Qwt User's Guide 6.3.0
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Base class for items on the plot canvas. More...
#include <qwt_plot_item.h>
Public Types | |
enum | RttiValues { Rtti_PlotItem = 0 , Rtti_PlotGrid , Rtti_PlotScale , Rtti_PlotLegend , Rtti_PlotMarker , Rtti_PlotCurve , Rtti_PlotSpectroCurve , Rtti_PlotIntervalCurve , Rtti_PlotHistogram , Rtti_PlotSpectrogram , Rtti_PlotGraphic , Rtti_PlotTradingCurve , Rtti_PlotBarChart , Rtti_PlotMultiBarChart , Rtti_PlotShape , Rtti_PlotTextLabel , Rtti_PlotZone , Rtti_PlotVectorField , Rtti_PlotUserItem = 1000 } |
Runtime type information. More... | |
enum | ItemAttribute { Legend = 0x01 , AutoScale = 0x02 , Margins = 0x04 } |
Plot Item Attributes. More... | |
enum | ItemInterest { ScaleInterest = 0x01 , LegendInterest = 0x02 } |
Plot Item Interests. More... | |
enum | RenderHint { RenderAntialiased = 0x1 } |
Render hints. More... | |
typedef QFlags< ItemAttribute > | ItemAttributes |
typedef QFlags< ItemInterest > | ItemInterests |
typedef QFlags< RenderHint > | RenderHints |
Public Member Functions | |
QwtPlotItem () | |
QwtPlotItem (const QString &title) | |
QwtPlotItem (const QwtText &title) | |
virtual | ~QwtPlotItem () |
Destroy the QwtPlotItem. | |
void | attach (QwtPlot *plot) |
Attach the item to a plot. | |
void | detach () |
This method detaches a QwtPlotItem from any QwtPlot it has been associated with. | |
QwtPlot * | plot () const |
Return attached plot. | |
void | setTitle (const QString &title) |
void | setTitle (const QwtText &title) |
const QwtText & | title () const |
virtual int | rtti () const |
void | setItemAttribute (ItemAttribute, bool on=true) |
bool | testItemAttribute (ItemAttribute) const |
void | setItemInterest (ItemInterest, bool on=true) |
bool | testItemInterest (ItemInterest) const |
void | setRenderHint (RenderHint, bool on=true) |
bool | testRenderHint (RenderHint) const |
void | setRenderThreadCount (uint numThreads) |
uint | renderThreadCount () const |
void | setLegendIconSize (const QSize &) |
QSize | legendIconSize () const |
double | z () const |
void | setZ (double z) |
Set the z value. | |
void | show () |
Show the item. | |
void | hide () |
Hide the item. | |
virtual void | setVisible (bool) |
bool | isVisible () const |
void | setAxes (QwtAxisId xAxis, QwtAxisId yAxis) |
void | setXAxis (QwtAxisId) |
QwtAxisId | xAxis () const |
Return xAxis. | |
void | setYAxis (QwtAxisId) |
QwtAxisId | yAxis () const |
Return yAxis. | |
virtual void | itemChanged () |
virtual void | legendChanged () |
virtual void | draw (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect) const =0 |
Draw the item. | |
virtual QRectF | boundingRect () const |
virtual void | getCanvasMarginHint (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, double &left, double &top, double &right, double &bottom) const |
Calculate a hint for the canvas margin. | |
virtual void | updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &) |
Update the item to changes of the axes scale division. | |
virtual void | updateLegend (const QwtPlotItem *, const QList< QwtLegendData > &) |
Update the item to changes of the legend info. | |
QRectF | scaleRect (const QwtScaleMap &, const QwtScaleMap &) const |
Calculate the bounding scale rectangle of 2 maps. | |
QRectF | paintRect (const QwtScaleMap &, const QwtScaleMap &) const |
Calculate the bounding paint rectangle of 2 maps. | |
virtual QList< QwtLegendData > | legendData () const |
Return all information, that is needed to represent the item on the legend. | |
virtual QwtGraphic | legendIcon (int index, const QSizeF &) const |
Protected Member Functions | |
QwtGraphic | defaultIcon (const QBrush &, const QSizeF &) const |
Return a default icon from a brush. | |
Base class for items on the plot canvas.
