com.google.devtools.depan.view_doc.layout.jung.JungLayoutRunner.java Source code

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/*
 * Copyright 2013 The Depan Project Authors
 *
 * 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.devtools.depan.view_doc.layout.jung;

import com.google.devtools.depan.model.GraphEdge;
import com.google.devtools.depan.model.GraphNode;
import com.google.devtools.depan.view_doc.layout.LayoutRunner;
import com.google.devtools.depan.view_doc.model.Point2dUtils;

import com.google.common.collect.Maps;

import edu.uci.ics.jung.algorithms.layout.Layout;
import edu.uci.ics.jung.algorithms.util.IterativeContext;

import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.Collection;
import java.util.Map;

/**
 * Define a few standard variations of the {@link LayoutRunner} that are
 * useful for JUNG-based layout algorithms.
 * 
 * @author <a href="leeca@pnambic.com">Lee Carver</a>
 */
public abstract class JungLayoutRunner implements LayoutRunner {

    private final Layout<GraphNode, GraphEdge> jungLayout;

    /** Scales the layout positions into their overall graph position. */
    private final Rectangle2D region;

    protected JungLayoutRunner(Rectangle2D region, Layout<GraphNode, GraphEdge> jungLayout) {
        this.jungLayout = jungLayout;
        this.region = region;
    }

    @Override
    public Map<GraphNode, Point2D> getPositions(Collection<GraphNode> nodes) {
        // Collect the positions from the Jung layout tool.
        Map<GraphNode, Point2D> result = Maps.newHashMapWithExpectedSize(nodes.size());
        for (GraphNode node : nodes) {
            Point2D position = jungLayout.apply(node);
            result.put(node, position);
        }

        Point2dUtils.translatePos(region, nodes, result);
        return result;
    }

    public static class Direct extends JungLayoutRunner {

        protected Direct(Rectangle2D region, Layout<GraphNode, GraphEdge> jungLayout) {
            super(region, jungLayout);
        }

        @Override
        public int layoutCost() {
            return 0;
        }

        @Override
        public void layoutStep() {
        }

        @Override
        public boolean layoutDone() {
            return true;
        }
    }

    public static class Iterative extends JungLayoutRunner {
        private final IterativeContext runner;
        private final int layoutCost;

        protected Iterative(Rectangle2D region, Layout<GraphNode, GraphEdge> jungLayout, int layoutCost) {
            super(region, jungLayout);
            this.layoutCost = layoutCost;
            this.runner = (IterativeContext) jungLayout;
        }

        @Override
        public int layoutCost() {
            return layoutCost;
        }

        @Override
        public void layoutStep() {
            runner.step();
        }

        @Override
        public boolean layoutDone() {
            return runner.done();
        }
    }

    /**
     * The Spring layout algorithms never claims completion.
     */
    public static class Counted extends Iterative {
        private int stepsRemaining;

        protected Counted(Rectangle2D region, Layout<GraphNode, GraphEdge> jungLayout, int layoutCost) {
            super(region, jungLayout, layoutCost);
            stepsRemaining = layoutCost;
        }

        @Override
        public void layoutStep() {
            super.layoutStep();

            if (stepsRemaining > 0)
                stepsRemaining--;
        }

        @Override
        public boolean layoutDone() {
            if (stepsRemaining <= 0)
                return true;

            return super.layoutDone();
        }
    }
}