.TH "QwtPlotRasterItem" 3 "Mon Aug 1 2011" "Version 5.2.2" "Qwt User's Guide" \" -*- nroff -*- .ad l .nh .SH NAME QwtPlotRasterItem \- .PP A class, which displays raster data. .SH SYNOPSIS .br .PP .PP \fC#include \fP .PP Inherits \fBQwtPlotItem\fP. .PP Inherited by \fBQwtPlotSpectrogram\fP. .SS "Public Types" .in +1c .ti -1c .RI "enum \fBCachePolicy\fP { \fBNoCache\fP, \fBPaintCache\fP, \fBScreenCache\fP }" .br .ti -1c .RI "enum \fBItemAttribute\fP { \fBLegend\fP = 1, \fBAutoScale\fP = 2 }" .br .ti -1c .RI "enum \fBRenderHint\fP { \fBRenderAntialiased\fP = 1 }" .br .ti -1c .RI "enum \fBRttiValues\fP { \fBRtti_PlotItem\fP = 0, \fBRtti_PlotGrid\fP, \fBRtti_PlotScale\fP, \fBRtti_PlotMarker\fP, \fBRtti_PlotCurve\fP, \fBRtti_PlotHistogram\fP, \fBRtti_PlotSpectrogram\fP, \fBRtti_PlotSVG\fP, \fBRtti_PlotUserItem\fP = 1000 }" .br .in -1c .SS "Public Member Functions" .in +1c .ti -1c .RI "int \fBalpha\fP () const " .br .ti -1c .RI "void \fBattach\fP (\fBQwtPlot\fP *plot)" .br .ti -1c .RI "virtual QwtDoubleRect \fBboundingRect\fP () const " .br .ti -1c .RI "\fBCachePolicy\fP \fBcachePolicy\fP () const " .br .ti -1c .RI "void \fBdetach\fP ()" .br .ti -1c .RI "virtual void \fBdraw\fP (QPainter *p, const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap, const QRect &rect) const " .br .ti -1c .RI "void \fBhide\fP ()" .br .ti -1c .RI "void \fBinvalidateCache\fP ()" .br .ti -1c .RI "QwtDoubleRect \fBinvTransform\fP (const \fBQwtScaleMap\fP &, const \fBQwtScaleMap\fP &, const QRect &) const " .br .ti -1c .RI "bool \fBisVisible\fP () const " .br .ti -1c .RI "virtual void \fBitemChanged\fP ()" .br .ti -1c .RI "virtual QWidget * \fBlegendItem\fP () const " .br .ti -1c .RI "QRect \fBpaintRect\fP (const \fBQwtScaleMap\fP &, const \fBQwtScaleMap\fP &) const " .br .ti -1c .RI "\fBQwtPlot\fP * \fBplot\fP () const " .br .ti -1c .RI "\fBQwtPlotRasterItem\fP (const QString &title=QString::null)" .br .ti -1c .RI "\fBQwtPlotRasterItem\fP (const \fBQwtText\fP &title)" .br .ti -1c .RI "virtual QSize \fBrasterHint\fP (const QwtDoubleRect &) const " .br .ti -1c .RI "virtual int \fBrtti\fP () const " .br .ti -1c .RI "QwtDoubleRect \fBscaleRect\fP (const \fBQwtScaleMap\fP &, const \fBQwtScaleMap\fP &) const " .br .ti -1c .RI "void \fBsetAlpha\fP (int alpha)" .br .ti -1c .RI "void \fBsetAxis\fP (int xAxis, int yAxis)" .br .ti -1c .RI "void \fBsetCachePolicy\fP (\fBCachePolicy\fP)" .br .ti -1c .RI "void \fBsetItemAttribute\fP (\fBItemAttribute\fP, bool on=true)" .br .ti -1c .RI "void \fBsetRenderHint\fP (\fBRenderHint\fP, bool on=true)" .br .ti -1c .RI "void \fBsetTitle\fP (const QString &title)" .br .ti -1c .RI "void \fBsetTitle\fP (const \fBQwtText\fP &title)" .br .ti -1c .RI "virtual void \fBsetVisible\fP (bool)" .br .ti -1c .RI "void \fBsetXAxis\fP (int axis)" .br .ti -1c .RI "void \fBsetYAxis\fP (int axis)" .br .ti -1c .RI "void \fBsetZ\fP (double z)" .br .ti -1c .RI "void \fBshow\fP ()" .br .ti -1c .RI "bool \fBtestItemAttribute\fP (\fBItemAttribute\fP) const " .br .ti -1c .RI "bool \fBtestRenderHint\fP (\fBRenderHint\fP) const " .br .ti -1c .RI "const \fBQwtText\fP & \fBtitle\fP () const " .br .ti -1c .RI "QRect \fBtransform\fP (const \fBQwtScaleMap\fP &, const \fBQwtScaleMap\fP &, const QwtDoubleRect &) const " .br .ti -1c .RI "virtual void \fBupdateLegend\fP (\fBQwtLegend\fP *) const " .br .ti -1c .RI "virtual void \fBupdateScaleDiv\fP (const \fBQwtScaleDiv\fP &, const \fBQwtScaleDiv\fP &)" .br .ti -1c .RI "int \fBxAxis\fP () const " .br .ti -1c .RI "int \fByAxis\fP () const " .br .ti -1c .RI "double \fBz\fP () const " .br .ti -1c .RI "virtual \fB~QwtPlotRasterItem\fP ()" .br .in -1c .SS "Protected Member Functions" .in +1c .ti -1c .RI "virtual QImage \fBrenderImage\fP (const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap, const QwtDoubleRect &area) const =0" .br .in -1c .SH "Detailed Description" .PP A class, which displays raster data. Raster data is a grid of pixel values, that can be represented as a QImage. It is used for many types of information like spectrograms, cartograms, geographical maps ... .PP Often a plot has several types of raster data organized in layers. ( f.e a geographical map, with weather statistics ). Using \fBsetAlpha()\fP raster items can be stacked easily. .PP \fBQwtPlotRasterItem\fP is only implemented for images of the following formats: QImage::Format_Indexed8, QImage::Format_ARGB32. .PP \fBSee also:\fP .RS 4 \fBQwtPlotSpectrogram\fP .RE .PP .SH "Member Enumeration Documentation" .PP .SS "enum \fBQwtPlotRasterItem::CachePolicy\fP".IP "\(bu" 2 NoCache .br \fBrenderImage()\fP is called, whenever the item has to be repainted .IP "\(bu" 2 PaintCache .br \fBrenderImage()\fP is called, whenever the image cache is not valid, or the scales, or the size of the canvas has changed. This type of cache is only useful for improving the performance of hide/show operations. All other situations are already handled by the plot canvas cache. .IP "\(bu" 2 ScreenCache .br The screen cache is an image in size of the screen. As long as the scales don't change the target image is scaled from the cache. This might improve the performance when resizing the plot widget, but suffers from scaling effects. .PP .PP The default policy is NoCache .SS "enum \fBQwtPlotItem::ItemAttribute\fP\fC [inherited]\fP"Plot Item Attributes .PP .IP "\(bu" 2 Legend .br The item is represented on the legend. .IP "\(bu" 2 AutoScale .br The \fBboundingRect()\fP of the item is included in the autoscaling calculation. .PP .PP \fBSee also:\fP .RS 4 \fBsetItemAttribute()\fP, \fBtestItemAttribute()\fP .RE .PP .SS "enum \fBQwtPlotItem::RenderHint\fP\fC [inherited]\fP" .PP Render hints. .SS "enum \fBQwtPlotItem::RttiValues\fP\fC [inherited]\fP" .PP Runtime type information. RttiValues is used to cast plot items, without having to enable runtime type information of the compiler. .SH "Constructor & Destructor Documentation" .PP .SS "QwtPlotRasterItem::QwtPlotRasterItem (const QString &title = \fCQString::null\fP)\fC [explicit]\fP" .PP Constructor. .SS "QwtPlotRasterItem::QwtPlotRasterItem (const \fBQwtText\fP &title)\fC [explicit]\fP" .PP Constructor. .SS "QwtPlotRasterItem::~QwtPlotRasterItem ()\fC [virtual]\fP" .PP Destructor. .SH "Member Function Documentation" .PP .SS "int QwtPlotRasterItem::alpha () const"\fBReturns:\fP .RS 4 Alpha value of the raster item .RE .PP \fBSee also:\fP .RS 4 \fBsetAlpha()\fP .RE .PP .SS "void QwtPlotItem::attach (\fBQwtPlot\fP *plot)\fC [inherited]\fP" .PP Attach the item to a plot. This method will attach a \fBQwtPlotItem\fP to the \fBQwtPlot\fP argument. It will first detach the \fBQwtPlotItem\fP from any plot from a previous call to attach (if necessary). If a NULL argument is passed, it will detach from any \fBQwtPlot\fP it was attached to. .PP \fBParameters:\fP .RS 4 \fIplot\fP Plot widget .RE .PP \fBSee also:\fP .RS 4 \fBQwtPlotItem::detach()\fP .RE .PP .SS "QwtDoubleRect QwtPlotItem::boundingRect () const\fC [virtual, inherited]\fP"\fBReturns:\fP .RS 4 An invalid bounding rect: QwtDoubleRect(1.0, 1.0, \-2.0, \-2.0) .RE .PP .PP Reimplemented in \fBQwtPlotCurve\fP, \fBQwtPlotMarker\fP, \fBQwtPlotSpectrogram\fP, and \fBQwtPlotSvgItem\fP. .SS "\fBQwtPlotRasterItem::CachePolicy\fP QwtPlotRasterItem::cachePolicy () const"\fBReturns:\fP .RS 4 Cache policy .RE .PP \fBSee also:\fP .RS 4 \fBCachePolicy\fP, \fBsetCachePolicy()\fP .RE .PP .SS "void QwtPlotItem::detach ()\fC [inline, inherited]\fP" .PP This method detaches a \fBQwtPlotItem\fP from any \fBQwtPlot\fP it has been associated with. \fBdetach()\fP is equivalent to calling attach( NULL ) .PP \fBSee also:\fP .RS 4 \fBattach( QwtPlot* plot )\fP .RE .PP .SS "void QwtPlotRasterItem::draw (QPainter *painter, const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap, const QRect &canvasRect) const\fC [virtual]\fP" .PP Draw the raster data. \fBParameters:\fP .RS 4 \fIpainter\fP Painter .br \fIxMap\fP X-Scale Map .br \fIyMap\fP Y-Scale Map .br \fIcanvasRect\fP Contents rect of the plot canvas .RE .PP .PP Implements \fBQwtPlotItem\fP. .PP Reimplemented in \fBQwtPlotSpectrogram\fP. .SS "void QwtPlotItem::hide ()\fC [inherited]\fP" .PP Hide the item. .SS "void QwtPlotRasterItem::invalidateCache ()"Invalidate the paint cache .PP \fBSee also:\fP .RS 4 \fBsetCachePolicy()\fP .RE .PP .SS "QwtDoubleRect QwtPlotItem::invTransform (const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap, const QRect &rect) const\fC [inherited]\fP"Transform a rectangle from paint to scale coordinates .PP \fBParameters:\fP .RS 4 \fIxMap\fP X map .br \fIyMap\fP Y map .br \fIrect\fP Rectangle in paint coordinates .RE .PP \fBReturns:\fP .RS 4 Rectangle in scale coordinates .RE .PP \fBSee also:\fP .RS 4 \fBtransform()\fP .RE .PP .SS "bool QwtPlotItem::isVisible () const\fC [inherited]\fP"\fBReturns:\fP .RS 4 true if visible .RE .PP \fBSee also:\fP .RS 4 \fBsetVisible()\fP, \fBshow()\fP, \fBhide()\fP .RE .PP .SS "void QwtPlotItem::itemChanged ()\fC [virtual, inherited]\fP"Update the legend and call \fBQwtPlot::autoRefresh\fP for the parent plot. .PP \fBSee also:\fP .RS 4 \fBupdateLegend()\fP .RE .PP .SS "QWidget * QwtPlotItem::legendItem () const\fC [virtual, inherited]\fP" .PP Allocate the widget that represents the item on the legend. The default implementation is made for \fBQwtPlotCurve\fP and returns a QwtLegendItem(), but an item could be represented by any type of widget, by overloading \fBlegendItem()\fP and \fBupdateLegend()\fP. .PP \fBReturns:\fP .RS 4 QwtLegendItem() .RE .PP \fBSee also:\fP .RS 4 \fBupdateLegend()\fP QwtLegend() .RE .PP .PP Implements \fBQwtLegendItemManager\fP. .SS "QRect QwtPlotItem::paintRect (const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap) const\fC [inherited]\fP" .PP Calculate the bounding paint rect of 2 maps. \fBParameters:\fP .RS 4 \fIxMap\fP X map .br \fIyMap\fP X map .RE .PP \fBReturns:\fP .RS 4 Bounding rect of the scale maps .RE .PP .SS "\fBQwtPlot\fP * QwtPlotItem::plot () const\fC [inherited]\fP" .PP Return attached plot. .SS "QSize QwtPlotRasterItem::rasterHint (const QwtDoubleRect &) const\fC [virtual]\fP" .PP Returns the recommended raster for a given rect. F.e the raster hint can be used to limit the resolution of the image that is rendered. .PP The default implementation returns an invalid size (QSize()), what means: no hint. .PP Reimplemented in \fBQwtPlotSpectrogram\fP. .SS "virtual QImage QwtPlotRasterItem::renderImage (const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap, const QwtDoubleRect &area) const\fC [protected, pure virtual]\fP"Renders an image for an area .PP The format of the image must be QImage::Format_Indexed8, QImage::Format_RGB32 or QImage::Format_ARGB32 .PP \fBParameters:\fP .RS 4 \fIxMap\fP Maps x-values into pixel coordinates. .br \fIyMap\fP Maps y-values into pixel coordinates. .br \fIarea\fP Requested area for the image in scale coordinates .RE .PP .PP Implemented in \fBQwtPlotSpectrogram\fP. .SS "int QwtPlotItem::rtti () const\fC [virtual, inherited]\fP"Return rtti for the specific class represented. \fBQwtPlotItem\fP is simply a virtual interface class, and base classes will implement this method with specific rtti values so a user can differentiate them. .PP The rtti value is useful for environments, where the runtime type information is disabled and it is not possible to do a dynamic_cast<...>. .PP \fBReturns:\fP .RS 4 rtti value .RE .PP \fBSee also:\fP .RS 4 \fBRttiValues\fP .RE .PP .PP Reimplemented in \fBQwtPlotCurve\fP, \fBQwtPlotGrid\fP, \fBQwtPlotMarker\fP, \fBQwtPlotScaleItem\fP, \fBQwtPlotSpectrogram\fP, and \fBQwtPlotSvgItem\fP. .SS "QwtDoubleRect QwtPlotItem::scaleRect (const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap) const\fC [inherited]\fP" .PP Calculate the bounding scale rect of 2 maps. \fBParameters:\fP .RS 4 \fIxMap\fP X map .br \fIyMap\fP X map .RE .PP \fBReturns:\fP .RS 4 Bounding rect of the scale maps .RE .PP .SS "void QwtPlotRasterItem::setAlpha (intalpha)" .PP Set an alpha value for the raster data. Often a plot has several types of raster data organized in layers. ( f.e a geographical map, with weather statistics ). Using \fBsetAlpha()\fP raster items can be stacked easily. .PP The alpha value is a value [0, 255] to control the transparency of the image. 