QCPAxisPainterPrivate Class Reference

Public Member Functions
	QCPAxisPainterPrivate (QCustomPlot *parentPlot)
QRect	axisSelectionBox () const
void	clearCache ()
virtual void	draw (QCPPainter *painter)
QRect	labelSelectionBox () const
virtual int	size ()
QRect	tickLabelsSelectionBox () const

Public Attributes
bool	abbreviateDecimalPowers
QRect	axisRect
QPen	basePen
QString	label
QColor	labelColor
QFont	labelFont
int	labelPadding
QCPLineEnding	lowerEnding
bool	numberMultiplyCross
int	offset
bool	reversedEndings
bool	substituteExponent
int	subTickLengthIn
int	subTickLengthOut
QPen	subTickPen
QVector< double >	subTickPositions
QColor	tickLabelColor
QFont	tickLabelFont
int	tickLabelPadding
double	tickLabelRotation
QVector< QString >	tickLabels
QCPAxis::LabelSide	tickLabelSide
int	tickLengthIn
int	tickLengthOut
QPen	tickPen
QVector< double >	tickPositions
QCPAxis::AxisType	type
QCPLineEnding	upperEnding
QRect	viewportRect

Protected Member Functions
virtual void	drawTickLabel (QCPPainter *painter, double x, double y, const TickLabelData &labelData) const
virtual QByteArray	generateLabelParameterHash () const
virtual void	getMaxTickLabelSize (const QFont &font, const QString &text, QSize *tickLabelsSize) const
virtual TickLabelData	getTickLabelData (const QFont &font, const QString &text) const
virtual QPointF	getTickLabelDrawOffset (const TickLabelData &labelData) const
virtual void	placeTickLabel (QCPPainter *painter, double position, int distanceToAxis, const QString &text, QSize *tickLabelsSize)

Protected Attributes
QRect	mAxisSelectionBox
QCache< QString, CachedLabel >	mLabelCache
QByteArray	mLabelParameterHash
QRect	mLabelSelectionBox
QCustomPlot *	mParentPlot
QRect	mTickLabelsSelectionBox

Detailed Description

(Private)

This is a private class and not part of the public QCustomPlot interface.

It is used by QCPAxis to do the low-level drawing of axis backbone, tick marks, tick labels and axis label. It also buffers the labels to reduce replot times. The parameters are configured by directly accessing the public member variables.

Definition at line 2368 of file qcustomplot.h.

Constructor & Destructor Documentation

QCPAxisPainterPrivate()

QCPAxisPainterPrivate::QCPAxisPainterPrivate ( QCustomPlot *  parentPlot )

explicit

Constructs a QCPAxisPainterPrivate instance. Make sure to not create a new instance on every redraw, to utilize the caching mechanisms.

Definition at line 9882 of file qcustomplot.cpp.

Member Function Documentation

clearCache()

void QCPAxisPainterPrivate::clearCache

(

)

Clears the internal label cache. Upon the next draw, all labels will be created new. This method is called automatically in draw, if any parameters have changed that invalidate the cached labels, such as font, color, etc.

Definition at line 10157 of file qcustomplot.cpp.

draw()

void QCPAxisPainterPrivate::draw ( QCPPainter *  painter )

virtual

Draws the axis with the specified painter.

The selection boxes (mAxisSelectionBox, mTickLabelsSelectionBox, mLabelSelectionBox) are set here, too.

Definition at line 9918 of file qcustomplot.cpp.

drawTickLabel()

void QCPAxisPainterPrivate::drawTickLabel ( QCPPainter *  painter, double  x, double  y, const TickLabelData &  labelData  ) const

protectedvirtual

This is a placeTickLabel helper function.

Draws the tick label specified in labelData with painter at the pixel positions x and y. This function is used by placeTickLabel to create new tick labels for the cache, or to directly draw the labels on the QCustomPlot surface when label caching is disabled, i.e. when QCP::phCacheLabels plotting hint is not set.

Definition at line 10290 of file qcustomplot.cpp.

generateLabelParameterHash()

QByteArray QCPAxisPainterPrivate::generateLabelParameterHash ( ) const

protectedvirtual

Returns a hash that allows uniquely identifying whether the label parameters have changed such that the cached labels must be refreshed (clearCache). It is used in draw. If the return value of this method hasn't changed since the last redraw, the respective label parameters haven't changed and cached labels may be used.

Definition at line 10169 of file qcustomplot.cpp.

getMaxTickLabelSize()

void QCPAxisPainterPrivate::getMaxTickLabelSize ( const QFont &  font, const QString &  text, QSize *  tickLabelsSize  ) const

protectedvirtual

Simulates the steps done by placeTickLabel by calculating bounding boxes of the text label to be drawn, depending on number format etc. Since only the largest tick label is wanted for the margin calculation, the passed tickLabelsSize is only expanded, if it's currently set to a smaller width/height.

Definition at line 10512 of file qcustomplot.cpp.

getTickLabelData()

QCPAxisPainterPrivate::TickLabelData QCPAxisPainterPrivate::getTickLabelData ( const QFont &  font, const QString &  text  ) const

protectedvirtual

This is a placeTickLabel helper function.

Transforms the passed text and font to a tickLabelData structure that can then be further processed by getTickLabelDrawOffset and drawTickLabel. It splits the text into base and exponent if necessary (member substituteExponent) and calculates appropriate bounding boxes.

Definition at line 10329 of file qcustomplot.cpp.

getTickLabelDrawOffset()

QPointF QCPAxisPainterPrivate::getTickLabelDrawOffset ( const TickLabelData &  labelData ) const

protectedvirtual

This is a placeTickLabel helper function.

Calculates the offset at which the top left corner of the specified tick label shall be drawn. The offset is relative to a point right next to the tick the label belongs to.

This function is thus responsible for e.g. centering tick labels under ticks and positioning them appropriately when they are rotated.

Definition at line 10411 of file qcustomplot.cpp.

placeTickLabel()

void QCPAxisPainterPrivate::placeTickLabel ( QCPPainter *  painter, double  position, int  distanceToAxis, const QString &  text, QSize *  tickLabelsSize  )

protectedvirtual

Draws a single tick label with the provided painter, utilizing the internal label cache to significantly speed up drawing of labels that were drawn in previous calls. The tick label is always bound to an axis, the distance to the axis is controllable via distanceToAxis in pixels. The pixel position in the axis direction is passed in the position parameter. Hence for the bottom axis, position would indicate the horizontal pixel position (not coordinate), at which the label should be drawn.

In order to later draw the axis label in a place that doesn't overlap with the tick labels, the largest tick label size is needed. This is acquired by passing a tickLabelsSize to the drawTickLabel calls during the process of drawing all tick labels of one axis. In every call, tickLabelsSize is expanded, if the drawn label exceeds the value tickLabelsSize currently holds.

The label is drawn with the font and pen that are currently set on the painter. To draw superscripted powers, the font is temporarily made smaller by a fixed factor (see getTickLabelData).

Definition at line 10201 of file qcustomplot.cpp.

size()

int QCPAxisPainterPrivate::size ( )

virtual

Returns the size ("margin" in QCPAxisRect context, so measured perpendicular to the axis backbone direction) needed to fit the axis.

Definition at line 10111 of file qcustomplot.cpp.

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

• qcustomplot.h
• qcustomplot.cpp