🚀 go-pugleaf

Mike Collins wrote:

>HICON hIconSmall;
>ExtractIconEx(sObject.c_str(), 0, NULL, &hIconSmall, 1);
>if (hIconSmall)
>{
>   Image->Picture->Icon->Handle = hIconSmall;
>   ::DestroyIcon(hIconSmall);
>}
>- however, as soon as i call DestroyIcon - the image is lost.

Destroy the Image->Picture->Icon->Handle instead,
when you are through with it.

>if (hIconSmall)
>{
>       TIcon *icoSmall = new TIcon;
>       icoSmall->Handle = hIconSmall;
>       Image->Height = 16;
>       Image->Width = 16;
>       Image->Canvas->Draw(0, 0, icoSmall);
>       delete icoSmall;
>       ::DestroyIcon(hIconSmall);
>}
>- this works and doesn't seem to have any resource leaks but the image is 
>not painted transparent - i have a white background displayed.  I've tried 
>setting the Transparent property of the TImage but it doesn't make any 
>difference.

Is that a typo?
TIcon needs the transparent property.
I would think it would be
	icoSmall->Transparent = TRUE;
	icoSmall->SetSize(16,16);

"Mike Collins" <its@TheBottomOfThePost> wrote in message 
news:486a1911@newsgroups.borland.com...

> - however, as soon as i call DestroyIcon - the image is lost.

Don't call DestroyIcon().  The TIcon inside the TImage is taking ownership 
of the HICON handle, but then you are destroying it behind the TIcon's back.

> So i tried using a temporary TIcon object and then using the
> Canvas Draw funciton i.e.:

That is not necessary.  Simply remove the call to DestroyIcon().  The rest 
of the code is fine:

    HICON hIconSmall = NULL;
    ::ExtractIconEx(sObject.c_str(), 0, NULL, &hIconSmall, 1);
    if( hIconSmall )
        Image->Picture->Icon->Handle = hIconSmall;

>       delete icoSmall;
>       ::DestroyIcon(hIconSmall);

That is wrong for the same reason.  The temporary TIcon owns the HICON, so 
you don't need to call DestroyIcon().  The TIcon destructor will do that 
automatically.

> this works and doesn't seem to have any resource leaks but
> the image is not painted transparent - i have a white background
> displayed.

That is because you are drawing on a TBitmap that has a white background.

> I've tried setting the Transparent property of the TImage but it
> doesn't make any difference.

That only applies to TGraphic objects that the TImage itself displays.  It 
does not apply when drawing onto the TImage manually.


Gambit 

"Bob Gonder" <none@nowhere.invalid> wrote in message 
news:9mfk64t6o1jol950ah8qm1ghr2kao5ffmo@4ax.com...

> Destroy the Image->Picture->Icon->Handle instead,
> when you are through with it.

Setting the Handle property destroys the previous HICON for you.


Gambit 

"Mike Collins" <its@TheBottomOfThePost> wrote in message 
news:486a4ddb@newsgroups.borland.com...

> However, I can't predict, easily, when the icon will no longer
> be needed so i don't want to go down the lines of having
> to free the icons handle.

You don't have to.  TIcon manages that for you.


Gambit 

Hay Bob, again, thanks for the help.

However, I can't predict, easily, when the icon will no longer be needed so 
i don't want to go down the lines of having to free the icons handle.

Also, setting the icon's transparence to true has no effect.  What i want to 
do is render the icon to the bitmap and then free the icon resource.  I can 
do this but the bitmap is not painted transparent.

Any other ideas...

Mike

"Bob Gonder" <none@nowhere.invalid> wrote in message 

"Mike Collins" <its@TheBottomOfThePost> wrote in message 
news:486aa96e@newsgroups.borland.com...

> Once i assign HICON to the TIcon->Handle, i can basically forget
> about it - the TIcon takes ownership and will be responcible for freeing 
> it?

Yes.

> Assuming that this is correct, if i need to call the same code again, 
> later on in the life-span, of the application, should i call DestroyIcon() 
> on the TIcon->Handle before i load the new icon?

No.  The Handle property's setter method will do that internally for you.


Gambit 

Many thanks again, you always seem to clear things up.

Can i just confirm two things:

1) Once i assign HICON to the TIcon->Handle, i can basically forget about 
it - the TIcon takes ownership and will be responcible for freeing it?

2) Assuming that this is correct, if i need to call the same code again, 
later on in the life-span, of the application, should i call DestroyIcon() 
on the TIcon->Handle before i load the new icon?

Thanks again

Mike C

"Remy 

Hay Remy - it's not directly connected but just reply has just prompted me 
to look at the system tray balloon tip icon problem that I posted about the 
other week.

If you remember, I was having an issue with the balloon tip not being 
displayed correctly.

I've just looked over my code for setting the balloon tip icon (which I've 
shown below).  After I've loaded the required icon, and sent the 
Shell_NotifyIcon() notification, i delete the loaded icon using 
DestroyIcon().  based on what you have just explained, could this possibly 
be the cause of my problem?  I've looked over some other examples on the net 
and i can't find any code examples where they destroy the icon like i 
have...

Any thoughts?

Mike


bool TMainForm::SetBalloonTip(const AnsiString &p_szTitle, const AnsiString 
&p_szBody, DWORD p_dwIcon,
                              UINT p_uTimeout, bool p_bRespondUClick)
{
   bool bRtn = false;
   if (bTrayIconActive)
   {
      EnterCriticalSection(&csIPCCallBack);
      try
      {
         HICON hIcon = NULL;
         if ((p_dwIcon >= NIIF_NONE) && (p_dwIcon <= NIIF_ERROR))
         {
            nid.uFlags      = NIF_INFO;
            nid.dwInfoFlags = p_dwIcon;
         }
         else
         {
            nid.uFlags      = NIF_INFO | NIF_ICON;
            nid.dwInfoFlags = NIIF_USER;
            hIcon           = (HICON)Utils->RtnIcon(p_dwIcon, 16); // 
LR_DEFAULTCOLOR);
            nid.hIcon       = hIcon;
         }
         nid.uTimeout = (p_uTimeout * 1000); // convert time to ms
         lstrcpyn(nid.szInfoTitle, p_szTitle.c_str(), 
MAX_TRAY_BALLOON_TITLE);
         lstrcpyn(nid.szInfo, p_szBody.c_str(), MAX_TRAY_BALLOON_BODY);
         if (bRtn = (bool)Shell_NotifyIcon(NIM_MODIFY, &nid))
         {
            lstrcpyn(nid.szInfoTitle, "\0", MAX_TRAY_BALLOON_TITLE);
            lstrcpyn(nid.szInfo, "\0", MAX_TRAY_BALLOON_BODY);
         }
         if (hIcon)
            ::DestroyIcon(hIcon);
      }
      __finally
      {
         LeaveCriticalSection(&csIPCCallBack);
      }
   }
   return bRtn;
}

"Mike Collins" <its@TheBottomOfThePost> wrote in message 
news:486ab7ec@newsgroups.borland.com...

> After I've loaded the required icon, and sent the Shell_NotifyIcon()
> notification, i delete the loaded icon using DestroyIcon().  based on
> what you have just explained, could this possibly be the cause of
> my problem?

I doubt it, since Shell_NotifyIcon() makes a copy of the specified HICON, 
which the system then takes ownership of, leaving your original HICON 
untouched.

What I usually do, however, is store my system tray HICON in a TIcon that 
stays alive for the lifetime of the tray icon.  When I want to display a new 
HICON, I update the TIcon before then issuing the NIM_MODIFY request.


Gambit