Sources_For_Linux/Qwt/doc/man/man3/QwtPlotShapeItem.3

.TH "QwtPlotShapeItem" 3 "Mon Dec 28 2020" "Version 6.1.6" "Qwt User's Guide" \" -*- nroff -*-
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.SH NAME
QwtPlotShapeItem \- A plot item, which displays any graphical shape, that can be defined by a QPainterPath\&.  

.SH SYNOPSIS
.br
.PP
.PP
\fC#include <qwt_plot_shapeitem\&.h>\fP
.PP
Inherits \fBQwtPlotItem\fP\&.
.SS "Public Types"

.in +1c
.ti -1c
.RI "enum \fBPaintAttribute\fP { \fBClipPolygons\fP = 0x01 }"
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.ti -1c
.RI "enum \fBLegendMode\fP { \fBLegendShape\fP, \fBLegendColor\fP }"
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.RI "Mode how to display the item on the legend\&. "
.ti -1c
.RI "typedef QFlags< \fBPaintAttribute\fP > \fBPaintAttributes\fP"
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.RI "Paint attributes\&. "
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.SS "Public Member Functions"

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.ti -1c
.RI "\fBQwtPlotShapeItem\fP (const QString &\fBtitle\fP=QString())"
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.RI "Constructor\&. "
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.RI "\fBQwtPlotShapeItem\fP (const \fBQwtText\fP &\fBtitle\fP)"
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.RI "Constructor\&. "
.ti -1c
.RI "virtual \fB~QwtPlotShapeItem\fP ()"
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.RI "Destructor\&. "
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.RI "void \fBsetPaintAttribute\fP (\fBPaintAttribute\fP, bool on=true)"
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.ti -1c
.RI "bool \fBtestPaintAttribute\fP (\fBPaintAttribute\fP) const"
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.RI "void \fBsetLegendMode\fP (\fBLegendMode\fP)"
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.RI "\fBLegendMode\fP \fBlegendMode\fP () const"
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.ti -1c
.RI "void \fBsetRect\fP (const QRectF &)"
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.RI "Set a path built from a rectangle\&. "
.ti -1c
.RI "void \fBsetPolygon\fP (const QPolygonF &)"
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.RI "Set a path built from a polygon\&. "
.ti -1c
.RI "void \fBsetShape\fP (const QPainterPath &)"
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.RI "Set the shape to be displayed\&. "
.ti -1c
.RI "QPainterPath \fBshape\fP () const"
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.RI "void \fBsetPen\fP (const QColor &, qreal width=0\&.0, Qt::PenStyle=Qt::SolidLine)"
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.ti -1c
.RI "void \fBsetPen\fP (const QPen &)"
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.RI "Assign a pen\&. "
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.RI "QPen \fBpen\fP () const"
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.RI "void \fBsetBrush\fP (const QBrush &)"
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.RI "QBrush \fBbrush\fP () const"
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.RI "void \fBsetRenderTolerance\fP (double)"
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.RI "Set the tolerance for the weeding optimization\&. "
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.RI "double \fBrenderTolerance\fP () const"
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.RI "virtual QRectF \fBboundingRect\fP () const"
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.RI "Bounding rectangle of the shape\&. "
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.RI "virtual void \fBdraw\fP (QPainter *, const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap, const QRectF &canvasRect) const"
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.RI "virtual \fBQwtGraphic\fP \fBlegendIcon\fP (int index, const QSizeF &) const"
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.RI "virtual int \fBrtti\fP () const"
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.SS "Additional Inherited Members"
.SH "Detailed Description"
.PP 
A plot item, which displays any graphical shape, that can be defined by a QPainterPath\&. 

A QPainterPath is a shape composed from intersecting and uniting regions, rectangles, ellipses or irregular areas defined by lines, and curves\&. \fBQwtPlotShapeItem\fP displays a shape with a pen and brush\&.
.PP
\fBQwtPlotShapeItem\fP offers a couple of optimizations like clipping or weeding\&. These algorithms need to convert the painter path into polygons that might be less performant for paths built from curves and ellipses\&.
.PP
\fBSee also\fP
.RS 4
QwtPlotZone 
.RE
.PP

.SH "Member Enumeration Documentation"
.PP 
.SS "enum \fBQwtPlotShapeItem::LegendMode\fP"

