paginator.java

textviewer 一个手机上的文本浏览器实现

package textViewer;

import java.util.Vector;

public class Paginator extends Object {

    private final int TEXT_CHUNK_LENGTH = 80; 	    // TODO: constant

    public Paginator() {}

    public int indexToPage(int index) {
	return (index / getTextChunkLength()) + 1; 
    }

   public int getTextChunkLength() {
	return TEXT_CHUNK_LENGTH;

    }

    public Vector paginate(String text) {
	return paginateByChars(text, getTextChunkLength());
	    // TODO: constant
    }

    private Vector paginateByChars(String text, int charsPerPage) {
	

	Vector pages = new Vector();
	

	//		pages.addElement("mem test"); 
	// pages.addElement(text);

	
	int pageCount = text.length() / charsPerPage + 1; 
	 
	//pages.addElement(Integer.toString(text.length()));
	

	try {
	    int curPos = 0;
	    int nextPos = curPos + charsPerPage;
	    for(int curPage = 1; curPage <= (pageCount - 1); curPage++) {
		pages.addElement(text.substring(curPos,nextPos));
		curPos += charsPerPage;
		nextPos += charsPerPage;
	}
	    // the last page is special because we don't want to read past the end of the string
	    pages.addElement(text.substring(curPos,text.length()));
	}
	catch (IndexOutOfBoundsException e) {
	    //TODO: error handle
	    pages.addElement("IndexOutOfBoundsException " + e.toString() + " stopped us here");
	}
					      
	//	System.gc();
				      
	return pages;
    }

    // TODO: move the rest of pagination to here
    
}