Pipe printf to modeless window Topic is solved

[widgeter]

In my old code, I use printf for tracing purpose. I want to show these trace log in the separate modeless window in real time. What is the best and easiest way of doing this in wxWidgets?
Thanks in advance.

[Avi]

Did you already look at wxLog?

[doublemax]

under MSW i prefer ::wxLogDebug() together with DebugView:
http://www.sysinternals.com/Utilities/DebugView.html

[widgeter]

Did you already look at wxLog?

Hi Avi, I have looked at the relevant documentation, but there are quite a few of them. All seems to be ok for the job. I don't know which one (or what combination) is the best and easiest. Although I have to said I am not completely understand them.

[widgeter]

under MSW i prefer ::wxLogDebug() together with DebugView:
http://www.sysinternals.com/Utilities/DebugView.html

Thanks doublemax, but is the DebugView portable? eg, do I get this in Linux?

[doublemax]

under MSW i prefer ::wxLogDebug() together with DebugView:
http://www.sysinternals.com/Utilities/DebugView.html

Thanks doublemax, but is the DebugView portable? eg, do I get this in Linux?

DebugView is Windows only, i don't know if there is any equivalent for other platforms.

[widgeter]

Thanks again doublemax.

I have had a go with wxLogWindow. It seems to be the closest thing I want.
I instantiate a wxLogWindow by:

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    wxLogWindow logWindow(NULL, "Trace");

When I debug the program, it generates an Unhandled exception from

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wxTextPos wxTextCtrl::GetLastPosition() const

The following is the stack trace when it happens:

• dialogs.exe!wxTextCtrl::GetLastPosition() Line 1170 + 0x11 bytes C++
  dialogs.exe!wxLogWindow::DoLogString(const char * szString=0x00f3df4c, __int64 __formal=1150640749) Line 648 + 0x10 bytes C++
  dialogs.exe!wxLog::DoLog(unsigned long level=6, const char * szString=0x0096a2e8, __int64 t=1150640749) Line 499 C++
  dialogs.exe!wxLogWindow::DoLog(unsigned long level=6, const char * szString=0x0096a2e8, __int64 t=1150640749) Line 639 C++
  dialogs.exe!wxLog::OnLog(unsigned long level=6, const char * szString=0x0096a2e8, __int64 t=1150640749) Line 154 C++
  dialogs.exe!wxVLogDebug(const char * szFormat=0x008a5110, char * argptr=0x018afdd8) Line 310 + 0x7b bytes C++
  dialogs.exe!wxLogDebug(const char * szFormat=0x008a5110, ...) Line 310 + 0x17 bytes C++
  dialogs.exe!wxMutexInternal::Unlock() Line 259 + 0x2e bytes C++
  ....snip

It starts from the wxLogLastError of the following code:

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wxMutexError wxMutexInternal::Unlock()
{
    if ( !::ReleaseMutex(m_mutex) )
    {
        wxLogLastError(_T("ReleaseMutex()"));

        return wxMUTEX_MISC_ERROR;
    }

    return wxMUTEX_NO_ERROR;
}

[doublemax]

what's the lifetime of your wxLogWindow? it looks like you create it on the stack.

Try:

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wxLogWindow *logWindow=new wxLogWindow(NULL, wxT("Trace"));

[widgeter]

You have solved my problem! Good man.. Thanks

Btw, what is the benefit of having "wxT" prepend to the string in wxT("Trace")?

[doublemax]

Btw, what is the benefit of having "wxT" prepend to the string in wxT("Trace")?

From the documentation:

wxT() is a macro which can be used with character and string literals (in other words, 'x' or "foo") to automatically convert them to Unicode in Unicode build configuration

Basically it makes sure that it compiles in both unicode and non-unicode builds

[widgeter]

Thanks guy, I was waiting to fix all the problem and post this to everyone, so I can mark it as solved.

My solution to this is by having a combination of wxLogWindow and wxLogDebug. Basically all printf will be relayed to wxLogDebug, and you will get all the output from the wxLogWindow automatically. Sweet!

If you are working on a multiple thread app. Look at the my other post "SendMessage causing deadlock!". The sample provided by micros is excellent!