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 java.io.Closeable;
023import java.io.IOException;
024import java.io.Writer;
025
026public class RenderWriter extends Writer implements Screenable {
027
028  /** . */
029  final ScreenContext out;
030
031  /** . */
032  private final Closeable closeable;
033
034  /** . */
035  private boolean closed;
036
037  /** . */
038  private boolean empty;
039
040  public RenderWriter(ScreenContext out) throws NullPointerException {
041    this(out, null);
042  }
043
044  public RenderWriter(ScreenContext out, Closeable closeable) throws NullPointerException {
045    if (out == null) {
046      throw new NullPointerException("No null appendable expected");
047    }
048
049    //
050    this.out = out;
051    this.empty = true;
052    this.closeable = closeable;
053  }
054
055  public boolean isEmpty() {
056    return empty;
057  }
058
059  public RenderWriter append(CharSequence s) throws IOException {
060    empty &= s.length() == 0;
061    out.append(s);
062    return this;
063  }
064
065  public Screenable append(Style style) throws IOException {
066    out.append(style);
067    return this;
068  }
069
070  public Screenable cls() throws IOException {
071    out.cls();
072    return this;
073  }
074
075  @Override
076  public void write(char[] cbuf, int off, int len) throws IOException {
077    if (closed) {
078      throw new IOException("Already closed");
079    }
080    if (len > 0) {
081      out.append(new String(cbuf, off, len));
082    }
083  }
084
085  @Override
086  public void flush() throws IOException {
087    if (closed) {
088      throw new IOException("Already closed");
089    }
090    try {
091      out.flush();
092    }
093    catch (IOException e) {
094      throw e;
095    }
096    catch (Exception e) {
097      // e.printStackTrace();
098      // just swallow ?
099    }
100  }
101
102  @Override
103  public void close() throws IOException {
104    if (!closed) {
105      closed = true;
106      if (closeable != null) {
107        closeable.close();
108      }
109    }
110  }
111}