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package org.netbeans.modules.cnd.api.model;
import java.util.Collection;
import java.util.Collections;
import org.openide.util.Lookup;
/**
* utility class to access Csm model
* @author Vladimir Voskresensky
*/
public final class CsmModelAccessor {
// singleton instance of model
private static CsmModel model;
private static CsmModel dummy;
private static CsmModelStateListener stateListener = new CsmModelStateListener() {
public void modelStateChanged(CsmModelState newState, CsmModelState oldState) {
if( newState == CsmModelState.OFF ) {
CsmListeners.getDefault().removeModelStateListener(stateListener);
model = null;
}
}
};
public static CsmModelState getModelState() {
CsmModel aModel = model;
return (aModel == null) ? CsmModelState.OFF : aModel.getState();
}
private static class ModelStub implements CsmModel {
public Collection<CsmProject> projects() {
return Collections.<CsmProject>emptyList();
}
public CsmProject getProject(Object id) {
return null;
}
public CsmFile findFile(CharSequence absPath) {
return null;
}
public CsmModelState getState() {
return CsmModelState.OFF;
}
public void enqueue(Runnable task) {}
public void enqueue(Runnable task, CharSequence name) {}
}
/** Creates a new instance of CsmModelAccessor */
private CsmModelAccessor() {
}
private static final boolean TRACE_GET_MODEL = Boolean.getBoolean("trace.get.model");
/**
* Gets CsmModel using Lookup
*/
public static CsmModel getModel() {
if( TRACE_GET_MODEL ) {
Thread.dumpStack();
}
if( model == null ) {
synchronized(CsmModel.class ) {
if( model == null ) {
model = (CsmModel) Lookup.getDefault().lookup(CsmModel.class);
if( model == null ) {
return getStub();
} else {
CsmListeners.getDefault().addModelStateListener(stateListener);
}
}
}
}
return model;
}
private static CsmModel getStub() {
if( dummy == null ) {
dummy = new ModelStub();
}
return dummy;
}
}
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