A plot item is "something", that can be painted on the plot canvas, or only affects the scales of the plot widget. They can be categorized as:
Depending on the QwtPlotItem::ItemAttribute flags, an item is included into autoscaling or has an entry on the legend.
Before misusing the existing item classes it might be better to implement a new type of plot item ( don't implement a watermark as spectrogram ). Deriving a new type of QwtPlotItem primarily means to implement the YourPlotItem::draw() method.
Definition at line 66 of file qwt_plot_item.h.
typedef QFlags<ItemAttribute > QwtPlotItem::ItemAttributes |
An ORed combination of ItemAttribute values.
Definition at line 167 of file qwt_plot_item.h.
typedef QFlags<ItemInterest > QwtPlotItem::ItemInterests |
An ORed combination of ItemInterest values.
Definition at line 200 of file qwt_plot_item.h.
typedef QFlags<RenderHint > QwtPlotItem::RenderHints |
An ORed combination of RenderHint values.
Definition at line 209 of file qwt_plot_item.h.
Plot Item Attributes.
Various aspects of a plot widget depend on the attributes of the attached plot items. If and how a single plot item participates in these updates depends on its attributes.
Enumerator | |
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Legend | The item is represented on the legend. |
AutoScale | The boundingRect() of the item is included in the autoscaling calculation as long as its width or height is >= 0.0. |
Margins | The item needs extra space to display something outside its bounding rectangle.
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Definition at line 147 of file qwt_plot_item.h.
Plot Item Interests.
Plot items might depend on the situation of the corresponding plot widget. By enabling an interest the plot item will be notified, when the corresponding attribute of the plot widgets has changed.
Enumerator | |
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ScaleInterest | The item is interested in updates of the scales
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LegendInterest | The item is interested in updates of the legend ( of other items ) This flag is intended for items, that want to implement a legend for displaying entries of other plot item.
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Definition at line 179 of file qwt_plot_item.h.
Render hints.
Enumerator | |
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RenderAntialiased | Enable antialiasing. |
Definition at line 203 of file qwt_plot_item.h.
Runtime type information.
RttiValues is used to cast plot items, without having to enable runtime type information of the compiler.
Enumerator | |
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Rtti_PlotItem | Unspecific value, that can be used, when it doesn't matter. |
Rtti_PlotGrid | For QwtPlotGrid. |
Rtti_PlotScale | For QwtPlotScaleItem. |
Rtti_PlotLegend | For QwtPlotLegendItem. |
Rtti_PlotMarker | For QwtPlotMarker. |
Rtti_PlotCurve | For QwtPlotCurve. |
Rtti_PlotSpectroCurve | For QwtPlotSpectroCurve. |
Rtti_PlotIntervalCurve | For QwtPlotIntervalCurve. |
Rtti_PlotHistogram | For QwtPlotHistogram. |
Rtti_PlotSpectrogram | For QwtPlotSpectrogram. |
Rtti_PlotGraphic | |
Rtti_PlotTradingCurve | For QwtPlotTradingCurve. |
Rtti_PlotBarChart | For QwtPlotBarChart. |
Rtti_PlotMultiBarChart | For QwtPlotMultiBarChart. |
Rtti_PlotShape | For QwtPlotShapeItem. |
Rtti_PlotTextLabel | For QwtPlotTextLabel. |
Rtti_PlotZone | For QwtPlotZoneItem. |
Rtti_PlotVectorField | For QwtPlotVectorField. |
Rtti_PlotUserItem | Values >= Rtti_PlotUserItem are reserved for plot items not implemented in the Qwt library. |
Definition at line 75 of file qwt_plot_item.h.
