/*
* This file is modified by Ivan Maidanski <ivmai@ivmaisoft.com>
* Project name: JCGO-SUNAWT (http://www.ivmaisoft.com/jcgo/)
**
* Comment: contains x11-specific fixes.
*/
/*
* @(#)GraphicsEnvironment.java 1.55 03/01/23
*
* Copyright 2003 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.awt;
import java.awt.image.BufferedImage;
import java.util.Hashtable;
import java.util.Locale;
import java.util.Map;
import java.io.InputStream;
import sun.java2d.HeadlessGraphicsEnvironment;
import sun.java2d.SunGraphicsEnvironment;
/**
*
* The <code>GraphicsEnvironment</code> class describes the collection
* of {@link GraphicsDevice} objects and {@link java.awt.Font} objects
* available to a Java(tm) application on a particular platform.
* The resources in this <code>GraphicsEnvironment</code> might be local
* or on a remote machine. <code>GraphicsDevice</code> objects can be
* screens, printers or image buffers and are the destination of
* {@link Graphics2D} drawing methods. Each <code>GraphicsDevice</code>
* has a number of {@link GraphicsConfiguration} objects associated with
* it. These objects specify the different configurations in which the
* <code>GraphicsDevice</code> can be used.
* @see GraphicsDevice
* @see GraphicsConfiguration
* @version 1.55, 01/23/03
*/
public abstract class GraphicsEnvironment {
private static GraphicsEnvironment localEnv;
/**
* The headless state of the Toolkit and GraphicsEnvironment
*/
private static Boolean headless;
/**
* This is an abstract class and cannot be instantiated directly.
* Instances must be obtained from a suitable factory or query method.
*/
protected GraphicsEnvironment() {
}
/**
* Returns the local <code>GraphicsEnvironment</code>.
* @return the local <code>GraphicsEnvironment</code>
*/
public static synchronized GraphicsEnvironment getLocalGraphicsEnvironment() {
if (localEnv == null) {
String nm = (String) java.security.AccessController.doPrivileged
(new sun.security.action.GetPropertyAction
("java.awt.graphicsenv", "sun.awt.X11GraphicsEnvironment"));
try {
localEnv =
(GraphicsEnvironment) Class.forName(nm).newInstance();
if (isHeadless()) {
localEnv = new HeadlessGraphicsEnvironment(localEnv);
}
} catch (ClassNotFoundException e) {
throw new Error("Could not find class: "+nm);
} catch (InstantiationException e) {
throw new Error("Could not instantiate Graphics Environment: "
+ nm);
} catch (IllegalAccessException e) {
throw new Error ("Could not access Graphics Environment: "
+ nm);
}
}
return localEnv;
}
/**
* 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.
* @return <code>true</code> if this environment cannot support
* a display, keyboard, and mouse; <code>false</code>
* otherwise
* @see java.awt.HeadlessException
* @since 1.4
*/
public static boolean isHeadless() {
return getHeadlessProperty();
}
/**
* @return the value of the property "java.awt.headless"
* @since 1.4
*/
private static boolean getHeadlessProperty() {
if (headless == null) {
String nm = (String)java.security.AccessController.doPrivileged(
new sun.security.action.GetPropertyAction(
"java.awt.headless", "false"));
if (nm.equals("true")) {
headless = Boolean.TRUE;
} else {
headless = Boolean.FALSE;
}
}
return headless.booleanValue();
}
/**
* Check for headless state and throw HeadlessException if headless
* @since 1.4
*/
static void checkHeadless() throws HeadlessException {
if (isHeadless()) {
throw new HeadlessException();
}
}
/**
* Returns whether or not a display, keyboard, and mouse can be
* supported in this graphics environment. If this returns true,
* <code>HeadlessException</code> will be thrown from areas of the
* graphics environment that are dependent on a display, keyboard, or
* mouse.
* @return <code>true</code> if a display, keyboard, and mouse
* can be supported in this environment; <code>false</code>
* otherwise
* @see java.awt.HeadlessException
* @see #isHeadless
* @since 1.4
*/
public boolean isHeadlessInstance() {
// By default (local graphics environment), simply check the
// headless property.
return getHeadlessProperty();
}
/**
* Returns an array of all of the screen <code>GraphicsDevice</code>
* objects.
