NAME¶

QwtScaleDraw - A class for drawing scales.

SYNOPSIS¶

#include <qwt_scale_draw.h> Inherits QwtAbstractScaleDraw.

Public Types¶

enum Alignment { BottomScale, TopScale, LeftScale, RightScale } enum ScaleComponent { Backbone = 1, Ticks = 2, Labels = 4 }

Public Member Functions¶

Alignment alignment () const QRect boundingLabelRect (const QFont &, double val) const virtual void draw (QPainter *, const QPalette &) const void enableComponent (ScaleComponent, bool enable=true) virtual int extent (const QPen &, const QFont &) const void getBorderDistHint (const QFont &, int &start, int &end) const bool hasComponent (ScaleComponent) const virtual QwtText label (double) const Qt::Alignment labelAlignment () const QPoint labelPosition (double val) const QRect labelRect (const QFont &, double val) const double labelRotation () const QSize labelSize (const QFont &, double val) const int length () const int majTickLength () const const QwtScaleMap & map () const int maxLabelHeight (const QFont &) const int maxLabelWidth (const QFont &) const int minimumExtent () const int minLabelDist (const QFont &) const int minLength (const QPen &, const QFont &) const void move (int x, int y) void move (const QPoint &) QwtScaleDraw & operator= (const QwtScaleDraw &other) Qt::Orientation orientation () const QPoint pos () const QwtScaleDraw (const QwtScaleDraw &) QwtScaleDraw () const QwtScaleDiv & scaleDiv () const QwtScaleMap & scaleMap () void setAlignment (Alignment) void setLabelAlignment (Qt::Alignment) void setLabelRotation (double rotation) void setLength (int length) void setMinimumExtent (int) void setScaleDiv (const QwtScaleDiv &s) void setSpacing (int margin) void setTickLength (QwtScaleDiv::TickType, int length) void setTransformation (QwtScaleTransformation *) int spacing () const int tickLength (QwtScaleDiv::TickType) const virtual ~QwtScaleDraw ()

Protected Member Functions¶

virtual void drawBackbone (QPainter *p) const virtual void drawLabel (QPainter *p, double val) const virtual void drawTick (QPainter *p, double val, int len) const void invalidateCache () QMatrix labelMatrix (const QPoint &, const QSize &) const const QwtText & tickLabel (const QFont &, double value) const

Detailed Description¶

A class for drawing scales. QwtScaleDraw can be used to draw linear or logarithmic scales. A scale has a position, an alignment and a length, which can be specified . The labels can be rotated and aligned to the ticks using setLabelRotation() and setLabelAlignment(). After a scale division has been specified as a QwtScaleDiv object using QwtAbstractScaleDraw::setScaleDiv(const QwtScaleDiv &s), the scale can be drawn with the QwtAbstractScaleDraw::draw() member.

Member Enumeration Documentation¶

enum QwtScaleDraw::Alignment Alignment of the scale draw¶

See also:

enum QwtAbstractScaleDraw::ScaleComponent [inherited] Components of a scale¶

•

Backbone

•

Ticks

•

Labels

See also:

Constructor & Destructor Documentation¶

QwtScaleDraw::QwtScaleDraw ()¶

Constructor. The range of the scale is initialized to [0, 100], The position is at (0, 0) with a length of 100. The orientation is QwtAbstractScaleDraw::Bottom.

QwtScaleDraw::QwtScaleDraw (const QwtScaleDraw &other)¶

Copy constructor.

QwtScaleDraw::~QwtScaleDraw () [virtual]¶

Destructor.

Member Function Documentation¶

QwtScaleDraw::Alignment QwtScaleDraw::alignment () const Return alignment of the scale¶

See also:

QRect QwtScaleDraw::boundingLabelRect (const QFont &font, doublevalue) const Find the bounding rect for the label. The coordinates of the rect are absolute coordinates ( calculated from pos() ). in direction of the tick.¶

Parameters: See also:

void QwtAbstractScaleDraw::draw (QPainter *painter, const QPalette &palette) const [virtual, inherited]¶

Draw the scale. Parameters:

void QwtScaleDraw::drawBackbone (QPainter *painter) const [protected, virtual] Draws the baseline of the scale¶

