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 * published by the Free Software Foundation.  Oracle designates this

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 * 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,

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 *

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package javax.swing;

import sun.swing.SwingUtilities2;

import java.awt.*;

import java.awt.event.*;

import java.beans.*;

import javax.swing.text.*;

import javax.swing.plaf.*;

import javax.swing.event.*;

import javax.accessibility.*;

import java.io.ObjectOutputStream;

import java.io.ObjectInputStream;

import java.io.IOException;

import java.io.Serializable;

/**

 * <code>JTextField</code> is a lightweight component that allows the editing

 * of a single line of text.

 * For information on and examples of using text fields,

 * see

 * <a href="http://java.sun.com/docs/books/tutorial/uiswing/components/textfield.html">How to Use Text Fields</a>

 * in <em>The Java Tutorial.</em>

 *

 * <p>

 * <code>JTextField</code> is intended to be source-compatible

 * with <code>java.awt.TextField</code> where it is reasonable to do so.  This

 * component has capabilities not found in the <code>java.awt.TextField</code>

 * class.  The superclass should be consulted for additional capabilities.

 * <p>

 * <code>JTextField</code> has a method to establish the string used as the

 * command string for the action event that gets fired.  The

 * <code>java.awt.TextField</code> used the text of the field as the command

 * string for the <code>ActionEvent</code>.

 * <code>JTextField</code> will use the command

 * string set with the <code>setActionCommand</code> method if not <code>null</code>,

 * otherwise it will use the text of the field as a compatibility with

 * <code>java.awt.TextField</code>.

 * <p>

 * The method <code>setEchoChar</code> and <code>getEchoChar</code>

 * are not provided directly to avoid a new implementation of a

 * pluggable look-and-feel inadvertently exposing password characters.

 * To provide password-like services a separate class <code>JPasswordField</code>

 * extends <code>JTextField</code> to provide this service with an independently

 * pluggable look-and-feel.

 * <p>

 * The <code>java.awt.TextField</code> could be monitored for changes by adding

 * a <code>TextListener</code> for <code>TextEvent</code>'s.

 * In the <code>JTextComponent</code> based

 * components, changes are broadcasted from the model via a

 * <code>DocumentEvent</code> to <code>DocumentListeners</code>.

 * The <code>DocumentEvent</code> gives

 * the location of the change and the kind of change if desired.

 * The code fragment might look something like:

 * <pre><code>

 *     DocumentListener myListener = ??;

 *     JTextField myArea = ??;

 *     myArea.getDocument().addDocumentListener(myListener);

 * </code></pre>

 * <p>

 * The horizontal alignment of <code>JTextField</code> can be set to be left

 * justified, leading justified, centered, right justified or trailing justified.

 * Right/trailing justification is useful if the required size

 * of the field text is smaller than the size allocated to it.

 * This is determined by the <code>setHorizontalAlignment</code>

 * and <code>getHorizontalAlignment</code> methods.  The default

 * is to be leading justified.

 * <p>

 * How the text field consumes VK_ENTER events depends

 * on whether the text field has any action listeners.

 * If so, then VK_ENTER results in the listeners

 * getting an ActionEvent,

 * and the VK_ENTER event is consumed.

 * This is compatible with how AWT text fields handle VK_ENTER events.

 * If the text field has no action listeners, then as of v 1.3 the VK_ENTER

 * event is not consumed.  Instead, the bindings of ancestor components

 * are processed, which enables the default button feature of

 * JFC/Swing to work.

 * <p>

 * Customized fields can easily be created by extending the model and

 * changing the default model provided.  For example, the following piece

 * of code will create a field that holds only upper case characters.  It

 * will work even if text is pasted into from the clipboard or it is altered via

 * programmatic changes.

 * <pre><code>

 public class UpperCaseField extends JTextField {

 

     public UpperCaseField(int cols) {

         super(cols);

     }

 

     protected Document createDefaultModel() {

         return new UpperCaseDocument();

     }

 

     static class UpperCaseDocument extends PlainDocument {

 

         public void insertString(int offs, String str, AttributeSet a)

             throws BadLocationException {

 

             if (str == null) {

                 return;

             }

             char[] upper = str.toCharArray();

&nbsp;            for (int i = 0; i < upper.length; i++) {

                 upper[i] = Character.toUpperCase(upper[i]);

             }

             super.insertString(offs, new String(upper), a);

         }

     }

 }

 * </code></pre>

 * <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<sup><font size="-2">TM</font></sup>

 * has been added to the <code>java.beans</code> package.

 * Please see {@link java.beans.XMLEncoder}.

 *

 * @beaninfo

 *   attribute: isContainer false

 * description: A component which allows for the editing of a single line of text.

 *

 * @author  Timothy Prinzing

 * @see #setActionCommand

 * @see JPasswordField

 * @see #addActionListener

 */

public class JTextField extends JTextComponent implements SwingConstants {

    /**

     * Constructs a new <code>TextField</code>.  A default model is created,

     * the initial string is <code>null</code>,

     * and the number of columns is set to 0.

