path: root/src/tools/qglobal.cpp

/****************************************************************************
**
** Global functions
**
** Created : 920604
**
** Copyright (C) 1992-2008 Trolltech ASA.  All rights reserved.
**
** This file is part of the tools module of the TQt GUI Toolkit.
**
** This file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free
** Software Foundation and appearing in the files LICENSE.GPL2
** and LICENSE.GPL3 included in the packaging of this file.
** Alternatively you may (at your option) use any later version
** of the GNU General Public License if such license has been
** publicly approved by Trolltech ASA (or its successors, if any)
** and the KDE Free TQt Foundation.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/.
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at sales@trolltech.com.
**
** This file may be used under the terms of the Q Public License as
** defined by Trolltech ASA and appearing in the file LICENSE.TQPL
** included in the packaging of this file.  Licensees holding valid TQt
** Commercial licenses may use this file in accordance with the TQt
** Commercial License Agreement provided with the Software.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
** herein.
**
**********************************************************************/

#include "qplatformdefs.h"

#include "tqasciidict.h"
#include <tqdatetime.h>
#include <limits.h>
#include <stdio.h>
#include <limits.h>
#include <stdarg.h>
#include <stdlib.h>

#if defined(Q_CC_MSVC) && !defined(Q_CC_MSVC_NET) && !defined(Q_OS_TEMP)
#include <crtdbg.h>
#endif


/*!
    \relates TQApplication

    Returns the TQt version number as a string, for example, "2.3.0" or
    "3.0.5".

    The \c TQT_VERSION define has the numeric value in the form:
    0xmmiibb (m = major, i = minor, b = bugfix). For example, TQt
    3.0.5's \c TQT_VERSION is 0x030005.
*/

const char *tqVersion()
{
    return TQT_VERSION_STR;
}

bool tqSharedBuild()
{
#ifdef QT_SHARED
    return TRUE;
#else
    return FALSE;
#endif
}

/*****************************************************************************
  System detection routines
 *****************************************************************************/

static bool si_alreadyDone = FALSE;
static int  si_wordSize;
static bool si_bigEndian;

/*!
    \relates TQApplication

    Obtains information about the system.

    The system's word size in bits (typically 32) is returned in \a
    *wordSize. The \a *bigEndian is set to TRUE if this is a big-endian
    machine, or to FALSE if this is a little-endian machine.

    In debug mode, this function calls tqFatal() with a message if the
    computer is truly weird (i.e. different endianness for 16 bit and
    32 bit integers); in release mode it returns FALSE.
*/

bool tqSysInfo( int *wordSize, bool *bigEndian )
{
#if defined(QT_CHECK_NULL)
    Q_ASSERT( wordSize != 0 );
    Q_ASSERT( bigEndian != 0 );
#endif

    if ( si_alreadyDone ) {			// run it only once
	*wordSize  = si_wordSize;
	*bigEndian = si_bigEndian;
	return TRUE;
    }

    si_wordSize = 0;
    TQ_ULONG n = (TQ_ULONG)(~0);
    while ( n ) {				// detect word size
	si_wordSize++;
	n /= 2;
    }
    *wordSize = si_wordSize;

    if ( *wordSize != 64 &&
	 *wordSize != 32 &&
	 *wordSize != 16 ) {			// word size: 16, 32 or 64
#if defined(QT_CHECK_RANGE)
	tqFatal( "qSysInfo: Unsupported system word size %d", *wordSize );
#endif
	return FALSE;
    }
    if ( sizeof(TQ_INT8) != 1 || sizeof(TQ_INT16) != 2 || sizeof(TQ_INT32) != 4 ||
	 sizeof(TQ_ULONG)*8 != si_wordSize || sizeof(float) != 4 || sizeof(double) != 8 ) {
#if defined(QT_CHECK_RANGE)
	tqFatal( "qSysInfo: Unsupported system data type size" );
#endif
	return FALSE;
    }

