jdk/src/share/classes/javax/swing/Box.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/swing/Box.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,437 @@
+/*
+ * Copyright 1997-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+
+package javax.swing;
+
+import java.awt.*;
+import java.awt.event.*;
+import java.beans.ConstructorProperties;
+import java.util.Locale;
+import java.io.Serializable;
+import javax.accessibility.*;
+
+/**
+ * A lightweight container
+ * that uses a BoxLayout object as its layout manager.
+ * Box provides several class methods
+ * that are useful for containers using BoxLayout --
+ * even non-Box containers.
+ *
+ * <p>
+ * The <code>Box</code> class can create several kinds
+ * of invisible components
+ * that affect layout:
+ * glue, struts, and rigid areas.
+ * If all the components your <code>Box</code> contains
+ * have a fixed size,
+ * you might want to use a glue component
+ * (returned by <code>createGlue</code>)
+ * to control the components' positions.
+ * If you need a fixed amount of space between two components,
+ * try using a strut
+ * (<code>createHorizontalStrut</code> or <code>createVerticalStrut</code>).
+ * If you need an invisible component
+ * that always takes up the same amount of space,
+ * get it by invoking <code>createRigidArea</code>.
+ * <p>
+ * If you are implementing a <code>BoxLayout</code> you
+ * can find further information and examples in
+ * <a
+ href="http://java.sun.com/docs/books/tutorial/uiswing/layout/box.html">How to Use BoxLayout</a>,
+ * a section in <em>The Java Tutorial.</em>
+ * <p>
+ * <strong>Warning:</strong>
+ * Serialized objects of this class will not be compatible with
+ * future Swing releases. The current serialization support is
+ * appropriate for short term storage or RMI between applications running
+ * the same version of Swing.  As of 1.4, support for long term storage
+ * of all JavaBeans<sup><font size="-2">TM</font></sup>
+ * has been added to the <code>java.beans</code> package.
+ * Please see {@link java.beans.XMLEncoder}.
+ *
+ * @see BoxLayout
+ *
+ * @author  Timothy Prinzing
+ */
+public class Box extends JComponent implements Accessible {
+
+    /**
+     * Creates a <code>Box</code> that displays its components
+     * along the the specified axis.
+     *
+     * @param axis  can be {@link BoxLayout#X_AXIS},
+     *              {@link BoxLayout#Y_AXIS},
+     *              {@link BoxLayout#LINE_AXIS} or
+     *              {@link BoxLayout#PAGE_AXIS}.
+     * @throws AWTError if the <code>axis</code> is invalid
+     * @see #createHorizontalBox
+     * @see #createVerticalBox
+     */
+    public Box(int axis) {
+        super();
+        super.setLayout(new BoxLayout(this, axis));
+    }
+
+    /**
+     * Creates a <code>Box</code> that displays its components
+     * from left to right. If you want a <code>Box</code> that
+     * respects the component orientation you should create the
+     * <code>Box</code> using the constructor and pass in
+     * <code>BoxLayout.LINE_AXIS</code>, eg:
+     * <pre>
+     *   Box lineBox = new Box(BoxLayout.LINE_AXIS);
+     * </pre>
+     *
+     * @return the box
+     */
+    public static Box createHorizontalBox() {
+        return new Box(BoxLayout.X_AXIS);
+    }
+
+    /**
+     * Creates a <code>Box</code> that displays its components
+     * from top to bottom. If you want a <code>Box</code> that
+     * respects the component orientation you should create the
+     * <code>Box</code> using the constructor and pass in
+     * <code>BoxLayout.PAGE_AXIS</code>, eg:
+     * <pre>
+     *   Box lineBox = new Box(BoxLayout.PAGE_AXIS);
+     * </pre>
+     *
+     * @return the box
+     */
+    public static Box createVerticalBox() {
+        return new Box(BoxLayout.Y_AXIS);
+    }
+
+    /**
+     * Creates an invisible component that's always the specified size.
+     * <!-- WHEN WOULD YOU USE THIS AS OPPOSED TO A STRUT? -->
+     *
+     * @param d the dimensions of the invisible component
+     * @return the component
+     * @see #createGlue
+     * @see #createHorizontalStrut
+     * @see #createVerticalStrut
+     */
+    public static Component createRigidArea(Dimension d) {
+        return new Filler(d, d, d);
+    }
+
+    /**
+     * Creates an invisible, fixed-width component.
+     * In a horizontal box,
+     * you typically use this method
+     * to force a certain amount of space between two components.
+     * In a vertical box,
+     * you might use this method
+     * to force the box to be at least the specified width.
