java.awt

Class GraphicsEnvironment

java.lang.Object

java.awt.GraphicsEnvironment

public abstract class GraphicsEnvironment
extends Object

The GraphicsEnvironment class describes the collection of GraphicsDevice objects and Font objects available to a Java(tm) application on a particular platform. The resources in this GraphicsEnvironment might be local or on a remote machine. GraphicsDevice objects can be screens, printers or image buffers and are the destination of Graphics2D drawing methods. Each GraphicsDevice has a number of GraphicsConfiguration objects associated with it. These objects specify the different configurations in which the GraphicsDevice can be used.

Version:

1.55, 01/23/03

See Also:

GraphicsDevice, GraphicsConfiguration

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	GraphicsEnvironment() This is an abstract class and cannot be instantiated directly.

Method Summary

Methods

Modifier and Type	Method and Description
abstract Graphics2D	createGraphics(BufferedImage img) Returns a Graphics2D object for rendering into the specified BufferedImage.
abstract String[]	getAvailableFontFamilyNames() Returns an array containing the names of all font families available in this GraphicsEnvironment.
abstract String[]	getAvailableFontFamilyNames(Locale l) Returns an array containing the localized names of all font families available in this GraphicsEnvironment.
abstract GraphicsDevice	getDefaultScreenDevice() Returns the default screen GraphicsDevice.
static GraphicsEnvironment	getLocalGraphicsEnvironment() Returns the local GraphicsEnvironment.
abstract GraphicsDevice[]	getScreenDevices() Returns an array of all of the screen GraphicsDevice objects.
static boolean	isHeadless() Tests whether or not a display and some form of input device can be supported in this environment.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GraphicsEnvironment

protected GraphicsEnvironment()

This is an abstract class and cannot be instantiated directly. Instances must be obtained from a suitable factory or query method.

Method Detail

getLocalGraphicsEnvironment

public static GraphicsEnvironment getLocalGraphicsEnvironment()

Returns the local GraphicsEnvironment.

Returns:

the local GraphicsEnvironment

isHeadless

public static boolean isHeadless()

Tests whether or not a display and some form of input device can be supported in this environment. If this method returns true, a HeadlessException is thrown from areas of the Toolkit and GraphicsEnvironment that are dependent on a display or input device.

Returns:

true if this environment cannot support a display and input device; false otherwise

Since:

1.4

See Also:

HeadlessException

getScreenDevices

public abstract GraphicsDevice[] getScreenDevices()
                                           throws HeadlessException

Returns an array of all of the screen GraphicsDevice objects.

Returns:

an array containing all the GraphicsDevice objects that represent screen devices

Throws:

HeadlessException - if isHeadless() returns true

See Also:

isHeadless()

getDefaultScreenDevice

public abstract GraphicsDevice getDefaultScreenDevice()
                                               throws HeadlessException

Returns the default screen GraphicsDevice.

Returns:

the GraphicsDevice that represents the default screen device

Throws:

HeadlessException - if isHeadless() returns true

See Also:

isHeadless()

createGraphics

public abstract Graphics2D createGraphics(BufferedImage img)

Returns a Graphics2D object for rendering into the specified BufferedImage.

Parameters:

img - the specified BufferedImage

Returns:

a Graphics2D to be used for rendering into the specified BufferedImage

getAvailableFontFamilyNames

public abstract String[] getAvailableFontFamilyNames()

Returns an array containing the names of all font families available in this GraphicsEnvironment. Typical usage would be to allow a user to select a particular family name and allow the application to choose related variants of the same family when the user specifies style attributes such as Bold or Italic.

This method provides for the application some control over which Font instance is used to render text, but allows the Font object more flexibility in choosing its own best match among multiple fonts in the same font family.

Returns:

an array of String containing names of font families

Since:

1.2

See Also:

Font, Font.getFamily()

getAvailableFontFamilyNames

public abstract String[] getAvailableFontFamilyNames(Locale l)

Returns an array containing the localized names of all font families available in this GraphicsEnvironment. Typical usage would be to allow a user to select a particular family name and allow the application to choose related variants of the same family when the user specifies style attributes such as Bold or Italic.

This method provides for the application some control over which Font instance used to render text, but allows the Font object more flexibility in choosing its own best match among multiple fonts in the same font family. If l is null, this method returns an array containing all font family names available in this GraphicsEnvironment.

Parameters:

l - a Locale object that represents a particular geographical, political, or cultural region

Returns:

an array of String objects containing names of font families specific to the specified Locale

Since:

1.2

See Also:

Font, Font.getFamily()