com.kk_electronic.gwt.rebind.ClassMapGenerator.java Source code

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Here is the source code for com.kk_electronic.gwt.rebind.ClassMapGenerator.java

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/*
 * Copyright 2010 kk-electronic a/s. 
 * 
 * This file is part of KKPortal.
 *
 * KKPortal is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * KKPortal is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with KKPortal.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
package com.kk_electronic.gwt.rebind;

import java.io.PrintWriter;
import java.util.HashMap;

import com.google.gwt.core.ext.Generator;
import com.google.gwt.core.ext.GeneratorContext;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.core.ext.typeinfo.JClassType;
import com.google.gwt.core.ext.typeinfo.NotFoundException;
import com.google.gwt.core.ext.typeinfo.TypeOracle;
import com.google.gwt.inject.client.GinModules;
import com.google.gwt.user.rebind.ClassSourceFileComposerFactory;
import com.google.gwt.user.rebind.SourceWriter;
import com.kk_electronic.kkportal.core.reflection.ClassMap;

public class ClassMapGenerator extends Generator {

    private String packageName;
    private String className;
    private TypeOracle typeOracle;
    private JClassType classType;
    private JClassType keyType;
    private JClassType valueType;
    private TreeLogger logger;

    @Override
    public String generate(TreeLogger logger, GeneratorContext context, String typeName)
            throws UnableToCompleteException {
        this.logger = logger;
        try {
            typeOracle = context.getTypeOracle();
            classType = typeOracle.getType(typeName);
            packageName = classType.getPackage().getName();
            className = classType.getSimpleSourceName() + "Impl";
            classType.getAnnotation(GinModules.class);
            generateClass(logger, context);
        } catch (NotFoundException e) {
            logger.log(TreeLogger.ERROR, "Exception during ClassMap creation.", e);
            throw new UnableToCompleteException();
        }
        return packageName + "." + className;
    }

    private void generateClass(TreeLogger logger, GeneratorContext context)
            throws UnableToCompleteException, NotFoundException {
        PrintWriter printWriter = context.tryCreate(logger, packageName, className);

        if (printWriter == null) {
            return;
        }

        ClassSourceFileComposerFactory composer = new ClassSourceFileComposerFactory(packageName, className);

        composer.addImport(HashMap.class.getCanonicalName());

        composer.addImplementedInterface(classType.getQualifiedSourceName());
        JClassType target = typeOracle.getType(ClassMap.class.getCanonicalName());
        for (JClassType interfaze : classType.getImplementedInterfaces()) {
            if (interfaze.getErasedType().equals(target.getErasedType())) {
                JClassType[] genericTypes = interfaze.isParameterized().getTypeArgs();
                keyType = genericTypes[0];
                valueType = genericTypes[1];
            }
        }

        //      if (!"java.lang.String".equals(keyType.getQualifiedSourceName())){
        //         logger.log(TreeLogger.ERROR, "keyType must be a String for now");
        //         throw new UnableToCompleteException();
        //      }

        composer.addImport(keyType.getQualifiedSourceName());
        composer.addImport(valueType.getQualifiedSourceName());

        SourceWriter sourceWriter = composer.createSourceWriter(context, printWriter);

        writeMethods(sourceWriter);
        writeData(sourceWriter);

        sourceWriter.outdent();
        sourceWriter.println("}");

        context.commit(logger, printWriter);
    }

    private void writeData(SourceWriter sw) throws UnableToCompleteException {
        sw.println();
        sw.println("{");
        sw.indent();
        for (JClassType classType : valueType.getSubtypes()) {
            String key = getKeyFromClass(classType);
            sw.println("map.put(" + key + "," + classType.getQualifiedSourceName() + ".class);");
            sw.println("reversemap.put(" + classType.getQualifiedSourceName() + ".class, " + key + ");");
        }
        sw.outdent();
        sw.println("}");
    }

    private void writeMethods(SourceWriter sw) {
        sw.print("private static HashMap<" + keyType.getName() + ", Class<? extends " + valueType.getName()
                + ">> map");
        sw.println("= new HashMap<" + keyType.getName() + ", Class<? extends " + valueType.getName() + ">>();");
        sw.print("private static HashMap<Class<? extends " + valueType.getName() + ">," + keyType.getName()
                + "> reversemap");
        sw.println("= new HashMap<Class<? extends " + valueType.getName() + ">," + keyType.getName() + ">();");
        sw.println();
        sw.println("@Override");
        sw.println("public Class<? extends " + valueType.getName() + "> getClassFromKey(" + keyType.getName()
                + " name) {");
        sw.println("   return map.get(name);");
        sw.println("}");
        sw.println();
        sw.println("@Override");
        sw.println("public " + keyType.getName() + " getKeyFromClass(Class<? extends " + valueType.getName()
                + "> clazz) {");
        sw.println("   return reversemap.get(clazz);");
        sw.println("}");
    }

    private String getKeyFromClass(JClassType j) throws UnableToCompleteException {
        MapKey x = j.getAnnotation(MapKey.class);
        if (x != null) {
            return x.value();
        }
        if ("java.lang.String".equals(keyType.getQualifiedSourceName())) {
            return "\"" + escape(j.getName()) + "\"";
        }
        if ("java.lang.Integer".equals(keyType.getQualifiedSourceName())) {
            return String.valueOf(j.getName().hashCode());
        }
        logger.log(TreeLogger.ERROR,
                "keyType can only be autogenerated for Integers and Strings - supply @MapKey annotation");
        throw new UnableToCompleteException();
    }
}