictures but it doesn�t work
> > with gif/jpg pictures. How can I use gif/jpg pictures?
>
> You don't.  Windows only supports bmps for wallpaper.  What you ask for
will
> require you to either:
>
> 1) simply convert the images to bmp first
>
> 2) use the IActiveDesktop interface instead (ActiveDesktop is a feature
> introduced in InternetExplorer4).  Note that this requires IE4 to be
> installed (all systems running Win98 or higher already have that - Win95
and
> WinNT need a separate installation), and that ActiveDesktop needs to be
> enabled by the user before it can be utilized.
>
>
> Gambit
>
>
>

"Fernando Alvarez" <ferjat@lycos.es> wrote in message
news:3ea319ae$1@newsgroups.borland.com...
> How can I convert gif/jpg to bmp?

For JPG, Builder has a native TJPEGImage class for working with jpg images.
You can load the jpg into an instance of TJPEGImage and then simply Assign()
the TJPEGImage to a TBitmap.

As for GIF, Builder has no native support for that format.  You will have to
use a third-party solution instead.  There are numerous third-party GIF
components available for download.  For example, if you go to
http://www.torry.net and do a search, TGIFImage by Anders Melander is a very
good component for working with GIF images, and you'll be able to Assign()
it to TBitmap as well for conversion purposes.


Gambit

Thank you very much.

"Remy Lebeau (TeamB)" <gambit47@yahoo.com> escribi� en el mensaje
news:3ea37c3b$1@newsgroups.borland.com...
>
> "Fernando Alvarez" <ferjat@lycos.es> wrote in message
> news:3ea319ae$1@newsgroups.borland.com...
> > How can I convert gif/jpg to bmp?
>
> For JPG, Builder has a native TJPEGImage class for working with jpg
images.
> You can load the jpg into an instance of TJPEGImage and then simply
Assign()
> the TJPEGImage to a TBitmap.
>
> As for GIF, Builder has no native support for that format.  You will have
to
> use a third-party solution instead.  There are numerous third-party GIF
> components available for download.  For example, if you go to
> http://www.torry.net and do a search, TGIFImage by Anders Melander is a
very
> good component for working with GIF images, and you'll be able to Assign()
> it to TBitmap as well for conversion purposes.
>
>
> Gambit
>
>

Hi Fernando,
> How can I convert gif/jpg to bmp?

The following function uses the IPicture interface to convert a GIF or JPEG
to a bitmap; it returns a TBitmap object which you can dump to a file via
TBitmap::SaveToFile()...

#include <ole2.h>
#include <olectl.h>
#include <memory>
Graphics::TBitmap* LoadImageFromFile(
   AnsiString filename
  )
{
  // open the file for shared reading
  HANDLE const hFile = CreateFile(
    filename.c_str(), GENERIC_READ, FILE_SHARE_READ, NULL,
    OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL
    );
  if (hFile == INVALID_HANDLE_VALUE)
  {
    throw EWin32Error("Error opening file.");
  }

  // allocate a global memory object of the file's size
  DWORD const dwSize = GetFileSize(hFile, NULL);
  HGLOBAL hData = GlobalAlloc(GMEM_MOVEABLE, dwSize);
  if (hData == NULL)
  {
    CloseHandle(hFile);
    throw EWin32Error("Error allocating memory.");
  }

  // grab a pointer to the memory
  LPVOID pData = GlobalLock(hData);
  if (pData == NULL)
  {
    GlobalFree(hData);
    CloseHandle(hFile);
    throw EWin32Error("Error accessing memory.");
  }

  // read the data from the file
  DWORD dwRead = 0;
  bool read_ok = ReadFile(hFile, pData, dwSize, &dwRead, NULL);
  if (!read_ok  || (dwRead != dwSize))
  {
    GlobalUnlock(hData);
    GlobalFree(hData);
    CloseHandle(hFile);
    throw EWin32Error("Error reading file.");
  }

  // clean up
  GlobalUnlock(hData);
  CloseHandle(hFile);

  // create an IStream object on hData
  IStream* pStream;
  HRESULT hRes = CreateStreamOnHGlobal(hData, false, &pStream);
  if (FAILED(hRes))
  {
    GlobalFree(hData);
    throw EWin32Error("Failed to create IStream.");
  }

  // load the picture (create an IPicture object)
  IPicture* pPicture;
  hRes = OleLoadPicture(
    pStream, 0, false, IID_IPicture,
    reinterpret_cast<void**>(&pPicture)
    );
  if (FAILED(hRes))
  {
    pStream->Release();
    GlobalFree(hData);
    throw EWin32Error("Failed to create IPicture.");
  }

