Custom debug/message handler class to work in conjunction with qDebug() family of functions. More...

#include "AppDebugMessageHandler.h"

Properties
int	appDebugOutputLevel
	Minimum severity level of messages to print. 0 = debug+; 1 = info+; 2 = warning+; 3 = critical+; 4 = fatal only. More...

bool	showFunctionDeclarations
	Enables or disables showing full function declarations (with return and attribute types) in the default message pattern. More...

bool	showSourcePath
	Enables or disabled showing the file path in the default message pattern. More...

bool	showTimestamp
	Enables or disables showing timestamps in the default message pattern. More...

QString	timestampFormat
	Set the timestamp format, as per Qt message pattern docs for `%{time` ...} options. E.g. one of "process", "boot", or a `QDateTime::toString()` format. More...

Properties inherited from QObject
	objectName

Public Member Functions
void	addOutputDevice (QIODevice *device)
	Add a new I/O stream for receiving messages. More...

quint8	appDebugOutputLevel () const

QString	defaultMessagePattern () const
	Returns the default message pattern. This format will take into account any properties set previously, such as `showSourcePath`, `showFunctionDeclarations`, `showTimestamp` and `timestampFormat`. More...

void	installAppMessageHandler ()
	This function must be called to initialize this custom message handler. E.g. `AppDebugMessageHandler::instance()->installAppMessageHandler()` More...

void	messageHandler (QtMsgType type, const QMessageLogContext &context, const QString &msg)
	Handle a debug message. This is typically called by the installed global message handler callback ( `g_appDebugMessageHandler()` ). More...

QString	messagePattern () const
	Returns the current message pattern in use. This will be either the one set specifically with `setMessagePattern()` or the `defaultMessagePattern()` otherwise. More...

void	removeOutputDevice (QIODevice *device)
	Remove a previously-added I/O stream. More...

void	setAppDebugOutputLevel (quint8 appDebugOutputLevel)

void	setMessagePattern (const QString &pattern=QString())
	Specifies a debug message pattern to use instead of the default. More...

void	setShowFunctionDeclarations (bool showFunctionDeclarations)

void	setShowSourcePath (bool showSourcePath)

void	setShowTimestamp (bool showTimestamp)

void	setSourceBasePath (const QString &path=QString())
	Set the base path for source file name filter, everything after this is kept. The string could be literal or a RegEx pattern (evaluated as non-greedy). More...

void	setTimestampFormat (const QString &timeFormat)

bool	showFunctionDeclarations () const

bool	showSourcePath () const

bool	showTimestamp () const

QString	timestampFormat () const

Public Member Functions inherited from QObject
	QObject (QObject *parent)

virtual	~QObject ()

bool	blockSignals (bool block)

const QObjectList &	children () const const

QMetaObject::Connection	connect (const QObject sender, const char signal, const char *method, Qt::ConnectionType type) const const

void	deleteLater ()

void	destroyed (QObject *obj)

bool	disconnect (const char signal, const QObject receiver, const char *method) const const

bool	disconnect (const QObject receiver, const char method) const const

void	dumpObjectInfo () const const

void	dumpObjectInfo ()

void	dumpObjectTree () const const

void	dumpObjectTree ()

QList< QByteArray >	dynamicPropertyNames () const const

virtual bool	event (QEvent *e)

virtual bool	eventFilter (QObject watched, QEvent event)

T	findChild (const QString &name, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QRegExp &regExp, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QString &name, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QRegularExpression &re, Qt::FindChildOptions options) const const

bool	inherits (const char *className) const const

void	installEventFilter (QObject *filterObj)

bool	isWidgetType () const const

bool	isWindowType () const const

void	killTimer (int id)

virtual const QMetaObject *	metaObject () const const

void	moveToThread (QThread *targetThread)

QString	objectName () const const

void	objectNameChanged (const QString &objectName)

