org.vectomatic.dev.svg.impl.gen.ExternalSVGResourceGenerator.java Source code

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Here is the source code for org.vectomatic.dev.svg.impl.gen.ExternalSVGResourceGenerator.java

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/*
 * Copyright 2008 Google Inc.
 * 
 * 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 org.vectomatic.dev.svg.impl.gen;

import java.net.URL;
import java.util.HashMap;
import java.util.Map;

import org.vectomatic.dom.svg.impl.ExternalSVGResourcePrototype;
import org.vectomatic.dom.svg.ui.SVGResource;
import org.vectomatic.dom.svg.ui.ExternalSVGResource.Validated;

import com.google.gwt.core.ext.Generator;
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.JMethod;
import com.google.gwt.core.ext.typeinfo.JType;
import com.google.gwt.core.ext.typeinfo.TypeOracle;
import com.google.gwt.dev.util.Util;
import com.google.gwt.resources.ext.AbstractResourceGenerator;
import com.google.gwt.resources.ext.ClientBundleFields;
import com.google.gwt.resources.ext.ClientBundleRequirements;
import com.google.gwt.resources.ext.ResourceContext;
import com.google.gwt.resources.ext.ResourceGeneratorUtil;
import com.google.gwt.user.rebind.SourceWriter;
import com.google.gwt.user.rebind.StringSourceWriter;

/**
 * Implementation of ExternalSVGResource derived from Google's original
 * ExternalTextResourceGenerator implementation
 * @author laaglu
 */
public class ExternalSVGResourceGenerator extends AbstractResourceGenerator {
    private StringBuffer data;
    private boolean first;
    private String urlExpression;
    private Map<String, Integer> hashes;
    private Map<String, Integer> offsets;
    private int currentIndex;

    private String externalSVGUrlIdent;

    private String externalSVGCacheIdent;

    @Override
    public String createAssignment(TreeLogger logger, ResourceContext context, JMethod method)
            throws UnableToCompleteException {
        String name = method.getName();

        SourceWriter sw = new StringSourceWriter();
        sw.println("new " + ExternalSVGResourcePrototype.class.getName() + "(");
        sw.indent();
        sw.println('"' + name + "\",");
        // These are field names
        sw.println(externalSVGUrlIdent + ", " + externalSVGCacheIdent + ", ");
        sw.println(offsets.get(method.getName()).toString());
        sw.outdent();
        sw.print(")");

        return sw.toString();
    }

    @Override
    public void createFields(TreeLogger logger, ResourceContext context, ClientBundleFields fields)
            throws UnableToCompleteException {
        data.append(']');

        urlExpression = context.deploy(
                context.getClientBundleType().getQualifiedSourceName().replace('.', '_') + "_jsonbundle.txt",
                "text/plain", data.toString().getBytes(), true);

        TypeOracle typeOracle = context.getGeneratorContext().getTypeOracle();
        JClassType stringType = typeOracle.findType(String.class.getName());
        assert stringType != null;

        externalSVGUrlIdent = fields.define(stringType, "externalSVGUrl", urlExpression, true, true);

        JClassType textResourceType = typeOracle.findType(SVGResource.class.getName());
        assert textResourceType != null;
        JType textResourceArrayType = typeOracle.getArrayType(textResourceType);

        externalSVGCacheIdent = fields.define(textResourceArrayType, "externalSVGCache",
                "new " + SVGResource.class.getName() + "[" + currentIndex + "]", true, true);
    }

    @Override
    public void init(TreeLogger logger, ResourceContext context) throws UnableToCompleteException {
        data = new StringBuffer("[\n");
        first = true;
        urlExpression = null;
        hashes = new HashMap<String, Integer>();
        offsets = new HashMap<String, Integer>();
        currentIndex = 0;
    }

    @Override
    public void prepare(TreeLogger logger, ResourceContext context, ClientBundleRequirements requirements,
            JMethod method) throws UnableToCompleteException {

        URL[] urls = ResourceGeneratorUtil.findResources(logger, context, method);

        if (urls.length != 1) {
            logger.log(TreeLogger.ERROR, "Exactly one resource must be specified", null);
            throw new UnableToCompleteException();
        }

        URL resource = urls[0];

        String toWrite = Util.readURLAsString(resource);
        if (getValidated(method)) {
            SVGValidator.validate(toWrite, resource.toExternalForm(), logger, null);
        }

        // This de-duplicates strings in the bundle.
        if (!hashes.containsKey(toWrite)) {
            hashes.put(toWrite, currentIndex++);

            if (!first) {
                data.append(",\n");
            } else {
                first = false;
            }

            data.append('"');
            data.append(Generator.escape(toWrite));
            data.append('"');
        }

        // Store the (possibly n:1) mapping of resource function to bundle
        // index.
        offsets.put(method.getName(), hashes.get(toWrite));
    }

    private boolean getValidated(JMethod method) {
        Validated validated = method.getAnnotation(Validated.class);
        if (validated == null) {
            return true;
        } else {
            return validated.validated();
        }
    }
}