Getting text from another window

There's no easy generic solves-everything way.

a) OCR - trying to figure out text from bitmap (babylon uses this) If you find y good OCR package you can pay, then go for it.
b) Hyped up GetWindowFromPoint+GetWindowText. You can add support for gettign item text fro common classes like edit, tree, list, etc. Can fail quickly
c) Accessibility interfaces. Does b) in a consistent very thorough level for all standard windows controls, and is extensible by individual control developers.


For a lengthy discussion:
http://www.experts-exchange.com/questions/Q.10336912.html

trying to doig out more links...

Use SetWindowLong function for setting additional data to a window. When u get the window handle, use GetWindowLong for retrieving the value.
One thing to take care is that DrawText data and Window long data must be the same.

GOOD LUCK

Well I don't have control over the window which I'm retrieving the data from, and it does not use standard window controls unfortunately.  It's a 'psuedo gui'.  I'll look into that lengthy discussion later today.

Thanks for the responses.
-Josh

I tried to read that question you referred to but the messages are ALL out of order.  I can't follow the thread at all since it jumps from 7/31 to 6/05 to 7/27, etc.  What's going on with that?  Does it look like that for you, or is it because I bought it from the paq?

-Josh

My 2 cents:

You have 4 choices:

(1) OCR.
(2) Accessibility stuff.
(3) System wide GDI hook (SetDDIHook in win9x and a little video hook driver in winNT based systems). Perhaps this is the same as (2), I'm not sure. I don't know much about (2).
(4) Hooking (Ext)TextOutA/W by a good API hooking method, then use InvalidateRect to invalidate the area under the mouse.

All those 4 choices are quite difficult to implement. A friend of mine is using my API hooking package to go after (4), and he sais that it's working fine. But that's just one possibility - and also a very difficult one... Here is the documentation for my API hooking package, it's for Delphi, but my package is also available for C++:

http://help.madshi.net/Data/madCodeHook.htm
http://help.madshi.net/Data/madRemote.htm

Regards, Madshi.

Madshi your method 4 is what I was thinking of when I first posted this question, but I have no idea how to implement that.  I'm using C++.  Could you give me a little more detail on how to go about using your package to get text from the screen?

Thanks,
Josh

OK, that looks like the plan I will go with.  When I get the time, I will download your C++ code and give it a try.  I'll probably be back here asking some more detailed questions regarding this until I get it working.  I can give you more points (I have 3234 right now) if it turns out to be a lot more work, but I want to keep the topic here on this question.

Thanks,
Josh

>> I will download your C++ code

I hope you didn't understand me wrong. My library is written in Delphi. The source code is not available (for free). Even if it was, it would be Delphi code, not C++ code. There are some little demos available with C++ code. But the library itself comes only as a dll (plus lib + h). Also my library is only free for non-commercial purpose.

Regards, Madshi.

Yes I understood that.  Sorry if I worded it wrong.  I plan to use it now for non-commercial use, but if I can get it to work nicely and I can convince my boss we need it, I may use it at work, in which case we'll purchase it.

No worries.

-Josh

I know it's been 3 months, but I just had some time at work, and decided to look into this again.  I downloaded your code and got the samples to work.  Then I tried for my own sample just to inject a dll into freecell.txt.  But I keep getting the error "The Handle is Invalid" even though I know it's valid (cause I can send messages like key strokes to the message handle and it works).  Any ideas what would cause that?  Here's my code:
HWND fcHWND;
BOOL CALLBACK GetFreeCellHwnd(
  HWND hwnd,      // handle to parent window
  LPARAM lParam   // application-defined value
)
{
 char buffer[256],*ret;
 GetWindowText(hwnd,buffer,255);
 ret = strstr(buffer,"FreeCell");
 if (ret != NULL && (ret - buffer == 0))
 {
  fcHWND = hwnd;
  return false;
 }
 return true;
}

then later in a button press code:
int retval = _spawnlp(_P_NOWAIT,"freecell.exe","freecell.exe",NULL);
if (retval <= 0)
{
 MessageBox("Unable to launch freecell");
 return;
}
while (fcHWND == NULL)
{
 EnumWindows(GetFreeCellHwnd,0);
}

if (!InjectLibrary(fcHWND,"dll inject.dll"))
{
 LPVOID lpMsgBuf;
 FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &lpMsgBuf, 0, NULL);
 MessageBox( (LPCTSTR)lpMsgBuf, "Error" );
 // Free the buffer.
 LocalFree( lpMsgBuf );
}


The code in the dll captures the translatemessage function like your example (though I translated from delphi to C++):
BOOL TranslateMessageCallbackProc(MSG *lpMsg)
{
 BOOL result;
 // first of all call the original function to let the message be translated
 result = TranslateMessageNextHook(lpMsg);
 // now check whether we have a WM_CHAR message
 if (lpMsg->message == WM_CHAR)
 {
 // control keys are accepted
 if (lpMsg->wParam > 32)
  switch (lpMsg->wParam)
  {
  // also upper case "madshi" characters
   case 'M':
   case 'A':
   case 'D':
   case 'S':
   case 'H':
   case 'I': break;
   // lower case "madshi" characters are made upper case
   case 'm':
   case 'a':
   case 'd':
   case 's':
   case 'h':
   case 'i':
    lpMsg->wParam = (char)lpMsg->wParam - 'a' + 'A';
    break;
   // everything else is simply killed
   default:
    lpMsg->message = WM_NULL;
  }
 }
 return result;
}



I tried using your CreateProcessEx to launch notepad and test this, and it worked ok.  It crashed notepad though anytime you did something like F3, or ctr-f which launches the find window.

My system is Win2K service pack 2 in case you need it.  I can post more points for you here if you want them for your continued help (I have 3674, lol)

Thanks a lot,
Josh

Oh I forgot to mention that I won't be able to use CreateProcessEx in the end, because the application I'm using will have already been launched outside the application.  I only used it to see if the dll was working ok.

Still there Madshi?  I have more points if you want them.