Hi Glenn, I admit I was looking at a slightly older version of the CVS (since I can't get access to CVS at work anymore), but most things are the same from what I checked at home.
You mention that messages are queued and combined. I'd not class myself as highly experienced with Windows messaging, but the PeekMessage call in DoEvents specifies "PM_REMOVE" to delete the message it captures from the queue, so this message should be removed. Are you saying that when one uses PeekMessage, WM_LBUTTONDOWN messages will be continually generated by windows, even if PM_REMOVE is specified? The problem is that if GetMessage is called when the mouse button is down, the WM_LBUTTONDOWN message is received, and if you then call GetMessage again, no message is received. However if you call PeekMessage with PM_REMOVE set you get the WM_LBUTTONDOWN message, then if you call PeekMessage again with PM_REMOVE set, you get the WM_LBUTTONDOWN message a second time, then a third time, over and over *until another event occurs such as WM_PAINT or WM_MOUSEMOVE*. There is a function (WaitForInputIdle)that "waits until the specified process is waiting for user input with no input pending, or until the time-out interval has elapsed" and a flag for PeekMessage (PM_NOYIELD) that "prevents the system from releasing any thread that is waiting for the caller to go idle" Perhaps these might fix the problem? I'm pretty sure that the textfield character-doubling could be to do with the fact that one gets both WM_KEYDOWN and WM_KEYUP messages when a key is pressed, and a character is produced for both for some reason. I will muck about with the CVS version (which I can now obtain at work thanks to my cute PC-Anywhere-Via-HTTP-Proxy thingy :) ) and see if I can find a way to solve the problem. Steve -----Original Message----- From: Glenn Linderman [mailto:[EMAIL PROTECTED] Sent: 09 December 2003 19:03 To: Stephen Pick Cc: Win32 GUI Hackers Subject: Re: [perl-win32-gui-hackers] DoEvents() bug. On approximately 12/9/2003 2:59 AM, came the following characters from the keyboard of Stephen Pick: > Hi all. > > When I do this: > > Win32::GUI::Dialog() > > I receive all my events like WM_LBUTTONDOWN (-onMouseDown) once, as > should happen. > > When I do this: > > while(1) { > Win32::GUI::DoEvents() > print "Loop!\n"; > } > > I get endless calls to my event handler so long as the mouse button is > down. I have NO idea why. Must be some kind of windows internal thing. Certain Windows messages are "queued and combined" if you are not looking, but the more often you look, the more often you get them.... I could say if MouseDown is one of those, off hand. I have noticed that a difference between Dialog() and DoEvents() is that if used to process a dialog box containing a text box, that the former responds normally, but the latter generally doubles the characters received by the text box. One difference in my situation is that I was calling DoEvents() from an event, and that might cause some sort of reentrancy problem, but I couldn't understand what it would be if it is such. I gave up and restructured my code to use Dialog() only. > Additionally, since the code for DoEvents() and Dialog() is practically > identical except that DoEvents uses PeekMessage and Dialog uses > GetMessage, I copied both into seperate files and took a look at them in > WinMerge. Interesting. Dialog does ENTER; SAVETMPS; before doing > GetMessage and FREETMPS; LEAVE; at the end of it's while() loop. > DoEvents() doesn't do this. This is because Dialog is "long-running" and needs to be sure to do Perl temporary variable management, and DoEvents returns to Perl more often, so can let Perl do the temporary variable management. I think. > Also, DoEvents has the line "acc = > perlud->hAcc;", and Dialog() DOESNT have that. Dialog() does a > comparison on acc (acc != NULL) in the next few lines just like DoEvents > does, but this comparison will always yield false in Dialog(). I think that was one of the lines I "fixed" in making accelerator keys work. If not, it should have been. What version of source are you looking at? > So. I don't have a compiler here but this is weird. Surely these > functions should be identical but for the change from GetMessage to > PeekMessage. Moreover, if these functions should be identical then why > write the same code for both when a simple function that does either > PeekMessage or GetMessage depending on an argument would remove a lot of > redundant code, for example the new function checkEvents(hwnd, > peekmessage) would do the current Dialog() code with PeekMessage if > peekmessage was set to 1, otherwise it'd do GetMessage, and the Dialog() > and DoEvents() methods could be truncated to: Well, the exit condition is different too, not just the call to GetMessage vs PeekMessage. But that also could be based on the "argument". I agree there is much redundant code there, also see DoModal. > > DWORD > Dialog(hwnd=NULL) > HWND hwnd > CODE: > RETVAL = checkEvents(hwnd,0); > OUTPUT: > RETVAL > > DWORD > DoEvents(hwnd=NULL) > HWND hwnd > CODE: > RETVAL = checkEvents(hwnd,1); > OUTPUT: > RETVAL > > > > Steve > > > ------------------------------------------------------- > This SF.net email is sponsored by: SF.net Giveback Program. > Does SourceForge.net help you be more productive? Does it > help you create better code? SHARE THE LOVE, and help us help > YOU! Click Here: http://sourceforge.net/donate/ > _______________________________________________ > Perl-Win32-GUI-Hackers mailing list > Perl-Win32-GUI-Hackers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/perl-win32-gui-hackers > > -- Glenn -- http://nevcal.com/ =========================== Like almost everyone, I receive a lot of spam every day, much of it offering to help me get out of debt or get rich quick. It's ridiculous. -- Bill Gates And here is why it is ridiculous: The division that includes Windows posted an operating profit of $2.26 billion on revenue of $2.81 billion. --from Reuters via http://biz.yahoo.com/rc/031113/tech_microsoft_msn_1.html So that's profit of over 400% of investment... with a bit more investment in Windows technology, particularly in the area of reliability, the profit percentage might go down, but so might the bugs and security problems? Seems like it would be a reasonable tradeoff. WalMart earnings are 3.4% of investment.
