1. /*

  2.  * @(#)GraphicsEnvironment.java	1.42 00/02/02

  3.  *

  4.  * Copyright 1997-2000 Sun Microsystems, Inc. All Rights Reserved.

  5.  * 

  6.  * This software is the proprietary information of Sun Microsystems, Inc.  

  7.  * Use is subject to license terms.

  8.  * 

  9.  */

  10. 

  11. 

  12. package java.awt;

  13. 

  14. import java.awt.image.BufferedImage;

  15. import java.util.Hashtable;

  16. import java.util.Locale;

  17. import java.util.Map;

  18. import java.io.InputStream;

  19. 

  20. /**

  21.  *

  22.  * The <code>GraphicsEnvironment</code> class describes the collection

  23.  * of {@link GraphicsDevice} objects and {@link java.awt.Font} objects

  24.  * available to a Java(tm) application on a particular platform.

  25.  * The resources in this <code>GraphicsEnvironment</code> might be local

  26.  * or on a remote machine.  <code>GraphicsDevice</code> objects can be

  27.  * screens, printers or image buffers and are the destination of

  28.  * {@link Graphics2D} drawing methods.  Each <code>GraphicsDevice</code>

  29.  * has a number of {@link GraphicsConfiguration} objects associated with

  30.  * it.  These objects specify the different configurations in which the

  31.  * <code>GraphicsDevice</code> can be used.  

  32.  * @see GraphicsDevice

  33.  * @see GraphicsConfiguration

  34.  * @version 	1.42, 02/02/00

  35.  */

  36. 

  37. public abstract class GraphicsEnvironment {

  38.     private static GraphicsEnvironment localEnv;

  39. 

  40.     /**

  41.      * This is an abstract class and cannot be instantiated directly.

  42.      * Instances must be obtained from a suitable factory or query method.

  43.      */

  44.     protected GraphicsEnvironment() {

  45.     }

  46. 

  47.     /**

  48.      * Returns the local <code>GraphicsEnvironment</code>.

  49.      * @return this <code>GraphicsEnvironment</code>.

  50.      */

  51.     public static synchronized GraphicsEnvironment getLocalGraphicsEnvironment() {

  52. 	if (localEnv == null) {

  53. 	    String nm = (String) java.security.AccessController.doPrivileged

  54. 		(new sun.security.action.GetPropertyAction

  55. 		 ("java.awt.graphicsenv", null));

  56. 

  57. 	    try {

  58. 		localEnv =

  59. 		    (GraphicsEnvironment) Class.forName(nm).newInstance();

  60. 	    } catch (ClassNotFoundException e) {

  61.                 throw new Error("Could not find class: "+nm);

  62.             } catch (InstantiationException e) {

  63.                 throw new Error("Could not instantiate Graphics Environment: "

  64. 				+ nm);

  65.             } catch (IllegalAccessException e) {

  66.                 throw new Error ("Could not access Graphics Environment: "

  67. 				 + nm);

  68.             }

  69.         }

  70. 

  71. 	return localEnv;

  72.     }

  73. 

  74.     /**

  75.      * Returns an array of all of the screen <code>GraphicsDevice</code>

  76.      * objects.

  77.      * @return an array containing all the <code>GraphicsDevice</code>

  78.      * objects that represent screen devices.

  79.      */

  80.     public abstract GraphicsDevice[] getScreenDevices();

  81. 

  82.     /**

  83.      * Returns the default screen <code>GraphicsDevice</code>.

  84.      * @return the <code>GraphicsDevice</code> that represents the

  85.      * default screen device.

  86.      */

  87.     public abstract GraphicsDevice getDefaultScreenDevice();

  88. 

  89.     /**

  90.      * Returns a <code>Graphics2D</code> object for rendering into the

  91.      * specified {@link BufferedImage}.

  92.      * @param img the specified <code>BufferedImage</code>

  93.      * @return a <code>Graphics2D</code> to be used for rendering into

  94.      * the specified <code>BufferedImage</code>.

  95.      */

  96.     public abstract Graphics2D createGraphics(BufferedImage img);

  97. 

  98.     /**

  99.      * Returns an array containing a one-point size instance of all fonts

  100.      * available in this <code>GraphicsEnvironment</code>.  Typical usage

  101.      * would be to allow a user to select a particular font.  Then, the

  102.      * application can size the font and set various font attributes by

  103.      * calling the <code>deriveFont</code> method on the choosen instance.

  104.      * <p>

  105.      * This method provides for the application the most precise control

  106.      * over which <code>Font</code> instance is used to render text.

  107.      * If a font in this <code>GraphicsEnvironment</code> has multiple

  108.      * programmable variations, only one

  109.      * instance of that <code>Font</code> is returned in the array, and

  110.      * other variations must be derived by the application.

  111.      * <p>

  112.      * If a font in this environment has multiple programmable variations,

  113.      * such as Multiple-Master fonts, only one instance of that font is

  114.      * returned in the <code>Font</code> array.  The other variations

  115.      * must be derived by the application.

  116.      * @return an array of <code>Font</code> objects.

  117.      * @see #getAvailableFontFamilyNames

  118.      * @see java.awt.Font

  119.      * @see java.awt.Font#deriveFont

  120.      * @see java.awt.Font#getFontName

  121.      * @since 1.2

  122.      */

  123.     public abstract Font[] getAllFonts();

  124. 

  125.     /**

  126.      * Returns an array containing the names of all font families available

  127.      * in this <code>GraphicsEnvironment</code>.

  128.      * Typical usage would be to allow a user to select a particular family

  129.      * name and allow the application to choose related variants of the

  130.      * same family when the user specifies style attributes such

  131.      * as Bold or Italic.

  132.      * <p>

  133.      * This method provides for the application some control over which

  134.      * <code>Font</code> instance is used to render text, but allows the 

  135.      * <code>Font</code> object more flexibility in choosing its own best

  136.      * match among multiple fonts in the same font family.

  137.      * @return an array of <code>String</code> containing names of font

  138.      * families.

  139.      * @see #getAllFonts

  140.      * @see java.awt.Font

  141.      * @see java.awt.Font#getFamily

  142.      * @since 1.2

  143.      */

  144.     public abstract String[] getAvailableFontFamilyNames();

  145. 

  146.     /**

  147.      * Returns an array containing the localized names of all font families

  148.      * available in this <code>GraphicsEnvironment</code>.

  149.      * Typical usage would be to allow a user to select a particular family

  150.      * name and allow the application to choose related variants of the

  151.      * same family when the user specifies style attributes such

  152.      * as Bold or Italic.

  153.      * <p>

  154.      * This method provides for the application some control over which

  155.      * <code>Font</code> instance used to render text, but allows the 

  156.      * <code>Font</code> object more flexibility in choosing its own best

  157.      * match among multiple fonts in the same font family.

  158.      * If <code>l</code> is <code>null</code>, this method returns an 

  159.      * array containing all font family names available in this

  160.      * <code>GraphicsEnvironment</code>.

  161.      * @param l a {@link Locale} object that represents a

  162.      * particular geographical, political, or cultural region

  163.      * @return an array of <code>String</code> objects containing names of

  164.      * font families specific to the specified <code>Locale</code>.

  165.      * @see #getAllFonts

  166.      * @see java.awt.Font

  167.      * @see java.awt.Font#getFamily

  168.      * @since 1.2

  169.      */

  170.     public abstract String[] getAvailableFontFamilyNames(Locale l);

  171. 

  172. }