/*
 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
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 *
 *
 *
 *
 *
 *
 *
 */

package javax.swing;

import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.*;
import java.beans.Transient;
import java.util.Vector;
import java.util.Enumeration;

import java.io.Serializable;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;

import javax.swing.event.*;
import javax.swing.border.Border;
import javax.swing.plaf.*;
import javax.accessibility.*;

/**
 * An implementation of a menu bar. You add <code>JMenu</code> objects to the
 * menu bar to construct a menu. When the user selects a <code>JMenu</code>
 * object, its associated <code>JPopupMenu</code> is displayed, allowing the
 * user to select one of the <code>JMenuItems</code> on it.
 * <p>
 * For information and examples of using menu bars see
 * <a
 href="https://docs.oracle.com/javase/tutorial/uiswing/components/menu.html">How to Use Menus</a>,
 * a section in <em>The Java Tutorial.</em>
 * <p>
 * <strong>Warning:</strong> Swing is not thread safe. For more
 * information see <a
 * href="package-summary.html#threading">Swing's Threading
 * Policy</a>.
 * <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}.
 * <p>
 * <strong>Warning:</strong>
 * By default, pressing the Tab key does not transfer focus from a <code>
 * JMenuBar</code> which is added to a container together with other Swing
 * components, because the <code>focusTraversalKeysEnabled</code> property
 * of <code>JMenuBar</code> is set to <code>false</code>. To resolve this,
 * you should call the <code>JMenuBar.setFocusTraversalKeysEnabled(true)</code>
 * method.
 * @beaninfo
 * attribute: isContainer true
 * description: A container for holding and displaying menus.
 *
 * @author Georges Saab
 * @author David Karlton
 * @author Arnaud Weber
 * @see JMenu
 * @see JPopupMenu
 * @see JMenuItem
 */
@SuppressWarnings("serial")
public class JMenuBar extends JComponent implements Accessible,MenuElement
{
 /**
 * @see #getUIClassID
 * @see #readObject
 */
 private static final String uiClassID = "MenuBarUI";

 /*
 * Model for the selected subcontrol.
 */
 private transient SingleSelectionModel selectionModel;

 private boolean paintBorder = true;
 private Insets margin = null;

 /* diagnostic aids -- should be false for production builds. */
 private static final boolean TRACE = false; // trace creates and disposes
 private static final boolean VERBOSE = false; // show reuse hits/misses
 private static final boolean DEBUG = false; // show bad params, misc.

 /**
 * Creates a new menu bar.
 */
 public JMenuBar() {
 super();
 setFocusTraversalKeysEnabled(false);
 setSelectionModel(new DefaultSingleSelectionModel());
 updateUI();
 }

 /**
 * Returns the menubar's current UI.
 * @see #setUI
 */
 public MenuBarUI getUI() {
 return (MenuBarUI)ui;
 }

 /**
 * Sets the L&amp;F object that renders this component.
 *
 * @param ui the new MenuBarUI L&amp;F object
 * @see UIDefaults#getUI
 * @beaninfo
 * bound: true
 * hidden: true
 * attribute: visualUpdate true
 * description: The UI object that implements the Component's LookAndFeel.
 */
 public void setUI(MenuBarUI ui) {
 super.setUI(ui);
 }

 /**
 * Resets the UI property with a value from the current look and feel.
 *
 * @see JComponent#updateUI
 */
 public void updateUI() {
 setUI((MenuBarUI)UIManager.getUI(this));
 }


 /**
 * Returns the name of the L&amp;F class that renders this component.
 *
 * @return the string "MenuBarUI"
 * @see JComponent#getUIClassID
 * @see UIDefaults#getUI
 */
 public String getUIClassID() {
 return uiClassID;
 }


 /**
 * Returns the model object that handles single selections.
 *
 * @return the <code>SingleSelectionModel</code> property
 * @see SingleSelectionModel
 */
 public SingleSelectionModel getSelectionModel() {
 return selectionModel;
 }

