com.google.gxp.compiler.dot.DotWriter.java Source code

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Here is the source code for com.google.gxp.compiler.dot.DotWriter.java

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/*
 * Copyright (C) 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 com.google.gxp.compiler.dot;

import com.google.common.base.CharEscaper;
import com.google.common.base.CharEscaperBuilder;
import com.google.common.base.Joiner;
import com.google.common.collect.Lists;
import com.google.gxp.compiler.io.CIndenter;

import java.io.*;
import java.util.*;

/**
 * A {@link GraphSink} that writes graphviz "dot" format to an {@code
 * Appendable}.
 */
public class DotWriter implements GraphSink {
    private final CIndenter out;

    public DotWriter(Appendable out) {
        this.out = new CIndenter(out);
    }

    public void digraphStart(String name) {
        out.appendLine(String.format("digraph %s {", name));
    }

    public void digraphEnd() {
        out.appendLine("}");
    }

    public void simpleNode(String nodeId, NodeShape shape, String label) {
        out.appendLine(String.format("node%s [label=\"%s\",shape=%s];", nodeId, dotEscape(label), shape));
    }

    public void recordNode(String nodeId, Map<String, String> properties) {
        List<String> names = Lists.newArrayListWithExpectedSize(properties.size());
        List<String> values = Lists.newArrayListWithExpectedSize(properties.size());
        for (Map.Entry<String, String> entry : properties.entrySet()) {
            names.add(dotEscape(entry.getKey()));
            values.add(dotEscape(entry.getValue()));
        }
        out.appendLine(String.format("node%s [label=\"{%s} | {%s}\",shape=Mrecord];", nodeId,
                Joiner.on(" | ").join(names), Joiner.on(" | ").join(values)));
    }

    public void edge(String fromNodeId, String label, String toNodeId) {
        String suffix = (label == null) ? "" : String.format(" [label=\"%s\"]", dotEscape(label));
        out.appendLine(String.format("node%s -> node%s%s;\n", fromNodeId, toNodeId, suffix));
    }

    private static CharEscaper DOT_ESCAPER = new CharEscaperBuilder().addEscape('\n', "\\n").addEscape('\r', "\\r")
            .addEscape('\t', "\\t").addEscape('\\', "\\\\").addEscape('\"', "\\\"").addEscape('{', "\\{")
            .addEscape('}', "\\}").addEscape('<', "\\<").addEscape('>', "\\>").addEscape('|', "\\|")
            .addEscape(' ', "\\ ").toEscaper();

    private static String dotEscape(String s) {
        return DOT_ESCAPER.escape(s);
    }
}