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 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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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="https://docs.oracle.com/javase/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&trade;
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @see BoxLayout
 *
 * @author Timothy Prinzing
 */
@SuppressWarnings("serial")
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 &gt;= 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 &gt;= 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&trade;
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 */
 @SuppressWarnings("serial")
 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.
 */
 @SuppressWarnings("serial")
 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.
 */
 @SuppressWarnings("serial")
 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
}