/*
* Created on Jan 12, 2005
*
*/
package org.rubypeople.rdt.internal.ui.text.folding;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.Platform;
import org.rubypeople.rdt.internal.ui.RubyPlugin;
import org.rubypeople.rdt.ui.PreferenceConstants;
import org.rubypeople.rdt.ui.text.folding.IRubyFoldingStructureProvider;
/**
* @author cawilliams
*
*/
public class RubyFoldingStructureProviderRegistry {
private static final String EXTENSION_POINT = "foldingStructureProviders"; //$NON-NLS-1$
/** The map of descriptors, indexed by their identifiers. */
private Map fDescriptors;
/**
* Creates a new instance.
*/
public RubyFoldingStructureProviderRegistry() {
}
/**
* Returns an array of <code>IRubyFoldingProviderDescriptor</code>
* describing all extension to the <code>foldingProviders</code> extension
* point.
*
* @return the list of extensions to the
* <code>quickDiffReferenceProvider</code> extension point.
*/
public RubyFoldingStructureProviderDescriptor[] getFoldingProviderDescriptors() {
synchronized (this) {
ensureRegistered();
return (RubyFoldingStructureProviderDescriptor[]) fDescriptors.values().toArray(
new RubyFoldingStructureProviderDescriptor[fDescriptors.size()]);
}
}
/**
* Returns the folding provider with identifier <code>id</code> or
* <code>null</code> if no such provider is registered.
*
* @param id
* the identifier for which a provider is wanted
* @return the corresponding provider, or <code>null</code> if none can be
* found
*/
public RubyFoldingStructureProviderDescriptor getFoldingProviderDescriptor(String id) {
synchronized (this) {
ensureRegistered();
return (RubyFoldingStructureProviderDescriptor) fDescriptors.get(id);
}
}
/**
* Instantiates and returns the provider that is currently configured in the
* preferences.
*
* @return the current provider according to the preferences
*/
public IRubyFoldingStructureProvider getCurrentFoldingProvider() {
String id = RubyPlugin.getDefault().getPreferenceStore().getString(
PreferenceConstants.EDITOR_FOLDING_PROVIDER);
RubyFoldingStructureProviderDescriptor desc = getFoldingProviderDescriptor(id);
if (desc != null) {
try {
return desc.createProvider();
} catch (CoreException e) {
RubyPlugin.log(e);
}
}
return null;
}
/**
* Ensures that the extensions are read and stored in
* <code>fDescriptors</code>.
*/
private void ensureRegistered() {
if (fDescriptors == null) reloadExtensions();
}
/**
* Reads all extensions.
* <p>
* This method can be called more than once in order to reload from a
* changed extension registry.
* </p>
*/
public void reloadExtensions() {
IExtensionRegistry registry = Platform.getExtensionRegistry();
Map map = new HashMap();
IConfigurationElement[] elements = registry.getConfigurationElementsFor(RubyPlugin
.getPluginId(), EXTENSION_POINT);
for (int i = 0; i < elements.length; i++) {
RubyFoldingStructureProviderDescriptor desc = new RubyFoldingStructureProviderDescriptor(
elements[i]);
map.put(desc.getId(), desc);
}
synchronized (this) {
fDescriptors = Collections.unmodifiableMap(map);
}
}
}