QwtScaleDraw(3) Qwt User's Guide QwtScaleDraw(3) NAME QwtScaleDraw - A class for drawing scales. SYNOPSIS #include Inherits QwtAbstractScaleDraw. Inherited by QwtDateScaleDraw. Public Types enum Alignment { BottomScale, TopScale, LeftScale, RightScale } Public Member Functions QwtScaleDraw () Constructor. virtual ~QwtScaleDraw () Destructor. void getBorderDistHint (const QFont &, int &start, int &end) const Determine the minimum border distance. int minLabelDist (const QFont &) const int minLength (const QFont &) const virtual double extent (const QFont &) const override void move (double x, double y) void move (const QPointF &) Move the position of the scale. void setLength (double length) Alignment alignment () const void setAlignment (Alignment) Qt::Orientation orientation () const QPointF pos () const double length () const void setLabelAlignment (Qt::Alignment) Change the label flags. Qt::Alignment labelAlignment () const void setLabelRotation (double rotation) double labelRotation () const int maxLabelHeight (const QFont &) const int maxLabelWidth (const QFont &) const QPointF labelPosition (double value) const QRectF labelRect (const QFont &, double value) const QSizeF labelSize (const QFont &, double value) const QRect boundingLabelRect (const QFont &, double value) const Find the bounding rectangle for the label. Protected Member Functions QTransform labelTransformation (const QPointF &, const QSizeF &) const virtual void drawTick (QPainter *, double value, double len) const override virtual void drawBackbone (QPainter *) const override virtual void drawLabel (QPainter *, double value) const override 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. Definition at line 35 of file qwt_scale_draw.h. Member Enumeration Documentation enum QwtScaleDraw::Alignment Alignment of the scale draw See also setAlignment(), alignment() Enumerator BottomScale The scale is below. TopScale The scale is above. LeftScale The scale is left. RightScale The scale is right. Definition at line 42 of file qwt_scale_draw.h. 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. Definition at line 292 of file qwt_scale_draw.cpp. Member Function Documentation QwtScaleDraw::Alignment QwtScaleDraw::alignment () const Return alignment of the scale See also setAlignment() Returns Alignment of the scale Definition at line 309 of file qwt_scale_draw.cpp. QRect QwtScaleDraw::boundingLabelRect (const QFont & font, double value) const Find the bounding rectangle for the label. The coordinates of the rectangle are absolute ( calculated from pos() ). in direction of the tick. Parameters font Font used for painting value Value Returns Bounding rectangle See also labelRect() Definition at line 798 of file qwt_scale_draw.cpp. void QwtScaleDraw::drawBackbone (QPainter * painter) const [override], [protected], [virtual] Draws the baseline of the scale Parameters painter Painter See also drawTick(), drawLabel() Implements QwtAbstractScaleDraw. Definition at line 668 of file qwt_scale_draw.cpp. void QwtScaleDraw::drawLabel (QPainter * painter, double value) const [override], [protected], [virtual] Draws the label for a major scale tick Parameters painter Painter value Value See also drawTick(), drawBackbone(), boundingLabelRect() Implements QwtAbstractScaleDraw. Definition at line 766 of file qwt_scale_draw.cpp. void QwtScaleDraw::drawTick (QPainter * painter, double value, double len) const [override], [protected], [virtual] Draw a tick Parameters painter Painter value Value of the tick len Length of the tick See also drawBackbone(), drawLabel() Implements QwtAbstractScaleDraw. Definition at line 649 of file qwt_scale_draw.cpp. double QwtScaleDraw::extent (const QFont & font) const [override], [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 font Font used for painting the labels Returns Extent See also minLength() Implements QwtAbstractScaleDraw. Definition at line 523 of file qwt_scale_draw.cpp. 