  // grab a handle to the Picture's palette, if present
  HPALETTE hPal = NULL;
  pPicture->get_hPal(reinterpret_cast<OLE_HANDLE*>(hPal));
  if (hPal != NULL)
  {
    int const num_entries =
      GetPaletteEntries(hPal, 0, 0, NULL);
    long const size = sizeof(LOGPALETTE) +
      (num_entries - 1) * sizeof(PALETTEENTRY);

    // copy the palette (because IPicture owns it)
    LPLOGPALETTE pLogPal =
      reinterpret_cast<LPLOGPALETTE>(GlobalAlloc(GPTR, size));
    if (pLogPal != NULL)
    {
      int const num_got = GetPaletteEntries(
        hPal, 0, num_entries, pLogPal->palPalEntry
        );
      pLogPal->palVersion = 0x300;
      pLogPal->palNumEntries = num_got;
      hPal = CreatePalette(pLogPal);
      GlobalFree(pLogPal);
    }
  }

  // retrieve the width and height of the picture
  SIZE SHiMetric = {0, 0};
  pPicture->get_Width(&SHiMetric.cx);
  pPicture->get_Height(&SHiMetric.cy);

  // convert HIMETRIC units to pixels
  HDC hScreenDC = GetDC(NULL);
  int const width = MulDiv(
    SHiMetric.cx, GetDeviceCaps(hScreenDC, LOGPIXELSX), 2540
    );
  int const height = MulDiv(
    SHiMetric.cy, GetDeviceCaps(hScreenDC, LOGPIXELSY), 2540
    );
  ReleaseDC(NULL, hScreenDC);

  // create a TBitmap object
  std::auto_ptr<Graphics::TBitmap> Bitmap(new Graphics::TBitmap());
  try
  {
    // set the bitmap's attributes
    Bitmap->PixelFormat = pf24bit;
    Bitmap->Width = width;
    Bitmap->Height = height;

    // grab a handle to the bitmap's memory DC
    HDC const hMemDC = Bitmap->Canvas->Handle;

    // associate the palette (if present) with the bitmap's DC
    HPALETTE hOldPal = NULL;
    if (hPal != NULL)
    {
      Bitmap->Palette = hPal;
      hOldPal = SelectPalette(hMemDC, hPal, false);
      RealizePalette(hMemDC);
    }

    // render the picture to the memory DC
    pPicture->Render(
      hMemDC, 0, 0, width, height, 0, SHiMetric.cy,
      SHiMetric.cx, -SHiMetric.cy, NULL
      );

    // clean up
    if (hOldPal != NULL)
    {
      SelectPalette(hMemDC, hOldPal, false);
    }
    pPicture->Release();
    pStream->Release();
    GlobalFree(hData);
  }
  catch (...)
  {
    // clean up
    pPicture->Release();
    pStream->Release();
    GlobalFree(hData);
    throw;
  }
  
  // retun the bitmap (caller assumes ownership)
  return Bitmap.release();
}  

HTH,
-- 
Damon (TeamB)
BCBCAQ--http://bcbcaq.bytamin-c.com

how could I use that in a project? what would I need to call the
function....?
I assume it should be defined as so in the header:
Graphics::TBitmap* LoadImageFromFile(AnsiString filename);
so far all my attempts at creating a TBitmap and then assigning it the
bitmap from the function have failed, could you show me how to do it?
--Sub

How could I do this using  IActiveDesktop? what headers are needed and how
do I access the SetWallPaper function? could you post and example please as
all the ones I can find are VC++ oriantated and have som header files which
create errors rather than fix them.
--Sub

"Subliminal" <doug@cowie3.fsnet.co.uk> wrote in message
news:3ea7d63a@newsgroups.borland.com...

> so far all my attempts at creating a TBitmap and then
> assigning it the bitmap from the function have failed,
> could you show me how to do it?

Please show your actual source code.


Gambit

"Subliminal" <doug@cowie3.fsnet.co.uk> wrote in message
news:3ea7f5ab@newsgroups.borland.com...
> what headers are needed

shlobj.h

> and how do I access the SetWallPaper function?

You need to create an instance of the IActiveDesktop interface, then you
simply call SetWallPaper() like you would any other class method.

