QColorOutput Class Reference

\nonreentrant More...

#include <qcoloroutput_p.h>

Collaboration diagram for QColorOutput:

Public Types
enum	ColorCodeComponent {   BlackForeground = 1 << ForegroundShift , BlueForeground = 2 << ForegroundShift , GreenForeground = 3 << ForegroundShift , CyanForeground = 4 << ForegroundShift ,   RedForeground = 5 << ForegroundShift , PurpleForeground = 6 << ForegroundShift , BrownForeground = 7 << ForegroundShift , LightGrayForeground = 8 << ForegroundShift ,   DarkGrayForeground = 9 << ForegroundShift , LightBlueForeground = 10 << ForegroundShift , LightGreenForeground = 11 << ForegroundShift , LightCyanForeground = 12 << ForegroundShift ,   LightRedForeground = 13 << ForegroundShift , LightPurpleForeground = 14 << ForegroundShift , YellowForeground = 15 << ForegroundShift , WhiteForeground = 16 << ForegroundShift ,   BlackBackground = 1 << BackgroundShift , BlueBackground = 2 << BackgroundShift , GreenBackground = 3 << BackgroundShift , CyanBackground = 4 << BackgroundShift ,   RedBackground = 5 << BackgroundShift , PurpleBackground = 6 << BackgroundShift , BrownBackground = 7 << BackgroundShift , DefaultColor = 1 << SpecialShift }
using	ColorCode = QFlags< ColorCodeComponent >
using	ColorMapping = QHash< int, ColorCode >

Public Member Functions
	QColorOutput ()
	~QColorOutput ()
bool	isSilent () const
void	setSilent (bool silent)
void	insertMapping (int colorID, ColorCode colorCode)
void	writeUncolored (const QString &message)
void	write (const QStringView message, int color=-1)
Q_WEAK_OVERLOAD void	write (const QString &message, int color=-1)
void	writePrefixedMessage (const QString &message, QtMsgType type, const QString &prefix=QString())
QString	colorify (QStringView message, int color=-1) const

Detailed Description

\nonreentrant

Outputs colored messages to stderr.

QColorOutput is a convenience class for outputting messages to stderr using color escape codes, as mandated in ECMA-48. QColorOutput will only color output when it is detected to be suitable. For instance, if stderr is detected to be attached to a file instead of a TTY, no coloring will be done.

QColorOutput does its best attempt. but it is generally undefined what coloring or effect the various coloring flags has. It depends strongly on what terminal software that is being used.

When using ‘echo -e 'my escape sequence’`, {\033} works as an initiator but not when printing from a C++ program, despite having escaped the backslash. That's why we below use characters with value 0x1B.

It can be convenient to subclass QColorOutput with a private scope, such that the functions are directly available in the class using it.

To output messages, call write() or writeUncolored(). write() takes as second argument an integer, which QColorOutput uses as a lookup key to find the color it should color the text in. The mapping from keys to colors is done using insertMapping(). Typically this is used by having enums for the various kinds of messages, which subsequently are registered.

enum MyMessage
{
  Error,
  Important
};
 
QColorOutput output;
output.insertMapping(Error, QColorOutput::RedForeground);
output.insertMapping(Import, QColorOutput::BlueForeground);
 
output.write("This is important", Important);
output.write("Jack, I'm only the selected official!", Error);

See also

{http://tldp.org/HOWTO/Bash-Prompt-HOWTO/x329.html}{Bash Prompt HOWTO, 6.1. Colors}, {http://linuxgazette.net/issue51/livingston-blade.html}{Linux Gazette, Tweaking Eterm, Edward Livingston-Blade}, {http://www.ecma-international.org/publications/standards/Ecma-048.htm}{Standard ECMA-48, Control Functions for Coded Character Sets, ECMA International}, {http://en.wikipedia.org/wiki/ANSI_escape_code}{Wikipedia, ANSI escape code}, {http://linuxgazette.net/issue65/padala.html}{Linux Gazette, So You Like Color!, Pradeep Padala}

Definition at line 27 of file qcoloroutput_p.h.

Member Typedef Documentation

ColorCode

using QColorOutput::ColorCode = QFlags<ColorCodeComponent>

Definition at line 68 of file qcoloroutput_p.h.

ColorMapping

using QColorOutput::ColorMapping = QHash<int, ColorCode>

Definition at line 69 of file qcoloroutput_p.h.

Member Enumeration Documentation

ColorCodeComponent

enum QColorOutput::ColorCodeComponent

\value BlackForeground \value BlueForeground \value GreenForeground \value CyanForeground \value RedForeground \value PurpleForeground \value BrownForeground \value LightGrayForeground \value DarkGrayForeground \value LightBlueForeground \value LightGreenForeground \value LightCyanForeground \value LightRedForeground \value LightPurpleForeground \value YellowForeground \value WhiteForeground \value BlackBackground \value BlueBackground \value GreenBackground \value CyanBackground \value RedBackground \value PurpleBackground \value BrownBackground

\value DefaultColor QColorOutput performs no coloring. This typically means black on white or white on black, depending on the settings of the user's terminal.

