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java.awt
Class GraphicsEnvironment  view GraphicsEnvironment download GraphicsEnvironment.java

java.lang.Object
  extended byjava.awt.GraphicsEnvironment

public abstract class GraphicsEnvironment
extends java.lang.Object

This descibes the collection of GraphicsDevice and Font objects available on a given platform. The resources might be local or remote, and specify the valid configurations for displaying graphics.

Since:
1.4

Field Summary
private static GraphicsEnvironment localGraphicsEnvironment
           
 
Constructor Summary
protected GraphicsEnvironment()
          The environment must be obtained from a factory or query method, hence this constructor is protected.
 
Method Summary
abstract  Graphics2D createGraphics(java.awt.image.BufferedImage image)
          Return a Graphics2D object which will render into the specified image.
abstract  Font[] getAllFonts()
          Returns an array of the one-point size fonts available in this environment.
abstract  java.lang.String[] getAvailableFontFamilyNames()
          Returns an array of the font family names available in this environment.
abstract  java.lang.String[] getAvailableFontFamilyNames(java.util.Locale l)
          Returns an array of the font family names available in this environment, localized to the current Locale if l is non-null.
 Point getCenterPoint()
          Returns the point where a window should be centered.
abstract  GraphicsDevice getDefaultScreenDevice()
          Get the default screen GraphicsDevice object.
static GraphicsEnvironment getLocalGraphicsEnvironment()
          Returns the local graphics environment.
 Rectangle getMaximumWindowBounds()
          Returns the maximum bounds for a centered window object.
abstract  GraphicsDevice[] getScreenDevices()
          Get an array of all the GraphicsDevice objects.
static boolean isHeadless()
          Check if the local environment is headless, meaning that it does not support a display, keyboard, or mouse.
 boolean isHeadlessInstance()
          Check if the given environment is headless, meaning that it does not support a display, keyboard, or mouse.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

localGraphicsEnvironment

private static GraphicsEnvironment localGraphicsEnvironment
Constructor Detail

GraphicsEnvironment

protected GraphicsEnvironment()
The environment must be obtained from a factory or query method, hence this constructor is protected.

Method Detail

getLocalGraphicsEnvironment

public static GraphicsEnvironment getLocalGraphicsEnvironment()
Returns the local graphics environment. If the java.awt.graphicsenv system property is set, it instantiates the specified class, otherwise it assume that the awt toolkit is a ClasspathToolkit and delegates to it to create the instance.


isHeadless

public static boolean isHeadless()
Check if the local environment is headless, meaning that it does not support a display, keyboard, or mouse. Many methods in the Abstract Windows Toolkit (java.awt) throw a HeadlessException if this returns true. This method returns true if the java.awt.headless property is set to "true".

Since:
1.4

isHeadlessInstance

public boolean isHeadlessInstance()
Check if the given environment is headless, meaning that it does not support a display, keyboard, or mouse. Many methods in the Abstract Windows Toolkit (java.awt) throw a HeadlessException if this returns true. This default implementation returns isHeadless(), so subclasses need only override it if they differ.

Since:
1.4

getScreenDevices

public abstract GraphicsDevice[] getScreenDevices()
Get an array of all the GraphicsDevice objects.


getDefaultScreenDevice

public abstract GraphicsDevice getDefaultScreenDevice()
Get the default screen GraphicsDevice object.


createGraphics

public abstract Graphics2D createGraphics(java.awt.image.BufferedImage image)
Return a Graphics2D object which will render into the specified image.


getAllFonts

public abstract Font[] getAllFonts()
Returns an array of the one-point size fonts available in this environment. From there, the user can select the font and derive the correct one of proper size and attributes, using deriveFont. Only one master version of each font appears in this array; if a font can be derived from another, it must be created in that way.

Since:
1.2

getAvailableFontFamilyNames

public abstract java.lang.String[] getAvailableFontFamilyNames()
Returns an array of the font family names available in this environment. This allows flexibility in choosing the style of font, while still letting the Font class decide its best match.

Since:
1.2

getAvailableFontFamilyNames

public abstract java.lang.String[] getAvailableFontFamilyNames(java.util.Locale l)
Returns an array of the font family names available in this environment, localized to the current Locale if l is non-null. This allows flexibility in choosing the style of font, while still letting the Font class decide its best match.

Since:
1.2

getCenterPoint

public Point getCenterPoint()
Returns the point where a window should be centered. You should probably also check that the window fits within the screen bounds. The default simply returns the center of the maximum window bounds; subclasses should override this if native objects (like scrollbars) make that off-centered.

Since:
1.4

getMaximumWindowBounds

public Rectangle getMaximumWindowBounds()
Returns the maximum bounds for a centered window object. The default implementation simply returns the bounds of the default configuration of the default screen; subclasses should override this to if native objects (like scrollbars) reduce what is truly available. Also, subclasses should override this if the window should be centered across a multi-screen display.

Since:
1.4