/*
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.flex.compiler.internal.fxg.sax;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;
import org.apache.flex.compiler.fxg.FXGVersion;
/**
* Maintains a registry of FXGVersionHandlers
*/
public class FXGVersionHandlerRegistry
{
private static HashMap<FXGVersion, IFXGVersionHandler> versionHandlers = new HashMap<FXGVersion, IFXGVersionHandler>(4);
public static FXGVersion defaultVersion = FXGVersion.v2_0;
private static boolean registered = false;
/**
* Registers known FXGVersionHandlers for FXG 1.0 and FXG 2.0
*/
private static void registerKnownHandlers()
{
if (registered)
return;
registerHandler(FXGVersion.v1_0, new FXG_v1_0_Handler());
registerHandler(FXGVersion.v2_0, new FXG_v2_0_Handler());
registered = true;
}
/**
* Returns the default FXGVersion Handler - FXG 2.0 in this case
*
* @return The default FXG version handler.
*/
protected static IFXGVersionHandler getDefaultHandler()
{
registerKnownHandlers();
return (versionHandlers.get(defaultVersion));
}
/**
* Register new IFXGVersionHandler that can overwrite existing
* IFXGVersionHandler if one already exists for that FXG version.
*
* @param version The FXGVersion of the new handler.
* @param obj The IFXGVersionHandler.
*/
protected static void registerHandler(FXGVersion version,
IFXGVersionHandler obj)
{
if (versionHandlers != null)
{
IFXGVersionHandler vHandler = versionHandlers.get(version);
FXGVersion fxgVersion = (vHandler != null) ? vHandler.getVersion() : version;
versionHandlers.put(fxgVersion, obj);
}
}
/**
* Unregister handler for the specified FXGVersion
*
* @param version The FXG version as an FXGVersion.
*/
protected static void unregisterHandler(FXGVersion version)
{
if (versionHandlers != null)
{
IFXGVersionHandler vHandler = versionHandlers.get(version);
if (vHandler != null)
{
FXGVersion fxgVersion = vHandler.getVersion();
versionHandlers.remove(fxgVersion);
}
}
}
/**
* Returns a Set of FXGVersions that correspond to the registered
* FXGVersionHandlers
*
* @return A set of FXG versions that correspond to the registered
* FXG version handlers.
*/
protected static Set<FXGVersion> getVersionsForRegisteredHandlers()
{
if (versionHandlers == null)
return null;
registerKnownHandlers();
return versionHandlers.keySet();
}
/**
* Returns the IFXGVersionHandler for the FXGVersion specified. Note that
* FXGVersionHandlers are matched first for an exact match. If exact match
* is not found, then a handler with the same major version is returned.
*
* @param fxgVersion The FXG version as a FXGVersion.
* @return The FXG version handler.
*/
protected static IFXGVersionHandler getVersionHandler(FXGVersion fxgVersion)
{
if (versionHandlers == null || fxgVersion == null)
return null;
Set<FXGVersion> versions = getVersionsForRegisteredHandlers();
// look for exact matches on the version
Iterator<FXGVersion> iter = versions.iterator();
while (iter.hasNext())
{
FXGVersion version = iter.next();
if (version.equalTo(fxgVersion))
return versionHandlers.get(version);
}
// look for matches based on matching major version
iter = versions.iterator();
while (iter.hasNext())
{
FXGVersion version = iter.next();
if (version.getMajorVersion() == fxgVersion.getMajorVersion())
return versionHandlers.get(version);
}
return null;
}
/**
* Returns the IFXGVersionHandler for the FXGVersion specified. Note that
* FXGVersionHandlers are matched first for an exact match. If exact match
* is not found, then a handler with the same major version is returned.
*
* @param version The FXG version as a double.
* @return The FXG version handler.
*/
protected static IFXGVersionHandler getVersionHandler(double version)
{
FXGVersion fxgVersion = FXGVersion.newInstance(version);
return getVersionHandler(fxgVersion);
}
/**
* Returns the IFXGVersionHandler for the latest version handler registered.
*
* @return The latest FXG version handler.
*/
protected static IFXGVersionHandler getLatestVersionHandler()
{
if (versionHandlers == null)
return null;
Set<FXGVersion> versions = getVersionsForRegisteredHandlers();
// look for exact matches on the version
Iterator<FXGVersion> iter = versions.iterator();
FXGVersion latest = null;
while (iter.hasNext())
{
FXGVersion version = iter.next();
if (latest == null)
{
latest = version;
}
else
{
if (version.greaterThan(latest))
latest = version;
}
}
return versionHandlers.get(latest);
}
}