QCPPainter Class Reference

QPainter subclass used internally. More...

Inheritance diagram for QCPPainter:

Public Types
enum	PainterMode { pmDefault = 0x00, pmVectorized = 0x01, pmNoCaching = 0x02, pmNonCosmetic = 0x04 }

Public Member Functions
	QCPPainter ()
	QCPPainter (QPaintDevice *device)
bool	antialiasing () const
PainterModes	modes () const
void	setAntialiasing (bool enabled)
void	setMode (PainterMode mode, bool enabled=true)
void	setModes (PainterModes modes)
bool	begin (QPaintDevice *device)
void	setPen (const QPen &pen)
void	setPen (const QColor &color)
void	setPen (Qt::PenStyle penStyle)
void	drawLine (const QLineF &line)
void	drawLine (const QPointF &p1, const QPointF &p2)
void	save ()
void	restore ()
void	makeNonCosmetic ()

Protected Attributes
PainterModes	mModes
bool	mIsAntialiasing
QStack< bool >	mAntialiasingStack

Detailed Description

QPainter subclass used internally.

This internal class is used to provide some extended functionality e.g. for tweaking position consistency between antialiased and non-antialiased painting. Further it provides workarounds for QPainter quirks.

Warning

This class intentionally hides non-virtual functions of QPainter, e.g. setPen, save and restore. So while it is possible to pass a QCPPainter instance to a function that expects a QPainter pointer, some of the workarounds and tweaks will be unavailable to the function (because it will call the base class implementations of the functions actually hidden by QCPPainter).

Member Enumeration Documentation

enum QCPPainter::PainterMode

Defines special modes the painter can operate in. They disable or enable certain subsets of features/fixes/workarounds, depending on whether they are wanted on the respective output device.

Enumerator
pmDefault	0x00 Default mode for painting on screen devices
pmVectorized	0x01 Mode for vectorized painting (e.g. PDF export). For example, this prevents some antialiasing fixes.
pmNoCaching	0x02 Mode for all sorts of exports (e.g. PNG, PDF,...). For example, this prevents using cached pixmap labels
pmNonCosmetic	0x04 Turns pen widths 0 to 1, i.e. disables cosmetic pens. (A cosmetic pen is always drawn with width 1 pixel in the vector image/pdf viewer, independent of zoom.)

Constructor & Destructor Documentation

QCPPainter::QCPPainter

(

)

Creates a new QCPPainter instance and sets default values

QCPPainter::QCPPainter

(

QPaintDevice *

device

)

Creates a new QCPPainter instance on the specified paint device and sets default values. Just like the analogous QPainter constructor, begins painting on device immediately.

Like begin, this method sets QPainter::NonCosmeticDefaultPen in Qt versions before Qt5.

Member Function Documentation

bool QCPPainter::begin

(

QPaintDevice *

device

)

Sets the QPainter::NonCosmeticDefaultPen in Qt versions before Qt5 after beginning painting on device. This is necessary to get cosmetic pen consistency across Qt versions, because since Qt5, all pens are non-cosmetic by default, and in Qt4 this render hint must be set to get that behaviour.

The Constructor QCPPainter(QPaintDevice *device) which directly starts painting also sets the render hint as appropriate.

Note

this function hides the non-virtual base class implementation.

void QCPPainter::drawLine

(

const QLineF &

line

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Works around a Qt bug introduced with Qt 4.8 which makes drawing QLineF unpredictable when antialiasing is disabled. Thus when antialiasing is disabled, it rounds the line to integer coordinates and then passes it to the original drawLine.

Note

this function hides the non-virtual base class implementation.

void QCPPainter::makeNonCosmetic

(

)

Changes the pen width to 1 if it currently is 0. This function is called in the setPen overrides when the pmNonCosmetic mode is set.

void QCPPainter::restore

(

)

Restores the painter (see QPainter::restore). Since QCPPainter adds some new internal state to QPainter, the save/restore functions are reimplemented to also save/restore those members.

Note

this function hides the non-virtual base class implementation.

See also

save

void QCPPainter::save

(

)

Saves the painter (see QPainter::save). Since QCPPainter adds some new internal state to QPainter, the save/restore functions are reimplemented to also save/restore those members.

Note

this function hides the non-virtual base class implementation.

See also

restore

void QCPPainter::setAntialiasing

(

bool

enabled

)

Sets whether painting uses antialiasing or not. Use this method instead of using setRenderHint with QPainter::Antialiasing directly, as it allows QCPPainter to regain pixel exactness between antialiased and non-antialiased painting (Since Qt < 5.0 uses slightly different coordinate systems for AA/Non-AA painting).

void QCPPainter::setMode	(	QCPPainter::PainterMode	mode,
		bool	enabled = true
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Sets the mode of the painter. This controls whether the painter shall adjust its fixes/workarounds optimized for certain output devices.

void QCPPainter::setModes

(

PainterModes

modes

)

Sets the mode of the painter. This controls whether the painter shall adjust its fixes/workarounds optimized for certain output devices.

void QCPPainter::setPen

(

const QPen &

pen

)

Sets the pen of the painter and applies certain fixes to it, depending on the mode of this QCPPainter.

Note

this function hides the non-virtual base class implementation.

void QCPPainter::setPen

(

const QColor &

color

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Sets the pen (by color) of the painter and applies certain fixes to it, depending on the mode of this QCPPainter.

Note

this function hides the non-virtual base class implementation.

void QCPPainter::setPen

(

Qt::PenStyle

penStyle

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Sets the pen (by style) of the painter and applies certain fixes to it, depending on the mode of this QCPPainter.

Note

this function hides the non-virtual base class implementation.

---

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

• qcustomplot.h
• qcustomplot.cpp