QwtAbstractScaleDraw(3) Qwt User's Guide QwtAbstractScaleDraw(3) NAME QwtAbstractScaleDraw - A abstract base class for drawing scales. SYNOPSIS #include Inherited by QwtRoundScaleDraw, and QwtScaleDraw. Public Types enum ScaleComponent { Backbone = 0x01, Ticks = 0x02, Labels = 0x04 } typedef QFlags< ScaleComponent > ScaleComponents Public Member Functions QwtAbstractScaleDraw () Constructor. virtual ~QwtAbstractScaleDraw () Destructor. void setScaleDiv (const QwtScaleDiv &) const QwtScaleDiv & scaleDiv () const void setTransformation (QwtTransform *) const QwtScaleMap & scaleMap () const QwtScaleMap & scaleMap () void enableComponent (ScaleComponent, bool enable=true) bool hasComponent (ScaleComponent) const void setTickLength (QwtScaleDiv::TickType, double length) double tickLength (QwtScaleDiv::TickType) const double maxTickLength () const void setSpacing (double) Set the spacing between tick and labels. double spacing () const Get the spacing. void setPenWidthF (qreal width) Specify the width of the scale pen. qreal penWidthF () const virtual void draw (QPainter *, const QPalette &) const Draw the scale. virtual QwtText label (double) const Convert a value into its representing label. virtual double extent (const QFont &font) const =0 void setMinimumExtent (double) Set a minimum for the extent. double minimumExtent () const void invalidateCache () Protected Member Functions virtual void drawTick (QPainter *painter, double value, double len) const =0 virtual void drawBackbone (QPainter *painter) const =0 virtual void drawLabel (QPainter *painter, double value) const =0 const QwtText & tickLabel (const QFont &, double value) const Convert a value into its representing label and cache it. Detailed Description A abstract base class for drawing scales. QwtAbstractScaleDraw can be used to draw linear or logarithmic scales. After a scale division has been specified as a QwtScaleDiv object using setScaleDiv(), the scale can be drawn with the draw() member. Definition at line 31 of file qwt_abstract_scale_draw.h. Member Typedef Documentation typedef QFlags QwtAbstractScaleDraw::ScaleComponents An ORed combination of ScaleComponent values. Definition at line 51 of file qwt_abstract_scale_draw.h. Member Enumeration Documentation enum QwtAbstractScaleDraw::ScaleComponent Components of a scale See also enableComponent(), hasComponent Enumerator Backbone Backbone = the line where the ticks are located. Ticks Ticks. Labels Labels. Definition at line 39 of file qwt_abstract_scale_draw.h. Constructor & Destructor Documentation QwtAbstractScaleDraw::QwtAbstractScaleDraw () Constructor. The range of the scale is initialized to [0, 100], The spacing (distance between ticks and labels) is set to 4, the tick lengths are set to 4,6 and 8 pixels Definition at line 60 of file qwt_abstract_scale_draw.cpp. Member Function Documentation void QwtAbstractScaleDraw::draw (QPainter * painter, const QPalette & palette) const [virtual] Draw the scale. Parameters painter The painter palette Palette, text color is used for the labels, foreground color for ticks and backbone Definition at line 169 of file qwt_abstract_scale_draw.cpp. virtual void QwtAbstractScaleDraw::drawBackbone (QPainter * painter) const [protected], [pure virtual] Draws the baseline of the scale Parameters painter Painter See also drawTick(), drawLabel() Implemented in QwtScaleDraw, and QwtRoundScaleDraw. virtual void QwtAbstractScaleDraw::drawLabel (QPainter * painter, double value) const [protected], [pure virtual] Draws the label for a major scale tick Parameters painter Painter value Value See also drawTick(), drawBackbone() Implemented in QwtScaleDraw, and QwtRoundScaleDraw. virtual void QwtAbstractScaleDraw::drawTick (QPainter * painter, double value, double len) const [protected], [pure virtual] Draw a tick Parameters painter Painter value Value of the tick len Length of the tick See also drawBackbone(), drawLabel() Implemented in QwtScaleDraw, and QwtRoundScaleDraw. void QwtAbstractScaleDraw::enableComponent (ScaleComponent component, bool enable = true) En/Disable a component of the scale Parameters component Scale component enable On/Off See also hasComponent() Definition at line 79 of file qwt_abstract_scale_draw.cpp. virtual double QwtAbstractScaleDraw::extent (const QFont & font) const [pure virtual] Calculate the extent The extent is the distance from the baseline to the outermost pixel of the scale draw in opposite to its orientation. It is at least minimumExtent() pixels. Parameters