com.googlecode.mgwt.css.rebind.StyleSheetUrlHolderGenerator.java Source code

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Here is the source code for com.googlecode.mgwt.css.rebind.StyleSheetUrlHolderGenerator.java

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/*
 * Copyright 2014 Daniel Kurka
 *
 * Licensed 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 com.googlecode.mgwt.css.rebind;

import java.io.PrintWriter;
import java.util.List;

import com.google.gwt.core.ext.BadPropertyValueException;
import com.google.gwt.core.ext.ConfigurationProperty;
import com.google.gwt.core.ext.Generator;
import com.google.gwt.core.ext.GeneratorContext;
import com.google.gwt.core.ext.PropertyOracle;
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.user.rebind.ClassSourceFileComposerFactory;
import com.google.gwt.user.rebind.SourceWriter;

import com.googlecode.mgwt.css.client.updater.StyleSheetUrlHolderDefaultImpl;
import com.googlecode.mgwt.css.client.updater.StyleSheetUrlHolderNoopImpl;

public class StyleSheetUrlHolderGenerator extends Generator {

    private static final String KEY_ENABLED = "mgwt.css.updater.enabled";
    private static final String KEY_INTERVAL = "mgwt.css.updater.interval";
    private static final String KEY_URLS = "mgwt.css.updater.urls";

    @Override
    public String generate(TreeLogger logger, GeneratorContext context, String typeName)
            throws UnableToCompleteException {
        // get the property oracle
        PropertyOracle propertyOracle = context.getPropertyOracle();
        String enablePropertyValue = getSingleValue(propertyOracle, KEY_ENABLED, logger);

        if (!"true".equals(enablePropertyValue)) {
            return StyleSheetUrlHolderNoopImpl.class.getName();
        }

        List<String> urls = getValues(propertyOracle, KEY_URLS, logger);

        int interval = Integer.parseInt(getSingleValue(propertyOracle, KEY_INTERVAL, logger));

        JClassType classType = null;

        try {
            // get the type we are looking for
            classType = context.getTypeOracle().getType(typeName);
        } catch (NotFoundException e) {
            // if we can`t get it die
            logger.log(TreeLogger.ERROR, "can not find type: '" + typeName + "'", e);
            throw new UnableToCompleteException();
        }

        // get the package name
        String packageName = classType.getPackage().getName();
        // build name for implementation class
        String simpleName = classType.getSimpleSourceName() + "_generated";
        // combine package name and simple name to full qualified
        String fullName = packageName + "." + simpleName;

        PrintWriter printWriter = context.tryCreate(logger, packageName, simpleName);

        if (printWriter == null) {
            return fullName;
        }

        ClassSourceFileComposerFactory composer = new ClassSourceFileComposerFactory(packageName, simpleName);
        composer.setSuperclass(StyleSheetUrlHolderDefaultImpl.class.getName());
        composer.addImport(StyleSheetUrlHolderDefaultImpl.class.getName());

        // start writing the implementation
        SourceWriter writer = composer.createSourceWriter(context, printWriter);

        writer.println("public " + simpleName + "() {");
        writer.print("super(");

        boolean first = true;
        for (String url : urls) {
            if (first) {
                first = false;
            } else {
                writer.print(",");
            }
            writer.print("\"" + url + "\"");
        }
        writer.print(");\n");

        writer.println("}");

        writer.println("public int interval() {");
        writer.println("return " + interval + ";");
        writer.println("}");
        writer.commit(logger);

        return fullName;
    }

    private String getSingleValue(PropertyOracle propertyOracle, String name, TreeLogger logger)
            throws UnableToCompleteException {
        ConfigurationProperty configProperty = getConfigurationProperty(propertyOracle, logger, name);
        return configProperty.getValues().get(0);
    }

    private List<String> getValues(PropertyOracle propertyOracle, String name, TreeLogger logger)
            throws UnableToCompleteException {
        ConfigurationProperty configProperty = getConfigurationProperty(propertyOracle, logger, name);
        return configProperty.getValues();
    }

    private ConfigurationProperty getConfigurationProperty(PropertyOracle propertyOracle, TreeLogger logger,
            String name) throws UnableToCompleteException {
        try {
            return propertyOracle.getConfigurationProperty(name);
        } catch (BadPropertyValueException e) {
            // if we can`t find it die
            logger.log(TreeLogger.ERROR, "can not resolve " + name, e);
            throw new UnableToCompleteException();
        }
    }
}