    bool  be16, be32;				// determine byte ordering
    short ns = 0x1234;
    int	  nl = 0x12345678;

    unsigned char *p = (unsigned char *)(&ns);	// 16-bit integer
    be16 = *p == 0x12;

    p = (unsigned char *)(&nl);			// 32-bit integer
    if ( p[0] == 0x12 && p[1] == 0x34 && p[2] == 0x56 && p[3] == 0x78 )
	be32 = TRUE;
    else
    if ( p[0] == 0x78 && p[1] == 0x56 && p[2] == 0x34 && p[3] == 0x12 )
	be32 = FALSE;
    else
	be32 = !be16;

    if ( be16 != be32 ) {			// strange machine!
#if defined(QT_CHECK_RANGE)
	tqFatal( "qSysInfo: Inconsistent system byte order" );
#endif
	return FALSE;
    }

    *bigEndian = si_bigEndian = be32;
    si_alreadyDone = TRUE;
    return TRUE;
}

#if defined(Q_OS_MAC)

#include "qt_mac.h"

// This function has descended from Apple Source Code (FSpLocationFromFullPath),
// but changes have been made. [Creates a minimal alias from the full pathname]
OSErr qt_mac_create_fsspec(const TQString &file, FSSpec *spec)
{
    FSRef fref;
    TQCString utfs = file.utf8();
    OSErr ret = FSPathMakeRef((const UInt8 *)utfs.data(), &fref, NULL);
    if(ret == noErr)
	ret = FSGetCatalogInfo(&fref, kFSCatInfoNone, NULL, NULL, spec, NULL);
    return ret;
}

CFStringRef tqstring2cfstring(const TQString &str)
{
    return CFStringCreateWithCharacters(0, (UniChar *)str.unicode(), str.length());
}

TQString cfstring2qstring(CFStringRef str)
{
    if(!str)
	return TQString();

    CFIndex length = CFStringGetLength(str);
    if(const UniChar *chars = CFStringGetCharactersPtr(str))
	return TQString((TQChar *)chars, length);
    UniChar *buffer = (UniChar*)malloc(length * sizeof(UniChar));
    CFStringGetCharacters(str, CFRangeMake(0, length), buffer);
    TQString ret((TQChar *)buffer, length);
    free(buffer);
    return ret;
}

unsigned char *p_str(const TQString &s)
{
    CFStringRef cfstr = tqstring2cfstring(s);
    uchar *p = (uchar*)malloc(256);
    CFStringGetPascalString(cfstr, p, 256, CFStringGetSystemEncoding());
    CFRelease(cfstr);
    return p;
}

TQString p2qstring(const unsigned char *c) {
    CFStringRef cfstr = CFStringCreateWithPascalString(0, c, CFStringGetSystemEncoding());
    TQString str = cfstring2qstring(cfstr);
    CFRelease(cfstr);
    return str;
}

int qMacVersion()
{
    static int macver = TQt::MV_Unknown;
    static bool first = TRUE;
    if(first) {
	first = FALSE;
	long gestalt_version;
	if(Gestalt(gestaltSystemVersion, &gestalt_version) == noErr) {
            macver = ((gestalt_version & 0x00f0) >> 4) + 2;

	}
    }
    return macver;
}
TQt::MacintoshVersion qt_macver = (TQt::MacintoshVersion)qMacVersion();

