ptolemy.plot.plotml
Class HistogramMLParser

java.lang.Object
  |
  +--com.microstar.xml.HandlerBase
        |
        +--ptolemy.plot.plotml.PlotBoxMLParser
              |
              +--ptolemy.plot.plotml.PlotMLParser
                    |
                    +--ptolemy.plot.plotml.HistogramMLParser

public class HistogramMLParser

extends PlotMLParser

This class constructs a histogram from specifications in PlotML (Plot Markup Language), which is an XML language. This class supports extends the base class to ensure that the associated plotter is an instance of Histogram. It ignores unrecognized elements in the DTD. The class contains an instance of the Microstar Ælfred XML parser and implements callback methods to interpret the parsed XML. The way to use this class is to construct it with a reference to a Plot object and then call its parse() method.

Version:

$Id: HistogramMLParser.java,v 1.3 1999/08/19 02:03:50 cxh Exp $

Author:

Edward A. Lee

Fields inherited from class ptolemy.plot.plotml.PlotMLParser

_bars, _connected, _currentDataset, _currentPointCount

Fields inherited from class ptolemy.plot.plotml.PlotBoxMLParser

_attributes, _currentCharData, _parser, _plot

Constructor Summary

HistogramMLParser(Histogram plot)
Construct an parser to parse commands for the specified plot object.

Method Summary

protected void	_addPoint(boolean connected, java.lang.String element) Add a point based on the current attributes.
void	endElement(java.lang.String elementName) End an element.
void	startElement(java.lang.String elementName) Start an element.

Methods inherited from class ptolemy.plot.plotml.PlotMLParser

startDocument

Methods inherited from class ptolemy.plot.plotml.PlotBoxMLParser

_checkForNull, _currentExternalEntity, attribute, charData, endDocument, error, parse, resolveEntity, startExternalEntity

Methods inherited from class com.microstar.xml.HandlerBase

doctypeDecl, endExternalEntity, ignorableWhitespace, processingInstruction

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

HistogramMLParser

public HistogramMLParser(Histogram plot)

Construct an parser to parse commands for the specified plot object.

Parameters:

plot - The plot object to which to apply the commands.

Method Detail

endElement

public void endElement(java.lang.String elementName)
                throws java.lang.Exception

End an element. Override the base class to ignore non-histogram operations. Ælfred will call this method at the end of each element (including EMPTY elements).

Overrides:

endElement in class PlotMLParser

Parameters:

elementName - The element type name.

startElement

public void startElement(java.lang.String elementName)
                  throws XmlException

Start an element. This is called at the beginning of each XML element. By the time it is called, all of the attributes for the element will already have been reported using the attribute() method. Unrecognized elements are ignored.

Overrides:

startElement in class PlotMLParser

Parameters:

elementName - The element type name.

Throws:

XmlException - If the element produces an error in constructing the model.

_addPoint

protected void _addPoint(boolean connected,
                         java.lang.String element)
                  throws java.lang.Exception

Add a point based on the current attributes. The second argument is the element name, used for error reporting.

Overrides:

_addPoint in class PlotMLParser

Parameters:

connected - Ignored.

element - The name of the element.