.PP
Mode how to display the item on the legend\&. 
.PP
\fBEnumerator\fP
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.TP
\fB\fILegendShape \fP\fP
Display a scaled down version of the shape\&. 
.TP
\fB\fILegendColor \fP\fP
Display a filled rectangle\&. 
.SS "enum \fBQwtPlotShapeItem::PaintAttribute\fP"
Attributes to modify the drawing algorithm\&. The default disables all attributes
.PP
\fBSee also\fP
.RS 4
\fBsetPaintAttribute()\fP, \fBtestPaintAttribute()\fP 
.RE
.PP

.PP
\fBEnumerator\fP
.in +1c
.TP
\fB\fIClipPolygons \fP\fP
Clip polygons before painting them\&. In situations, where points are far outside the visible area (f\&.e when zooming deep) this might be a substantial improvement for the painting performance
.PP
But polygon clipping will convert the painter path into polygons what might introduce a negative impact on the performance of paths composed from curves or ellipses\&. 
.SH "Constructor & Destructor Documentation"
.PP 
.SS "QwtPlotShapeItem::QwtPlotShapeItem (const QString & title = \fCQString()\fP)\fC [explicit]\fP"

.PP
Constructor\&. Sets the following item attributes:
.IP "\(bu" 2
\fBQwtPlotItem::AutoScale\fP: true
.IP "\(bu" 2
\fBQwtPlotItem::Legend\fP: false
.PP
.PP
\fBParameters\fP
.RS 4
\fItitle\fP Title 
.RE
.PP

.SS "QwtPlotShapeItem::QwtPlotShapeItem (const \fBQwtText\fP & title)\fC [explicit]\fP"

.PP
Constructor\&. Sets the following item attributes:
.IP "\(bu" 2
\fBQwtPlotItem::AutoScale\fP: true
.IP "\(bu" 2
\fBQwtPlotItem::Legend\fP: false
.PP
.PP
\fBParameters\fP
.RS 4
\fItitle\fP Title 
.RE
.PP

.SH "Member Function Documentation"
.PP 
.SS "QBrush QwtPlotShapeItem::brush () const"

.PP
\fBReturns\fP
.RS 4
Brush used to fill the shape 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetBrush()\fP, \fBpen()\fP 
.RE
.PP

.SS "void QwtPlotShapeItem::draw (QPainter * painter, const \fBQwtScaleMap\fP & xMap, const \fBQwtScaleMap\fP & yMap, const QRectF & canvasRect) const\fC [virtual]\fP"
Draw the shape item
.PP
\fBParameters\fP
.RS 4
\fIpainter\fP Painter 
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\fIxMap\fP X-Scale Map 
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\fIyMap\fP Y-Scale Map 
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\fIcanvasRect\fP Contents rect of the plot canvas 
.RE
.PP

.PP
Implements \fBQwtPlotItem\fP\&.
.SS "\fBQwtGraphic\fP QwtPlotShapeItem::legendIcon (int index, const QSizeF & size) const\fC [virtual]\fP"

.PP
\fBReturns\fP
.RS 4
A rectangle filled with the color of the brush ( or the pen )
.RE
.PP
\fBParameters\fP
.RS 4
\fIindex\fP Index of the legend entry ( usually there is only one ) 
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\fIsize\fP Icon size
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetLegendIconSize()\fP, \fBlegendData()\fP 
.RE
.PP

.PP
Reimplemented from \fBQwtPlotItem\fP\&.
.SS "\fBQwtPlotShapeItem::LegendMode\fP QwtPlotShapeItem::legendMode () const"

.PP
\fBReturns\fP
.RS 4
Mode how to represent the item on the legend 
.RE
.PP
\fBSee also\fP
.RS 4
\fBlegendMode()\fP 
.RE
.PP

.SS "QPen QwtPlotShapeItem::pen () const"

.PP
\fBReturns\fP
.RS 4
Pen used to draw the outline of the shape 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetPen()\fP, \fBbrush()\fP 
.RE
.PP

.SS "double QwtPlotShapeItem::renderTolerance () const"

.PP
\fBReturns\fP
.RS 4
Tolerance for the weeding optimization 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetRenderTolerance()\fP 
.RE
.PP

.SS "int QwtPlotShapeItem::rtti () const\fC [virtual]\fP"