// HFS+ filesystems use decomposing unicode for certain layers in unicode
// In general these don't look great as a user visible string.
// Therefore it is a good idea to normalize them ourselves.
// These technotes on Apple's website:
// http://developer.apple.com/qa/qa2001/qa1235.html
// http://developer.apple.com/qa/qa2001/qa1173.html
TQString qt_mac_precomposeFileName(const TQString &str)
{
    if (str.isEmpty())
        return str;
    int strLength = str.length();
    CFMutableStringRef cfmstr = CFStringCreateMutable(0, strLength);
    CFStringAppendCharacters(cfmstr, (UniChar *)str.unicode(), strLength);
    CFStringNormalize(cfmstr, kCFStringNormalizationFormC);
    TQString newStr = cfstring2qstring(cfmstr);
    CFRelease(cfmstr);
    return newStr;
}
#elif defined(Q_OS_WIN32) || defined(Q_OS_CYGWIN) || defined(Q_OS_TEMP)
bool qt_winunicode;
# ifdef Q_OS_TEMP
  DWORD qt_cever = 0;
# endif // Q_OS_TEMP

#include "qt_windows.h"

int qWinVersion()
{
#ifndef VER_PLATFORM_WIN32s
#define VER_PLATFORM_WIN32s	    0
#endif
#ifndef VER_PLATFORM_WIN32_WINDOWS
#define VER_PLATFORM_WIN32_WINDOWS  1
#endif
#ifndef VER_PLATFORM_WIN32_NT
#define VER_PLATFORM_WIN32_NT	    2
#endif
#ifndef VER_PLATFORM_WIN32_CE
#define VER_PLATFORM_WIN32_CE	    3
#endif

    static int winver = TQt::WV_NT;
    static int t=0;
    if ( !t ) {
	t=1;
#ifndef Q_OS_TEMP
	OSVERSIONINFOA osver;
	osver.dwOSVersionInfoSize = sizeof(osver);
	GetVersionExA( &osver );
#else
	OSVERSIONINFOW osver;
	osver.dwOSVersionInfoSize = sizeof(osver);
	GetVersionEx( &osver );
	qt_cever = osver.dwMajorVersion * 100;
	qt_cever += osver.dwMinorVersion * 10;
#endif
	switch ( osver.dwPlatformId ) {
	case VER_PLATFORM_WIN32s:
	    winver = TQt::WV_32s;
	    break;
	case VER_PLATFORM_WIN32_WINDOWS:
	    // We treat Windows Me (minor 90) the same as Windows 98
	    if ( osver.dwMinorVersion == 90 )
		winver = TQt::WV_Me;
	    else if ( osver.dwMinorVersion == 10 )
		winver = TQt::WV_98;
	    else
		winver = TQt::WV_95;
	    break;
	case VER_PLATFORM_WIN32_CE:
#ifdef Q_OS_TEMP
	    if ( qt_cever >= 400 )
		winver = TQt::WV_CENET;
	    else
#endif
		winver = TQt::WV_CE;
	    break;
	default: // VER_PLATFORM_WIN32_NT
	    if ( osver.dwMajorVersion < 5 ) {
		winver = TQt::WV_NT;
	    } else if (osver.dwMajorVersion == 6) {
	    winver = TQt::WV_VISTA;
	    } else if ( osver.dwMinorVersion == 0 ) {
		winver = TQt::WV_2000;
	    } else if ( osver.dwMinorVersion == 1 ) {
		winver = TQt::WV_XP;
	    } else if ( osver.dwMinorVersion == 2 ) {
		winver = TQt::WV_2003;
	    } else {
		tqWarning("Untested Windows version detected!");
		winver = TQt::WV_NT_based;
	    }
	}
    }

#if defined(UNICODE)
    if ( winver & TQt::WV_NT_based )
	qt_winunicode = TRUE;
    else
#endif
	qt_winunicode = FALSE;

    return winver;
}

TQt::WindowsVersion qt_winver = (TQt::WindowsVersion)qWinVersion();
#endif


/*****************************************************************************
  Debug output routines
 *****************************************************************************/

/*!
    \fn void tqDebug( const char *msg, ... )

    \relates TQApplication

    Prints a debug message \a msg, or calls the message handler (if it
    has been installed).

    This function takes a format string and a list of arguments,
    similar to the C printf() function.

    Example:
    \code
	tqDebug( "my window handle = %x", myWidget->id() );
    \endcode

    Under X11, the text is printed to stderr. Under Windows, the text
    is sent to the debugger.