> could you post and example please

    #include <shlobj.h>
    #include <utilcls.h>

    TComInterface<IActiveDesktop> ActiveDesktop;

    CoCreateInstance(CLSID_ActiveDesktop, NULL, CLSCTX_INPROC_SERVER,
                      IID_IActiveDesktop, (LPVOID*)&ActiveDesktop);

    if( ActiveDesktop )
    {
        ActiveDesktop->SetWallpaper(WideString("path to file"), 0);

        WALLPAPEROPT opt;
        opt.dwSize = sizeof(WALLPAPEROPT);
        opt.dwStyle = WPSTYLE_STRETCH;
        ActiveDesktop->SetWallpaperOptions(&opt, 0);

        ActiveDesktop->ApplyChanges(AD_APPLY_ALL);
    }


Gambit

Cool!!!!. It works fine fine fine!!!!! Thank you, thank you very much.

"Damon Chandler (TeamB)" <dmc27@cornell.edu> escribi� en el mensaje
news:3EA63274.D0D9367F@cornell.edu...
> Hi Fernando,
> > How can I convert gif/jpg to bmp?
>
> The following function uses the IPicture interface to convert a GIF or
JPEG
> to a bitmap; it returns a TBitmap object which you can dump to a file via
> TBitmap::SaveToFile()...
>
> #include <ole2.h>
> #include <olectl.h>
> #include <memory>
> Graphics::TBitmap* LoadImageFromFile(
>    AnsiString filename
>   )
> {
>   // open the file for shared reading
>   HANDLE const hFile = CreateFile(
>     filename.c_str(), GENERIC_READ, FILE_SHARE_READ, NULL,
>     OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL
>     );
>   if (hFile == INVALID_HANDLE_VALUE)
>   {
>     throw EWin32Error("Error opening file.");
>   }
>
>   // allocate a global memory object of the file's size
>   DWORD const dwSize = GetFileSize(hFile, NULL);
>   HGLOBAL hData = GlobalAlloc(GMEM_MOVEABLE, dwSize);
>   if (hData == NULL)
>   {
>     CloseHandle(hFile);
>     throw EWin32Error("Error allocating memory.");
>   }
>
>   // grab a pointer to the memory
>   LPVOID pData = GlobalLock(hData);
>   if (pData == NULL)
>   {
>     GlobalFree(hData);
>     CloseHandle(hFile);
>     throw EWin32Error("Error accessing memory.");
>   }
>
>   // read the data from the file
>   DWORD dwRead = 0;
>   bool read_ok = ReadFile(hFile, pData, dwSize, &dwRead, NULL);
>   if (!read_ok  || (dwRead != dwSize))
>   {
>     GlobalUnlock(hData);
>     GlobalFree(hData);
>     CloseHandle(hFile);
>     throw EWin32Error("Error reading file.");
>   }
>
>   // clean up
>   GlobalUnlock(hData);
>   CloseHandle(hFile);
>
>   // create an IStream object on hData
>   IStream* pStream;
>   HRESULT hRes = CreateStreamOnHGlobal(hData, false, &pStream);
>   if (FAILED(hRes))
>   {
>     GlobalFree(hData);
>     throw EWin32Error("Failed to create IStream.");
>   }
>
>   // load the picture (create an IPicture object)
>   IPicture* pPicture;
>   hRes = OleLoadPicture(
>     pStream, 0, false, IID_IPicture,
>     reinterpret_cast<void**>(&pPicture)
>     );
>   if (FAILED(hRes))
>   {
>     pStream->Release();
>     GlobalFree(hData);
>     throw EWin32Error("Failed to create IPicture.");
>   }
>
>   // grab a handle to the Picture's palette, if present
>   HPALETTE hPal = NULL;
>   pPicture->get_hPal(reinterpret_cast<OLE_HANDLE*>(hPal));
>   if (hPal != NULL)
>   {
>     int const num_entries =
>       GetPaletteEntries(hPal, 0, 0, NULL);
>     long const size = sizeof(LOGPALETTE) +
>       (num_entries - 1) * sizeof(PALETTEENTRY);
>
>     // copy the palette (because IPicture owns it)
>     LPLOGPALETTE pLogPal =
>       reinterpret_cast<LPLOGPALETTE>(GlobalAlloc(GPTR, size));
>     if (pLogPal != NULL)
>     {
>       int const num_got = GetPaletteEntries(
>         hPal, 0, num_entries, pLogPal->palPalEntry
>         );
>       pLogPal->palVersion = 0x300;
>       pLogPal->palNumEntries = num_got;
>       hPal = CreatePalette(pLogPal);
>       GlobalFree(pLogPal);
>     }
>   }
>
>   // retrieve the width and height of the picture
>   SIZE SHiMetric = {0, 0};
>   pPicture->get_Width(&SHiMetric.cx);
>   pPicture->get_Height(&SHiMetric.cy);
>
>   // convert HIMETRIC units to pixels
>   HDC hScreenDC = GetDC(NULL);
>   int const width = MulDiv(
>     SHiMetric.cx, GetDeviceCaps(hScreenDC, LOGPIXELSX), 2540
>     );
>   int const height = MulDiv(
>     SHiMetric.cy, GetDeviceCaps(hScreenDC, LOGPIXELSY), 2540
>     );
>   ReleaseDC(NULL, hScreenDC);
>
>   // create a TBitmap object
>   std::auto_ptr<Graphics::TBitmap> Bitmap(new Graphics::TBitmap());
>   try
>   {
>     // set the bitmap's attributes
>     Bitmap->PixelFormat = pf24bit;
>     Bitmap->Width = width;
>     Bitmap->Height = height;
>
>     // grab a handle to the bitmap's memory DC
>     HDC const hMemDC = Bitmap->Canvas->Handle;
>
>     // associate the palette (if present) with the bitmap's DC
>     HPALETTE hOldPal = NULL;
>     if (hPal != NULL)
>     {
>       Bitmap->Palette = hPal;
>       hOldPal = SelectPalette(hMemDC, hPal, false);
>       RealizePalette(hMemDC);
>     }
>
>     // render the picture to the memory DC
>     pPicture->Render(
>       hMemDC, 0, 0, width, height, 0, SHiMetric.cy,
>       SHiMetric.cx, -SHiMetric.cy, NULL
>       );
>
>     // clean up
>     if (hOldPal != NULL)
>     {
>       SelectPalette(hMemDC, hOldPal, false);
>     }
>     pPicture->Release();
>     pStream->Release();
>     GlobalFree(hData);
>   }
>   catch (...)
>   {
>     // clean up
>     pPicture->Release();
>     pStream->Release();
>     GlobalFree(hData);
>     throw;
>   }
>
>   // retun the bitmap (caller assumes ownership)
>   return Bitmap.release();
> }
>
> HTH,
> -- 
> Damon (TeamB)
> BCBCAQ--http://bcbcaq.bytamin-c.com

