source: other-projects/trunk/realistic-books/packages/AntInstaller/src/org/tp23/antinstaller/renderer/text/Pager.java@ 19253

/* 
 * Copyright 2005 Paul Hinds
 *
 * 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 org.tp23.antinstaller.renderer.text;

import java.io.PrintStream;


/**
 *
 * <p>Used for the Text/Console input to show pages of text as opposed to displaying
* a long list of text that scrolls off the top of the page. </p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: tp23</p>
 * @author Paul Hinds
 * @version $Id: Pager.java,v 1.2 2006/12/21 00:09:19 teknopaul Exp $
 */
public class Pager {

    private char[] text;
    private int linesPerPage = 20;
    private int charsPerLine = 80;
    private int stringIndex = 0;

    public Pager(String text) {
        this.text = text.toCharArray();
    }
    public Pager(){
    }

    public String getText() {
        return new String(text);
    }

    public void setText(String text) {
        this.text = text.toCharArray();
    }
    /**
     * Print the rest of the text
     */
    public void rest(PrintStream out){
        while(next(out));
}
    /**
     * Print the next page
     * @param out PrintStream
     * @return boolean true if there is more text
     */
    public boolean next(PrintStream out){
        int lineChars = 0;
        int lastSpace = -1;
        // loop past charaters, increment with lines
        char[] lineBuffer = new char[charsPerLine+1];
        for (int lines = 0; lines < linesPerPage;) {
            if(stringIndex >= text.length){
                return false;
            }
            lineBuffer[lineChars] = text[stringIndex];
            if(text[stringIndex] == ' '){
                lastSpace = lineChars;
            }
            if(text[stringIndex] == '\n'){
                String tmp = new String(lineBuffer, 0, lineChars + 1);
                out.print(tmp);
                lines++;
                lineChars = 0;
                lastSpace = -1;
            }
            else if(lineChars == charsPerLine){
                // handle lines ending with the last full word
                if(lastSpace != -1){
                    out.println(new String(lineBuffer, 0, lastSpace));
                    stringIndex = stringIndex - (charsPerLine - lastSpace);
                }
                else {
                    out.println(new String(lineBuffer, 0, lineChars));
                }
                lines++;
                lineChars = 0;
                lastSpace = -1;
            }
            else{
                lineChars++;
            }
            stringIndex++;
        }
        return true;
    }
}