[jfreechart-dev] [ jfreechart-Bugs-1593156 ] StackedXYAreaRenderer with line plotting causes NPE

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Bugs item #1593156, was opened at 2006-11-09 06:22
Message generated for change (Comment added) made by mungady
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>Category: General
>Group: 1.0.x
>Status: Closed
>Resolution: Fixed
Priority: 5
Private: No
Submitted By: Alex Mont (alex319)
>Assigned to: David Gilbert (mungady)
Summary: StackedXYAreaRenderer with line plotting causes NPE

Initial Comment:
If you create a StackedXYAreaRenderer with line
plotting turned on (i.e. with "type" set to LINES or
SHAPES_AND_LINES), it will throw a null pointer
exception when you call drawItem() on it with pass == 0
and item > 0.

This is caused because the result of
areaState.getLine(), which is the field areaState.line,
is dereferenced at lines 457, 461, and 464. However
areaState.line will always be null, because it is set
to null during the constructor for
StackedXYAreaRendererState, and there is no possible
way it can be set to anything else. (line is a private
field of StackedXYAreaRendererState, and that class has
no functions which could modify line).

The following is a test case which demonstrates the error:

----

import org.jfree.chart.renderer.xy.StackedXYAreaRenderer;
import org.jfree.chart.renderer.xy.XYItemRendererState;
import org.jfree.data.statistics.*;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.plot.FastScatterPlot;
import org.jfree.chart.plot.PlotRenderingInfo;
import org.jfree.chart.plot.CrosshairState;
import org.jfree.data.xy.DefaultTableXYDataset;
import org.jfree.data.xy.XYSeries;
import java.awt.Graphics2D;
import java.awt.Button;
import java.awt.geom.Rectangle2D;
import java.awt.geom.Point2D;
import java.util.ArrayList;
import java.lang.Double;

Button aButton = new Button();
Graphics2D theGraphics = (Graphics2D)aButton.getGraphics();
Rectangle2D theRectangle = new Rectangle2D.Double(0.0,
0.0, 1.0, 1.0);
PlotRenderingInfo thePlotRenderingInfo = null;
XYPlot theXYPlot = new XYPlot();
StackedXYAreaRenderer theRenderer = new
StackedXYAreaRenderer(org.jfree.chart.renderer.xy.XYAreaRenderer.LINES);
theRenderer.setPlot(theXYPlot);
NumberAxis theXAxis = new NumberAxis("X axis");
NumberAxis theYAxis = new NumberAxis("Y axis");
XYSeries theSeries = new XYSeries("The Series", false,
false);
theSeries.add(0.8, 0.3);
theSeries.add(0.6, 0.6);
theSeries.add(0.4, 0.9);
DefaultTableXYDataset theData = new
DefaultTableXYDataset();
theData.addSeries(theSeries);
int series = 0;
CrosshairState theCrosshairState = new CrosshairState();
int thePass = 0;
XYItemRendererState theState =
theRenderer.initialise(theGraphics, theRectangle,
theXYPlot, theData, thePlotRenderingInfo);
try{
theRenderer.drawItem(theGraphics, theState,
theRectangle, thePlotRenderingInfo, theXYPlot,
theXAxis, theYAxis, theData, series, 0,
theCrosshairState, thePass);
theRenderer.drawItem(theGraphics, theState,
theRectangle, thePlotRenderingInfo, theXYPlot,
theXAxis, theYAxis, theData, series, 1,
theCrosshairState, thePass);
}
catch(NullPointerException e){
	System.out.println("A null pointer exception has
occurred.");
}

----

----------------------------------------------------------------------

>Comment By: David Gilbert (mungady)
Date: 2006-11-10 11:10

Message:
Logged In: YES 
user_id=112975

Thanks for the report.  I've committed a fix to CVS, for
inclusion in the 1.0.3 release.

Regards,

Dave Gilbert
JFreeChart Project Leader

----------------------------------------------------------------------

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