+     * The invisible component has no height
+     * unless excess space is available,
+     * in which case it takes its share of available space,
+     * just like any other component that has no maximum height.
+     *
+     * @param width the width of the invisible component, in pixels >= 0
+     * @return the component
+     * @see #createVerticalStrut
+     * @see #createGlue
+     * @see #createRigidArea
+     */
+    public static Component createHorizontalStrut(int width) {
+        return new Filler(new Dimension(width,0), new Dimension(width,0),
+                          new Dimension(width, Short.MAX_VALUE));
+    }
+
+    /**
+     * Creates an invisible, fixed-height component.
+     * In a vertical box,
+     * you typically use this method
+     * to force a certain amount of space between two components.
+     * In a horizontal box,
+     * you might use this method
+     * to force the box to be at least the specified height.
+     * The invisible component has no width
+     * unless excess space is available,
+     * in which case it takes its share of available space,
+     * just like any other component that has no maximum width.
+     *
+     * @param height the height of the invisible component, in pixels >= 0
+     * @return the component
+     * @see #createHorizontalStrut
+     * @see #createGlue
+     * @see #createRigidArea
+     */
+    public static Component createVerticalStrut(int height) {
+        return new Filler(new Dimension(0,height), new Dimension(0,height),
+                          new Dimension(Short.MAX_VALUE, height));
+    }
+
+    /**
+     * Creates an invisible "glue" component
+     * that can be useful in a Box
+     * whose visible components have a maximum width
+     * (for a horizontal box)
+     * or height (for a vertical box).
+     * You can think of the glue component
+     * as being a gooey substance
+     * that expands as much as necessary
+     * to fill the space between its neighboring components.
+     *
+     * <p>
+     *
+     * For example, suppose you have
+     * a horizontal box that contains two fixed-size components.
+     * If the box gets extra space,
+     * the fixed-size components won't become larger,
+    * so where does the extra space go?
+     * Without glue,
+     * the extra space goes to the right of the second component.
+     * If you put glue between the fixed-size components,
+     * then the extra space goes there.
+     * If you put glue before the first fixed-size component,
+     * the extra space goes there,
+     * and the fixed-size components are shoved against the right
+     * edge of the box.
+     * If you put glue before the first fixed-size component
+     * and after the second fixed-size component,
+     * the fixed-size components are centered in the box.
+     *
+     * <p>
+     *
+     * To use glue,
+     * call <code>Box.createGlue</code>
+     * and add the returned component to a container.
+     * The glue component has no minimum or preferred size,
+     * so it takes no space unless excess space is available.
+     * If excess space is available,
+     * then the glue component takes its share of available
+     * horizontal or vertical space,
+     * just like any other component that has no maximum width or height.
+     *
+     * @return the component
+     */
+    public static Component createGlue() {
+        return new Filler(new Dimension(0,0), new Dimension(0,0),
+                          new Dimension(Short.MAX_VALUE, Short.MAX_VALUE));
+    }
+
+    /**
+     * Creates a horizontal glue component.
+     *
+     * @return the component
+     */
+    public static Component createHorizontalGlue() {
+        return new Filler(new Dimension(0,0), new Dimension(0,0),
+                          new Dimension(Short.MAX_VALUE, 0));
+    }
+
+    /**
+     * Creates a vertical glue component.
+     *
+     * @return the component
+     */
+    public static Component createVerticalGlue() {
+        return new Filler(new Dimension(0,0), new Dimension(0,0),
+                          new Dimension(0, Short.MAX_VALUE));
+    }
+
+    /**
+     * Throws an AWTError, since a Box can use only a BoxLayout.
+     *
+     * @param l the layout manager to use
+     */
+    public void setLayout(LayoutManager l) {
+        throw new AWTError("Illegal request");
+    }
+
+    /**
+     * Paints this <code>Box</code>.  If this <code>Box</code> has a UI this
+     * method invokes super's implementation, otherwise if this
+     * <code>Box</code> is opaque the <code>Graphics</code> is filled
+     * using the background.
+     *
+     * @param g the <code>Graphics</code> to paint to
+     * @throws NullPointerException if <code>g</code> is null
+     * @since 1.6
+     */
+    protected void paintComponent(Graphics g) {
+        if (ui != null) {
+            // On the off chance some one created a UI, honor it
+            super.paintComponent(g);
+        } else if (isOpaque()) {
+            g.setColor(getBackground());
+            g.fillRect(0, 0, getWidth(), getHeight());
+        }
+    }
+
+
+    /**
+     * An implementation of a lightweight component that participates in
+     * layout but has no view.
