The GraphicsEnvironment class describes the collection
of
GraphicsDevice objects and
java.awt.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.
See Also:GraphicsDevice See Also:GraphicsConfiguration version: 1.74, 06/04/07
Constructor Summary
protected
GraphicsEnvironment() This is an abstract class and cannot be instantiated directly.
getAvailableFontFamilyNames() Returns an array containing the names of all font families in this
GraphicsEnvironment localized for the default locale,
as returned by Locale.getDefault().
Typical usage would be for presentation to a user for selection of
a particular family name.
getAvailableFontFamilyNames(Locale l) Returns an array containing the names of all font families in this
GraphicsEnvironment localized for the specified locale.
Typical usage would be for presentation to a user for selection of
a particular family name.
getMaximumWindowBounds() Returns the maximum bounds for centered Windows.
These bounds account for objects in the native windowing system such as
task bars and menu bars.
getScreenDevices() Returns an array of all of the screen GraphicsDevice
objects.
public static boolean
isHeadless() Tests whether or not a display, keyboard, and mouse can be
supported in this environment.
public boolean
isHeadlessInstance() Returns whether or not a display, keyboard, and mouse can be
supported in this graphics environment.
public void
preferLocaleFonts() Indicates a preference for locale-specific fonts in the mapping of
logical fonts to physical fonts.
public 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.
Returns a Graphics2D object for rendering into the
specified
BufferedImage .
Parameters: img - the specified BufferedImage a Graphics2D to be used for rendering intothe specified BufferedImage throws: NullPointerException - if img is null
Returns an array containing a one-point size instance of all fonts
available in this GraphicsEnvironment. 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 the deriveFont method on the choosen instance.
This method provides for the application the most precise control
over which Font instance is used to render text.
If a font in this GraphicsEnvironment has multiple
programmable variations, only one
instance of that Font is returned in the array, and
other variations must be derived by the application.
Returns an array containing the names of all font families in this
GraphicsEnvironment localized for the default locale,
as returned by Locale.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.
an array of String containing font family nameslocalized for the default locale, or a suitable alternativename if no name exists for this locale. See Also:GraphicsEnvironment.getAllFonts See Also:java.awt.Font See Also:java.awt.Font.getFamily since: 1.2
Returns an array containing the names of all font families in this
GraphicsEnvironment localized 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 Locale object that represents aparticular geographical, political, or cultural region.Specifying null is equivalent tospecifying Locale.getDefault(). an array of String containing font family nameslocalized for the specified Locale, or asuitable alternative name if no name exists for the specified locale. See Also:GraphicsEnvironment.getAllFonts See Also:java.awt.Font See Also:java.awt.Font.getFamily since: 1.2
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().
the point where Windows should be centered exception: HeadlessException - if isHeadless() returns true See Also:GraphicsEnvironment.getMaximumWindowBounds since: 1.4
Returns the default screen GraphicsDevice.
the GraphicsDevice that represents thedefault screen device exception: HeadlessException - if isHeadless() returns true See Also:GraphicsEnvironment.isHeadless()
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.
Returns an array of all of the screen GraphicsDevice
objects.
an array containing all the GraphicsDeviceobjects that represent screen devices exception: HeadlessException - if isHeadless() returns true See Also:GraphicsEnvironment.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.
true if this environment cannot support a display, keyboard, and mouse; false otherwise See Also:java.awt.HeadlessException since: 1.4
Returns whether or not a display, keyboard, and mouse can be
supported in this graphics environment. If this returns true,
HeadlessException will be thrown from areas of the
graphics environment that are dependent on a display, keyboard, or
mouse.
true if a display, keyboard, and mouse can be supported in this environment; falseotherwise See Also:java.awt.HeadlessException See Also:GraphicsEnvironment.isHeadless since: 1.4
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
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
Registers a createdFontin this
GraphicsEnvironment.
A created font is one that was returned from calling
Font.createFont , or derived from a created font by
calling
Font.deriveFont .
After calling this method for such a font, it is available to
be used in constructing new Fonts by name or family name,
and is enumerated by
GraphicsEnvironment.getAvailableFontFamilyNames and
GraphicsEnvironment.getAllFonts 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 false are:
The font is not a createdFont.
The font conflicts with a non-created Font already
in this GraphicsEnvironment. For example if the name
is that of a system font, or a logical font as described in the
documentation of the
Font class. 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.
true if the font is successfullyregistered in this GraphicsEnvironment. throws: NullPointerException - if font is null since: 1.6