Parameters: See also: Implements QwtAbstractScaleDraw.

void QwtScaleDraw::drawLabel (QPainter *painter, doublevalue) const [protected, virtual] Draws the label for a major scale tick¶

Parameters: See also: Implements QwtAbstractScaleDraw.

void QwtScaleDraw::drawTick (QPainter *painter, doublevalue, intlen) const [protected, virtual] Draw a tick¶

Parameters: See also: Implements QwtAbstractScaleDraw.

void QwtAbstractScaleDraw::enableComponent (ScaleComponentcomponent, boolenable = true) [inherited] En/Disable a component of the scale¶

Parameters: See also:

int QwtScaleDraw::extent (const QPen &pen, const QFont &font) const [virtual] Calculate the width/height that is needed for a vertical/horizontal scale.¶

The extent is calculated from the pen width of the backbone, the major tick length, the spacing and the maximum width/height of the labels. Parameters: See also: Implements QwtAbstractScaleDraw.

void QwtScaleDraw::getBorderDistHint (const QFont &font, int &start, int &end) const¶

Determine the minimum border distance. This member function returns the minimum space needed to draw the mark labels at the scale's endpoints. Parameters:

bool QwtAbstractScaleDraw::hasComponent (ScaleComponentcomponent) const [inherited] Check if a component is enabled¶

See also:

void QwtAbstractScaleDraw::invalidateCache () [protected, inherited] Invalidate the cache used by QwtAbstractScaleDraw::tickLabel¶

The cache is invalidated, when a new QwtScaleDiv is set. If the labels need to be changed. while the same QwtScaleDiv is set, QwtAbstractScaleDraw::invalidateCache needs to be called manually.

QwtText QwtAbstractScaleDraw::label (doublevalue) const [virtual, inherited]¶

Convert a value into its representing label. The value is converted to a plain text using QLocale::system().toString(value). This method is often overloaded by applications to have individual labels. Parameters: Returns: Reimplemented in QwtDialScaleDraw.

Qt::Alignment QwtScaleDraw::labelAlignment () const Returns:¶

See also:

QMatrix QwtScaleDraw::labelMatrix (const QPoint &pos, const QSize &size) const [protected] Calculate the matrix that is needed to paint a label depending on its alignment and rotation.¶

Parameters: See also:

QPoint QwtScaleDraw::labelPosition (doublevalue) const Find the position, where to paint a label¶

The position has a distance of majTickLength() + spacing() + 1 from the backbone. The direction depends on the alignment() Parameters:

QRect QwtScaleDraw::labelRect (const QFont &font, doublevalue) const Find the bounding rect for the label. The coordinates of the rect are relative to spacing + ticklength from the backbone in direction of the tick.¶

Parameters:

double QwtScaleDraw::labelRotation () const Returns:¶

See also:

QSize QwtScaleDraw::labelSize (const QFont &font, doublevalue) const Calculate the size that is needed to draw a label¶

Parameters:

int QwtScaleDraw::length () const Returns:¶

See also:

int QwtAbstractScaleDraw::majTickLength () const [inherited] The same as QwtAbstractScaleDraw::tickLength(QwtScaleDiv::MajorTick).¶

const QwtScaleMap & QwtAbstractScaleDraw::map () const [inherited] Returns:¶

int QwtScaleDraw::maxLabelHeight (const QFont &font) const Parameters:¶

Returns:

int QwtScaleDraw::maxLabelWidth (const QFont &font) const Parameters:¶

Returns:

int QwtAbstractScaleDraw::minimumExtent () const [inherited] Get the minimum extent¶

See also:

int QwtScaleDraw::minLabelDist (const QFont &font) const Determine the minimum distance between two labels, that is necessary that the texts don't overlap.¶

Parameters: Returns: See also:

int QwtScaleDraw::minLength (const QPen &pen, const QFont &font) const Calculate the minimum length that is needed to draw the scale¶

Parameters: See also:

void QwtScaleDraw::move (intx, inty) [inline] Move the position of the scale¶

See also:

void QwtScaleDraw::move (const QPoint &pos)¶

Move the position of the scale. The meaning of the parameter pos depends on the alignment:

QwtScaleDraw::LeftScale

The origin is the topmost point of the backbone. The backbone is a vertical line. Scale marks and labels are drawn at the left of the backbone.

