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.IOException;
023import java.util.LinkedList;
024
025public class RenderAppendable implements ScreenContext {
026
027  /** . */
028  private final ScreenContext context;
029
030  /** . */
031  private LinkedList<Style.Composite> stack;
032
033  public RenderAppendable(ScreenContext context) {
034    this.context = context;
035  }
036
037  @Override
038  public RenderAppendable append(CharSequence s) {
039    try {
040      context.append(s);
041    }
042    catch (java.io.IOException ignore) {
043    }
044    return this;
045  }
046
047  @Override
048  public Screenable append(char c) {
049    try {
050      context.append(c);
051    }
052    catch (java.io.IOException ignore) {
053    }
054    return this;
055  }
056
057  @Override
058  public Screenable append(CharSequence csq, int start, int end) {
059    try {
060      context.append(csq, start, end);
061    }
062    catch (java.io.IOException ignore) {
063    }
064    return this;
065  }
066
067  @Override
068  public Screenable append(Style style) {
069    try {
070      context.append(style);
071    }
072    catch (java.io.IOException ignore) {
073    }
074    return this;
075  }
076
077  @Override
078  public Screenable cls() {
079    try {
080      context.cls();
081    }
082    catch (java.io.IOException ignore) {
083    }
084    return this;
085  }
086
087  public int getWidth() {
088    // Use one less char to have a correct display on windows
089    return Math.max(0, context.getWidth() - 1);
090  }
091
092  public int getHeight() {
093    return context.getHeight();
094  }
095
096  public void flush() throws IOException {
097    context.flush();
098  }
099
100  public void enterStyle(Style.Composite style) {
101    if (stack == null) {
102      stack = new LinkedList<Style.Composite>();
103    }
104    append(style);
105    stack.addLast(style);
106  }
107
108  public Style.Composite leaveStyle() {
109    if (stack == null || stack.isEmpty()) {
110      throw new IllegalStateException("Cannot leave non existing style");
111    }
112    Style.Composite last = stack.removeLast();
113    if (stack.size() > 0) {
114
115      // Compute merged
116      Style.Composite merged = getMerged();
117
118      // Compute diff with removed
119      Boolean bold = foo(last.getBold(), merged.getBold());
120      Boolean underline = foo(last.getUnderline(), merged.getUnderline());
121      Boolean blink = foo(last.getBlink(), merged.getBlink());
122
123      // For now we assume that black is the default background color
124      // and white is the default foreground color
125      Color fg = foo(last.getForeground(), merged.getForeground(), Color.def);
126      Color bg = foo(last.getBackground(), merged.getBackground(), Color.def);
127
128      //
129      Style.Composite bilto = Style.style(bold, underline, blink, fg, bg);
130
131      //   
132      append(bilto);
133    } else {
134      append(Style.reset);
135    }
136    return last;
137  }
138
139  /**
140   * Compute the current merged style.
141   *
142   * @return the merged style
143   */
144  private Style.Composite getMerged() {
145    Style.Composite merged = Style.style();
146    for (Style s : stack) {
147      merged = (Style.Composite)merged.merge(s);
148    }
149    return merged;
150  }
151
152  private Boolean foo(Boolean last, Boolean merged) {
153    if (last != null) {
154      if (merged != null) {
155        return merged;
156      } else {
157        return !last;
158      }
159    } else {
160      return null;
161    }
162  }
163
164  private Color foo(Color last, Color merged, Color def) {
165    if (last != null) {
166      if (merged != null) {
167        return merged;
168      } else {
169        return def;
170      }
171    } else {
172      return null;
173    }
174  }
175
176  public void styleOff() {
177    if (stack != null && stack.size() > 0) {
178      append(Style.reset);
179    }
180  }
181
182  public void styleOn() {
183    if (stack != null && stack.size() > 0) {
184      append(getMerged());
185    }
186  }
187}