/*
 * Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 *
 */
package java.awt;

import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import java.awt.peer.TextAreaPeer;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;
import javax.accessibility.*;

/**
 * A <code>TextArea</code> object is a multi-line region
 * that displays text. It can be set to allow editing or
 * to be read-only.
 * <p>
 * The following image shows the appearance of a text area:
 * <p>
 * <img src="doc-files/TextArea-1.gif" alt="A TextArea showing the word 'Hello!'"
 * style="float:center; margin: 7px 10px;">
 * <p>
 * This text area could be created by the following line of code:
 *
 * <hr><blockquote><pre>
 * new TextArea("Hello", 5, 40);
 * </pre></blockquote><hr>
 * <p>
 * @author Sami Shaio
 * @since JDK1.0
 */
public class TextArea extends TextComponent {

 /**
 * The number of rows in the <code>TextArea</code>.
 * This parameter will determine the text area's height.
 * Guaranteed to be non-negative.
 *
 * @serial
 * @see #getRows()
 * @see #setRows(int)
 */
 int rows;

 /**
 * The number of columns in the <code>TextArea</code>.
 * A column is an approximate average character
 * width that is platform-dependent.
 * This parameter will determine the text area's width.
 * Guaranteed to be non-negative.
 *
 * @serial
 * @see #setColumns(int)
 * @see #getColumns()
 */
 int columns;

 private static final String base = "text";
 private static int nameCounter = 0;

 /**
 * Create and display both vertical and horizontal scrollbars.
 * @since JDK1.1
 */
 public static final int SCROLLBARS_BOTH = 0;

 /**
 * Create and display vertical scrollbar only.
 * @since JDK1.1
 */
 public static final int SCROLLBARS_VERTICAL_ONLY = 1;

 /**
 * Create and display horizontal scrollbar only.
 * @since JDK1.1
 */
 public static final int SCROLLBARS_HORIZONTAL_ONLY = 2;

 /**
 * Do not create or display any scrollbars for the text area.
 * @since JDK1.1
 */
 public static final int SCROLLBARS_NONE = 3;

 /**
 * Determines which scrollbars are created for the
 * text area. It can be one of four values :
 * <code>SCROLLBARS_BOTH</code> = both scrollbars.<BR>
 * <code>SCROLLBARS_HORIZONTAL_ONLY</code> = Horizontal bar only.<BR>
 * <code>SCROLLBARS_VERTICAL_ONLY</code> = Vertical bar only.<BR>
 * <code>SCROLLBARS_NONE</code> = No scrollbars.<BR>
 *
 * @serial
 * @see #getScrollbarVisibility()
 */
 private int scrollbarVisibility;

 /**
 * Cache the Sets of forward and backward traversal keys so we need not
 * look them up each time.
 */
 private static Set<AWTKeyStroke> forwardTraversalKeys, backwardTraversalKeys;

 /*
 * JDK 1.1 serialVersionUID
 */
 private static final long serialVersionUID = 3692302836626095722L;

 /**
 * Initialize JNI field and method ids
 */
 private static native void initIDs();

 static {
 /* ensure that the necessary native libraries are loaded */
 Toolkit.loadLibraries();
 if (!GraphicsEnvironment.isHeadless()) {
 initIDs();
 }
 forwardTraversalKeys = KeyboardFocusManager.initFocusTraversalKeysSet(
 "ctrl TAB",
 new HashSet<AWTKeyStroke>());
 backwardTraversalKeys = KeyboardFocusManager.initFocusTraversalKeysSet(
 "ctrl shift TAB",
 new HashSet<AWTKeyStroke>());
 }

 /**
 * Constructs a new text area with the empty string as text.
 * This text area is created with scrollbar visibility equal to
 * {@link #SCROLLBARS_BOTH}, so both vertical and horizontal
 * scrollbars will be visible for this text area.
 * @exception HeadlessException if
 * <code>GraphicsEnvironment.isHeadless</code> returns true
 * @see java.awt.GraphicsEnvironment#isHeadless()
 */
 public TextArea() throws HeadlessException {
 this("", 0, 0, SCROLLBARS_BOTH);
 }

