- java.lang.Object
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- java.awt.GraphicsEnvironment
 
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 public abstract class GraphicsEnvironment extends Object TheGraphicsEnvironmentclass describes the collection ofGraphicsDeviceobjects andFontobjects available to a Java(tm) application on a particular platform. The resources in thisGraphicsEnvironmentmight be local or on a remote machine.GraphicsDeviceobjects can be screens, printers or image buffers and are the destination ofGraphics2Ddrawing methods. EachGraphicsDevicehas a number ofGraphicsConfigurationobjects associated with it. These objects specify the different configurations in which theGraphicsDevicecan be used.- See Also:
- GraphicsDevice,- GraphicsConfiguration
 
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Constructor SummaryConstructors Modifier Constructor Description protectedGraphicsEnvironment()This is an abstract class and cannot be instantiated directly.
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Method SummaryAll Methods Static Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description abstract Graphics2DcreateGraphics(BufferedImage img)Returns aGraphics2Dobject for rendering into the specifiedBufferedImage.abstract Font[]getAllFonts()Returns an array containing a one-point size instance of all fonts available in thisGraphicsEnvironment.abstract String[]getAvailableFontFamilyNames()Returns an array containing the names of all font families in thisGraphicsEnvironmentlocalized for the default locale, as returned byLocale.getDefault().abstract String[]getAvailableFontFamilyNames(Locale l)Returns an array containing the names of all font families in thisGraphicsEnvironmentlocalized for the specified locale.PointgetCenterPoint()Returns the Point where Windows should be centered.abstract GraphicsDevicegetDefaultScreenDevice()Returns the default screenGraphicsDevice.static GraphicsEnvironmentgetLocalGraphicsEnvironment()Returns the localGraphicsEnvironment.RectanglegetMaximumWindowBounds()Returns the maximum bounds for centered Windows.abstract GraphicsDevice[]getScreenDevices()Returns an array of all of the screenGraphicsDeviceobjects.static booleanisHeadless()Tests whether or not a display, keyboard, and mouse can be supported in this environment.booleanisHeadlessInstance()Returns whether or not a display, keyboard, and mouse can be supported in this graphics environment.voidpreferLocaleFonts()Indicates a preference for locale-specific fonts in the mapping of logical fonts to physical fonts.voidpreferProportionalFonts()Indicates a preference for proportional over non-proportional (e.g.booleanregisterFont(Font font)Registers a createdFontin thisGraphicsEnvironment.
 
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Method Detail- 
getLocalGraphicsEnvironmentpublic static GraphicsEnvironment getLocalGraphicsEnvironment() Returns the localGraphicsEnvironment.- Returns:
- the local GraphicsEnvironment
 
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isHeadlesspublic static boolean isHeadless() Tests whether or not a display, keyboard, and mouse 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, keyboard, or mouse.- Returns:
- trueif this environment cannot support a display, keyboard, and mouse;- falseotherwise
- Since:
- 1.4
- See Also:
- HeadlessException
 
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isHeadlessInstancepublic boolean isHeadlessInstance() Returns whether or not a display, keyboard, and mouse can be supported in this graphics environment. If this returns true,HeadlessExceptionwill be thrown from areas of the graphics environment that are dependent on a display, keyboard, or mouse.- Returns:
- trueif a display, keyboard, and mouse can be supported in this environment;- falseotherwise
- Since:
- 1.4
- See Also:
- HeadlessException,- isHeadless()
 
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getScreenDevicespublic abstract GraphicsDevice[] getScreenDevices() throws HeadlessException Returns an array of all of the screenGraphicsDeviceobjects.- Returns:
- an array containing all the GraphicsDeviceobjects that represent screen devices
- Throws:
- HeadlessException- if isHeadless() returns true
- See Also:
- isHeadless()
 
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getDefaultScreenDevicepublic abstract GraphicsDevice getDefaultScreenDevice() throws HeadlessException Returns the default screenGraphicsDevice.- Returns:
- the GraphicsDevicethat represents the default screen device
- Throws:
- HeadlessException- if isHeadless() returns true
- See Also:
- isHeadless()
 
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createGraphicspublic abstract Graphics2D createGraphics(BufferedImage img) Returns aGraphics2Dobject for rendering into the specifiedBufferedImage.- Parameters:
- img- the specified- BufferedImage
- Returns:
- a Graphics2Dto be used for rendering into the specifiedBufferedImage
- Throws:
- NullPointerException- if- imgis null
 
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getAllFontspublic abstract Font[] getAllFonts() Returns an array containing a one-point size instance of all fonts available in thisGraphicsEnvironment. Typical usage would be to allow a user to select a particular font. Then, the application can size the font and set various font attributes by calling thederiveFontmethod on the chosen instance.This method provides for the application the most precise control over which Fontinstance is used to render text. If a font in thisGraphicsEnvironmenthas multiple programmable variations, only one instance of thatFontis returned in the array, and other variations must be derived by the application.If a font in this environment has multiple programmable variations, such as Multiple-Master fonts, only one instance of that font is returned in the Fontarray. The other variations must be derived by the application.- Returns:
- an array of Fontobjects
- Since:
- 1.2
- See Also:
- getAvailableFontFamilyNames(),- Font,- Font.deriveFont(int, float),- Font.getFontName()
 