 /**
 * Sets the model object to handle single selections.
 *
 * @param model the <code>SingleSelectionModel</code> to use
 * @see SingleSelectionModel
 * @beaninfo
 * bound: true
 * description: The selection model, recording which child is selected.
 */
 public void setSelectionModel(SingleSelectionModel model) {
 SingleSelectionModel oldValue = selectionModel;
 this.selectionModel = model;
 firePropertyChange("selectionModel", oldValue, selectionModel);
 }


 /**
 * Appends the specified menu to the end of the menu bar.
 *
 * @param c the <code>JMenu</code> component to add
 * @return the menu component
 */
 public JMenu add(JMenu c) {
 super.add(c);
 return c;
 }

 /**
 * Returns the menu at the specified position in the menu bar.
 *
 * @param index an integer giving the position in the menu bar, where
 * 0 is the first position
 * @return the <code>JMenu</code> at that position, or <code>null</code> if
 * if there is no <code>JMenu</code> at that position (ie. if
 * it is a <code>JMenuItem</code>)
 */
 public JMenu getMenu(int index) {
 Component c = getComponentAtIndex(index);
 if (c instanceof JMenu)
 return (JMenu) c;
 return null;
 }

 /**
 * Returns the number of items in the menu bar.
 *
 * @return the number of items in the menu bar
 */
 public int getMenuCount() {
 return getComponentCount();
 }

 /**
 * Sets the help menu that appears when the user selects the
 * "help" option in the menu bar. This method is not yet implemented
 * and will throw an exception.
 *
 * @param menu the JMenu that delivers help to the user
 */
 public void setHelpMenu(JMenu menu) {
 throw new Error("setHelpMenu() not yet implemented.");
 }

 /**
 * Gets the help menu for the menu bar. This method is not yet
 * implemented and will throw an exception.
 *
 * @return the <code>JMenu</code> that delivers help to the user
 */
 @Transient
 public JMenu getHelpMenu() {
 throw new Error("getHelpMenu() not yet implemented.");
 }

 /**
 * Returns the component at the specified index.
 *
 * @param i an integer specifying the position, where 0 is first
 * @return the <code>Component</code> at the position,
 * or <code>null</code> for an invalid index
 * @deprecated replaced by <code>getComponent(int i)</code>
 */
 @Deprecated
 public Component getComponentAtIndex(int i) {
 if(i < 0 || i >= getComponentCount()) {
 return null;
 }
 return getComponent(i);
 }

 /**
 * Returns the index of the specified component.
 *
 * @param c the <code>Component</code> to find
 * @return an integer giving the component's position, where 0 is first;
 * or -1 if it can't be found
 */
 public int getComponentIndex(Component c) {
 int ncomponents = this.getComponentCount();
 Component[] component = this.getComponents();
 for (int i = 0 ; i < ncomponents ; i++) {
 Component comp = component[i];
 if (comp == c)
 return i;
 }
 return -1;
 }

 /**
 * Sets the currently selected component, producing a
 * a change to the selection model.
 *
 * @param sel the <code>Component</code> to select
 */
 public void setSelected(Component sel) {
 SingleSelectionModel model = getSelectionModel();
 int index = getComponentIndex(sel);
 model.setSelectedIndex(index);
 }

 /**
 * Returns true if the menu bar currently has a component selected.
 *
 * @return true if a selection has been made, else false
 */
 public boolean isSelected() {
 return selectionModel.isSelected();
 }

 /**
 * Returns true if the menu bars border should be painted.
 *
 * @return true if the border should be painted, else false
 */
 public boolean isBorderPainted() {
 return paintBorder;
 }

 /**
 * Sets whether the border should be painted.
 *
 * @param b if true and border property is not <code>null</code>,
 * the border is painted.
 * @see #isBorderPainted
 * @beaninfo
 * bound: true
 * attribute: visualUpdate true
 * description: Whether the border should be painted.
 */
 public void setBorderPainted(boolean b) {
 boolean oldValue = paintBorder;
 paintBorder = b;
 firePropertyChange("borderPainted", oldValue, paintBorder);
 if (b != oldValue) {
 revalidate();
 repaint();
 }
 }