+     * <p>
+     * <strong>Warning:</strong>
+     * Serialized objects of this class will not be compatible with
+     * future Swing releases. The current serialization support is
+     * appropriate for short term storage or RMI between applications running
+     * the same version of Swing.  As of 1.4, support for long term storage
+     * of all JavaBeans<sup><font size="-2">TM</font></sup>
+     * has been added to the <code>java.beans</code> package.
+     * Please see {@link java.beans.XMLEncoder}.
+     */
+    public static class Filler extends JComponent implements Accessible {
+
+        /**
+         * Constructor to create shape with the given size ranges.
+         *
+         * @param min   Minimum size
+         * @param pref  Preferred size
+         * @param max   Maximum size
+         */
+        @ConstructorProperties({"minimumSize", "preferredSize", "maximumSize"})
+        public Filler(Dimension min, Dimension pref, Dimension max) {
+            setMinimumSize(min);
+            setPreferredSize(pref);
+            setMaximumSize(max);
+        }
+
+        /**
+         * Change the size requests for this shape.  An invalidate() is
+         * propagated upward as a result so that layout will eventually
+         * happen with using the new sizes.
+         *
+         * @param min   Value to return for getMinimumSize
+         * @param pref  Value to return for getPreferredSize
+         * @param max   Value to return for getMaximumSize
+         */
+        public void changeShape(Dimension min, Dimension pref, Dimension max) {
+            setMinimumSize(min);
+            setPreferredSize(pref);
+            setMaximumSize(max);
+            revalidate();
+        }
+
+        // ---- Component methods ------------------------------------------
+
+        /**
+         * Paints this <code>Filler</code>.  If this
+         * <code>Filler</code> has a UI this method invokes super's
+         * implementation, otherwise if this <code>Filler</code> is
+         * opaque the <code>Graphics</code> is filled using the
+         * background.
+         *
+         * @param g the <code>Graphics</code> to paint to
+         * @throws NullPointerException if <code>g</code> is null
+         * @since 1.6
+         */
+        protected void paintComponent(Graphics g) {
+            if (ui != null) {
+                // On the off chance some one created a UI, honor it
+                super.paintComponent(g);
+            } else if (isOpaque()) {
+                g.setColor(getBackground());
+                g.fillRect(0, 0, getWidth(), getHeight());
+            }
+        }
+
+/////////////////
+// Accessibility support for Box$Filler
+////////////////
+
+        /**
+         * Gets the AccessibleContext associated with this Box.Filler.
+         * For box fillers, the AccessibleContext takes the form of an
+         * AccessibleBoxFiller.
+         * A new AccessibleAWTBoxFiller instance is created if necessary.
+         *
+         * @return an AccessibleBoxFiller that serves as the
+         *         AccessibleContext of this Box.Filler.
+         */
+        public AccessibleContext getAccessibleContext() {
+            if (accessibleContext == null) {
+                accessibleContext = new AccessibleBoxFiller();
+            }
+            return accessibleContext;
+        }
+
+        /**
+         * This class implements accessibility support for the
+         * <code>Box.Filler</code> class.
+         */
+        protected class AccessibleBoxFiller extends AccessibleAWTComponent {
+            // AccessibleContext methods
+            //
+            /**
+             * Gets the role of this object.
+             *
+             * @return an instance of AccessibleRole describing the role of
+             *   the object (AccessibleRole.FILLER)
+             * @see AccessibleRole
+             */
+            public AccessibleRole getAccessibleRole() {
+                return AccessibleRole.FILLER;
+            }
+        }
+    }
+
+/////////////////
+// Accessibility support for Box
+////////////////
+
+    /**
+     * Gets the AccessibleContext associated with this Box.
+     * For boxes, the AccessibleContext takes the form of an
+     * AccessibleBox.
+     * A new AccessibleAWTBox instance is created if necessary.
+     *
+     * @return an AccessibleBox that serves as the
+     *         AccessibleContext of this Box
+     */
+    public AccessibleContext getAccessibleContext() {
+        if (accessibleContext == null) {
+            accessibleContext = new AccessibleBox();
+        }
+        return accessibleContext;
+    }
+
+    /**
+     * This class implements accessibility support for the
+     * <code>Box</code> class.
+     */
+    protected class AccessibleBox extends AccessibleAWTContainer {
+        // AccessibleContext methods
+        //
+        /**
+         * Gets the role of this object.
+         *
+         * @return an instance of AccessibleRole describing the role of the
+         *   object (AccessibleRole.FILLER)
+         * @see AccessibleRole
+         */
+        public AccessibleRole getAccessibleRole() {
+            return AccessibleRole.FILLER;
+        }
+    } // inner class AccessibleBox
+}