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explicit |
Constructor
Definition at line 55 of file qwt_plot_item.cpp.
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explicit |
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explicit |
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virtual |
Destroy the QwtPlotItem.
Definition at line 81 of file qwt_plot_item.cpp.
void QwtPlotItem::attach | ( | QwtPlot * | plot | ) |
Attach the item to a plot.
This method will attach a QwtPlotItem to the QwtPlot argument. It will first detach the QwtPlotItem from any plot from a previous call to attach (if necessary). If a NULL argument is passed, it will detach from any QwtPlot it was attached to.
plot | Plot widget |
Definition at line 98 of file qwt_plot_item.cpp.
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Reimplemented in QwtPlotBarChart, QwtPlotGraphicItem, QwtPlotHistogram, QwtPlotIntervalCurve, QwtPlotMarker, QwtPlotMultiBarChart, QwtPlotRasterItem, QwtPlotSeriesItem, QwtPlotShapeItem, QwtPlotTradingCurve, QwtPlotVectorField, and QwtPlotZoneItem.
Definition at line 568 of file qwt_plot_item.cpp.
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protected |
Return a default icon from a brush.
The default icon is a filled rectangle used in several derived classes as legendIcon().
brush | Fill brush |
size | Icon size |
Definition at line 422 of file qwt_plot_item.cpp.
void QwtPlotItem::detach | ( | ) |
This method detaches a QwtPlotItem from any QwtPlot it has been associated with.
detach() is equivalent to calling attach( NULL )
Definition at line 119 of file qwt_plot_item.cpp.
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pure virtual |
Draw the item.
painter | Painter |
xMap | Maps x-values into pixel coordinates. |
yMap | Maps y-values into pixel coordinates. |
canvasRect | Contents rect of the canvas in painter coordinates |
Implemented in QwtPlotTextLabel, QwtPlotZoneItem, QwtPlotMarker, QwtPlotGraphicItem, QwtPlotGrid, QwtPlotLegendItem, QwtPlotRasterItem, QwtPlotScaleItem, QwtPlotSeriesItem, QwtPlotShapeItem, and QwtPlotSpectrogram.
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virtual |
Calculate a hint for the canvas margin.
When the QwtPlotItem::Margins flag is enabled the plot item indicates, that it needs some margins at the borders of the canvas. This is f.e. used by bar charts to reserve space for displaying the bars.
The margins are in target device coordinates ( pixels on screen )
xMap | Maps x-values into pixel coordinates. |
yMap | Maps y-values into pixel coordinates. |
canvasRect | Contents rectangle of the canvas in painter coordinates |
left | Returns the left margin |
top | Returns the top margin |
right | Returns the right margin |
bottom | Returns the bottom margin |
The default implementation returns 0 for all margins
Reimplemented in QwtPlotAbstractBarChart.
Definition at line 595 of file qwt_plot_item.cpp.
void QwtPlotItem::hide | ( | ) |
Hide the item.
Definition at line 446 of file qwt_plot_item.cpp.
bool QwtPlotItem::isVisible | ( | ) | const |
Definition at line 470 of file qwt_plot_item.cpp.
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virtual |
Update the legend and call QwtPlot::autoRefresh() for the parent plot.
Definition at line 481 of file qwt_plot_item.cpp.
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virtual |
Update the legend of the parent plot.
Definition at line 491 of file qwt_plot_item.cpp.
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Return all information, that is needed to represent the item on the legend.
Most items are represented by one entry on the legend showing an icon and a text, but f.e. QwtPlotMultiBarChart displays one entry for each bar.
QwtLegendData is basically a list of QVariants that makes it possible to overload and reimplement legendData() to return almost any type of information, that is understood by the receiver that acts as the legend.
The default implementation returns one entry with the title() of the item and the legendIcon().