Enumerator
BlackForeground
BlueForeground
GreenForeground
CyanForeground
RedForeground
PurpleForeground
BrownForeground
LightGrayForeground
DarkGrayForeground
LightBlueForeground
LightGreenForeground
LightCyanForeground
LightRedForeground
LightPurpleForeground
YellowForeground
WhiteForeground
BlackBackground
BlueBackground
GreenBackground
CyanBackground
RedBackground
PurpleBackground
BrownBackground
DefaultColor

Definition at line 39 of file qcoloroutput_p.h.

Constructor & Destructor Documentation

QColorOutput()

QColorOutput::QColorOutput

(

)

Constructs a QColorOutput instance, ready for use.

Definition at line 203 of file qcoloroutput.cpp.

~QColorOutput()

QColorOutput::~QColorOutput ( )

default

Member Function Documentation

colorify()

QString QColorOutput::colorify	(	QStringView	message,
		int	colorID = -1
	)		const

Treats message and colorID identically to write(), but instead of writing message to stderr, it is prepared for being written to stderr, but is then returned.

This is useful when the colored string is inserted into a translated string(dividing the string into several small strings prevents proper translation).

Definition at line 268 of file qcoloroutput.cpp.

References QString::append(), arg, QColorOutputPrivate::backgrounds, QColorOutputPrivate::color(), QColorOutputPrivate::coloringEnabled(), QColorOutputPrivate::containsColor(), DefaultColor, QColorOutputPrivate::escapeCode(), QColorOutputPrivate::foregrounds, QString::fromLatin1(), Q_ASSERT_X, Q_FUNC_INFO, qPrintable, and QColorOutputPrivate::setCurrentColorID().

Referenced by write().

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insertMapping()

void QColorOutput::insertMapping	(	int	colorID,
		ColorCode	colorCode
	)

Adds a color mapping from colorID to colorCode, for this QColorOutput instance.

Definition at line 320 of file qcoloroutput.cpp.

References QColorOutputPrivate::insertColor().

Referenced by QQmlJSLogger::QQmlJSLogger().

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isSilent()

bool QColorOutput::isSilent

(

)

const

Definition at line 208 of file qcoloroutput.cpp.

References QColorOutputPrivate::isSilent().

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setSilent()

void QColorOutput::setSilent

(

bool

silent

)

Definition at line 209 of file qcoloroutput.cpp.

References QColorOutputPrivate::setSilent().

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write() [1/2]

Q_WEAK_OVERLOAD void QColorOutput::write ( const QString &  message, int  color = -1  )

inline

Definition at line 82 of file qcoloroutput_p.h.

References write().

Referenced by write().

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write() [2/2]

void QColorOutput::write	(	const QStringView	message,
		int	colorID = -1
	)

Sends message to stderr, using the color looked up in the color mapping using colorID.

If color isn't available in the color mapping, result and behavior is undefined.

If colorID is 0, which is the default value, the previously used coloring is used. QColorOutput is initialized to not color at all.

If message is empty, effects are undefined.

message will be printed as is. For instance, no line endings will be inserted.

Definition at line 224 of file qcoloroutput.cpp.

References colorify(), QColorOutputPrivate::isSilent(), and QColorOutputPrivate::write().

Referenced by QQmlJSLogger::processMessages(), and writePrefixedMessage().

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writePrefixedMessage()

void QColorOutput::writePrefixedMessage	(	const QString &	message,
		QtMsgType	type,
		const QString &	prefix = QString()
	)

Definition at line 230 of file qcoloroutput.cpp.

References QHash< Key, T >::contains(), QString::front(), QString::isEmpty(), QChar::isUpper(), Q_ASSERT, QStringLiteral, QtCriticalMsg, QtDebugMsg, QtInfoMsg, QtWarningMsg, write(), and writeUncolored().

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writeUncolored()

void QColorOutput::writeUncolored

(

const QString &

message

)

Writes message to stderr as if for instance QTextStream would have been used, and adds a line ending at the end.

This function can be practical to use such that one can use QColorOutput for all forms of writing.

Definition at line 253 of file qcoloroutput.cpp.

References QColorOutputPrivate::isSilent(), and QColorOutputPrivate::write().

Referenced by writePrefixedMessage().

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The documentation for this class was generated from the following files:

• qtdeclarative/src/qmlcompiler/qcoloroutput_p.h
• qtdeclarative/src/qmlcompiler/qcoloroutput.cpp