AWT/Swing merge from GNU Classpath.

From-SVN: r56147

libjava/java/awt/GraphicsEnvironment.java

@@ -0,0 +1,210 @@
+/* GraphicsEnvironment.java -- information about the graphics environment
+   Copyright (C) 2002 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package java.awt;
+
+import java.awt.image.BufferedImage;
+import java.util.Locale;
+
+/**
+ * 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.
+ *
+ * @author Eric Blake <ebb9@email.byu.edu>
+ * @see GraphicsDevice
+ * @see GraphicsConfiguration
+ * @since 1.4
+ * @status updated to 1.4
+ */
+public abstract class GraphicsEnvironment
+{
+  /**
+   * The environment must be obtained from a factory or query method, hence
+   * this constructor is protected.
+   */
+  protected GraphicsEnvironment()
+  {
+  }
+
+  /**
+   * Returns the local graphics environment.
+   *
+   * XXX Not implemented in Classpath yet.
+   * @return the local environment
+   */
+  public static GraphicsEnvironment getLocalGraphicsEnvironment()
+  {
+    throw new Error("not implemented");
+  }
+
+  /**
+   * 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 {@link HeadlessException} if this
+   * returns true.
+   *
+   * XXX For now, Classpath assumes that it is never headless.
+   *
+   * @return true if the environment is headless, meaning that graphics are
+   *         unsupported
+   * @since 1.4
+   */
+  public static boolean isHeadless()
+  {
+    // XXX Should be: getLocalGraphicsEnvironment().isHeadlessInstance();
+    return false;
+  }
+
+  /**
+   * 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 {@link HeadlessException} if this
+   * returns true. This default implementation returns false, so subclasses
+   * need only override it if they are headless.
+   *
+   * @return true if the environment is headless, meaning that graphics are
+   *         unsupported
+   * @since 1.4
+   */
+  public boolean isHeadlessInstance()
+  {
+    return false;
+  }
+
+  /**
+   * Get an array of all the GraphicsDevice objects.
+   *
+   * @return the available graphics devices, may be 0 length
+   * @throws HeadlessException if the environment is headless
+   */
+  public abstract GraphicsDevice[] getScreenDevices();
+
+  /**
+   * Get the default screen GraphicsDevice object.
+   *
+   * @return the default screen device
+   * @throws HeadlessException if the environment is headless
+   */
+  public abstract GraphicsDevice getDefaultScreenDevice();
+
+  /**
+   * Return a Graphics2D object which will render into the specified image.
+   *
+   * @param image the image to render into
+   * @return the object that renders into the image
+   */
+  public abstract Graphics2D createGraphics(BufferedImage image);
+
+  /**
+   * 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 <code>deriveFont</code>.
+   * 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.
+   *
+   * @return the array of available fonts
+   * @see #getAvailableFontFamilyNames()
+   * @see Font#deriveFont(int, float)
+   * @since 1.2
+   */
+  public abstract Font[] getAllFonts();
+
+  /**
+   * 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.
+   *
+   * @return the array of available font families
+   * @see #getAllFonts()
+   * @see Font#getFamily()
+   * @since 1.2
+   */
+  public abstract String[] getAvailableFontFamilyNames();
+
+  /**
+   * 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.
+   *
+   * @param l the locale to use
+   * @return the array of available font families, localized
+   * @see #getAllFonts()
+   * @see Font#getFamily()
+   * @since 1.2
+   */
+  public abstract String[] getAvailableFontFamilyNames(Locale l);
+
+  /**
+   * 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.
+   *
+   * @return the centering point
+   * @throws HeadlessException if the environment is headless
+   * @see #getMaximumWindowBounds()
+   * @since 1.4
+   */
+  public Point getCenterPoint()
+  {
+    Rectangle r = getMaximumWindowBounds();
+    return new Point(r.x + r.width / 2, r.y + r.height / 2);
+  }
+
+  /**
+   * 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.
+   *
+   * @return the maximum window bounds
+   * @throws HeadlessException if the environment is headless
+   * @see #getCenterPoint()
+   * @see GraphicsConfiguration#getBounds()
+   * @see Toolkit#getScreenInsets(GraphicsConfiguration)
+   * @since 1.4
+   */
+  public Rectangle getMaximumWindowBounds()
+  {
+    return getDefaultScreenDevice().getDefaultConfiguration().getBounds();
+  }
+} // class GraphicsEnvironment