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getAvailableFontFamilyNamespublic abstract String[] getAvailableFontFamilyNames() Returns an array containing the names of all font families in thisGraphicsEnvironmentlocalized for the default locale, as returned byLocale.getDefault().Typical usage would be for presentation to a user for selection of a particular family name. An application can then specify this name when creating a font, in conjunction with a style, such as bold or italic, giving the font system flexibility in choosing its own best match among multiple fonts in the same font family. - Returns:
- an array of Stringcontaining font family names localized for the default locale, or a suitable alternative name if no name exists for this locale.
- Since:
- 1.2
- See Also:
- getAllFonts(),- Font,- Font.getFamily()
 
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getAvailableFontFamilyNamespublic abstract String[] getAvailableFontFamilyNames(Locale l) Returns an array containing the names of all font families in thisGraphicsEnvironmentlocalized for the specified locale.Typical usage would be for presentation to a user for selection of a particular family name. An application can then specify this name when creating a font, in conjunction with a style, such as bold or italic, giving the font system flexibility in choosing its own best match among multiple fonts in the same font family. - Parameters:
- l- a- Localeobject that represents a particular geographical, political, or cultural region. Specifying- nullis equivalent to specifying- Locale.getDefault().
- Returns:
- an array of Stringcontaining font family names localized for the specifiedLocale, or a suitable alternative name if no name exists for the specified locale.
- Since:
- 1.2
- See Also:
- getAllFonts(),- Font,- Font.getFamily()
 
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registerFontpublic boolean registerFont(Font font) Registers a createdFontin thisGraphicsEnvironment. A created font is one that was returned from callingFont.createFont(int, java.io.InputStream), or derived from a created font by callingFont.deriveFont(int, float). After calling this method for such a font, it is available to be used in constructing newFonts by name or family name, and is enumerated bygetAvailableFontFamilyNames()andgetAllFonts()within the execution context of this application or applet. This means applets cannot register fonts in a way that they are visible to other applets.Reasons that this method might not register the font and therefore return falseare:- The font is not a created Font.
- The font conflicts with a non-created Fontalready in thisGraphicsEnvironment. For example if the name is that of a system font, or a logical font as described in the documentation of theFontclass. It is implementation dependent whether a font may also conflict if it has the same family name as a system font.Notice that an application can supersede the registration of an earlier created font with a new one. 
 - Parameters:
- font- the font to be registered
- Returns:
- true if the fontis successfully registered in thisGraphicsEnvironment.
- Throws:
- NullPointerException- if- fontis null
- Since:
- 1.6
 
- The font is not a created 
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preferLocaleFontspublic void preferLocaleFonts() Indicates a preference for locale-specific fonts in the mapping of logical fonts to physical fonts. Calling this method indicates that font rendering should primarily use fonts specific to the primary writing system (the one indicated by the default encoding and the initial default locale). For example, if the primary writing system is Japanese, then characters should be rendered using a Japanese font if possible, and other fonts should only be used for characters for which the Japanese font doesn't have glyphs.The actual change in font rendering behavior resulting from a call to this method is implementation dependent; it may have no effect at all, or the requested behavior may already match the default behavior. The behavior may differ between font rendering in lightweight and peered components. Since calling this method requests a different font, clients should expect different metrics, and may need to recalculate window sizes and layout. Therefore this method should be called before user interface initialisation. - Since:
- 1.5
 
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preferProportionalFontspublic void preferProportionalFonts() Indicates a preference for proportional over non-proportional (e.g. dual-spaced CJK fonts) fonts in the mapping of logical fonts to physical fonts. If the default mapping contains fonts for which proportional and non-proportional variants exist, then calling this method indicates the mapping should use a proportional variant.The actual change in font rendering behavior resulting from a call to this method is implementation dependent; it may have no effect at all. The behavior may differ between font rendering in lightweight and peered components. Since calling this method requests a different font, clients should expect different metrics, and may need to recalculate window sizes and layout. Therefore this method should be called before user interface initialisation. - Since:
- 1.5
 
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getCenterPointpublic Point getCenterPoint() throws HeadlessException Returns the Point where Windows should be centered. It is recommended that centered Windows be checked to ensure they fit within the available display area using getMaximumWindowBounds().- Returns:
- the point where Windows should be centered
- Throws:
- HeadlessException- if isHeadless() returns true
- Since:
- 1.4
- See Also:
- getMaximumWindowBounds()
 
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getMaximumWindowBoundspublic Rectangle getMaximumWindowBounds() throws HeadlessException Returns the maximum bounds for centered Windows. These bounds account for objects in the native windowing system such as task bars and menu bars. The returned bounds will reside on a single display with one exception: on multi-screen systems where Windows should be centered across all displays, this method returns the bounds of the entire display area.To get the usable bounds of a single display, use GraphicsConfiguration.getBounds()andToolkit.getScreenInsets().- Returns:
- the maximum bounds for centered Windows
- Throws:
- HeadlessException- if isHeadless() returns true
- Since:
- 1.4
- See Also:
- getCenterPoint(),- GraphicsConfiguration.getBounds(),- Toolkit.getScreenInsets(java.awt.GraphicsConfiguration)
 
 
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