Reimplemented in QwtPlotBarChart, and QwtPlotMultiBarChart.
Definition at line 626 of file qwt_plot_item.cpp.
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virtual |
The default implementation returns an invalid icon
index | Index of the legend entry ( usually there is only one ) |
size | Icon size |
Reimplemented in QwtPlotBarChart, QwtPlotCurve, QwtPlotHistogram, QwtPlotIntervalCurve, QwtPlotMarker, QwtPlotMultiBarChart, QwtPlotShapeItem, QwtPlotTradingCurve, and QwtPlotVectorField.
Definition at line 402 of file qwt_plot_item.cpp.
QSize QwtPlotItem::legendIconSize | ( | ) | const |
Definition at line 386 of file qwt_plot_item.cpp.
QRectF QwtPlotItem::paintRect | ( | const QwtScaleMap & | xMap, |
const QwtScaleMap & | yMap ) const |
Calculate the bounding paint rectangle of 2 maps.
xMap | Maps x-values into pixel coordinates. |
yMap | Maps y-values into pixel coordinates. |
Definition at line 720 of file qwt_plot_item.cpp.
QwtPlot * QwtPlotItem::plot | ( | ) | const |
Return attached plot.
Definition at line 142 of file qwt_plot_item.cpp.
uint QwtPlotItem::renderThreadCount | ( | ) | const |
Definition at line 360 of file qwt_plot_item.cpp.
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virtual |
Return rtti for the specific class represented. QwtPlotItem is simply a virtual interface class, and base classes will implement this method with specific rtti values so a user can differentiate them.
The rtti value is useful for environments, where the runtime type information is disabled and it is not possible to do a dynamic_cast<...>.
Reimplemented in QwtPlotBarChart, QwtPlotCurve, QwtPlotGraphicItem, QwtPlotGrid, QwtPlotHistogram, QwtPlotIntervalCurve, QwtPlotLegendItem, QwtPlotMarker, QwtPlotMultiBarChart, QwtPlotScaleItem, QwtPlotShapeItem, QwtPlotSpectroCurve, QwtPlotSpectrogram, QwtPlotTextLabel, QwtPlotTradingCurve, QwtPlotVectorField, and QwtPlotZoneItem.
Definition at line 136 of file qwt_plot_item.cpp.
QRectF QwtPlotItem::scaleRect | ( | const QwtScaleMap & | xMap, |
const QwtScaleMap & | yMap ) const |
Calculate the bounding scale rectangle of 2 maps.
xMap | Maps x-values into pixel coordinates. |
yMap | Maps y-values into pixel coordinates. |
Definition at line 705 of file qwt_plot_item.cpp.
void QwtPlotItem::setAxes | ( | QwtAxisId | xAxisId, |
QwtAxisId | yAxisId ) |
Set X and Y axis
The item will painted according to the coordinates of its Axes.
xAxisId | X Axis |
yAxisId | Y Axis |
Definition at line 507 of file qwt_plot_item.cpp.
void QwtPlotItem::setItemAttribute | ( | ItemAttribute | attribute, |
bool | on = true ) |
Toggle an item attribute
attribute | Attribute type |
on | true/false |
Definition at line 228 of file qwt_plot_item.cpp.
void QwtPlotItem::setItemInterest | ( | ItemInterest | interest, |
bool | on = true ) |
Toggle an item interest
interest | Interest type |
on | true/false |
Definition at line 279 of file qwt_plot_item.cpp.
void QwtPlotItem::setLegendIconSize | ( | const QSize & | size | ) |
Set the size of the legend icon
The default setting is 8x8 pixels
size | Size |
Definition at line 373 of file qwt_plot_item.cpp.
void QwtPlotItem::setRenderHint | ( | RenderHint | hint, |
bool | on = true ) |
Toggle an render hint
hint | Render hint |
on | true/false |
Definition at line 312 of file qwt_plot_item.cpp.
void QwtPlotItem::setRenderThreadCount | ( | uint | numThreads | ) |
On multi core systems rendering of certain plot item ( f.e QwtPlotRasterItem ) can be done in parallel in several threads.