QObject *	parent () const const

QVariant	property (const char *name) const const

virtual int	qt_metacall (QMetaObject::Call, int, void **)

virtual void *	qt_metacast (const char *)

void	removeEventFilter (QObject *obj)

void	setObjectName (const QString &name)

void	setParent (QObject *parent)

bool	setProperty (const char *name, const QVariant &value)

bool	signalsBlocked () const const

int	startTimer (int interval, Qt::TimerType timerType)

int	startTimer (std::chrono::milliseconds time, Qt::TimerType timerType)

QThread *	thread () const const

Static Public Member Functions
static AppDebugMessageHandler *	instance ()
	Get the singleton instance of this object. The instance is created automatically if necessary. More...

static QHash< int, QString > &	shortTypeNames ()
	Returns a reference to the mapping of `QtMsgType` enum values to abbreviated names. More...

Static Public Member Functions inherited from QObject
QMetaObject::Connection	connect (const QObject sender, const char signal, const QObject receiver, const char method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject sender, PointerToMemberFunction signal, const QObject receiver, PointerToMemberFunction method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, Functor functor)

QMetaObject::Connection	connect (const QObject sender, PointerToMemberFunction signal, const QObject context, Functor functor, Qt::ConnectionType type)

bool	disconnect (const QMetaObject::Connection &connection)

bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char method)

bool	disconnect (const QObject sender, PointerToMemberFunction signal, const QObject receiver, PointerToMemberFunction method)

bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method)

QString	tr (const char sourceText, const char disambiguation, int n)

QString	trUtf8 (const char sourceText, const char disambiguation, int n)

Signals
void	messageOutput (quint8 level, const QString &msg)
	Notifies when a new log massage is available. More...

Related Functions
(Note that these are not member functions.)
#define	APP_DBG_HANDLER_DEFAULT_LEVEL 0
	Default log level. More...

#define	APP_DBG_HANDLER_ENABLE 1
	Enable/disable this custom handler handler entirely. More...

#define	APP_DBG_HANDLER_SHOW_FUNCTION_DECL 0
	Show full function declaration with return and attribute types instead of just the Class::Name. More...

#define	APP_DBG_HANDLER_SHOW_SRC_PATH 0
	Include source file path/name in output (filtered with APP_DBG_HANDLER_SRC_PATH). More...

#define	APP_DBG_HANDLER_SHOW_TIMESTAMP 0
	Include timestamp in default message pattern. More...

#define	APP_DBG_HANDLER_SRC_PATH ".*src"
	base path for source file name filter, everything after this is kept; RegEx, non-greedy More...

#define	APP_DBG_HANDLER_TIMESTAMP_FORMAT "process"
	Default timestamp format (as per Qt message pattern docs for %{time ...} options). More...

void	g_appDebugMessageHandler (QtMsgType, const QMessageLogContext &, const QString &)

Additional Inherited Members
Protected Member Functions inherited from QObject
virtual void	childEvent (QChildEvent *event)

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const QMetaMethod &signal)

bool	isSignalConnected (const QMetaMethod &signal) const const

int	receivers (const char *signal) const const

QObject *	sender () const const

int	senderSignalIndex () const const

virtual void	timerEvent (QTimerEvent *event)

Detailed Description

Custom debug/message handler class to work in conjunction with qDebug() family of functions.

Version: 2.0.0

AppDebugMessageHandler helps with formatting all stderr output generated by the application in a consistent manner. For example the function and line from which the debug message is called is always printed. It can also be used by other event listeners to intercept messages they may be interested in (connect to messageOutput() signal or add a QIODevice to receive the output).

You can set a minimum logging level for all messages by setting the appDebugOutputLevel property or APP_DBG_HANDLER_DEFAULT_LEVEL macro.

There are several properties which control the default output message formatting. Optionally, a custom pattern can be set with setMessagePattern(). This type of custom pattern allows for additional placeholder values which are not available with the default Qt handler. See setMessagePattern() for details.

Note that the message format can still be overridden by setting QT_MESSAGE_PATTERN environment variable at run-time. see: https://doc.qt.io/qt-5/qtglobal.html#qSetMessagePattern

Include this header to use qInfo() safely with Qt < v5.5 (qInfo becomes alias for qDebug).