 /**
 * Constructs a new text area with the specified text.
 * This text area is created with scrollbar visibility equal to
 * {@link #SCROLLBARS_BOTH}, so both vertical and horizontal
 * scrollbars will be visible for this text area.
 * @param text the text to be displayed; if
 * <code>text</code> is <code>null</code>, the empty
 * string <code>""</code> will be displayed
 * @exception HeadlessException if
 * <code>GraphicsEnvironment.isHeadless</code> returns true
 * @see java.awt.GraphicsEnvironment#isHeadless()
 */
 public TextArea(String text) throws HeadlessException {
 this(text, 0, 0, SCROLLBARS_BOTH);
 }

 /**
 * Constructs a new text area with the specified number of
 * rows and columns and the empty string as text.
 * A column is an approximate average character
 * width that is platform-dependent. The text area is created with
 * scrollbar visibility equal to {@link #SCROLLBARS_BOTH}, so both
 * vertical and horizontal scrollbars will be visible for this
 * text area.
 * @param rows the number of rows
 * @param columns the number of columns
 * @exception HeadlessException if
 * <code>GraphicsEnvironment.isHeadless</code> returns true
 * @see java.awt.GraphicsEnvironment#isHeadless()
 */
 public TextArea(int rows, int columns) throws HeadlessException {
 this("", rows, columns, SCROLLBARS_BOTH);
 }

 /**
 * Constructs a new text area with the specified text,
 * and with the specified number of rows and columns.
 * A column is an approximate average character
 * width that is platform-dependent. The text area is created with
 * scrollbar visibility equal to {@link #SCROLLBARS_BOTH}, so both
 * vertical and horizontal scrollbars will be visible for this
 * text area.
 * @param text the text to be displayed; if
 * <code>text</code> is <code>null</code>, the empty
 * string <code>""</code> will be displayed
 * @param rows the number of rows
 * @param columns the number of columns
 * @exception HeadlessException if
 * <code>GraphicsEnvironment.isHeadless</code> returns true
 * @see java.awt.GraphicsEnvironment#isHeadless()
 */
 public TextArea(String text, int rows, int columns)
 throws HeadlessException {
 this(text, rows, columns, SCROLLBARS_BOTH);
 }

 /**
 * Constructs a new text area with the specified text,
 * and with the rows, columns, and scroll bar visibility
 * as specified. All <code>TextArea</code> constructors defer to
 * this one.
 * <p>
 * The <code>TextArea</code> class defines several constants
 * that can be supplied as values for the
 * <code>scrollbars</code> argument:
 * <ul>
 * <li><code>SCROLLBARS_BOTH</code>,
 * <li><code>SCROLLBARS_VERTICAL_ONLY</code>,
 * <li><code>SCROLLBARS_HORIZONTAL_ONLY</code>,
 * <li><code>SCROLLBARS_NONE</code>.
 * </ul>
 * Any other value for the
 * <code>scrollbars</code> argument is invalid and will result in
 * this text area being created with scrollbar visibility equal to
 * the default value of {@link #SCROLLBARS_BOTH}.
 * @param text the text to be displayed; if
 * <code>text</code> is <code>null</code>, the empty
 * string <code>""</code> will be displayed
 * @param rows the number of rows; if
 * <code>rows</code> is less than <code>0</code>,
 * <code>rows</code> is set to <code>0</code>
 * @param columns the number of columns; if
 * <code>columns</code> is less than <code>0</code>,
 * <code>columns</code> is set to <code>0</code>
 * @param scrollbars a constant that determines what
 * scrollbars are created to view the text area
 * @since JDK1.1
 * @exception HeadlessException if
 * <code>GraphicsEnvironment.isHeadless</code> returns true
 * @see java.awt.GraphicsEnvironment#isHeadless()
 */
 public TextArea(String text, int rows, int columns, int scrollbars)
 throws HeadlessException {
 super(text);

 this.rows = (rows >= 0) ? rows : 0;
 this.columns = (columns >= 0) ? columns : 0;

 if (scrollbars >= SCROLLBARS_BOTH && scrollbars <= SCROLLBARS_NONE) {
 this.scrollbarVisibility = scrollbars;
 } else {
 this.scrollbarVisibility = SCROLLBARS_BOTH;
 }

 setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
 forwardTraversalKeys);
 setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
 backwardTraversalKeys);
 }

