001/*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019
020package org.crsh.text;
021
022import org.crsh.text.ui.LabelElement;
023
024import java.util.ArrayList;
025import java.util.Iterator;
026import java.util.ServiceConfigurationError;
027import java.util.ServiceLoader;
028
029/**
030 * Provide a renderable.
031 */
032public abstract class Renderer<E> {
033
034  /** . */
035  private static final Renderer<?>[] renderables;
036
037  static {
038    ArrayList<Renderer<?>> tmp = new ArrayList<Renderer<?>>();
039    Iterator<Renderer> i = ServiceLoader.load(Renderer.class).iterator();
040    while (i.hasNext()) {
041      try {
042        Renderer renderable = i.next();
043        tmp.add(renderable);
044      }
045      catch (ServiceConfigurationError e) {
046        // Config error
047      }
048    }
049    renderables = tmp.toArray(new Renderer<?>[tmp.size()]);
050  }
051
052  public static Renderer<Object> ANY = new Renderer<Object>() {
053    @Override
054    public Class<Object> getType() {
055      return Object.class;
056    }
057
058    @Override
059    public LineRenderer renderer(Iterator<Object> stream) {
060      StringBuilder sb = new StringBuilder();
061      while (stream.hasNext()) {
062        Object next = stream.next();
063        if (next instanceof CharSequence) {
064          sb.append((CharSequence)next);
065        } else {
066          sb.append(next);
067        }
068      }
069      return new LabelElement(sb.toString()).renderer();
070    }
071  };
072
073  public static <I> Renderer<? super I> getRenderable(Class<I> itemType) {
074    for (Renderer<?> formatter : renderables) {
075      try {
076        if (formatter.getType().isAssignableFrom(itemType)) {
077          return (Renderer<I>)formatter;
078        }
079      }
080      catch (Exception e) {
081      }
082      catch (NoClassDefFoundError e) {
083      }
084    }
085    return null;
086  }
087
088  public abstract Class<E> getType();
089
090  public abstract LineRenderer renderer(Iterator<E> stream);
091
092}