    \warning The internal buffer is limited to 8196 bytes (including
    the '\0'-terminator).

    \warning Passing (const char *)0 as argument to tqDebug might lead
    to crashes on certain platforms due to the platforms printf implementation.

    \sa tqWarning(), tqFatal(), qInstallMsgHandler(),
	\link debug.html Debugging\endlink
*/

/*!
    \fn void tqWarning( const char *msg, ... )

    \relates TQApplication

    Prints a warning message \a msg, or calls the message handler (if
    it has been installed).

    This function takes a format string and a list of arguments,
    similar to the C printf() function.

    Example:
    \code
	void f( int c )
	{
	    if ( c > 200 )
		tqWarning( "f: bad argument, c == %d", c );
	}
    \endcode

    Under X11, the text is printed to stderr. Under Windows, the text
    is sent to the debugger.

    \warning The internal buffer is limited to 8196 bytes (including
    the '\0'-terminator).

    \warning Passing (const char *)0 as argument to tqWarning might lead
    to crashes on certain platforms due to the platforms printf implementation.

    \sa tqDebug(), tqFatal(), qInstallMsgHandler(),
    \link debug.html Debugging\endlink
*/

/*!
    \fn void tqFatal( const char *msg, ... )

    \relates TQApplication

    Prints a fatal error message \a msg and exits, or calls the
    message handler (if it has been installed).

    This function takes a format string and a list of arguments,
    similar to the C printf() function.

    Example:
    \code
	int divide( int a, int b )
	{
	    if ( b == 0 )				// program error
		tqFatal( "divide: cannot divide by zero" );
	    return a/b;
	}
    \endcode

    Under X11, the text is printed to stderr. Under Windows, the text
    is sent to the debugger.

    \warning The internal buffer is limited to 8196 bytes (including
    the '\0'-terminator).

    \warning Passing (const char *)0 as argument to tqFatal might lead
    to crashes on certain platforms due to the platforms printf implementation.

    \sa tqDebug(), tqWarning(), qInstallMsgHandler(),
    \link debug.html Debugging\endlink
*/


static TQtMsgHandler handler = 0;		// pointer to debug handler
static const int QT_BUFFER_LENGTH = 8196;	// internal buffer length


#ifdef Q_CC_MWERKS

#include "qt_mac.h"

extern bool tqt_is_gui_used;
static void mac_default_handler( const char *msg )
{
    if ( tqt_is_gui_used ) {
	const unsigned char *p = p_str(msg);
	DebugStr(p);
	free((void*)p);
    } else {
	fprintf( stderr, msg );
    }
}

#endif

void handle_buffer(const char *buf, TQtMsgType msgType)
{
    if ( handler ) {
	(*handler)( msgType, buf );
    } else if (msgType == TQtFatalMsg) {
#if defined(Q_CC_MWERKS)
        mac_default_handler(buf);
#else
	fprintf( stderr, "%s\n", buf );		// add newline
#endif
#if defined(Q_OS_UNIX) && defined(QT_DEBUG)
	abort();				// trap; generates core dump
#elif defined(Q_OS_TEMP) && defined(QT_DEBUG)
	TQString fstr;
	fstr.sprintf( "%s:%s %s %s\n", __FILE__, __LINE__, TQT_VERSION_STR, buf );
	OutputDebugString( fstr.ucs2() );
#elif defined(_CRT_ERROR) && defined(_DEBUG)
	_CrtDbgReport( _CRT_ERROR, __FILE__, __LINE__, TQT_VERSION_STR, buf );
#else
	exit( 1 );				// goodbye cruel world
#endif
    } else {
#if defined(Q_CC_MWERKS)
        mac_default_handler(buf);
#elif defined(Q_OS_TEMP)
	TQString fstr( buf );
	OutputDebugString( (fstr + "\n").ucs2() );
#else
	fprintf( stderr, "%s\n", buf );		// add newline
#endif
    }
}