I copy and pasted your code directly and only added a button and TOpenDialog
to the form yet receive the following errors:

Build
  [C++ Error] shobjidl.h(2193): E2238 Multiple declaration for
'FOLDERSETTINGS'
  [C++ Error] shobjidl.h(8095): E2238 Multiple declaration for
'DESKBANDINFO'
  [C++ Error] shlobj.h(1422): E2238 Multiple declaration for 'FVSHOWINFO'
  [C++ Error] shlobj.h(3457): E2238 Multiple declaration for
'SHELLFLAGSTATE'
  [C++ Error] Unit1.cpp(25): E2015 Ambiguity between 'CLSID_ActiveDesktop'
and 'Shlobj::CLSID_ActiveDesktop'

using C++Builder v6, I assume the active desktop is declared somewere else
(obviously) but I am unsure of where, if I commecnt out shlobj.h then
IActiveDesktop is called an undefined symbol and therefore there are other
errors. When I click an error it opens up shobjidl.h btw. Hope you can
locate the problem
--Sub

"Subliminal" <doug@cowie3.fsnet.co.uk> wrote in message
news:3ea9a584@newsgroups.borland.com...
> I copy and pasted your code directly and only
> added a button and TOpenDialog to the form
> yet receive the following errors:
<snip>

Go into the Project Options and add NO_WIN32_LEAN_AND_MEAN to the
Conditionals list.


Gambit

Thanks thats reduced the errors to the last one:
[C++ Error] Unit1.cpp(25): E2015 Ambiguity between 'CLSID_ActiveDesktop'
and 'Shlobj::CLSID_ActiveDesktop'
 which I still get when I comment  "#include <shlobj.h>" out.
I changed
CoCreateInstance(Shlobj::CLSID_ActiveDesktop......
and it worked fine.
Thanks Remy

"Subliminal" <doug@cowie3.fsnet.co.uk> wrote in message
news:3eaba62f@newsgroups.borland.com...

> [C++ Error] Unit1.cpp(25): E2015 Ambiguity between
> 'CLSID_ActiveDesktop' and 'Shlobj::CLSID_ActiveDesktop'

Are you including the VCL's ShlObj.hpp header file as well as the API's
shlobj.h header file?  If so, don't.  They can't be included together.
Choose one or the other, not both.


Gambit