QwtScaleDraw::RightScale

The origin is the topmost point of the backbone. The backbone is a vertical line. Scale marks and labels are drawn at the right of the backbone.

QwtScaleDraw::TopScale

The origin is the leftmost point of the backbone. The backbone is a horizontal line. Scale marks and labels are drawn above the backbone.

QwtScaleDraw::BottomScale

The origin is the leftmost point of the backbone. The backbone is a horizontal line Scale marks and labels are drawn below the backbone.

Parameters: See also:

QwtScaleDraw & QwtScaleDraw::operator= (const QwtScaleDraw &other)¶

Assignment operator.

Qt::Orientation QwtScaleDraw::orientation () const Return the orientation¶

TopScale, BottomScale are horizontal (Qt::Horizontal) scales, LeftScale, RightScale are vertical (Qt::Vertical) scales. See also:

QPoint QwtScaleDraw::pos () const Returns:¶

See also:

const QwtScaleDiv & QwtAbstractScaleDraw::scaleDiv () const [inherited] Returns:¶

QwtScaleMap & QwtAbstractScaleDraw::scaleMap () [inherited] Returns:¶

void QwtScaleDraw::setAlignment (Alignmentalign) Set the alignment of the scale¶

The default alignment is QwtScaleDraw::BottomScale See also:

void QwtScaleDraw::setLabelAlignment (Qt::Alignmentalignment)¶

Change the label flags. Labels are aligned to the point ticklength + spacing away from the backbone. The alignment is relative to the orientation of the label text. In case of an flags of 0 the label will be aligned depending on the orientation of the scale: QwtScaleDraw::TopScale: Qt::AlignHCenter | Qt::AlignTop
QwtScaleDraw::BottomScale: Qt::AlignHCenter | Qt::AlignBottom
QwtScaleDraw::LeftScale: Qt::AlignLeft | Qt::AlignVCenter
QwtScaleDraw::RightScale: Qt::AlignRight | Qt::AlignVCenter Changing the alignment is often necessary for rotated labels. Parameters: See also: Warning:

void QwtScaleDraw::setLabelRotation (doublerotation) Rotate all labels.¶

When changing the rotation, it might be necessary to adjust the label flags too. Finding a useful combination is often the result of try and error. Parameters: See also:

void QwtScaleDraw::setLength (intlength) Set the length of the backbone.¶

The length doesn't include the space needed for overlapping labels. See also:

void QwtAbstractScaleDraw::setMinimumExtent (intminExtent) [inherited]¶

Set a minimum for the extent. The extent is calculated from the coomponents of the scale draw. In situations, where the labels are changing and the layout depends on the extent (f.e scrolling a scale), setting an upper limit as minimum extent will avoid jumps of the layout. Parameters: See also:

void QwtAbstractScaleDraw::setScaleDiv (const QwtScaleDiv &sd) [inherited] Change the scale division¶

Parameters:

void QwtAbstractScaleDraw::setSpacing (intspacing) [inherited]¶

Set the spacing between tick and labels. The spacing is the distance between ticks and labels. The default spacing is 4 pixels. Parameters: See also:

void QwtAbstractScaleDraw::setTickLength (QwtScaleDiv::TickTypetickType, intlength) [inherited] Set the length of the ticks¶

Parameters: Warning:

void QwtAbstractScaleDraw::setTransformation (QwtScaleTransformation *transformation) [inherited] Change the transformation of the scale¶

Parameters:

int QwtAbstractScaleDraw::spacing () const [inherited]¶

Get the spacing. The spacing is the distance between ticks and labels. The default spacing is 4 pixels. See also:

const QwtText & QwtAbstractScaleDraw::tickLabel (const QFont &font, doublevalue) const [protected, inherited]¶

Convert a value into its representing label and cache it. The conversion between value and label is called very often in the layout and painting code. Unfortunately the calculation of the label sizes might be slow (really slow for rich text in Qt4), so it's necessary to cache the labels. Parameters: Returns:

int QwtAbstractScaleDraw::tickLength (QwtScaleDiv::TickTypetickType) const [inherited] Return the length of the ticks¶

See also:

Author¶

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