This is an app-wide "global" thread-safe singleton class, use it with AppDebugMessageHandler::instance(). For example, at start of application:

QApplication app(argc, argv);

AppDebugMessageHandler::instance()->installAppMessageHandler();

To connect to a signal:

connect(AppDebugMessageHandler::instance(), &AppDebugMessageHandler::messageOutput, this, &DebugOutput::onAppDebugMessage);}

To add a new I/O stream for receiving messages (eg. a log file):

addOutputDevice(myQFile);

When adding a QIODevice in this way, you may optionally set a minimum severity level below which you do not want messages written to this device. Use the Qt property system to set a properly named level on the QIODevice. For example:

myQFile.setProperty("level", 2); // only warning and higher

Definition at line 137 of file AppDebugMessageHandler.h.

Property Documentation

◆ appDebugOutputLevel

int AppDebugMessageHandler::appDebugOutputLevel

readwrite

Minimum severity level of messages to print. 0 = debug+; 1 = info+; 2 = warning+; 3 = critical+; 4 = fatal only.

Access functions:: appDebugOutputLevel(void), setAppDebugOutputLevel()

Definition at line 141 of file AppDebugMessageHandler.h.

◆ showFunctionDeclarations

bool AppDebugMessageHandler::showFunctionDeclarations

readwrite

Enables or disables showing full function declarations (with return and attribute types) in the default message pattern.

Access functions:: showFunctionDeclarations(void), setShowFunctionDeclarations()

Definition at line 145 of file AppDebugMessageHandler.h.

◆ showSourcePath

bool AppDebugMessageHandler::showSourcePath

readwrite

Enables or disabled showing the file path in the default message pattern.

Access functions:: showSourcePath(void), setShowSourcePath()

See also: setSourceBasePath()

Definition at line 143 of file AppDebugMessageHandler.h.

◆ showTimestamp

bool AppDebugMessageHandler::showTimestamp

readwrite

Enables or disables showing timestamps in the default message pattern.

Access functions:: showTimestamp(void), setShowTimestamp()

See also: timestampFormat

Definition at line 147 of file AppDebugMessageHandler.h.

◆ timestampFormat

QString AppDebugMessageHandler::timestampFormat

readwrite

Set the timestamp format, as per Qt message pattern docs for %{time ...} options. E.g. one of "process", "boot", or a QDateTime::toString() format.

Access functions:: timestampFormat(void), setTimestampFormat()

See also: showTimestamp

Definition at line 149 of file AppDebugMessageHandler.h.

Member Function Documentation

◆ addOutputDevice()

void AppDebugMessageHandler::addOutputDevice ( QIODevice * device )

Add a new I/O stream for receiving messages.

Definition at line 102 of file AppDebugMessageHandler.cpp.

◆ appDebugOutputLevel()

quint8 AppDebugMessageHandler::appDebugOutputLevel ( void ) const

inline

See also: appDebugOutputLevel

Definition at line 157 of file AppDebugMessageHandler.h.

◆ defaultMessagePattern()

QString AppDebugMessageHandler::defaultMessagePattern ( ) const

Returns the default message pattern. This format will take into account any properties set previously, such as showSourcePath, showFunctionDeclarations, showTimestamp and timestampFormat.

Definition at line 126 of file AppDebugMessageHandler.cpp.

◆ installAppMessageHandler()

void AppDebugMessageHandler::installAppMessageHandler ( )

This function must be called to initialize this custom message handler. E.g. AppDebugMessageHandler::instance()->installAppMessageHandler()

Definition at line 160 of file AppDebugMessageHandler.cpp.

◆ instance()

AppDebugMessageHandler * AppDebugMessageHandler::instance ( )

static

Get the singleton instance of this object. The instance is created automatically if necessary.

Definition at line 50 of file AppDebugMessageHandler.cpp.

◆ messageHandler()

void AppDebugMessageHandler::messageHandler	(	QtMsgType	type,
		const QMessageLogContext &	context,
		const QString &	msg
	)

Handle a debug message. This is typically called by the installed global message handler callback ( g_appDebugMessageHandler() ).