font Font used for drawing the tick labels Returns Number of pixels See also setMinimumExtent(), minimumExtent() Implemented in QwtScaleDraw, and QwtRoundScaleDraw. bool QwtAbstractScaleDraw::hasComponent (ScaleComponent component) const Check if a component is enabled Parameters component Component type Returns true, when component is enabled See also enableComponent() Definition at line 95 of file qwt_abstract_scale_draw.cpp. void QwtAbstractScaleDraw::invalidateCache () Invalidate the cache used by tickLabel() The cache is invalidated, when a new QwtScaleDiv is set. If the labels need to be changed. while the same QwtScaleDiv is set, invalidateCache() needs to be called manually. Definition at line 417 of file qwt_abstract_scale_draw.cpp. QwtText QwtAbstractScaleDraw::label (double value) const [virtual] Convert a value into its representing label. The value is converted to a plain text using QLocale().toString(value). This method is often overloaded by applications to have individual labels. Parameters value Value Returns Label string. Reimplemented in QwtDateScaleDraw, and QwtCompassScaleDraw. Definition at line 375 of file qwt_abstract_scale_draw.cpp. double QwtAbstractScaleDraw::maxTickLength () const Returns Length of the longest tick Useful for layout calculations See also tickLength(), setTickLength() Definition at line 355 of file qwt_abstract_scale_draw.cpp. double QwtAbstractScaleDraw::minimumExtent () const Get the minimum extent Returns Minimum extent See also extent(), setMinimumExtent() Definition at line 302 of file qwt_abstract_scale_draw.cpp. qreal QwtAbstractScaleDraw::penWidthF () const Returns Scale pen width See also setPenWidth() Definition at line 156 of file qwt_abstract_scale_draw.cpp. const QwtScaleDiv & QwtAbstractScaleDraw::scaleDiv () const Returns scale division Definition at line 133 of file qwt_abstract_scale_draw.cpp. QwtScaleMap & QwtAbstractScaleDraw::scaleMap () Returns Map how to translate between scale and pixel values Definition at line 127 of file qwt_abstract_scale_draw.cpp. const QwtScaleMap & QwtAbstractScaleDraw::scaleMap () const Returns Map how to translate between scale and pixel values Definition at line 121 of file qwt_abstract_scale_draw.cpp. void QwtAbstractScaleDraw::setMinimumExtent (double minExtent) Set a minimum for the extent. The extent is calculated from the components 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 minExtent Minimum extent See also extent(), minimumExtent() Definition at line 289 of file qwt_abstract_scale_draw.cpp. void QwtAbstractScaleDraw::setPenWidthF (qreal width) Specify the width of the scale pen. Parameters width Pen width See also penWidth() Definition at line 144 of file qwt_abstract_scale_draw.cpp. void QwtAbstractScaleDraw::setScaleDiv (const QwtScaleDiv & scaleDiv) Change the scale division Parameters scaleDiv New scale division Definition at line 104 of file qwt_abstract_scale_draw.cpp. void QwtAbstractScaleDraw::setSpacing (double spacing) Set the spacing between tick and labels. The spacing is the distance between ticks and labels. The default spacing is 4 pixels. Parameters spacing Spacing See also spacing() Definition at line 254 of file qwt_abstract_scale_draw.cpp. void QwtAbstractScaleDraw::setTickLength (QwtScaleDiv::TickType tickType, double length) Set the length of the ticks Parameters tickType Tick type length New length Warning the length is limited to [0..1000] Definition at line 315 of file qwt_abstract_scale_draw.cpp. void QwtAbstractScaleDraw::setTransformation (QwtTransform * transformation) Change the transformation of the scale Parameters transformation New scale transformation Definition at line 115 of file qwt_abstract_scale_draw.cpp. double QwtAbstractScaleDraw::spacing () const Get the spacing. The spacing is the distance between ticks and labels. The default spacing is 4 pixels. Returns Spacing See also setSpacing() Definition at line 271 of file qwt_abstract_scale_draw.cpp. const QwtText & QwtAbstractScaleDraw::tickLabel (const QFont & font, double value) const [protected] 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 font Font value Value Returns Tick label Definition at line 393 of file qwt_abstract_scale_draw.cpp. double QwtAbstractScaleDraw::tickLength (QwtScaleDiv::TickType tickType) const Returns Length of the ticks See also setTickLength(), maxTickLength() Definition at line 338 of file qwt_abstract_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 QwtAbstractScaleDraw(3)