* @return an array containing all the <code>GraphicsDevice</code>
* objects that represent screen devices
* @exception HeadlessException if isHeadless() returns true
* @see #isHeadless()
*/
public abstract GraphicsDevice[] getScreenDevices()
throws HeadlessException;
/**
* Returns the default screen <code>GraphicsDevice</code>.
* @return the <code>GraphicsDevice</code> that represents the
* default screen device
* @exception HeadlessException if isHeadless() returns true
* @see #isHeadless()
*/
public abstract GraphicsDevice getDefaultScreenDevice()
throws HeadlessException;
/**
* Returns a <code>Graphics2D</code> object for rendering into the
* specified {@link BufferedImage}.
* @param img the specified <code>BufferedImage</code>
* @return a <code>Graphics2D</code> to be used for rendering into
* the specified <code>BufferedImage</code>
*/
public abstract Graphics2D createGraphics(BufferedImage img);
/**
* Returns an array containing a one-point size instance of all fonts
* available in this <code>GraphicsEnvironment</code>. 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 <code>deriveFont</code> method on the choosen instance.
* <p>
* This method provides for the application the most precise control
* over which <code>Font</code> instance is used to render text.
* If a font in this <code>GraphicsEnvironment</code> has multiple
* programmable variations, only one
* instance of that <code>Font</code> is returned in the array, and
* other variations must be derived by the application.
* <p>
* 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 <code>Font</code> array. The other variations
* must be derived by the application.
*
* @return an array of <code>Font</code> objects
* @see #getAvailableFontFamilyNames
* @see java.awt.Font
* @see java.awt.Font#deriveFont
* @see java.awt.Font#getFontName
* @since 1.2
*/
public abstract Font[] getAllFonts();
/**
* Returns an array containing the names of all font families available
* in this <code>GraphicsEnvironment</code>.
* 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.
* <p>
* This method provides for the application some control over which
* <code>Font</code> instance is used to render text, but allows the
* <code>Font</code> object more flexibility in choosing its own best
* match among multiple fonts in the same font family.
*
* @return an array of <code>String</code> containing names of font
* families
* @see #getAllFonts
* @see java.awt.Font
* @see java.awt.Font#getFamily
* @since 1.2
*/
public abstract String[] getAvailableFontFamilyNames();
/**
* Returns an array containing the localized names of all font families
* available in this <code>GraphicsEnvironment</code>.
* 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.
* <p>
* This method provides for the application some control over which
* <code>Font</code> instance used to render text, but allows the
* <code>Font</code> object more flexibility in choosing its own best
* match among multiple fonts in the same font family.
* If <code>l</code> is <code>null</code>, this method returns an
* array containing all font family names available in this
* <code>GraphicsEnvironment</code>.
*
* @param l a {@link Locale} object that represents a
* particular geographical, political, or cultural region
* @return an array of <code>String</code> objects containing names of
* font families specific to the specified <code>Locale</code>
* @see #getAllFonts
* @see java.awt.Font
* @see java.awt.Font#getFamily
* @since 1.2
*/
public abstract String[] getAvailableFontFamilyNames(Locale l);
/**
* 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().
* @return the point where Windows should be centered
*
* @exception HeadlessException if isHeadless() returns true
* @see #getMaximumWindowBounds
* @since 1.4
*/
public Point getCenterPoint() throws HeadlessException {
// Default implementation: return the center of the usable bounds of the
// default screen device.
Rectangle usableBounds =
SunGraphicsEnvironment.getUsableBounds(getDefaultScreenDevice());
return new Point((usableBounds.width / 2) + usableBounds.x,
(usableBounds.height / 2) + usableBounds.y);
}
/**
* 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.
* <p>
* To get the usable bounds of a single display, use
* <code>GraphicsConfiguration.getBounds()</code> and
* <code>Toolkit.getScreenInsets()</code>.
* @return the maximum bounds for centered Windows
*
* @exception HeadlessException if isHeadless() returns true
* @see #getCenterPoint
* @see GraphicsConfiguration#getBounds
* @see Toolkit#getScreenInsets
* @since 1.4
*/
public Rectangle getMaximumWindowBounds() throws HeadlessException {
// Default implementation: return the usable bounds of the default screen
// device. This is correct for Microsoft Windows and non-Xinerama X11.
return SunGraphicsEnvironment.getUsableBounds(getDefaultScreenDevice());
}
}