Definition at line 169 of file AppDebugMessageHandler.cpp.

◆ messageOutput

void AppDebugMessageHandler::messageOutput	(	quint8	level,
		const QString &	msg
	)

signal

Notifies when a new log massage is available.

◆ messagePattern()

QString AppDebugMessageHandler::messagePattern ( ) const

Returns the current message pattern in use. This will be either the one set specifically with setMessagePattern() or the defaultMessagePattern() otherwise.

Definition at line 155 of file AppDebugMessageHandler.cpp.

◆ removeOutputDevice()

void AppDebugMessageHandler::removeOutputDevice ( QIODevice * device )

Remove a previously-added I/O stream.

Definition at line 109 of file AppDebugMessageHandler.cpp.

◆ setAppDebugOutputLevel()

void AppDebugMessageHandler::setAppDebugOutputLevel ( quint8 appDebugOutputLevel )

See also: appDebugOutputLevel

Definition at line 56 of file AppDebugMessageHandler.cpp.

◆ setMessagePattern()

void AppDebugMessageHandler::setMessagePattern ( const QString & pattern = QString() )

Specifies a debug message pattern to use instead of the default.

The pattern is the same as for qSetMessagePattern() but extended with the following attributes:

%{short-type} : Short type name (eg. "W" for warning, "D" for debug, etc) (as returned by shortTypeNames())
%{full-function} : Full function declaration including return and attribute types (if any)

Call this function with a blank QString to reset the message pattern back to default.

Definition at line 96 of file AppDebugMessageHandler.cpp.

◆ setShowFunctionDeclarations()

void AppDebugMessageHandler::setShowFunctionDeclarations ( bool showFunctionDeclarations )

See also: showFunctionDeclarations

Definition at line 75 of file AppDebugMessageHandler.cpp.

◆ setShowSourcePath()

void AppDebugMessageHandler::setShowSourcePath ( bool showSourcePath )

See also: showSourcePath

Definition at line 62 of file AppDebugMessageHandler.cpp.

◆ setShowTimestamp()

void AppDebugMessageHandler::setShowTimestamp ( bool showTimestamp )

See also: showTimestamp

Definition at line 82 of file AppDebugMessageHandler.cpp.

◆ setSourceBasePath()

void AppDebugMessageHandler::setSourceBasePath ( const QString & path = QString() )

Set the base path for source file name filter, everything after this is kept. The string could be literal or a RegEx pattern (evaluated as non-greedy).

Definition at line 69 of file AppDebugMessageHandler.cpp.

◆ setTimestampFormat()

void AppDebugMessageHandler::setTimestampFormat ( const QString & timeFormat )

See also: timestampFormat

Definition at line 89 of file AppDebugMessageHandler.cpp.

◆ shortTypeNames()

QHash< int, QString > & AppDebugMessageHandler::shortTypeNames ( )

static

Returns a reference to the mapping of QtMsgType enum values to abbreviated names.

New names can be specified by setting this reference to a new value. For example:

AppDebugMessageHandler::shortTypeNames() = {
  {QtDebugMsg,    QStringLiteral("DBG")},
  {QtWarningMsg,  QStringLiteral("WRN")},
  {QtCriticalMsg, QStringLiteral("CRT")},
  {QtFatalMsg,    QStringLiteral("FTL")},
  {QtInfoMsg,     QStringLiteral("INF")}
};

Definition at line 246 of file AppDebugMessageHandler.cpp.

◆ showFunctionDeclarations()

bool AppDebugMessageHandler::showFunctionDeclarations ( void ) const

inline

See also: showFunctionDeclarations

Definition at line 165 of file AppDebugMessageHandler.h.

◆ showSourcePath()

bool AppDebugMessageHandler::showSourcePath ( void ) const

inline

See also: showSourcePath

Definition at line 160 of file AppDebugMessageHandler.h.

◆ showTimestamp()

bool AppDebugMessageHandler::showTimestamp ( void ) const

inline

See also: showTimestamp

Definition at line 168 of file AppDebugMessageHandler.h.