     */

    public JTextField() {

        this(null, null, 0);

    }

    /**

     * Constructs a new <code>TextField</code> initialized with the

     * specified text. A default model is created and the number of

     * columns is 0.

     *

     * @param text the text to be displayed, or <code>null</code>

     */

    public JTextField(String text) {

        this(null, text, 0);

    }

    /**

     * Constructs a new empty <code>TextField</code> with the specified

     * number of columns.

     * A default model is created and the initial string is set to

     * <code>null</code>.

     *

     * @param columns  the number of columns to use to calculate

     *   the preferred width; if columns is set to zero, the

     *   preferred width will be whatever naturally results from

     *   the component implementation

     */

    public JTextField(int columns) {

        this(null, null, columns);

    }

    /**

     * Constructs a new <code>TextField</code> initialized with the

     * specified text and columns.  A default model is created.

     *

     * @param text the text to be displayed, or <code>null</code>

     * @param columns  the number of columns to use to calculate

     *   the preferred width; if columns is set to zero, the

     *   preferred width will be whatever naturally results from

     *   the component implementation

     */

    public JTextField(String text, int columns) {

        this(null, text, columns);

    }

    /**

     * Constructs a new <code>JTextField</code> that uses the given text

     * storage model and the given number of columns.

     * This is the constructor through which the other constructors feed.

     * If the document is <code>null</code>, a default model is created.

     *

     * @param doc  the text storage to use; if this is <code>null</code>,

     *          a default will be provided by calling the

     *          <code>createDefaultModel</code> method

     * @param text  the initial string to display, or <code>null</code>

     * @param columns  the number of columns to use to calculate

     *   the preferred width >= 0; if <code>columns</code>

     *   is set to zero, the preferred width will be whatever

     *   naturally results from the component implementation

     * @exception IllegalArgumentException if <code>columns</code> < 0

     */

    public JTextField(Document doc, String text, int columns) {

        if (columns < 0) {

            throw new IllegalArgumentException("columns less than zero.");

        }

        visibility = new DefaultBoundedRangeModel();

        visibility.addChangeListener(new ScrollRepainter());

        this.columns = columns;

        if (doc == null) {

            doc = createDefaultModel();

        }

        setDocument(doc);

        if (text != null) {

            setText(text);

        }

    }

    /**

     * Gets the class ID for a UI.

     *

     * @return the string "TextFieldUI"

     * @see JComponent#getUIClassID

     * @see UIDefaults#getUI

     */

    public String getUIClassID() {

        return uiClassID;

    }

    /**

     * Associates the editor with a text document.

     * The currently registered factory is used to build a view for

     * the document, which gets displayed by the editor after revalidation.

     * A PropertyChange event ("document") is propagated to each listener.

     *

     * @param doc  the document to display/edit

     * @see #getDocument

     * @beaninfo

     *  description: the text document model

     *        bound: true

     *       expert: true

     */

    public void setDocument(Document doc) {

        if (doc != null) {

            doc.putProperty("filterNewlines", Boolean.TRUE);

        }

        super.setDocument(doc);

    }

    /**

     * Calls to <code>revalidate</code> that come from within the

     * textfield itself will

     * be handled by validating the textfield, unless the textfield

     * is contained within a <code>JViewport</code>,

     * in which case this returns false.

     *

     * @return if the parent of this textfield is a <code>JViewPort</code>

     *          return false, otherwise return true

     *

     * @see JComponent#revalidate

     * @see JComponent#isValidateRoot

     * @see java.awt.Container#isValidateRoot

     */

    @Override

    public boolean isValidateRoot() {

        return !(SwingUtilities.getUnwrappedParent(this) instanceof JViewport);

    }

    /**

     * Returns the horizontal alignment of the text.

     * Valid keys are:

     * <ul>

     * <li><code>JTextField.LEFT</code>

     * <li><code>JTextField.CENTER</code>

     * <li><code>JTextField.RIGHT</code>

     * <li><code>JTextField.LEADING</code>

     * <li><code>JTextField.TRAILING</code>

     * </ul>

     *

     * @return the horizontal alignment

     */

    public int getHorizontalAlignment() {

        return horizontalAlignment;

    }

    /**

     * Sets the horizontal alignment of the text.

     * Valid keys are:

     * <ul>

     * <li><code>JTextField.LEFT</code>

     * <li><code>JTextField.CENTER</code>

     * <li><code>JTextField.RIGHT</code>

     * <li><code>JTextField.LEADING</code>

     * <li><code>JTextField.TRAILING</code>

     * </ul>

     * <code>invalidate</code> and <code>repaint</code> are called when the

     * alignment is set,

     * and a <code>PropertyChange</code> event ("horizontalAlignment") is fired.

