Qwt User's Guide 5.2.2
|
A class, which displays raster data. More...
#include <qwt_plot_rasteritem.h>
Public Types | |
enum | CachePolicy { NoCache, PaintCache, ScreenCache } |
enum | ItemAttribute { Legend = 1, AutoScale = 2 } |
enum | RenderHint { RenderAntialiased = 1 } |
enum | RttiValues { Rtti_PlotItem = 0, Rtti_PlotGrid, Rtti_PlotScale, Rtti_PlotMarker, Rtti_PlotCurve, Rtti_PlotHistogram, Rtti_PlotSpectrogram, Rtti_PlotSVG, Rtti_PlotUserItem = 1000 } |
Public Member Functions | |
int | alpha () const |
void | attach (QwtPlot *plot) |
virtual QwtDoubleRect | boundingRect () const |
CachePolicy | cachePolicy () const |
void | detach () |
virtual void | draw (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRect &rect) const |
void | hide () |
void | invalidateCache () |
QwtDoubleRect | invTransform (const QwtScaleMap &, const QwtScaleMap &, const QRect &) const |
bool | isVisible () const |
virtual void | itemChanged () |
virtual QWidget * | legendItem () const |
QRect | paintRect (const QwtScaleMap &, const QwtScaleMap &) const |
QwtPlot * | plot () const |
QwtPlotRasterItem (const QString &title=QString::null) | |
QwtPlotRasterItem (const QwtText &title) | |
virtual QSize | rasterHint (const QwtDoubleRect &) const |
virtual int | rtti () const |
QwtDoubleRect | scaleRect (const QwtScaleMap &, const QwtScaleMap &) const |
void | setAlpha (int alpha) |
void | setAxis (int xAxis, int yAxis) |
void | setCachePolicy (CachePolicy) |
void | setItemAttribute (ItemAttribute, bool on=true) |
void | setRenderHint (RenderHint, bool on=true) |
void | setTitle (const QString &title) |
void | setTitle (const QwtText &title) |
virtual void | setVisible (bool) |
void | setXAxis (int axis) |
void | setYAxis (int axis) |
void | setZ (double z) |
void | show () |
bool | testItemAttribute (ItemAttribute) const |
bool | testRenderHint (RenderHint) const |
const QwtText & | title () const |
QRect | transform (const QwtScaleMap &, const QwtScaleMap &, const QwtDoubleRect &) const |
virtual void | updateLegend (QwtLegend *) const |
virtual void | updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &) |
int | xAxis () const |
int | yAxis () const |
double | z () const |
virtual | ~QwtPlotRasterItem () |
Protected Member Functions | |
virtual QImage | renderImage (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtDoubleRect &area) const =0 |
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 ...
Often a plot has several types of raster data organized in layers. ( f.e a geographical map, with weather statistics ). Using setAlpha() raster items can be stacked easily.
QwtPlotRasterItem is only implemented for images of the following formats: QImage::Format_Indexed8, QImage::Format_ARGB32.
The default policy is NoCache
enum QwtPlotItem::ItemAttribute [inherited] |
Plot Item Attributes
enum QwtPlotItem::RenderHint [inherited] |
Render hints.
enum QwtPlotItem::RttiValues [inherited] |
Runtime type information.
RttiValues is used to cast plot items, without having to enable runtime type information of the compiler.
QwtPlotRasterItem::QwtPlotRasterItem | ( | const QString & | title = QString::null | ) | [explicit] |
Constructor.
QwtPlotRasterItem::QwtPlotRasterItem | ( | const QwtText & | title | ) | [explicit] |
Constructor.
QwtPlotRasterItem::~QwtPlotRasterItem | ( | ) | [virtual] |
Destructor.
int QwtPlotRasterItem::alpha | ( | ) | const |
void QwtPlotItem::attach | ( | QwtPlot * | plot | ) | [inherited] |
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 |
QwtDoubleRect QwtPlotItem::boundingRect | ( | ) | const [virtual, inherited] |
Reimplemented in QwtPlotCurve, QwtPlotMarker, QwtPlotSpectrogram, and QwtPlotSvgItem.
QwtPlotRasterItem::CachePolicy QwtPlotRasterItem::cachePolicy | ( | ) | const |
void QwtPlotItem::detach | ( | ) | [inline, inherited] |
This method detaches a QwtPlotItem from any QwtPlot it has been associated with.
detach() is equivalent to calling attach( NULL )
void QwtPlotRasterItem::draw | ( | QPainter * | painter, |
const QwtScaleMap & | xMap, | ||
const QwtScaleMap & | yMap, | ||
const QRect & | canvasRect | ||
) | const [virtual] |
Draw the raster data.
painter | Painter |
xMap | X-Scale Map |
yMap | Y-Scale Map |
canvasRect | Contents rect of the plot canvas |
Implements QwtPlotItem.
Reimplemented in QwtPlotSpectrogram.
void QwtPlotItem::hide | ( | ) | [inherited] |
Hide the item.
void QwtPlotRasterItem::invalidateCache | ( | ) |
Invalidate the paint cache
QwtDoubleRect QwtPlotItem::invTransform | ( | const QwtScaleMap & | xMap, |
const QwtScaleMap & | yMap, | ||
const QRect & | rect | ||
) | const [inherited] |
Transform a rectangle from paint to scale coordinates
xMap | X map |
yMap | Y map |
rect | Rectangle in paint coordinates |
bool QwtPlotItem::isVisible | ( | ) | const [inherited] |
void QwtPlotItem::itemChanged | ( | ) | [virtual, inherited] |
Update the legend and call QwtPlot::autoRefresh for the parent plot.
