\section jkqtplotter_graphsgroup_classstructure_basics Graph Class Structure
Each type of graph is represented by another class, which has to be derived from JKQTPPlotElement. This class provides a basic virtual interface
that allows JKQTPlotter to draw the graphs represented by them. This interface consists of these functions:
- JKQTPPlotElement::draw() draws the graph onto a given JKQTPEnhancedPainter (derived from <a href="http://doc.qt.io/qt-5/qpainter.html">QPainter</a>)
- JKQTPPlotElement::drawKeyMarker() draws the small marker image in the plot legend
- JKQTPPlotElement::getKeyLabelColor() returns a color for the legend entry for the graph
- JKQTPPlotElement::getXMinMax() returns the extent of the graph in x-direction (e.g. for auto-zooming)
- JKQTPPlotElement::getYMinMax() returns the extent of the graph in Y-direction (e.g. for auto-zooming)
.
In addition to these basic functions, there are additional functions that can be used to draw something outside the actual plot rectangle.
These are used to e.g. add color-scales to the side of the graph:
- JKQTPPlotElement::getOutsideSize() returns the amount of space required outside the plot rectangle
- JKQTPPlotElement::drawOutside() draws the elements outside the plot rectangle
.
Usually if writing a new graph, one would not directly
derive from JKQTPPlotElement, but from a cass in it's hirarchy of children. These children already provide certain facilities for certain types of graphs.
noteJKQTPGeometricPlotElement [shape="note", color="lightyellow",style=filled,fontsize=8,label="base class for all\nnon-graph elements,\ne.g. geometric elements"];
noteJKQTPSingleColumnGraph [shape="note", color="lightyellow",style=filled,fontsize=8,label="base class for all\ngraphs based on only\n a single column of data"];
noteJJKQTPXYAndVectorGraph [shape="note", color="lightyellow",style=filled,fontsize=8,label="base class for all\nvector field graphs based on\n (x, y, dx, dy) data quadruples"];
noteJJKQTPXYBaselineGraph [shape="note", color="lightyellow",style=filled,fontsize=8,label="base class for all\ngraphs based on\n (x,y) data pairs and a baseline"];
noteJKQTPEvaluatedFunctionGraphBase [shape="note", color="lightyellow",style=filled,fontsize=8,label="base class for all\ngraphs that represent \ndynamically evaluated functions"];
noteJKQTPBoxplotGraphBase [shape="note", color="lightyellow",style=filled,fontsize=8,label="base class for all\ngraphs that represent \na set of boxplots"];
noteJKQTPBoxplotElementBase [shape="note", color="lightyellow",style=filled,fontsize=8,label="base class for all\ngraphs that represent \na single boxplot"];
noteJKQTPViolinplotElementBase [shape="note", color="lightyellow",style=filled,fontsize=8,label="base class for all\ngraphs that represent \na single violin plot"];