     *

     * @param alignment the alignment

     * @exception IllegalArgumentException if <code>alignment</code>

     *  is not a valid key

     * @beaninfo

     *   preferred: true

     *       bound: true

     * description: Set the field alignment to LEFT, CENTER, RIGHT,

     *              LEADING (the default) or TRAILING

     *        enum: LEFT JTextField.LEFT CENTER JTextField.CENTER RIGHT JTextField.RIGHT

     *              LEADING JTextField.LEADING TRAILING JTextField.TRAILING

     */

     public void setHorizontalAlignment(int alignment) {

        if (alignment == horizontalAlignment) return;

        int oldValue = horizontalAlignment;

        if ((alignment == LEFT) || (alignment == CENTER) ||

            (alignment == RIGHT)|| (alignment == LEADING) ||

            (alignment == TRAILING)) {

            horizontalAlignment = alignment;

        } else {

            throw new IllegalArgumentException("horizontalAlignment");

        }

        firePropertyChange("horizontalAlignment", oldValue, horizontalAlignment);

        invalidate();

        repaint();

    }

    /**

     * Creates the default implementation of the model

     * to be used at construction if one isn't explicitly

     * given.  An instance of <code>PlainDocument</code> is returned.

     *

     * @return the default model implementation

     */

    protected Document createDefaultModel() {

        return new PlainDocument();

    }

    /**

     * Returns the number of columns in this <code>TextField</code>.

     *

     * @return the number of columns >= 0

     */

    public int getColumns() {

        return columns;

    }

    /**

     * Sets the number of columns in this <code>TextField</code>,

     * and then invalidate the layout.

     *

     * @param columns the number of columns >= 0

     * @exception IllegalArgumentException if <code>columns</code>

     *          is less than 0

     * @beaninfo

     * description: the number of columns preferred for display

     */

    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 the column width.

     * The meaning of what a column is can be considered a fairly weak

     * notion for some fonts.  This method is used to define the width

     * of a column.  By default this is defined to be the width of the

     * character <em>m</em> for the font used.  This method can be

     * redefined to be some alternative amount

     *

     * @return the column width >= 1

     */

    protected int getColumnWidth() {

        if (columnWidth == 0) {

            FontMetrics metrics = getFontMetrics(getFont());

            columnWidth = metrics.charWidth('m');

        }

        return columnWidth;

    }

    /**

     * Returns the preferred size <code>Dimensions</code> needed for this

     * <code>TextField</code>.  If a non-zero number of columns has been

     * set, the width is set to the columns multiplied by

     * the column width.

     *

     * @return the dimension of this textfield

     */

    public Dimension getPreferredSize() {

        Dimension size = super.getPreferredSize();

        if (columns != 0) {

            Insets insets = getInsets();

            size.width = columns * getColumnWidth() +

                insets.left + insets.right;

        }

        return size;

    }

    /**

     * Sets the current font.  This removes cached row height and column

     * width so the new font will be reflected.

     * <code>revalidate</code> is called after setting the font.

     *

     * @param f the new font

     */

    public void setFont(Font f) {

        super.setFont(f);

        columnWidth = 0;

    }

    /**

     * Adds the specified action listener to receive

     * action events from this textfield.

     *

     * @param l the action listener to be added

     */

    public synchronized void addActionListener(ActionListener l) {

        listenerList.add(ActionListener.class, l);

    }

    /**

     * Removes the specified action listener so that it no longer

     * receives action events from this textfield.

     *

     * @param l the action listener to be removed

     */

    public synchronized void removeActionListener(ActionListener l) {

        if ((l != null) && (getAction() == l)) {

            setAction(null);

        } else {

            listenerList.remove(ActionListener.class, l);

        }

    }

    /**

     * Returns an array of all the <code>ActionListener</code>s added

     * to this JTextField with addActionListener().

     *

     * @return all of the <code>ActionListener</code>s added or an empty

     *         array if no listeners have been added

     * @since 1.4

     */

    public synchronized ActionListener[] getActionListeners() {

        return listenerList.getListeners(ActionListener.class);

    }

    /**

     * Notifies all listeners that have registered interest for

     * notification on this event type.  The event instance

     * is lazily created.

     * The listener list is processed in last to

     * first order.

     * @see EventListenerList

     */

    protected void fireActionPerformed() {

        // Guaranteed to return a non-null array

        Object[] listeners = listenerList.getListenerList();

        int modifiers = 0;

        AWTEvent currentEvent = EventQueue.getCurrentEvent();

        if (currentEvent instanceof InputEvent) {

            modifiers = ((InputEvent)currentEvent).getModifiers();

        } else if (currentEvent instanceof ActionEvent) {

            modifiers = ((ActionEvent)currentEvent).getModifiers();

        }

        ActionEvent e =

            new ActionEvent(this, ActionEvent.ACTION_PERFORMED,

                            (command != null) ? command : getText(),

                            EventQueue.getMostRecentEventTime(), modifiers);

        // Process the listeners last to first, notifying

        // those that are interested in this event

        for (int i = listeners.length-2; i>=0; i-=2) {

            if (listeners[i]==ActionListener.class) {

                ((ActionListener)listeners[i+1]).actionPerformed(e);

            }

        }

    }

    /**

     * Sets the command string used for action events.

     *

     * @param command the command string

     */

    public void setActionCommand(String command) {

        this.command = command;

    }

    private Action action;

    private PropertyChangeListener actionPropertyChangeListener;

    /**

     * Sets the <code>Action</code> for the <code>ActionEvent</code> source.