 /**
 * Construct a name for this component. Called by <code>getName</code>
 * when the name is <code>null</code>.
 */
 String constructComponentName() {
 synchronized (TextArea.class) {
 return base + nameCounter++;
 }
 }

 /**
 * Creates the <code>TextArea</code>'s peer. The peer allows us to modify
 * the appearance of the <code>TextArea</code> without changing any of its
 * functionality.
 */
 public void addNotify() {
 synchronized (getTreeLock()) {
 if (peer == null)
 peer = getToolkit().createTextArea(this);
 super.addNotify();
 }
 }

 /**
 * Inserts the specified text at the specified position
 * in this text area.
 * <p>Note that passing <code>null</code> or inconsistent
 * parameters is invalid and will result in unspecified
 * behavior.
 *
 * @param str the non-<code>null</code> text to insert
 * @param pos the position at which to insert
 * @see java.awt.TextComponent#setText
 * @see java.awt.TextArea#replaceRange
 * @see java.awt.TextArea#append
 * @since JDK1.1
 */
 public void insert(String str, int pos) {
 insertText(str, pos);
 }

 /**
 * @deprecated As of JDK version 1.1,
 * replaced by <code>insert(String, int)</code>.
 */
 @Deprecated
 public synchronized void insertText(String str, int pos) {
 TextAreaPeer peer = (TextAreaPeer)this.peer;
 if (peer != null) {
 peer.insert(str, pos);
 }
 text = text.substring(0, pos) + str + text.substring(pos);
 }

 /**
 * Appends the given text to the text area's current text.
 * <p>Note that passing <code>null</code> or inconsistent
 * parameters is invalid and will result in unspecified
 * behavior.
 *
 * @param str the non-<code>null</code> text to append
 * @see java.awt.TextArea#insert
 * @since JDK1.1
 */
 public void append(String str) {
 appendText(str);
 }

 /**
 * @deprecated As of JDK version 1.1,
 * replaced by <code>append(String)</code>.
 */
 @Deprecated
 public synchronized void appendText(String str) {
 insertText(str, getText().length());
 }

 /**
 * Replaces text between the indicated start and end positions
 * with the specified replacement text. The text at the end
 * position will not be replaced. The text at the start
 * position will be replaced (unless the start position is the
 * same as the end position).
 * The text position is zero-based. The inserted substring may be
 * of a different length than the text it replaces.
 * <p>Note that passing <code>null</code> or inconsistent
 * parameters is invalid and will result in unspecified
 * behavior.
 *
 * @param str the non-<code>null</code> text to use as
 * the replacement
 * @param start the start position
 * @param end the end position
 * @see java.awt.TextArea#insert
 * @since JDK1.1
 */
 public void replaceRange(String str, int start, int end) {
 replaceText(str, start, end);
 }

 /**
 * @deprecated As of JDK version 1.1,
 * replaced by <code>replaceRange(String, int, int)</code>.
 */
 @Deprecated
 public synchronized void replaceText(String str, int start, int end) {
 TextAreaPeer peer = (TextAreaPeer)this.peer;
 if (peer != null) {
 peer.replaceRange(str, start, end);
 }
 text = text.substring(0, start) + str + text.substring(end);
 }

 /**
 * Returns the number of rows in the text area.
 * @return the number of rows in the text area
 * @see #setRows(int)
 * @see #getColumns()
 * @since JDK1
 */
 public int getRows() {
 return rows;
 }

 /**
 * Sets the number of rows for this text area.
 * @param rows the number of rows
 * @see #getRows()
 * @see #setColumns(int)
 * @exception IllegalArgumentException if the value
 * supplied for <code>rows</code>
 * is less than <code>0</code>
 * @since JDK1.1
 */
 public void setRows(int rows) {
 int oldVal = this.rows;
 if (rows < 0) {
 throw new IllegalArgumentException("rows less than zero.");
 }
 if (rows != oldVal) {
 this.rows = rows;
 invalidate();
 }
 }