◆ timestampFormat()

QString AppDebugMessageHandler::timestampFormat ( void ) const

inline

See also: timestampFormat

Definition at line 171 of file AppDebugMessageHandler.h.

Friends And Related Function Documentation

◆ APP_DBG_HANDLER_DEFAULT_LEVEL

#define APP_DBG_HANDLER_DEFAULT_LEVEL 0

See also: AppDebugMessageHandler::appDebugOutputLevel

Definition at line 45 of file AppDebugMessageHandler.h.

◆ APP_DBG_HANDLER_ENABLE

#define APP_DBG_HANDLER_ENABLE 1

Definition at line 40 of file AppDebugMessageHandler.h.

◆ APP_DBG_HANDLER_SHOW_FUNCTION_DECL

#define APP_DBG_HANDLER_SHOW_FUNCTION_DECL 0

See also: AppDebugMessageHandler::showFunctionDeclarations

Definition at line 57 of file AppDebugMessageHandler.h.

◆ APP_DBG_HANDLER_SHOW_SRC_PATH

#define APP_DBG_HANDLER_SHOW_SRC_PATH 0

See also: AppDebugMessageHandler::showSourcePath

Definition at line 51 of file AppDebugMessageHandler.h.

◆ APP_DBG_HANDLER_SHOW_TIMESTAMP

#define APP_DBG_HANDLER_SHOW_TIMESTAMP 0

See also: AppDebugMessageHandler::showTimestamp

Definition at line 62 of file AppDebugMessageHandler.h.

◆ APP_DBG_HANDLER_SRC_PATH

#define APP_DBG_HANDLER_SRC_PATH ".*src"

See also: AppDebugMessageHandler::setSourceBasePath()

Definition at line 74 of file AppDebugMessageHandler.h.

◆ APP_DBG_HANDLER_TIMESTAMP_FORMAT

#define APP_DBG_HANDLER_TIMESTAMP_FORMAT "process"

See also: AppDebugMessageHandler::timestampFormat

Definition at line 68 of file AppDebugMessageHandler.h.

◆ g_appDebugMessageHandler()

void g_appDebugMessageHandler	(	QtMsgType	,
		const QMessageLogContext &	,
		const QString &
	)

Message handler which is installed using qInstallMessageHandler. This needs to be global. Use AppDebugMessageHandler::instance()->installAppMessageHandler(); instead of installing this function directly (it will verify this handler is enabled, etc).

Definition at line 274 of file AppDebugMessageHandler.cpp.

Properties

Public Member Functions

Static Public Member Functions

Signals

Related Functions

Additional Inherited Members

Detailed Description

Property Documentation

◆ appDebugOutputLevel

◆ showFunctionDeclarations

◆ showSourcePath

◆ showTimestamp

◆ timestampFormat

Member Function Documentation

◆ addOutputDevice()

◆ appDebugOutputLevel()

◆ defaultMessagePattern()

◆ installAppMessageHandler()

◆ instance()

◆ messageHandler()

◆ messageOutput

◆ messagePattern()

◆ removeOutputDevice()

◆ setAppDebugOutputLevel()

◆ setMessagePattern()

◆ setShowFunctionDeclarations()

◆ setShowSourcePath()

◆ setShowTimestamp()

◆ setSourceBasePath()

◆ setTimestampFormat()

◆ shortTypeNames()

◆ showFunctionDeclarations()

◆ showSourcePath()

◆ showTimestamp()

◆ timestampFormat()

Friends And Related Function Documentation

◆ APP_DBG_HANDLER_DEFAULT_LEVEL

◆ APP_DBG_HANDLER_ENABLE

◆ APP_DBG_HANDLER_SHOW_FUNCTION_DECL

◆ APP_DBG_HANDLER_SHOW_SRC_PATH

◆ APP_DBG_HANDLER_SHOW_TIMESTAMP

◆ APP_DBG_HANDLER_SRC_PATH

◆ APP_DBG_HANDLER_TIMESTAMP_FORMAT

◆ g_appDebugMessageHandler()