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 font Font start Start border distance end End border distance Definition at line 361 of file qwt_scale_draw.cpp. Qt::Alignment QwtScaleDraw::labelAlignment () const Returns the label flags See also setLabelAlignment(), labelRotation() Definition at line 982 of file qwt_scale_draw.cpp. QPointF QwtScaleDraw::labelPosition (double value) const Find the position, where to paint a label The position has a distance that depends on the length of the ticks in direction of the alignment(). Parameters value Value Returns Position, where to paint a label Definition at line 596 of file qwt_scale_draw.cpp. QRectF QwtScaleDraw::labelRect (const QFont & font, double value) const Find the bounding rectangle for the label. The coordinates of the rectangle are relative to spacing + tick length from the backbone in direction of the tick. Parameters font Font used for painting value Value Returns Bounding rectangle that is needed to draw a label Definition at line 891 of file qwt_scale_draw.cpp. double QwtScaleDraw::labelRotation () const Returns the label rotation See also setLabelRotation(), labelAlignment() Definition at line 943 of file qwt_scale_draw.cpp. QSizeF QwtScaleDraw::labelSize (const QFont & font, double value) const Calculate the size that is needed to draw a label Parameters font Label font value Value Returns Size that is needed to draw a label Definition at line 916 of file qwt_scale_draw.cpp. QTransform QwtScaleDraw::labelTransformation (const QPointF & pos, const QSizeF & size) const [protected] Calculate the transformation that is needed to paint a label depending on its alignment and rotation. Parameters pos Position where to paint the label size Size of the label Returns Transformation matrix See also setLabelAlignment(), setLabelRotation() Definition at line 821 of file qwt_scale_draw.cpp. double QwtScaleDraw::length () const Returns the length of the backbone See also setLength(), pos() Definition at line 753 of file qwt_scale_draw.cpp. int QwtScaleDraw::maxLabelHeight (const QFont & font) const Parameters font Font Returns the maximum height of a label Definition at line 1014 of file qwt_scale_draw.cpp. int QwtScaleDraw::maxLabelWidth (const QFont & font) const Parameters font Font Returns the maximum width of a label Definition at line 991 of file qwt_scale_draw.cpp. int QwtScaleDraw::minLabelDist (const QFont & font) const Determine the minimum distance between two labels, that is necessary that the texts don't overlap. Parameters font Font Returns The maximum width of a label See also getBorderDistHint() Definition at line 436 of file qwt_scale_draw.cpp. int QwtScaleDraw::minLength (const QFont & font) const Calculate the minimum length that is needed to draw the scale Parameters font Font used for painting the labels Returns Minimum length that is needed to draw the scale See also extent() Definition at line 560 of file qwt_scale_draw.cpp. void QwtScaleDraw::move (const QPointF & 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() Definition at line 707 of file qwt_scale_draw.cpp. void QwtScaleDraw::move (double x, double y) [inline] Move the position of the scale Parameters x X coordinate y Y coordinate See also move(const QPointF &) Definition at line 118 of file qwt_scale_draw.h. Qt::Orientation QwtScaleDraw::orientation () const Return the orientation TopScale, BottomScale are horizontal (Qt::Horizontal) scales, LeftScale, RightScale are vertical (Qt::Vertical) scales. Returns Orientation of the scale See also alignment() Definition at line 337 of file qwt_scale_draw.cpp. QPointF QwtScaleDraw::pos () const Returns Origin of the scale See also move(), length() Definition at line 717 of file qwt_scale_draw.cpp. void QwtScaleDraw::setAlignment (Alignment align) Set the alignment of the scale Parameters align Alignment of the scale The default alignment is QwtScaleDraw::BottomScale See also alignment() Definition at line 322 of file qwt_scale_draw.cpp. void QwtScaleDraw::setLabelAlignment (Qt::Alignment alignment) Change the label flags. Labels are aligned to the point tick length + 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 alignment Or'd Qt::AlignmentFlags see 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(). Definition at line 973 of file qwt_scale_draw.cpp. 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. Parameters rotation Angle in degrees. When changing the label rotation, the label flags often needs to be adjusted too. See also setLabelAlignment(), labelRotation(), labelAlignment(). Definition at line 934 of file qwt_scale_draw.cpp. void QwtScaleDraw::setLength (double length) Set the length of the backbone. The length doesn't include the space needed for overlapping labels. Parameters length Length of the backbone See also move(), minLabelDist() Definition at line 732 of file qwt_scale_draw.cpp. Author Generated automatically by Doxygen for Qwt User's Guide from the source code. Version 6.2.0 Sun Jul 18 2021 QwtScaleDraw(3)