There exist some parts of AWT and Java2D that are specific to * the underlying platform, but for which the {@link Toolkit} class * does not provide suitable abstractions. Examples include some * methods of {@link Font} or {@link GraphicsEnvironment}. Those * methods use ClasspathToolkit as a central place for obtaining * platform-specific functionality. * *
In addition, ClasspathToolkit implements some abstract methods * of {@link java.awt.Toolkit} that are not really platform-specific, * such as the maintenance of a cache of loaded images. * *
Thread Safety: The methods of this class may safely be * called without external synchronization. This also hold for any * inherited {@link Toolkit} methods. Subclasses are responsible for * the necessary synchronization. * * @author Sascha Brawer (brawer@dandelis.ch) */ public abstract class ClasspathToolkit extends Toolkit { /** * Returns a shared instance of the local, platform-specific * graphics environment. * *
This method is specific to GNU Classpath. It gets called by * the Classpath implementation of {@link * GraphicsEnvironment.getLocalGraphcisEnvironment()}. */ public abstract GraphicsEnvironment getLocalGraphicsEnvironment(); /** * Acquires an appropriate {@link ClasspathFontPeer}, for use in * classpath's implementation of {@link java.awt.Font}. * * @param name The logical name of the font. This may be either a face * name or a logical font name, or may even be null. A default * implementation of name decoding is provided in * {@link ClasspathFontPeer}, but may be overridden in other toolkits. * * @param attrs Any extra {@link java.awt.font.TextAttribute} attributes * this font peer should have, such as size, weight, family name, or * transformation. */ public abstract ClasspathFontPeer getClasspathFontPeer (String name, Map attrs); /** * Creates a {@link Font}, in a platform-specific manner. * * The default implementation simply constructs a {@link Font}, but some * toolkits may wish to override this, to return {@link Font} subclasses * which implement {@link java.awt.font.OpenType} or * {@link java.awt.font.MultipleMaster}. */ public Font getFont (String name, Map attrs) { Font f = null; // Circumvent the package-privateness of the // java.awt.Font.Font(String,Map) constructor. try { Constructor fontConstructor = Font.class.getDeclaredConstructor (new Class[] { String.class, Map.class }); AccessController.doPrivileged(new SetAccessibleAction(fontConstructor)); f = (Font) fontConstructor.newInstance(new Object[] { name, attrs }); } catch (IllegalAccessException e) { throw new AssertionError(e); } catch (NoSuchMethodException e) { throw new AssertionError(e); } catch (InstantiationException e) { throw new AssertionError(e); } catch (InvocationTargetException e) { throw new AssertionError(e); } return f; } /** * Creates a font, reading the glyph definitions from a stream. * *
This method provides the platform-specific implementation for
* the static factory method {@link Font#createFont(int,
* java.io.InputStream)}.
*
* @param format the format of the font data, such as {@link
* Font#TRUETYPE_FONT}. An implementation may ignore this argument
* if it is able to automatically recognize the font format from the
* provided data.
*
* @param stream an input stream from where the font data is read
* in. The stream will be advanced to the position after the font
* data, but not closed.
*
* @throws IllegalArgumentException if format is
* not supported.
*
* @throws FontFormatException if stream does not
* contain data in the expected format, or if required tables are
* missing from a font.
*
* @throws IOException if a problem occurs while reading in the
* contents of stream.
*/
public abstract Font createFont(int format, InputStream stream);
/**
* Creates a RobotPeer on a given GraphicsDevice.
*/
public abstract RobotPeer createRobot (GraphicsDevice screen)
throws AWTException;
/**
* Creates an embedded window peer, and associates it with an
* EmbeddedWindow object.
*
* @param w The embedded window with which to associate a peer.
*/
public abstract EmbeddedWindowPeer createEmbeddedWindow (EmbeddedWindow w);
/**
* Used to register ImageIO SPIs provided by the toolkit.
*
* Our default implementation does nothing.
*/
public void registerImageIOSpis(IIORegistry reg)
{
}
/**
* Returns the number of mouse buttons.
* (used by java.awt.MouseInfo).
*
* This dummy implementation returns -1 (no mouse).
* toolkit implementors should overload this method if possible.
* @since 1.5
*/
public int getMouseNumberOfButtons()
{
return -1;
}
/* (non-Javadoc)
* @see java.awt.Toolkit#createDesktopPeer(java.awt.Desktop)
*/
protected DesktopPeer createDesktopPeer(Desktop target)
throws HeadlessException
{
if (GraphicsEnvironment.isHeadless())
throw new HeadlessException();
return ClasspathDesktopPeer.getDesktop();
}
}