font.java

Micro Window Toolkit(MWT)是一个用于开发J2ME用户界面(UI)的工具包。它具有友好

/*
 * MWT - Micro Window Toolkit
 * Copyright (C) 2007 Lucas Domanico - [e-mail]
 * 
 * Licensed under the terms of the GNU Lesser General Public License:
 * 		http://www.opensource.org/licenses/lgpl-license.php
 * 
 * For further information visit:
 * 		http://j2me-mwt.sourceforge.net/
 */

package mwt;

import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;

/**
 * <p>The font class represents fonts, which are used to render text in a visible way.</p>
 * 
 * <p>MWT allows to use custom bitmap fonts or system fonts, depending on how the font is created.</p>
 * 
 * <br>
 * <br>
 * 
 * <h3>System Native Fonts</h3>
 * <p>System native fonts are created using {@link #Font(int, int, int, int)}.</br>
 * You can change the size, color, face and style using the appropriate values.</p>
 * <p>The main drawback of system fonts is that they may not fit with the look and feel of your
 * application as they are device dependent.</p>
 * <p>A system native font uses internally {@link javax.microedition.lcdui.Font}.</p>
 * 
 * <br>
 * <br>
 * 
 * <h3>Custom Bitmap Fonts</h3>
 * <p>Custom bitmap fonts are created using {@link #Font(Image, char[], int[], int)}
 * or {@link #Font(Image[], char[], int)}.<br>
 * </p>
 * A custom bitmap font is an immutable object, that means, you can't change the size or color.<br>
 * 
 * Please check the <a href="http://j2me-mwt.sourceforge.net/microfontmaker.html">
 * MicroFont-Maker</code>command line tool.<br> 
 *
<table width="800" border="0" cellspacing="4" cellpadding="0" style="border: 1px black solid">
  <tr>
    <td width="45">&nbsp;</td>
    <td colspan="3" bgcolor="#DBDBDB"><div align="center">System Native Fonts </div></td>
    <td colspan="3" bgcolor="#DBDBDB"><div align="center">Custom Bitmap Fonts </div></td>
  </tr>
  <tr>
    <td rowspan="3" bgcolor="#DBDBDB"><div align="center">Size</div></td>
    <td width="73" rowspan="3" valign="top" bgcolor="#CEDBFF"><p>Accepts constants values</p>    </td>
    <td width="232" bgcolor="#CEDBFF">{@link #SIZE_MEDIUM}</td>
    <td width="90" bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_size_med.png" width="90" height="30" /></td>
    <td width="60" rowspan="3" valign="top" bgcolor="#CFFFCA">Any value</td>
    <td width="225" bgcolor="#CFFFCA">17 (pixels)</td>
    <td width="43" bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_size_17.png" width="90" height="30" /></td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link #SIZE_SMALL}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_size_small.png" width="90" height="30" /></td>
    <td bgcolor="#CFFFCA">15 (pixels)</td>
    <td bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_size_15.png" width="90" height="30" /></td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link #SIZE_LARGE}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_size_large.png" width="90" height="30" /></td>
    <td bgcolor="#CFFFCA">19 (pixels)</td>
    <td bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_size_19.png" width="90" height="30" /></td>
  </tr>
  <tr>
    <td rowspan="4" bgcolor="#EEEEEE"><div align="center">Styles</div></td>
    <td rowspan="4" valign="top" bgcolor="#EAEFFF">Accepts constants values</td>
    <td bgcolor="#EAEFFF">{@link #STYLE_PLAIN}</td>
    <td bgcolor="#EAEFFF"><img src="{@docRoot}/resources/font_sys_style_plain.png" width="90" height="18" /></td>
    <td colspan="3" rowspan="4" valign="top" bgcolor="#ECFFEA">Not available (you can use different bitmap fonts for each style)</td>
  </tr>
  <tr>
    <td bgcolor="#EAEFFF">{@link #STYLE_BOLD}</td>
    <td bgcolor="#EAEFFF"><img src="{@docRoot}/resources/font_sys_style_bold.png" width="90" height="18" /></td>
  </tr>
  <tr>
    <td bgcolor="#EAEFFF">{@link #STYLE_ITALIC}</td>
    <td bgcolor="#EAEFFF"><img src="{@docRoot}/resources/font_sys_style_italic.png" width="90" height="18" /></td>
  </tr>
  <tr>
    <td bgcolor="#EAEFFF">{@link #STYLE_UNDERLINED}</td>
    <td bgcolor="#EAEFFF"><img src="{@docRoot}/resources/font_sys_style_underlined.png" width="90" height="18" /></td>
  </tr>
  <tr>
    <td rowspan="3" bgcolor="#DBDBDB"><div align="center">Face</div></td>
    <td rowspan="3" valign="top" bgcolor="#CEDBFF"><p>Accepts constants values</p>    </td>
    <td bgcolor="#CEDBFF">{@link #FACE_SYSTEM}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_style_plain.png" width="90" height="18" /></td>
    <td colspan="3" rowspan="3" valign="top" bgcolor="#CFFFCA">Not available, however, you don't need this when using custom fonts </td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link #FACE_MONOSPACE}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_face_monospace.png" width="90" height="18" /></td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link #FACE_PROPORTIONAL}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_style_plain.png" width="90" height="18" /></td>
  </tr>
  <tr>
    <td bgcolor="#EEEEEE"><div align="center">Color</div></td>
    <td bgcolor="#EAEFFF">Any </td>
    <td bgcolor="#EAEFFF">0xA1C632</td>
    <td bgcolor="#EAEFFF"><img src="{@docRoot}/resources/font_sys_color_0xA1C632.png" width="90" height="18" /></td>
    <td bgcolor="#ECFFEA">Any </td>
    <td bgcolor="#ECFFEA">0xA1C632</td>
    <td bgcolor="#ECFFEA"><img src="{@docRoot}/resources/font_bmp_color_0xA1C632.png" width="90" height="18" /></td>
  </tr>
  <tr>
    <td rowspan="9" bgcolor="#DBDBDB"><div align="center">Anchor</div></td>
    <td rowspan="9" valign="top" bgcolor="#CEDBFF">Accepts constants values</td>
