Developing a DSL Graphical Notation - Eclipse Modeling Project: A Domain-Specific Language Toolkit - page 221

Attribute Parser Provider

For attributes, we want to enter name:Type in the label on the diagram and have
it parsed properly to set the name and dataType fields of the underlying
Attribute domain element. Of course, we want the label to display
name:Type even when changes are made to the underlying model through the
properties view, for example. To begin, we create a new (empty) org.
eclipse.dnc.diagram.custom plug-in to our workspace and contribute to
the parserProviders extension-point, as follows:

<extension

point="org.eclipse.gmf.runtime.common.ui.services.parserProviders">
<ParserProvider
class="org.eclipse.dnc.diagram.providers.AttributeParserProvider">
<Priority name="Low"/>
</ParserProvider>
</extension>

We need to provide the AttributeParserProvider class, which extends
the runtime's AbstractProvider and implements the IParserProvider
interface. This is the class, which still could use some optimization but works
well enough for now:

public class AttributeParserProvider extends AbstractProvider
implements IParserProvider {

private IParser myParser;

public IParser getParser(IAdaptable hint) {
if (myParser == null ) {
myParser = new ISemanticParser() {

public IContentAssistProcessor getCompletionProcessor(IAdaptable
element) {
return null;

}

public String getEditString(IAdaptable element, int flags) {
Attribute attribute = getAttribute(element);
return attribute.getName() != null ? attribute.getName()
+ ":" + (attribute.getDataType() != null ?
attribute.getDataType().getName() : "") : "";

}

public ICommand getParseCommand(IAdaptable element,
final String newString, int flags) {
int index = newString.indexOf(":");
final String name;
final String typeName;