void tqDebug( const TQString &msg )
{
    char buf[QT_BUFFER_LENGTH];
    strcpy( buf, TQDateTime::currentDateTime().toString("[yyyy/MM/dd hh:mm:ss.zzz] ").local8Bit() );
    int len = strlen(buf);
    strncpy( &buf[len], msg.local8Bit(), QT_BUFFER_LENGTH - len - 1 );
    len += msg.length();
    if (len >= QT_BUFFER_LENGTH) {
        len = QT_BUFFER_LENGTH - 1;
    }
    buf[len] = '\0';
    handle_buffer(buf, TQtDebugMsg);
}

void tqDebug( const char *msg, ... )
{
    char buf[QT_BUFFER_LENGTH];
    strcpy( buf, TQDateTime::currentDateTime().toString("[yyyy/MM/dd hh:mm:ss.zzz] ").local8Bit() );
    int len = strlen(buf);
    va_list ap;
    va_start( ap, msg );			// use variable arg list
#if defined(QT_VSNPRINTF)
    QT_VSNPRINTF( &buf[len], QT_BUFFER_LENGTH-len, msg, ap );
#else
    vsprintf( &buf[len], msg, ap );
#endif
    va_end( ap );
    handle_buffer(buf, TQtDebugMsg);
}

void tqDebug( const TQCString &s )
{
    tqDebug("%s", s.data());
}

void tqWarning( const TQString &msg )
{
    char buf[QT_BUFFER_LENGTH];
    strcpy( buf, TQDateTime::currentDateTime().toString("[yyyy/MM/dd hh:mm:ss.zzz] ").local8Bit() );
    int len = strlen(buf);
    strncpy( &buf[len], msg.local8Bit(), QT_BUFFER_LENGTH - len - 1 );
    len += msg.length();
    if (len >= QT_BUFFER_LENGTH) {
        len = QT_BUFFER_LENGTH - 1;
    }
    buf[len] = '\0';
    handle_buffer(buf, TQtWarningMsg);
}

void tqWarning( const char *msg, ... )
{
    char buf[QT_BUFFER_LENGTH];
    strcpy( buf, TQDateTime::currentDateTime().toString("[yyyy/MM/dd hh:mm:ss.zzz] ").local8Bit() );
    int len = strlen(buf);
    va_list ap;
    va_start( ap, msg );			// use variable arg list
#if defined(QT_VSNPRINTF)
    QT_VSNPRINTF( &buf[len], QT_BUFFER_LENGTH-len, msg, ap );
#else
    vsprintf( &buf[len], msg, ap );
#endif
    va_end( ap );
    handle_buffer(buf, TQtWarningMsg);
}

void tqWarning( const TQCString &s )
{
    tqWarning("%s", s.data());
}

void tqFatal( const TQString &msg )
{
    char buf[QT_BUFFER_LENGTH];
    strcpy( buf, TQDateTime::currentDateTime().toString("[yyyy/MM/dd hh:mm:ss.zzz] ").local8Bit() );
    int len = strlen(buf);
    strncpy( &buf[len], msg.local8Bit(), QT_BUFFER_LENGTH - len - 1 );
    len += msg.length();
    if (len >= QT_BUFFER_LENGTH) {
        len = QT_BUFFER_LENGTH - 1;
    }
    buf[len] = '\0';
    handle_buffer(buf, TQtFatalMsg);
}

void tqFatal( const char *msg, ... )
{
    char buf[QT_BUFFER_LENGTH];
    strcpy( buf, TQDateTime::currentDateTime().toString("[yyyy/MM/dd hh:mm:ss.zzz] ").local8Bit() );
    int len = strlen(buf);
    va_list ap;
    va_start( ap, msg );			// use variable arg list
#if defined(QT_VSNPRINTF)
    QT_VSNPRINTF( &buf[len], QT_BUFFER_LENGTH-len, msg, ap );
#else
    vsprintf( &buf[len], msg, ap );
#endif
    va_end( ap );
    handle_buffer(buf, TQtFatalMsg);
}

void tqFatal( const TQCString &s )
{
    tqWarning("%s", s.data());
}

/*!
  \relates TQApplication

  Prints the message \a msg and uses \a code to get a system specific
  error message. When \a code is -1 (the default), the system's last
  error code will be used if possible. Use this method to handle
  failures in platform specific API calls.