 /**
 * Paints the menubar's border if <code>BorderPainted</code>
 * property is true.
 *
 * @param g the <code>Graphics</code> context to use for painting
 * @see JComponent#paint
 * @see JComponent#setBorder
 */
 protected void paintBorder(Graphics g) {
 if (isBorderPainted()) {
 super.paintBorder(g);
 }
 }

 /**
 * Sets the margin between the menubar's border and
 * its menus. Setting to <code>null</code> will cause the menubar to
 * use the default margins.
 *
 * @param m an Insets object containing the margin values
 * @see Insets
 * @beaninfo
 * bound: true
 * attribute: visualUpdate true
 * description: The space between the menubar's border and its contents
 */
 public void setMargin(Insets m) {
 Insets old = margin;
 this.margin = m;
 firePropertyChange("margin", old, m);
 if (old == null || !old.equals(m)) {
 revalidate();
 repaint();
 }
 }

 /**
 * Returns the margin between the menubar's border and
 * its menus. If there is no previous margin, it will create
 * a default margin with zero size.
 *
 * @return an <code>Insets</code> object containing the margin values
 * @see Insets
 */
 public Insets getMargin() {
 if(margin == null) {
 return new Insets(0,0,0,0);
 } else {
 return margin;
 }
 }


 /**
 * Implemented to be a <code>MenuElement</code> -- does nothing.
 *
 * @see #getSubElements
 */
 public void processMouseEvent(MouseEvent event,MenuElement path[],MenuSelectionManager manager) {
 }

 /**
 * Implemented to be a <code>MenuElement</code> -- does nothing.
 *
 * @see #getSubElements
 */
 public void processKeyEvent(KeyEvent e,MenuElement path[],MenuSelectionManager manager) {
 }

 /**
 * Implemented to be a <code>MenuElement</code> -- does nothing.
 *
 * @see #getSubElements
 */
 public void menuSelectionChanged(boolean isIncluded) {
 }

 /**
 * Implemented to be a <code>MenuElement</code> -- returns the
 * menus in this menu bar.
 * This is the reason for implementing the <code>MenuElement</code>
 * interface -- so that the menu bar can be treated the same as
 * other menu elements.
 * @return an array of menu items in the menu bar.
 */
 public MenuElement[] getSubElements() {
 MenuElement result[];
 Vector<MenuElement> tmp = new Vector<MenuElement>();
 int c = getComponentCount();
 int i;
 Component m;

 for(i=0 ; i < c ; i++) {
 m = getComponent(i);
 if(m instanceof MenuElement)
 tmp.addElement((MenuElement) m);
 }

 result = new MenuElement[tmp.size()];
 for(i=0,c=tmp.size() ; i < c ; i++)
 result[i] = tmp.elementAt(i);
 return result;
 }

 /**
 * Implemented to be a <code>MenuElement</code>. Returns this object.
 *
 * @return the current <code>Component</code> (this)
 * @see #getSubElements
 */
 public Component getComponent() {
 return this;
 }


 /**
 * Returns a string representation of this <code>JMenuBar</code>.
 * This method
 * is intended to be used only for debugging purposes, and the
 * content and format of the returned string may vary between
 * implementations. The returned string may be empty but may not
 * be <code>null</code>.
 *
 * @return a string representation of this <code>JMenuBar</code>
 */
 protected String paramString() {
 String paintBorderString = (paintBorder ?
 "true" : "false");
 String marginString = (margin != null ?
 margin.toString() : "");

 return super.paramString() +
 ",margin=" + marginString +
 ",paintBorder=" + paintBorderString;
 }