 /**
 * Returns the number of columns in this text area.
 * @return the number of columns in the text area
 * @see #setColumns(int)
 * @see #getRows()
 */
 public int getColumns() {
 return columns;
 }

 /**
 * Sets the number of columns for this text area.
 * @param columns the number of columns
 * @see #getColumns()
 * @see #setRows(int)
 * @exception IllegalArgumentException if the value
 * supplied for <code>columns</code>
 * is less than <code>0</code>
 * @since JDK1.1
 */
 public void setColumns(int columns) {
 int oldVal = this.columns;
 if (columns < 0) {
 throw new IllegalArgumentException("columns less than zero.");
 }
 if (columns != oldVal) {
 this.columns = columns;
 invalidate();
 }
 }

 /**
 * Returns an enumerated value that indicates which scroll bars
 * the text area uses.
 * <p>
 * The <code>TextArea</code> class defines four integer constants
 * that are used to specify which scroll bars are available.
 * <code>TextArea</code> has one constructor that gives the
 * application discretion over scroll bars.
 *
 * @return an integer that indicates which scroll bars are used
 * @see java.awt.TextArea#SCROLLBARS_BOTH
 * @see java.awt.TextArea#SCROLLBARS_VERTICAL_ONLY
 * @see java.awt.TextArea#SCROLLBARS_HORIZONTAL_ONLY
 * @see java.awt.TextArea#SCROLLBARS_NONE
 * @see java.awt.TextArea#TextArea(java.lang.String, int, int, int)
 * @since JDK1.1
 */
 public int getScrollbarVisibility() {
 return scrollbarVisibility;
 }


 /**
 * Determines the preferred size of a text area with the specified
 * number of rows and columns.
 * @param rows the number of rows
 * @param columns the number of columns
 * @return the preferred dimensions required to display
 * the text area with the specified
 * number of rows and columns
 * @see java.awt.Component#getPreferredSize
 * @since JDK1.1
 */
 public Dimension getPreferredSize(int rows, int columns) {
 return preferredSize(rows, columns);
 }

 /**
 * @deprecated As of JDK version 1.1,
 * replaced by <code>getPreferredSize(int, int)</code>.
 */
 @Deprecated
 public Dimension preferredSize(int rows, int columns) {
 synchronized (getTreeLock()) {
 TextAreaPeer peer = (TextAreaPeer)this.peer;
 return (peer != null) ?
 peer.getPreferredSize(rows, columns) :
 super.preferredSize();
 }
 }

 /**
 * Determines the preferred size of this text area.
 * @return the preferred dimensions needed for this text area
 * @see java.awt.Component#getPreferredSize
 * @since JDK1.1
 */
 public Dimension getPreferredSize() {
 return preferredSize();
 }

 /**
 * @deprecated As of JDK version 1.1,
 * replaced by <code>getPreferredSize()</code>.
 */
 @Deprecated
 public Dimension preferredSize() {
 synchronized (getTreeLock()) {
 return ((rows > 0) && (columns > 0)) ?
 preferredSize(rows, columns) :
 super.preferredSize();
 }
 }

 /**
 * Determines the minimum size of a text area with the specified
 * number of rows and columns.
 * @param rows the number of rows
 * @param columns the number of columns
 * @return the minimum dimensions required to display
 * the text area with the specified
 * number of rows and columns
 * @see java.awt.Component#getMinimumSize
 * @since JDK1.1
 */
 public Dimension getMinimumSize(int rows, int columns) {
 return minimumSize(rows, columns);
 }

 /**
 * @deprecated As of JDK version 1.1,
 * replaced by <code>getMinimumSize(int, int)</code>.
 */
 @Deprecated
 public Dimension minimumSize(int rows, int columns) {
 synchronized (getTreeLock()) {
 TextAreaPeer peer = (TextAreaPeer)this.peer;
 return (peer != null) ?
 peer.getMinimumSize(rows, columns) :
 super.minimumSize();
 }
 }