  This function does nothing when TQt is built with \c TQT_NO_DEBUG
  defined.
*/
void tqSystemWarning( const char* msg, int code )
{
#ifndef TQT_NO_DEBUG
#if defined(Q_OS_WIN32)
    if ( code == -1 )
	code = GetLastError();

    if ( !code )
	return;

    unsigned short *string;
    QT_WA( {
	FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM,
		       NULL,
		       code,
		       MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
		       (LPTSTR)&string,
		       0,
		       NULL );

	tqWarning( "%s\n\tError code %d - %s", msg, code, TQString::fromUcs2(string).latin1() );
    }, {
	FormatMessageA( FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM,
			NULL,
			code,
			MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
			(char*)&string,
			0,
			NULL );

	tqWarning( "%s\n\tError code %d - %s", msg, code, (const char*)string );
    } );
    LocalFree( (HLOCAL)string );
#else
    if ( code != -1 )
	tqWarning( "%s\n\tError code %d - %s", msg, code, strerror( code ) );
    else
	tqWarning( "%s", msg );
#endif
#else
    Q_UNUSED( msg );
    Q_UNUSED( code );
#endif
}

/*!
    \fn void Q_ASSERT( bool test )

    \relates TQApplication

    Prints a warning message containing the source code file name and
    line number if \a test is FALSE.

    This is really a macro defined in \c ntqglobal.h.

    Q_ASSERT is useful for testing pre- and post-conditions.

    Example:
    \code
	//
	// File: div.cpp
	//

	#include <ntqglobal.h>

	int divide( int a, int b )
	{
	    Q_ASSERT( b != 0 );			// this is line 9
	    return a/b;
	}
    \endcode

    If \c b is zero, the Q_ASSERT statement will output the following
    message using the tqWarning() function:
    \code
	ASSERT: "b != 0" in div.cpp (9)
    \endcode

    \sa tqWarning(), \link debug.html Debugging\endlink
*/


/*!
    \fn void TQ_CHECK_PTR( void *p )

    \relates TQApplication

    If \a p is 0, prints a warning message containing the source code file
    name and line number, saying that the program ran out of memory.

    This is really a macro defined in \c ntqglobal.h.

    Example:
    \code
	int *a;

	TQ_CHECK_PTR( a = new int[80] );  // WRONG!

	a = new (nothrow) int[80];       // Right
	TQ_CHECK_PTR( a );
    \endcode

    \sa tqWarning(), \link debug.html Debugging\endlink
*/


//
// The TQ_CHECK_PTR macro calls this function to check if an allocation went ok.
//
bool tqt_check_pointer( bool c, const char *n, int l )
{
    if ( c )
	tqWarning( "In file %s, line %d: Out of memory", n, l );
    return TRUE;
}


static bool firstObsoleteWarning(const char *obj, const char *oldfunc )
{
    static TQAsciiDict<int> *obsoleteDict = 0;
    if ( !obsoleteDict ) {			// first time func is called
	obsoleteDict = new TQAsciiDict<int>;
#if defined(QT_DEBUG)
	tqDebug(
      "You are using obsolete functions in the TQt library. Call the function\n"
      "qSuppressObsoleteWarnings() to suppress obsolete warnings.\n"
	     );
#endif
    }
    TQCString s( obj );
    s += "::";
    s += oldfunc;
    if ( obsoleteDict->find(s.data()) == 0 ) {
	obsoleteDict->insert( s.data(), (int*)1 );	// anything different from 0
	return TRUE;
    }
    return FALSE;
}