The default setting is set to 1.
numThreads | Number of threads to be used for rendering. If numThreads is set to 0, the system specific ideal thread count is used. |
The default thread count is 1 ( = no additional threads )
Definition at line 350 of file qwt_plot_item.cpp.
void QwtPlotItem::setTitle | ( | const QString & | title | ) |
Set a new title
title | Title |
Definition at line 187 of file qwt_plot_item.cpp.
void QwtPlotItem::setTitle | ( | const QwtText & | title | ) |
Set a new title
title | Title |
Definition at line 198 of file qwt_plot_item.cpp.
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Show/Hide the item
on | Show if true, otherwise hide |
Definition at line 457 of file qwt_plot_item.cpp.
void QwtPlotItem::setXAxis | ( | QwtAxisId | axisId | ) |
Set the X axis
The item will painted according to the coordinates its Axes.
axisId | X Axis |
Definition at line 526 of file qwt_plot_item.cpp.
void QwtPlotItem::setYAxis | ( | QwtAxisId | axisId | ) |
Set the Y axis
The item will painted according to the coordinates its Axes.
axisId | Y Axis |
Definition at line 543 of file qwt_plot_item.cpp.
void QwtPlotItem::setZ | ( | double | z | ) |
Set the z value.
Plot items are painted in increasing z-order.
z | Z-value |
Definition at line 165 of file qwt_plot_item.cpp.
void QwtPlotItem::show | ( | ) |
Show the item.
Definition at line 440 of file qwt_plot_item.cpp.
bool QwtPlotItem::testItemAttribute | ( | ItemAttribute | attribute | ) | const |
Test an item attribute
attribute | Attribute type |
Definition at line 266 of file qwt_plot_item.cpp.
bool QwtPlotItem::testItemInterest | ( | ItemInterest | interest | ) | const |
Test an item interest
interest | Interest type |
Definition at line 299 of file qwt_plot_item.cpp.
bool QwtPlotItem::testRenderHint | ( | RenderHint | hint | ) | const |
Test a render hint
hint | Render hint |
Definition at line 332 of file qwt_plot_item.cpp.
const QwtText & QwtPlotItem::title | ( | ) | const |
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Update the item to changes of the legend info.
Plot items that want to display a legend ( not those, that want to be displayed on a legend ! ) will have to implement updateLegend().
updateLegend() is only called when the LegendInterest interest is enabled. The default implementation does nothing.
item | Plot item to be displayed on a legend |
data | Attributes how to display item on the legend |
Reimplemented in QwtPlotLegendItem.
Definition at line 690 of file qwt_plot_item.cpp.
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Update the item to changes of the axes scale division.
Update the item, when the axes of plot have changed. The default implementation does nothing, but items that depend on the scale division (like QwtPlotGrid()) have to reimplement updateScaleDiv()
updateScaleDiv() is only called when the ScaleInterest interest is enabled. The default implementation does nothing.
xScaleDiv | Scale division of the x-axis |
yScaleDiv | Scale division of the y-axis |
Reimplemented in QwtPlotScaleItem, QwtPlotSeriesItem, and QwtPlotGrid.
Definition at line 665 of file qwt_plot_item.cpp.
QwtAxisId QwtPlotItem::xAxis | ( | ) | const |
Return xAxis.
Definition at line 553 of file qwt_plot_item.cpp.
QwtAxisId QwtPlotItem::yAxis | ( | ) | const |
Return yAxis.
Definition at line 559 of file qwt_plot_item.cpp.
double QwtPlotItem::z | ( | ) | const |
Plot items are painted in increasing z-order.
Definition at line 152 of file qwt_plot_item.cpp.