/////////////////
// Accessibility support
////////////////

 /**
 * Gets the AccessibleContext associated with this JMenuBar.
 * For JMenuBars, the AccessibleContext takes the form of an
 * AccessibleJMenuBar.
 * A new AccessibleJMenuBar instance is created if necessary.
 *
 * @return an AccessibleJMenuBar that serves as the
 * AccessibleContext of this JMenuBar
 */
 public AccessibleContext getAccessibleContext() {
 if (accessibleContext == null) {
 accessibleContext = new AccessibleJMenuBar();
 }
 return accessibleContext;
 }

 /**
 * This class implements accessibility support for the
 * <code>JMenuBar</code> class. It provides an implementation of the
 * Java Accessibility API appropriate to menu bar user-interface
 * elements.
 * <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")
 protected class AccessibleJMenuBar extends AccessibleJComponent
 implements AccessibleSelection {

 /**
 * Get the accessible state set of this object.
 *
 * @return an instance of AccessibleState containing the current state
 * of the object
 */
 public AccessibleStateSet getAccessibleStateSet() {
 AccessibleStateSet states = super.getAccessibleStateSet();
 return states;
 }

 /**
 * Get the role of this object.
 *
 * @return an instance of AccessibleRole describing the role of the
 * object
 */
 public AccessibleRole getAccessibleRole() {
 return AccessibleRole.MENU_BAR;
 }

 /**
 * Get the AccessibleSelection associated with this object. In the
 * implementation of the Java Accessibility API for this class,
 * return this object, which is responsible for implementing the
 * AccessibleSelection interface on behalf of itself.
 *
 * @return this object
 */
 public AccessibleSelection getAccessibleSelection() {
 return this;
 }

 /**
 * Returns 1 if a menu is currently selected in this menu bar.
 *
 * @return 1 if a menu is currently selected, else 0
 */
 public int getAccessibleSelectionCount() {
 if (isSelected()) {
 return 1;
 } else {
 return 0;
 }
 }

 /**
 * Returns the currently selected menu if one is selected,
 * otherwise null.
 */
 public Accessible getAccessibleSelection(int i) {
 if (isSelected()) {
 if (i != 0) { // single selection model for JMenuBar
 return null;
 }
 int j = getSelectionModel().getSelectedIndex();
 if (getComponentAtIndex(j) instanceof Accessible) {
 return (Accessible) getComponentAtIndex(j);
 }
 }
 return null;
 }

 /**
 * Returns true if the current child of this object is selected.
 *
 * @param i the zero-based index of the child in this Accessible
 * object.
 * @see AccessibleContext#getAccessibleChild
 */
 public boolean isAccessibleChildSelected(int i) {
 return (i == getSelectionModel().getSelectedIndex());
 }

 /**
 * Selects the nth menu in the menu bar, forcing it to
 * pop up. If another menu is popped up, this will force
 * it to close. If the nth menu is already selected, this
 * method has no effect.
 *
 * @param i the zero-based index of selectable items
 * @see #getAccessibleStateSet
 */
 public void addAccessibleSelection(int i) {
 // first close up any open menu
 int j = getSelectionModel().getSelectedIndex();
 if (i == j) {
 return;
 }
 if (j >= 0 && j < getMenuCount()) {
 JMenu menu = getMenu(j);
 if (menu != null) {
 MenuSelectionManager.defaultManager().setSelectedPath(null);
// menu.setPopupMenuVisible(false);
 }
 }
 // now popup the new menu
 getSelectionModel().setSelectedIndex(i);
 JMenu menu = getMenu(i);
 if (menu != null) {
 MenuElement me[] = new MenuElement[3];
 me[0] = JMenuBar.this;
 me[1] = menu;
 me[2] = menu.getPopupMenu();
 MenuSelectionManager.defaultManager().setSelectedPath(me);
// menu.setPopupMenuVisible(true);
 }
 }

 /**
 * Removes the nth selected item in the object from the object's
 * selection. If the nth item isn't currently selected, this
 * method has no effect. Otherwise, it closes the popup menu.
 *
 * @param i the zero-based index of selectable items
 */
 public void removeAccessibleSelection(int i) {
 if (i >= 0 && i < getMenuCount()) {
 JMenu menu = getMenu(i);
 if (menu != null) {
 MenuSelectionManager.defaultManager().setSelectedPath(null);
// menu.setPopupMenuVisible(false);
 }
 getSelectionModel().setSelectedIndex(-1);
 }
 }