static bool suppressObsolete = FALSE;

void tqSuppressObsoleteWarnings( bool suppress )
{
    suppressObsolete = suppress;
}

void tqObsolete(	 const char *obj, const char *oldfunc, const char *newfunc )
{
    if ( suppressObsolete )
	return;
    if ( !firstObsoleteWarning(obj, oldfunc) )
	return;
    if ( obj )
	tqDebug( "%s::%s: This function is obsolete, use %s instead.",
	       obj, oldfunc, newfunc );
    else
	tqDebug( "%s: This function is obsolete, use %s instead.",
	       oldfunc, newfunc );
}

void tqObsolete(	 const char *obj, const char *oldfunc )
{
    if ( suppressObsolete )
	return;
    if ( !firstObsoleteWarning(obj, oldfunc) )
	return;
    if ( obj )
	tqDebug( "%s::%s: This function is obsolete.", obj, oldfunc );
    else
	tqDebug( "%s: This function is obsolete.", oldfunc );
}

void tqObsolete(	 const char *message )
{
    if ( suppressObsolete )
	return;
    if ( !firstObsoleteWarning( "TQt", message) )
	return;
    tqDebug( "%s", message );
}


/*!
    \relates TQApplication

    Installs a TQt message handler \a h. Returns a pointer to the
    message handler previously defined.

    The message handler is a function that prints out debug messages,
    warnings and fatal error messages. The TQt library (debug version)
    contains hundreds of warning messages that are printed when
    internal errors (usually invalid function arguments) occur. If you
    implement your own message handler, you get total control of these
    messages.

    The default message handler prints the message to the standard
    output under X11 or to the debugger under Windows. If it is a
    fatal message, the application aborts immediately.

    Only one message handler can be defined, since this is usually
    done on an application-wide basis to control debug output.

    To restore the message handler, call \c qInstallMsgHandler(0).

    Example:
    \code
	#include <ntqapplication.h>
	#include <stdio.h>
	#include <stdlib.h>

	void myMessageOutput( TQtMsgType type, const char *msg )
	{
	    switch ( type ) {
		case TQtDebugMsg:
		    fprintf( stderr, "Debug: %s\n", msg );
		    break;
		case TQtWarningMsg:
		    fprintf( stderr, "Warning: %s\n", msg );
		    break;
		case TQtFatalMsg:
		    fprintf( stderr, "Fatal: %s\n", msg );
		    abort();			// deliberately core dump
	    }
	}

	int main( int argc, char **argv )
	{
	    qInstallMsgHandler( myMessageOutput );
	    TQApplication a( argc, argv );
	    ...
	    return a.exec();
	}
    \endcode

    \sa tqDebug(), tqWarning(), tqFatal(), \link debug.html Debugging\endlink
*/

TQtMsgHandler qInstallMsgHandler( TQtMsgHandler h )
{
    TQtMsgHandler old = handler;
    handler = h;
    return old;
}


/*
    Dijkstra's bisection algorithm to find the square root as an integer.
    Deliberately not exported as part of the TQt API, but used in
    qsimplerichtext.cpp
*/
unsigned int qt_int_sqrt( unsigned int n )
{
    // n must be in the range 0...UINT_MAX/2-1
    if ( n >= ( UINT_MAX>>2 ) ) {
	unsigned int r = 2 * qt_int_sqrt( n / 4 );
	unsigned int r2 = r + 1;
	return ( n >= r2 * r2 ) ? r2 : r;
    }
    uint h, p= 0, q= 1, r= n;
    while ( q <= n )
        q <<= 2;
    while ( q != 1 ) {
        q >>= 2;
        h= p + q;
        p >>= 1;
        if ( r >= h ) {
            p += q;
            r -= h;
        }
    }
    return p;
}