 /**
 * Determines the minimum size of this text area.
 * @return the preferred dimensions needed for this text area
 * @see java.awt.Component#getPreferredSize
 * @since JDK1.1
 */
 public Dimension getMinimumSize() {
 return minimumSize();
 }

 /**
 * @deprecated As of JDK version 1.1,
 * replaced by <code>getMinimumSize()</code>.
 */
 @Deprecated
 public Dimension minimumSize() {
 synchronized (getTreeLock()) {
 return ((rows > 0) && (columns > 0)) ?
 minimumSize(rows, columns) :
 super.minimumSize();
 }
 }

 /**
 * Returns a string representing the state of this <code>TextArea</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 the parameter string of this text area
 */
 protected String paramString() {
 String sbVisStr;
 switch (scrollbarVisibility) {
 case SCROLLBARS_BOTH:
 sbVisStr = "both";
 break;
 case SCROLLBARS_VERTICAL_ONLY:
 sbVisStr = "vertical-only";
 break;
 case SCROLLBARS_HORIZONTAL_ONLY:
 sbVisStr = "horizontal-only";
 break;
 case SCROLLBARS_NONE:
 sbVisStr = "none";
 break;
 default:
 sbVisStr = "invalid display policy";
 }

 return super.paramString() + ",rows=" + rows +
 ",columns=" + columns +
 ",scrollbarVisibility=" + sbVisStr;
 }


 /*
 * Serialization support.
 */
 /**
 * The textArea Serialized Data Version.
 *
 * @serial
 */
 private int textAreaSerializedDataVersion = 2;

 /**
 * Read the ObjectInputStream.
 * @exception HeadlessException if
 * <code>GraphicsEnvironment.isHeadless()</code> returns
 * <code>true</code>
 * @see java.awt.GraphicsEnvironment#isHeadless
 */
 private void readObject(ObjectInputStream s)
 throws ClassNotFoundException, IOException, HeadlessException
 {
 // HeadlessException will be thrown by TextComponent's readObject
 s.defaultReadObject();

 // Make sure the state we just read in for columns, rows,
 // and scrollbarVisibility has legal values
 if (columns < 0) {
 columns = 0;
 }
 if (rows < 0) {
 rows = 0;
 }

 if ((scrollbarVisibility < SCROLLBARS_BOTH) ||
 (scrollbarVisibility > SCROLLBARS_NONE)) {
 this.scrollbarVisibility = SCROLLBARS_BOTH;
 }

 if (textAreaSerializedDataVersion < 2) {
 setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
 forwardTraversalKeys);
 setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
 backwardTraversalKeys);
 }
 }


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


 /**
 * Returns the <code>AccessibleContext</code> associated with
 * this <code>TextArea</code>. For text areas, the
 * <code>AccessibleContext</code> takes the form of an
 * <code>AccessibleAWTTextArea</code>.
 * A new <code>AccessibleAWTTextArea</code> instance is created if necessary.
 *
 * @return an <code>AccessibleAWTTextArea</code> that serves as the
 * <code>AccessibleContext</code> of this <code>TextArea</code>
 * @since 1.3
 */
 public AccessibleContext getAccessibleContext() {
 if (accessibleContext == null) {
 accessibleContext = new AccessibleAWTTextArea();
 }
 return accessibleContext;
 }

 /**
 * This class implements accessibility support for the
 * <code>TextArea</code> class. It provides an implementation of the
 * Java Accessibility API appropriate to text area user-interface elements.
 * @since 1.3
 */
 protected class AccessibleAWTTextArea extends AccessibleAWTTextComponent
 {
 /*
 * JDK 1.3 serialVersionUID
 */
 private static final long serialVersionUID = 3472827823632144419L;

 /**
 * Gets the state set of this object.
 *
 * @return an instance of AccessibleStateSet describing the states
 * of the object
 * @see AccessibleStateSet
 */
 public AccessibleStateSet getAccessibleStateSet() {
 AccessibleStateSet states = super.getAccessibleStateSet();
 states.add(AccessibleState.MULTI_LINE);
 return states;
 }
 }


}