 /**
 * Clears the selection in the object, so that nothing in the
 * object is selected. This will close any open menu.
 */
 public void clearAccessibleSelection() {
 int i = getSelectionModel().getSelectedIndex();
 if (i >= 0 && i < getMenuCount()) {
 JMenu menu = getMenu(i);
 if (menu != null) {
 MenuSelectionManager.defaultManager().setSelectedPath(null);
// menu.setPopupMenuVisible(false);
 }
 }
 getSelectionModel().setSelectedIndex(-1);
 }

 /**
 * Normally causes every selected item in the object to be selected
 * if the object supports multiple selections. This method
 * makes no sense in a menu bar, and so does nothing.
 */
 public void selectAllAccessibleSelection() {
 }
 } // internal class AccessibleJMenuBar


 /**
 * Subclassed to check all the child menus.
 * @since 1.3
 */
 protected boolean processKeyBinding(KeyStroke ks, KeyEvent e,
 int condition, boolean pressed) {
 // See if we have a local binding.
 boolean retValue = super.processKeyBinding(ks, e, condition, pressed);
 if (!retValue) {
 MenuElement[] subElements = getSubElements();
 for (MenuElement subElement : subElements) {
 if (processBindingForKeyStrokeRecursive(
 subElement, ks, e, condition, pressed)) {
 return true;
 }
 }
 }
 return retValue;
 }

 static boolean processBindingForKeyStrokeRecursive(MenuElement elem,
 KeyStroke ks, KeyEvent e, int condition, boolean pressed) {
 if (elem == null) {
 return false;
 }

 Component c = elem.getComponent();

 if ( !(c.isVisible() || (c instanceof JPopupMenu)) || !c.isEnabled() ) {
 return false;
 }

 if (c != null && c instanceof JComponent &&
 ((JComponent)c).processKeyBinding(ks, e, condition, pressed)) {

 return true;
 }

 MenuElement[] subElements = elem.getSubElements();
 for (MenuElement subElement : subElements) {
 if (processBindingForKeyStrokeRecursive(subElement, ks, e, condition, pressed)) {
 return true;
 // We don't, pass along to children JMenu's
 }
 }
 return false;
 }

 /**
 * Overrides <code>JComponent.addNotify</code> to register this
 * menu bar with the current keyboard manager.
 */
 public void addNotify() {
 super.addNotify();
 KeyboardManager.getCurrentManager().registerMenuBar(this);
 }

 /**
 * Overrides <code>JComponent.removeNotify</code> to unregister this
 * menu bar with the current keyboard manager.
 */
 public void removeNotify() {
 super.removeNotify();
 KeyboardManager.getCurrentManager().unregisterMenuBar(this);
 }


 private void writeObject(ObjectOutputStream s) throws IOException {
 s.defaultWriteObject();
 if (getUIClassID().equals(uiClassID)) {
 byte count = JComponent.getWriteObjCounter(this);
 JComponent.setWriteObjCounter(this, --count);
 if (count == 0 && ui != null) {
 ui.installUI(this);
 }
 }

 Object[] kvData = new Object[4];
 int n = 0;

 if (selectionModel instanceof Serializable) {
 kvData[n++] = "selectionModel";
 kvData[n++] = selectionModel;
 }

 s.writeObject(kvData);
 }


 /**
 * See JComponent.readObject() for information about serialization
 * in Swing.
 */
 private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException
 {
 s.defaultReadObject();
 Object[] kvData = (Object[])(s.readObject());

 for(int i = 0; i < kvData.length; i += 2) {
 if (kvData[i] == null) {
 break;
 }
 else if (kvData[i].equals("selectionModel")) {
 selectionModel = (SingleSelectionModel)kvData[i + 1];
 }
 }

 }
}