    <td bgcolor="#CEDBFF">{@link Component#ALIGN_TOP_LEFT}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_anchor_top_left.png" width="90" height="30" /></td>
    <td rowspan="9" valign="top" bgcolor="#CFFFCA">Accepts constants values</td>
    <td bgcolor="#CFFFCA">{@link Component#ALIGN_TOP_LEFT}</td>
    <td bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_anchor_top_left.png" width="90" height="30" /></td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link Component#ALIGN_TOP_CENTER}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_anchor_top_center.png" width="90" height="30" /></td>
    <td bgcolor="#CFFFCA">{@link Component#ALIGN_TOP_CENTER}</td>
    <td bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_anchor_top_center.png" width="90" height="30" /></td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link Component#ALIGN_TOP_RIGHT}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_anchor_top_right.png" width="90" height="30" /></td>
    <td bgcolor="#CFFFCA">{@link Component#ALIGN_TOP_RIGHT}</td>
    <td bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_anchor_top_right.png" width="90" height="30" /></td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link Component#ALIGN_MIDDLE_LEFT}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_anchor_middle_left.png" width="90" height="30" /></td>
    <td bgcolor="#CFFFCA">{@link Component#ALIGN_MIDDLE_LEFT}</td>
    <td bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_anchor_middle_left.png" width="90" height="30" /></td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link Component#ALIGN_MIDDLE_CENTER}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_anchor_middle_center.png" width="90" height="30" /></td>
    <td bgcolor="#CFFFCA">{@link Component#ALIGN_MIDDLE_CENTER}</td>
    <td bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_anchor_middle_center.png" width="90" height="30" /></td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link Component#ALIGN_MIDDLE_RIGHT}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_anchor_middle_right.png" width="90" height="30" /></td>
    <td bgcolor="#CFFFCA">{@link Component#ALIGN_MIDDLE_RIGHT}</td>
    <td bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_anchor_middle_right.png" width="90" height="30" /></td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link Component#ALIGN_BOTTOM_LEFT}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_anchor_bottom_left.png" width="90" height="30" /></td>
    <td bgcolor="#CFFFCA">{@link Component#ALIGN_BOTTOM_LEFT}</td>
    <td bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_anchor_bottom_left.png" width="90" height="30" /></td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link Component#ALIGN_BOTTOM_CENTER}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_anchor_bottom_center.png" width="90" height="30" /></td>
    <td bgcolor="#CFFFCA">{@link Component#ALIGN_BOTTOM_CENTER}</td>
    <td bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_anchor_bottom_center.png" width="90" height="30" /></td>
  </tr>
  <tr>
    <td bgcolor="#CEDBFF">{@link Component#ALIGN_BOTTOM_RIGHT}</td>
    <td bgcolor="#CEDBFF"><img src="{@docRoot}/resources/font_sys_anchor_bottom_right.png" width="90" height="30" /></td>
    <td bgcolor="#CFFFCA">{@link Component#ALIGN_BOTTOM_RIGHT}</td>
    <td bgcolor="#CFFFCA"><img src="{@docRoot}/resources/font_bmp_anchor_bottom_right.png" width="90" height="30" /></td>
  </tr>
</table>
 * 
 * 
 * 
 * <h3><a name="extending">Extending</a></h3> 
 * <p>Classes that extend a Font must override the following methods:
 * <ul>
 * <li>{@link #clone()}</li>
 * <li>{@link #copy(Font)}</li>
 * <li>{@link #getHeight()}</li>
 * <li>{@link #getWidth(String)}</li>
 * <li>{@link #write(Graphics, String, int, int, int)}</li>
 * </ul>
 * The contructor must call the system native font {@link #Font(InputStream, char[], int, int, int)}.
 * </p>
 * Example:
 * <pre>
 * class MyFont extends Font {
 *   int newAttribute = ...;
 *   
 *   public MyFont(int newAttribute) {
 *     super(0,0,0,0);
 *     this.newAttribute = newAttribute;
 *   }
 *   
 *   protected void copy(MyFont f) {
 *     super.copy(f);
 *     f.newAttribute = this.newAttribute;
 *   }
 *   
 *   private MyFont() {}
 *   public Font clone() {
 *     MyFont f = new MyFont();
 *     copy(f);
 *     return f;
 *   }
 *   
 *   public int getHeight() {
 *     // new implementation
 *   }
 *   
 *   public int getWidth(String s) {
 *     // new implementation
 *   }
 *   
 *   protected void write(Graphics g, String text, int x, int y, int anchor) {
 *     // new implementation
 *   }
 * }
 * </pre>
 */
public class Font {
	/** The plain style constant. */
    static final public int STYLE_PLAIN = 0;
    /** The bold style constant. */
    static final public int STYLE_BOLD = 1;
    /** The italicized style constant. */
    static final public int STYLE_ITALIC = 2;
    /** The underlined style constant. */
    static final public int STYLE_UNDERLINED = 4;
    /** The "small" system-dependent font size. */
    static final public int SIZE_SMALL = 8;
    /** The "medium" system-dependent font size. */
    static final public int SIZE_MEDIUM = 0;
    /** The "large" system-dependent font size. */
    static final public int SIZE_LARGE = 16;
    /** The "system" font face. */
    static final public int FACE_SYSTEM = 0;
    /** The "monospace" font face. */
    static final public int FACE_MONOSPACE = 32;
    /** The "proportional" font face. */
    static final public int FACE_PROPORTIONAL = 64;
    
