textrender.java

用Java开发的、实现类似Visio功能的应用程序源码

/**
 *    $Id:TextRender.java $
 *
 *    Copyright 2004 ~ 2005  JingFei International Cooperation LTD. All rights reserved. *
 */
package com.jfimagine.jfgraph.shape.decorate;


import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Color;
import java.awt.Font;
import java.awt.RenderingHints;

import java.awt.font.FontRenderContext;
import java.awt.font.LineBreakMeasurer;
import java.awt.font.TextLayout;
import java.awt.font.TextAttribute;

import java.awt.geom.AffineTransform;
import java.awt.geom.GeneralPath;
import java.awt.geom.Rectangle2D;

import java.util.Hashtable;


import java.text.AttributedCharacterIterator;
import java.text.AttributedCharacterIterator;
import java.text.AttributedString;
import java.text.BreakIterator;

import com.jfimagine.jfgraph.geom.Rect;
import com.jfimagine.utils.commonutil.CommonUtil;
import com.jfimagine.jfgraph.shape.rectangle.JFText;

 /**
 * TextRender class.  TextRender is a class to encapsulate text processing.
 *
 * @author     CookieMaker    
 *
 * @version $Revision: 1.00 $
 */  
 public class TextRender {
 
     // The LineBreakMeasurer used to line-break the paragraph.
    private LineBreakMeasurer lineMeasurer;

    // The index in the LineBreakMeasurer of the first character
    // in the paragraph.
    private int paragraphStart;

    // The index in the LineBreakMeasurer of the first character
    // after the end of the paragraph.
    private int paragraphEnd;
    
    //occurrence position of a new line char.	
    int[] lineLocations = new int[0];    

   
    /**
     * Initialize render string.
     * @param g  The graphics context to draw string
     * @param lines The string lines.
     * @param fontFormat the specified font format.
     */
    private void initRender(Graphics g, String lines, FontFormat fontFormat){
    	if (lines==null || lines.length()==0) lines=" ";  

	//if the first letter of the text is just a NewLine character,
	//append a space at the head of this text, to avoid text drawing error.    	
    	if (lines.charAt(0)==CommonUtil.newLine())
    		lines	=' '+lines;
    		
    	
    	//set rendering text font by current graphics context's font.
    	Hashtable map = new Hashtable();
   	map.put(TextAttribute.FONT,fontFormat.getZoomedFont());
    	
        AttributedString aString = new AttributedString(lines,map);

	AttributedCharacterIterator paragraph=aString.getIterator();

        //FontRenderContext frc = getDefaultFontRenderContext();
        Graphics2D g2	=(Graphics2D)g; 
        FontRenderContext frc = g2.getFontRenderContext();
        paragraphStart = paragraph.getBeginIndex();
        paragraphEnd = paragraph.getEndIndex();

        // Create a new LineBreakMeasurer from the paragraph.
        lineMeasurer = new LineBreakMeasurer(paragraph,frc);


	// create a line break(broken by new line char)position array
	int lineCount	=CommonUtil.getCharCount(lines,CommonUtil.newLine());
        lineLocations = new int[lineCount+1];


	int i=0;
	if (lineCount>0){
     		for (char c = paragraph.first(); c != paragraph.DONE; c = paragraph.next()) {
         		if (c == CommonUtil.newLine()) {
             			lineLocations[i] = paragraph.getIndex();
             			i++;
             		}
         	}
     	}
     	lineLocations[lineCount] = paragraph.getEndIndex();	

    }	


   /**
    *   Draw multiple lines string in a rectangle.
    *   @param g A graphics context.
    *   @param rect A rectangle used to specify the position and size of lines.
    *   @param lines String lines to be drawn. 
    *   @param fontFormat the specified font format for text rendering.
    *   @param textAlignment the alignment type
    */
    public void drawMultiLines(Graphics g, Rect rect, String lines,FontFormat fontFormat,int textAlignment) {


        Graphics2D g2 = (Graphics2D) g;
	
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_OFF);
                            	
	//initialize render text.
	initRender(g,lines,fontFormat);
	
        // Set formatting width and height to rectangle.
        float formatX 		= (float) rect.getX();
        float formatY 		= (float) rect.getY();
        float formatWidth 	= (float) rect.getWidth();
        float formatHeight	= (float) rect.getHeight();

        float drawPosY = formatY;

        lineMeasurer.setPosition(paragraphStart);
        int currentLine = 0;