0 represents a fully transparent color, while 255 represents a fully opaque color. .PP \fBParameters:\fP .RS 4 \fIalpha\fP Alpha value .RE .PP .IP "\(bu" 2 alpha >= 0 .br All alpha values of the pixels returned by \fBrenderImage()\fP will be set to alpha, beside those with an alpha value of 0 (invalid pixels). .IP "\(bu" 2 alpha < 0 The alpha values returned by \fBrenderImage()\fP are not changed. .PP .PP The default alpha value is \-1. .PP \fBSee also:\fP .RS 4 \fBalpha()\fP .RE .PP .SS "void QwtPlotItem::setAxis (intxAxis, intyAxis)\fC [inherited]\fP"Set X and Y axis .PP The item will painted according to the coordinates its Axes. .PP \fBParameters:\fP .RS 4 \fIxAxis\fP X Axis .br \fIyAxis\fP Y Axis .RE .PP \fBSee also:\fP .RS 4 \fBsetXAxis()\fP, \fBsetYAxis()\fP, \fBxAxis()\fP, \fByAxis()\fP .RE .PP .SS "void QwtPlotRasterItem::setCachePolicy (\fBQwtPlotRasterItem::CachePolicy\fPpolicy)"Change the cache policy .PP The default policy is NoCache .PP \fBParameters:\fP .RS 4 \fIpolicy\fP Cache policy .RE .PP \fBSee also:\fP .RS 4 \fBCachePolicy\fP, \fBcachePolicy()\fP .RE .PP .SS "void QwtPlotItem::setItemAttribute (\fBItemAttribute\fPattribute, boolon = \fCtrue\fP)\fC [inherited]\fP"Toggle an item attribute .PP \fBParameters:\fP .RS 4 \fIattribute\fP Attribute type .br \fIon\fP true/false .RE .PP \fBSee also:\fP .RS 4 \fBtestItemAttribute()\fP, \fBItemAttribute\fP .RE .PP .SS "void QwtPlotItem::setRenderHint (\fBRenderHint\fPhint, boolon = \fCtrue\fP)\fC [inherited]\fP"Toggle an render hint .PP \fBParameters:\fP .RS 4 \fIhint\fP Render hint .br \fIon\fP true/false .RE .PP \fBSee also:\fP .RS 4 \fBtestRenderHint()\fP, \fBRenderHint\fP .RE .PP .SS "void QwtPlotItem::setTitle (const QString &title)\fC [inherited]\fP"Set a new title .PP \fBParameters:\fP .RS 4 \fItitle\fP Title .RE .PP \fBSee also:\fP .RS 4 \fBtitle()\fP .RE .PP .SS "void QwtPlotItem::setTitle (const \fBQwtText\fP &title)\fC [inherited]\fP"Set a new title .PP \fBParameters:\fP .RS 4 \fItitle\fP Title .RE .PP \fBSee also:\fP .RS 4 \fBtitle()\fP .RE .PP .SS "void QwtPlotItem::setVisible (boolon)\fC [virtual, inherited]\fP"Show/Hide the item .PP \fBParameters:\fP .RS 4 \fIon\fP Show if true, otherwise hide .RE .PP \fBSee also:\fP .RS 4 \fBisVisible()\fP, \fBshow()\fP, \fBhide()\fP .RE .PP .SS "void QwtPlotItem::setXAxis (intaxis)\fC [inherited]\fP"Set the X axis .PP The item will painted according to the coordinates its Axes. .PP \fBParameters:\fP .RS 4 \fIaxis\fP X Axis .RE .PP \fBSee also:\fP .RS 4 \fBsetAxis()\fP, \fBsetYAxis()\fP, \fBxAxis()\fP .RE .PP .SS "void QwtPlotItem::setYAxis (intaxis)\fC [inherited]\fP"Set the Y axis .PP The item will painted according to the coordinates its Axes. .PP \fBParameters:\fP .RS 4 \fIaxis\fP Y Axis .RE .PP \fBSee also:\fP .RS 4 \fBsetAxis()\fP, \fBsetXAxis()\fP, \fByAxis()\fP .RE .PP .SS "void QwtPlotItem::setZ (doublez)\fC [inherited]\fP" .PP Set the z value. Plot items are painted in increasing z-order. .PP \fBParameters:\fP .RS 4 \fIz\fP Z-value .RE .PP \fBSee also:\fP .RS 4 \fBz()\fP, \fBQwtPlotDict::itemList()\fP .RE .PP .SS "void QwtPlotItem::show ()\fC [inherited]\fP" .PP Show the item. .SS "bool QwtPlotItem::testItemAttribute (\fBItemAttribute\fPattribute) const\fC [inherited]\fP"Test an item attribute .PP \fBParameters:\fP .RS 4 \fIattribute\fP Attribute type .RE .PP \fBReturns:\fP .RS 4 true/false .RE .PP \fBSee also:\fP .RS 4 \fBsetItemAttribute()\fP, \fBItemAttribute\fP .RE .PP .SS "bool QwtPlotItem::testRenderHint (\fBRenderHint\fPhint) const\fC [inherited]\fP"Test a render hint .PP \fBParameters:\fP .RS 4 \fIhint\fP Render hint .RE .PP \fBReturns:\fP .RS 4 true/false .RE .PP \fBSee also:\fP .RS 4 \fBsetRenderHint()\fP, \fBRenderHint\fP .RE .PP .SS "const \fBQwtText\fP & QwtPlotItem::title () const\fC [inherited]\fP"\fBReturns:\fP .RS 4 Title of the item .RE .PP \fBSee also:\fP .RS 4 \fBsetTitle()\fP .RE .PP .SS "QRect QwtPlotItem::transform (const \fBQwtScaleMap\fP &xMap, const \fBQwtScaleMap\fP &yMap, const QwtDoubleRect &rect) const\fC [inherited]\fP"Transform a rectangle .PP \fBParameters:\fP .RS 4 \fIxMap\fP X map .br \fIyMap\fP Y map .br \fIrect\fP Rectangle in scale coordinates .RE .PP \fBReturns:\fP .RS 4 Rectangle in paint coordinates .RE .PP \fBSee also:\fP .RS 4 \fBinvTransform()\fP .RE .PP .SS "void QwtPlotItem::updateLegend (\fBQwtLegend\fP *legend) const\fC [virtual, inherited]\fP" .PP Update the widget that represents the item on the legend. \fBupdateLegend()\fP is called from \fBitemChanged()\fP to adopt the widget representing the item on the legend to its new configuration. .PP The default implementation is made for \fBQwtPlotCurve\fP and updates a QwtLegendItem(), but an item could be represented by any type of widget, by overloading \fBlegendItem()\fP and \fBupdateLegend()\fP. .PP \fBParameters:\fP .RS 4 \fIlegend\fP Legend .RE .PP \fBSee also:\fP .RS 4 \fBlegendItem()\fP, \fBitemChanged()\fP, QwtLegend() .RE .PP .PP Implements \fBQwtLegendItemManager\fP. .PP Reimplemented in \fBQwtPlotCurve\fP. .SS "void QwtPlotItem::updateScaleDiv (const \fBQwtScaleDiv\fP &, const \fBQwtScaleDiv\fP &)\fC [virtual, inherited]\fP" .PP 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 \fBupdateScaleDiv()\fP .PP \fBParameters:\fP .RS 4 \fIxScaleDiv\fP Scale division of the x-axis .br \fIyScaleDiv\fP Scale division of the y-axis .RE .PP \fBSee also:\fP .RS 4 \fBQwtPlot::updateAxes()\fP .RE .PP .PP Reimplemented in \fBQwtPlotGrid\fP, and \fBQwtPlotScaleItem\fP. .SS "int QwtPlotItem::xAxis () const\fC [inherited]\fP" .PP Return xAxis. .SS "int QwtPlotItem::yAxis () const\fC [inherited]\fP" .PP Return yAxis. .SS "double QwtPlotItem::z () const\fC [inherited]\fP"Plot items are painted in increasing z-order. .PP \fBReturns:\fP .RS 4 \fBsetZ()\fP, \fBQwtPlotDict::itemList()\fP .RE .PP .SH "Author" .PP Generated automatically by Doxygen for Qwt User's Guide from the source code.