    static final public int TYPE_SYSTEM = 0;
    static final public int TYPE_MAPPED = 1;
    static final public int TYPE_STRIP = 2;
    
    private int type;
	private int color;
	private int face;
	private int size;
	private int style;
	private int charSpacing;	// the space between chars
	private int spaceWidth;		// the space char ' ' width
	private char[] charset;
	private Image[] images;
	
	private Image strip;	// since 1.2
	private int[] widths;	// since 1.2
	private int[] offsets;	// since 1.2
		
	
	/** Creates a system native font. */
	public Font(int color, int face, int size, int style) {
		this.color = color;
		this.face = face;
		this.size = size;
		this.style = style;
		this.type = TYPE_SYSTEM;
	}
	
	/**
	 * Creates a bitmap font using an {@link InputStream} formatted using
	 * <code>MicroFont-Maker</code> tool.<br>
	 * Optionally, you can specify which chars must be loaded.<br>
	 * <b>NOTE:</b> this method uses {@link Image#createImage(javax.microedition.lcdui.Image)}
	 * implementation which in some devices causes problems.
	 * Un such case, use {@link #Font(Image[], char[], int)} instead.<br>
	 * @param is the {@link InputStream} formatted using MicroFont-Maker tool
	 * @param charset The charset specifying which chars must be loaded or null to load the entire charset
	 * @param charSpacing The space within chars (negative values are valid)
	 * @param size The size value or 0 to use default size
	 * @param color The color value
	 * @throws IOException might be thrown by the {@link InputStream}
	 * @deprecated