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java.awt

Class GraphicsEnvironment

java.lang.Object
|
+--java.awt.GraphicsEnvironment


public abstract class GraphicsEnvironment

extends 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.

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Constructor Summary

GraphicsEnvironment()

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

Method Summary

java.awt.Graphics2DcreateGraphics(java.awt.image.BufferedImage image)

Return a Graphics2D object which will render into the specified image.
java.awt.Font[]getAllFonts()

Returns an array of the one-point size fonts available in this environment.
java.lang.String[]getAvailableFontFamilyNames()

Returns an array of the font family names available in this environment.
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.
java.awt.PointgetCenterPoint()

Returns the point where a window should be centered.
java.awt.GraphicsDevicegetDefaultScreenDevice()

Get the default screen GraphicsDevice object.
static java.awt.GraphicsEnvironmentgetLocalGraphicsEnvironment()

Returns the local graphics environment.
java.awt.RectanglegetMaximumWindowBounds()

Returns the maximum bounds for a centered window object.
java.awt.GraphicsDevice[]getScreenDevices()

Get an array of all the GraphicsDevice objects.
static booleanisHeadless()

Check if the local environment is headless, meaning that it does not support a display, keyboard, or mouse.
booleanisHeadlessInstance()

Check if the given environment is headless, meaning that it does not support a display, keyboard, or mouse.

Constructor Details

GraphicsEnvironment

protected GraphicsEnvironment()

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


Method Details

createGraphics

public Graphics2D createGraphics(java.awt.image.BufferedImage image)

Return a Graphics2D object which will render into the specified image.

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getAllFonts

public 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.

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getAvailableFontFamilyNames

public 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.

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getAvailableFontFamilyNames

public 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.

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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.

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getDefaultScreenDevice

public GraphicsDevice getDefaultScreenDevice()

Get the default screen GraphicsDevice object.

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getLocalGraphicsEnvironment

public static GraphicsEnvironment getLocalGraphicsEnvironment()

Returns the local graphics environment. XXX Not implemented in Classpath yet.

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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.

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getScreenDevices

public GraphicsDevice[] getScreenDevices()

Get an array of all the GraphicsDevice objects.

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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. XXX For now, Classpath assumes that it is never headless.

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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 false, so subclasses need only override it if they are headless.

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