.PP
\fBReturns\fP
.RS 4
\fBQwtPlotItem::Rtti_PlotShape\fP 
.RE
.PP

.PP
Reimplemented from \fBQwtPlotItem\fP\&.
.SS "void QwtPlotShapeItem::setBrush (const QBrush & brush)"
Assign a brush\&.
.PP
The brush is used to fill the path
.PP
\fBParameters\fP
.RS 4
\fIbrush\fP Brush 
.RE
.PP
\fBSee also\fP
.RS 4
\fBbrush()\fP, \fBpen()\fP 
.RE
.PP

.SS "void QwtPlotShapeItem::setLegendMode (\fBLegendMode\fP mode)"
Set the mode how to represent the item on the legend
.PP
\fBParameters\fP
.RS 4
\fImode\fP Mode 
.RE
.PP
\fBSee also\fP
.RS 4
\fBlegendMode()\fP 
.RE
.PP

.SS "void QwtPlotShapeItem::setPaintAttribute (\fBPaintAttribute\fP attribute, bool on = \fCtrue\fP)"
Specify an attribute how to draw the shape
.PP
\fBParameters\fP
.RS 4
\fIattribute\fP Paint attribute 
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\fIon\fP On/Off 
.RE
.PP
\fBSee also\fP
.RS 4
\fBtestPaintAttribute()\fP 
.RE
.PP

.SS "void QwtPlotShapeItem::setPen (const QColor & color, qreal width = \fC0\&.0\fP, Qt::PenStyle style = \fCQt::SolidLine\fP)"
Build and assign a pen
.PP
In Qt5 the default pen width is 1\&.0 ( 0\&.0 in Qt4 ) what makes it non cosmetic ( see QPen::isCosmetic() )\&. This method has been introduced to hide this incompatibility\&.
.PP
\fBParameters\fP
.RS 4
\fIcolor\fP Pen color 
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\fIwidth\fP Pen width 
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\fIstyle\fP Pen style
.RE
.PP
\fBSee also\fP
.RS 4
\fBpen()\fP, \fBbrush()\fP 
.RE
.PP

.SS "void QwtPlotShapeItem::setPen (const QPen & pen)"

.PP
Assign a pen\&. The pen is used to draw the outline of the shape
.PP
\fBParameters\fP
.RS 4
\fIpen\fP Pen 
.RE
.PP
\fBSee also\fP
.RS 4
\fBpen()\fP, \fBbrush()\fP 
.RE
.PP

.SS "void QwtPlotShapeItem::setPolygon (const QPolygonF & polygon)"

.PP
Set a path built from a polygon\&. 
.PP
\fBParameters\fP
.RS 4
\fIpolygon\fP Polygon 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetShape()\fP, \fBsetRect()\fP, \fBshape()\fP 
.RE
.PP

.SS "void QwtPlotShapeItem::setRect (const QRectF & rect)"

.PP
Set a path built from a rectangle\&. 
.PP
\fBParameters\fP
.RS 4
\fIrect\fP Rectangle 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetShape()\fP, \fBsetPolygon()\fP, \fBshape()\fP 
.RE
.PP

.SS "void QwtPlotShapeItem::setRenderTolerance (double tolerance)"

.PP
Set the tolerance for the weeding optimization\&. After translating the shape into target device coordinate ( usually widget geometries ) the painter path can be simplified by a point weeding algorithm ( Douglas-Peucker )\&.
.PP
For shapes built from curves and ellipses weeding might have the opposite effect because they have to be expanded to polygons\&.
.PP
\fBParameters\fP
.RS 4
\fItolerance\fP Accepted error when reducing the number of points A value <= 0\&.0 disables weeding\&.
.RE
.PP
\fBSee also\fP
.RS 4
\fBrenderTolerance()\fP, \fBQwtWeedingCurveFitter\fP 
.RE
.PP

.SS "void QwtPlotShapeItem::setShape (const QPainterPath & shape)"

.PP
Set the shape to be displayed\&. 
.PP
\fBParameters\fP
.RS 4
\fIshape\fP Shape 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetShape()\fP, \fBshape()\fP 
.RE
.PP

.SS "QPainterPath QwtPlotShapeItem::shape () const"

.PP
\fBReturns\fP
.RS 4
Shape to be displayed 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetShape()\fP 
.RE
.PP

.SS "bool QwtPlotShapeItem::testPaintAttribute (\fBPaintAttribute\fP attribute) const"

.PP
\fBReturns\fP
.RS 4
True, when attribute is enabled 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetPaintAttribute()\fP 
.RE
.PP


.SH "Author"
.PP 
Generated automatically by Doxygen for Qwt User's Guide from the source code\&.