QWidget * QwtPlotItem::legendItem | ( | ) | const [virtual, inherited] |
Allocate the widget that represents the item on the legend.
The default implementation is made for QwtPlotCurve and returns a QwtLegendItem(), but an item could be represented by any type of widget, by overloading legendItem() and updateLegend().
Implements QwtLegendItemManager.
QRect QwtPlotItem::paintRect | ( | const QwtScaleMap & | xMap, |
const QwtScaleMap & | yMap | ||
) | const [inherited] |
Calculate the bounding paint rect of 2 maps.
xMap | X map |
yMap | X map |
QwtPlot * QwtPlotItem::plot | ( | ) | const [inherited] |
Return attached plot.
QSize QwtPlotRasterItem::rasterHint | ( | const QwtDoubleRect & | ) | const [virtual] |
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.
The default implementation returns an invalid size (QSize()), what means: no hint.
Reimplemented in QwtPlotSpectrogram.
virtual QImage QwtPlotRasterItem::renderImage | ( | const QwtScaleMap & | xMap, |
const QwtScaleMap & | yMap, | ||
const QwtDoubleRect & | area | ||
) | const [protected, pure virtual] |
Renders an image for an area
The format of the image must be QImage::Format_Indexed8, QImage::Format_RGB32 or QImage::Format_ARGB32
xMap | Maps x-values into pixel coordinates. |
yMap | Maps y-values into pixel coordinates. |
area | Requested area for the image in scale coordinates |
Implemented in QwtPlotSpectrogram.
int QwtPlotItem::rtti | ( | ) | const [virtual, inherited] |
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 QwtPlotCurve, QwtPlotGrid, QwtPlotMarker, QwtPlotScaleItem, QwtPlotSpectrogram, and QwtPlotSvgItem.
QwtDoubleRect QwtPlotItem::scaleRect | ( | const QwtScaleMap & | xMap, |
const QwtScaleMap & | yMap | ||
) | const [inherited] |
Calculate the bounding scale rect of 2 maps.
xMap | X map |
yMap | X map |
void QwtPlotRasterItem::setAlpha | ( | int | alpha | ) |
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 setAlpha() raster items can be stacked easily.
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.
alpha | Alpha value |
The default alpha value is -1.
void QwtPlotItem::setAxis | ( | int | xAxis, |
int | yAxis | ||
) | [inherited] |
Set X and Y axis
The item will painted according to the coordinates its Axes.
xAxis | X Axis |
yAxis | Y Axis |
void QwtPlotRasterItem::setCachePolicy | ( | QwtPlotRasterItem::CachePolicy | policy | ) |
Change the cache policy
The default policy is NoCache
policy | Cache policy |
void QwtPlotItem::setItemAttribute | ( | ItemAttribute | attribute, |
bool | on = true |
||
) | [inherited] |
Toggle an item attribute
attribute | Attribute type |
on | true/false |
void QwtPlotItem::setRenderHint | ( | RenderHint | hint, |
bool | on = true |
||
) | [inherited] |
Toggle an render hint
hint | Render hint |
on | true/false |
void QwtPlotItem::setTitle | ( | const QString & | title | ) | [inherited] |
void QwtPlotItem::setTitle | ( | const QwtText & | title | ) | [inherited] |
void QwtPlotItem::setVisible | ( | bool | on | ) | [virtual, inherited] |
void QwtPlotItem::setXAxis | ( | int | axis | ) | [inherited] |
Set the X axis
The item will painted according to the coordinates its Axes.
axis | X Axis |
void QwtPlotItem::setYAxis | ( | int | axis | ) | [inherited] |
Set the Y axis
The item will painted according to the coordinates its Axes.
axis | Y Axis |
void QwtPlotItem::setZ | ( | double | z | ) | [inherited] |
Set the z value.
Plot items are painted in increasing z-order.
z | Z-value |
void QwtPlotItem::show | ( | ) | [inherited] |
Show the item.
bool QwtPlotItem::testItemAttribute | ( | ItemAttribute | attribute | ) | const [inherited] |
Test an item attribute
attribute | Attribute type |
bool QwtPlotItem::testRenderHint | ( | RenderHint | hint | ) | const [inherited] |
Test a render hint
hint | Render hint |
const QwtText & QwtPlotItem::title | ( | ) | const [inherited] |
QRect QwtPlotItem::transform | ( | const QwtScaleMap & | xMap, |
const QwtScaleMap & | yMap, | ||
const QwtDoubleRect & | rect | ||
) | const [inherited] |
Transform a rectangle
xMap | X map |
yMap | Y map |
rect | Rectangle in scale coordinates |
void QwtPlotItem::updateLegend | ( | QwtLegend * | legend | ) | const [virtual, inherited] |
Update the widget that represents the item on the legend.
updateLegend() is called from itemChanged() to adopt the widget representing the item on the legend to its new configuration.
The default implementation is made for QwtPlotCurve and updates a QwtLegendItem(), but an item could be represented by any type of widget, by overloading legendItem() and updateLegend().
legend | Legend |
Implements QwtLegendItemManager.
Reimplemented in QwtPlotCurve.
void QwtPlotItem::updateScaleDiv | ( | const QwtScaleDiv & | , |
const QwtScaleDiv & | |||
) | [virtual, inherited] |
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()
xScaleDiv | Scale division of the x-axis |
yScaleDiv | Scale division of the y-axis |
Reimplemented in QwtPlotGrid, and QwtPlotScaleItem.
int QwtPlotItem::xAxis | ( | ) | const [inherited] |
Return xAxis.
int QwtPlotItem::yAxis | ( | ) | const [inherited] |
Return yAxis.
double QwtPlotItem::z | ( | ) | const [inherited] |
Plot items are painted in increasing z-order.