        // Get lines from lineMeasurer until the entire
        // paragraph has been displayed.
        while (lineMeasurer.getPosition() < paragraphEnd) {

         	// lineContainsText is true after first segment is drawn
         	boolean lineContainsText = false;
            	
            	TextLayout layout;
         	while (true) {

		            		
            		// Retrieve next layout.
            		try{
            			layout = lineMeasurer.nextLayout(formatWidth,
            		 					    lineLocations[currentLine],
                                         			    lineContainsText);
                        }catch(Exception e){
                        	//System.out.println("error at "+currentLine+" "+e.getMessage());
                        	return;
                        }                 			  

             		// layout can be null if lineContainsText is true
             		if (layout != null) {

				float height	=(float)layout.getBounds().getHeight();
				float width	=(float)layout.getBounds().getWidth();

            			// Move y-coordinate by the ascent of the layout.
            			drawPosY += layout.getAscent();
            			if (drawPosY - formatY>formatHeight)
            				break;

            			// Compute pen x position.  If the paragraph is 
            			// right-to-left, we want to align the TextLayouts
            			// to the right edge of the panel.
            			float drawPosX = formatX;
            			switch (textAlignment){
            				case JFText.TEXTALIGNMENT_LEFT:
                				drawPosX  += 0;
                				break;
                			case JFText.TEXTALIGNMENT_RIGHT:
                				drawPosX += (float)(formatWidth - width);
                				break;
                			case JFText.TEXTALIGNMENT_MIDDLE:
                				drawPosX += (float)((formatWidth - width)/2);
                				break;
                			
            			}
				
				if (fontFormat.isUseStrokeAndFill()){
					AffineTransform textAt = new AffineTransform();
					textAt.translate(0, height);
        				java.awt.Shape shape = layout.getOutline(textAt);
					drawTextShape(g,shape,drawPosX,(float)(drawPosY-height),fontFormat);
				}else{
            				// Draw the TextLayout at (drawPosX, drawPosY).
            				layout.draw(g2, drawPosX, drawPosY);  
            			}

            			// Move y-coordinate in preparation for next layout.
            			drawPosY += layout.getDescent() + layout.getLeading();
            		}else{
            			break;
            		}
            		
             		lineContainsText = true;            		
             		if (lineMeasurer.getPosition() == paragraphEnd)
                 		break;

             		if (lineMeasurer.getPosition() == lineLocations[currentLine]) 
                 		currentLine++;
                 	
                 	if (currentLine>lineLocations.length-1)
                 		break;	
            	}
        }
        
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);        
    } 
    

    /***
     *   Draw a stroke and fill text according to the font format
     *
     *   @param g The graphics context
     *   @param s The text to be drawn
     *   @param x,y The position to draw the string
     *   @param fontFormat The font format of the text	     
     *   @param zoomScale Current zoom scale
     */
    public static void drawStrokeAndFillText(Graphics g, String s, float x, float y, FontFormat fontFormat, double zoomScale){
    	        
    	        if (g==null || s==null || s.length()==0 || fontFormat==null || !fontFormat.isUseStrokeAndFill())
    	        	return;
    	        
        	TextLayout textTl = new TextLayout(s, fontFormat.getZoomedFont(), new FontRenderContext(null, false, false));
		AffineTransform textAt = new AffineTransform();
		textAt.translate(0, (float)textTl.getBounds().getHeight());
        	java.awt.Shape shape = textTl.getOutline(textAt);

		drawTextShape(g,shape,x,y,fontFormat);
	}


    /***
     *   Draw a shape made by a text layout.
     *
     *   @param g The graphics context
     *   @param s The shape to be drawn
     *   @param x,y The position to draw the string
     *   @param fontFormat The font format of the text	     
     */
    private static void drawTextShape(Graphics g, java.awt.Shape s, float x, float y, FontFormat fontFormat){

    	        Graphics2D g2	=(Graphics2D)g;
		
		Rectangle2D  rect2D  =s.getBounds2D();
		Rect rect	=new Rect(rect2D.getX(),rect2D.getY(),rect2D.getWidth(),rect2D.getHeight());
		//rect.moveBy(x,y);
			
		g2.translate(x,y);        	
        	GeneralPath path   =new GeneralPath(s);
		fontFormat.getLineFormat().draw(g,path);
		fontFormat.getFillFormat().draw(g,path,rect);
		g2.translate(-x,-y);
    }

            
}