QwtScaleDraw(3)

📦 version 5.2.3a, in epel 9, fedora 43, fedora 44

👑 QwtScaleDraw 💅

okay bestie, welcome to the Qwt User's Guide glow-up edition ✨ this one's about QwtScaleDraw, and yes she's iconic, yes she's giving main character energy, and yes we're going through every single member together. no skimming. no skipping. periodt 🎀

🌸 NAME 🌸

QwtScaleDraw — the class that draws your scales. that's it, that's the name. lowkey understated for how much she does 🦋

✨ SYNOPSIS ✨

#include <qwt_scale_draw.h>

she Inherits QwtAbstractScaleDraw, so all that base-class lore is hers too 💖

🎀 Public Types

  • enum Alignment { BottomScale, TopScale, LeftScale, RightScale }

🦋 Public Member Functions

QwtScaleDraw ()
QwtScaleDraw (const QwtScaleDraw &)
virtual ~QwtScaleDraw ()
Alignment alignment () const
QRect boundingLabelRect (const QFont &, double val) const
virtual int extent (const QPen &, const QFont &) const
void getBorderDistHint (const QFont &, int &start, int &end) 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 maxLabelHeight (const QFont &) const
int maxLabelWidth (const QFont &) 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
void setAlignment (Alignment)
void setLabelAlignment (Qt::Alignment)
void setLabelRotation (double rotation)
void setLength (int length)

🧚 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
QMatrix labelMatrix (const QPoint &, const QSize &) const

💜 Detailed Description 💜

a whole class, dedicated to drawing scales. obsessed, honestly 🌈

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(). so cute, so flexible 💅

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. that's the whole flow, bestie: give her the div, then let her draw 🫶

🎀 Member Enumeration Documentation 🎀

enum QwtScaleDraw::Alignment

Alignment of the scale draw ✨

See also: setAlignment(), alignment()

🦋 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. yes bestie, she comes out of the box fully dressed 💖

💅 Member Function Documentation 💅

QwtScaleDraw::Alignment QwtScaleDraw::alignment () const

Return alignment of the scale.

See also: setAlignment()

QRect QwtScaleDraw::boundingLabelRect (const QFont &font, double value) 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:

  • font — Font used for painting
  • value — Value

See also: labelRect()

void QwtScaleDraw::drawBackbone (QPainter *painter) const [protected], [virtual]

Draws the baseline of the scale. the backbone! the spine! the moment 🦴✨

Parameters:

  • painter — Painter

See also: drawTick(), drawLabel()

Implements QwtAbstractScaleDraw.

void QwtScaleDraw::drawLabel (QPainter *painter, double value) const [protected], [virtual]

Draws the label for a major scale tick 🏷️

Parameters:

  • painter — Painter
  • value — Value

See also: drawTick(), drawBackbone(), boundingLabelRect()

Implements QwtAbstractScaleDraw.

void QwtScaleDraw::drawTick (QPainter *painter, double value, int len) const [protected], [virtual]

Draw a tick. just one little tick, doing its little tick thing 🐜

Parameters:

  • painter — Painter
  • value — Value of the tick
  • len — Lenght of the tick (yes the original says "Lenght", we don't fix typos around here, we preserve them like artifacts 💀)

See also: drawBackbone(), drawLabel()

Implements QwtAbstractScaleDraw.

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. so it's a whole math girlie situation 🧮💅

Parameters:

  • pen — Pen that is used for painting backbone and ticks
  • font — Font used for painting the labels

See also: minLength()

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. personal space matters 🫶

Parameters:

  • font — Font
  • start — Start border distance
  • end — End border distance

Qt::Alignment QwtScaleDraw::labelAlignment () const

Returns: the label flags 🚩

See also: setLabelAlignment(), labelRotation()

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. matrix math, but make it fashion ✨

Parameters:

  • pos — Position where to paint the label
  • size — Size of the label

See also: setLabelAlignment(), setLabelRotation()

QPoint QwtScaleDraw::labelPosition (double value) 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:

  • value — Value

QRect QwtScaleDraw::labelRect (const QFont &font, double value) 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. (compare with boundingLabelRect(), which is absolute — don't mix them up bestie, iykyk 😭)

Parameters:

  • font — Font used for painting
  • value — Value

double QwtScaleDraw::labelRotation () const

Returns: the label rotation 🔄

See also: setLabelRotation(), labelAlignment()

QSize QwtScaleDraw::labelSize (const QFont &font, double value) const

Calculate the size that is needed to draw a label 📐

Parameters:

  • font — Label font
  • value — Value

int QwtScaleDraw::length () const

Returns: the length of the backbone 🦴

See also: setLength(), pos()

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

Parameters:

  • font — Font

Returns: the maximum height of a label 📏

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

Parameters:

  • font — Font

Returns: the maximum width of a label 📏

int QwtScaleDraw::minLabelDist (const QFont &font) const

Determine the minimum distance between two labels, that is necessary that the texts don't overlap. nobody wants their labels kissing in public 💀

Parameters:

  • font — Font

Returns: The maximum width of a label

See also: getBorderDistHint()

int QwtScaleDraw::minLength (const QPen &pen, const QFont &font) const

Calculate the minimum length that is needed to draw the scale.

Parameters:

  • pen — Pen that is used for painting backbone and ticks
  • font — Font used for painting the labels

See also: extent()

void QwtScaleDraw::move (int x, int y) [inline]

Move the position of the scale.

See also: move(const QPoint &)

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:

  • pos — Origin of the scale

See also: pos(), setLength()

Qt::Orientation QwtScaleDraw::orientation () const

Return the orientation.

TopScale, BottomScale are horizontal (Qt::Horizontal) scales, LeftScale, RightScale are vertical (Qt::Vertical) scales. horizontal girlies vs vertical girlies, both valid 🌈

See also: alignment()

QPoint QwtScaleDraw::pos () const

Returns: Origin of the scale 📍

See also: move(), length()

void QwtScaleDraw::setAlignment (Alignment align)

Set the alignment of the scale.

the default alignment is QwtScaleDraw::BottomScale. she starts at the bottom and she's thriving 💅

See also: alignment()

void QwtScaleDraw::setLabelAlignment (Qt::Alignment alignment)

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. yeah, rotated labels are a whole situation 🔄😭

Parameters:

  • alignment — Or'd Qt::AlignmentFlags <see qnamespace.h>

See also: setLabelRotation(), labelRotation(), labelAlignment()

Warning: The various alignments might be confusing. The alignment of the label is not the alignment of the scale and is not the alignment of the flags (QwtText::flags()) returned from QwtAbstractScaleDraw::label(). not me getting three different "alignments" confused — read this part twice bestie 💀

void QwtScaleDraw::setLabelRotation (double rotation)

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. yes, that's the actual documented strategy. we love an honest API 🫶

Parameters:

  • rotation — Angle in degrees. When changing the label rotation, the label flags often needs to be adjusted too.

See also: setLabelAlignment(), labelRotation(), labelAlignment().

void QwtScaleDraw::setLength (int length)

Set the length of the backbone.

the length doesn't include the space needed for overlapping labels. so plan accordingly, she's not gonna do it for you 😌

See also: move(), minLabelDist()

💖 Author 💖

Generated automatically by Doxygen for Qwt User's Guide from the source code. so technically the author is a robot and we respect that 🤖✨

okay and that's the whole page bestie, no notes, 10/10, she ate 💅💖

this was Version 5.2.3, dated Tue Nov 20 2012 — yes it's an elder icon and we stan her anyway 👑🦋🌸

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