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 * 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle 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.
 *
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package javax.swing.text.html;

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import javax.swing.text.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.*;
import java.util.*;

HiddenTagView subclasses EditableView to contain a JTextField showing
the element name. When the textfield is edited the element name is
reset. As this inherits from EditableView if the JTextComponent is
not editable, the textfield will not be visible.
Author:
 Scott Violet/**
 * HiddenTagView subclasses EditableView to contain a JTextField showing
 * the element name. When the textfield is edited the element name is
 * reset. As this inherits from EditableView if the JTextComponent is
 * not editable, the textfield will not be visible.
 *
 * @author  Scott Violet
 */
class HiddenTagView extends EditableView implements DocumentListener {
    HiddenTagView(Element e) {
        super(e);
        yAlign = 1;
    }

    protected Component createComponent() {
        JTextField tf = new JTextField(getElement().getName());
        Document doc = getDocument();
        Font font;
        if (doc instanceof StyledDocument) {
            font = ((StyledDocument)doc).getFont(getAttributes());
            tf.setFont(font);
        }
        else {
            font = tf.getFont();
        }
        tf.getDocument().addDocumentListener(this);
        updateYAlign(font);

        // Create a panel to wrap the textfield so that the textfields
        // laf border shows through.
        JPanel panel = new JPanel(new BorderLayout());
        panel.setBackground(null);
        if (isEndTag()) {
            panel.setBorder(EndBorder);
        }
        else {
            panel.setBorder(StartBorder);
        }
        panel.add(tf);
        return panel;
    }

    public float getAlignment(int axis) {
        if (axis == View.Y_AXIS) {
            return yAlign;
        }
        return 0.5f;
    }

    public float getMinimumSpan(int axis) {
        if (axis == View.X_AXIS && isVisible()) {
            // Default to preferred.
            return Math.max(30, super.getPreferredSpan(axis));
        }
        return super.getMinimumSpan(axis);
    }

    public float getPreferredSpan(int axis) {
        if (axis == View.X_AXIS && isVisible()) {
            return Math.max(30, super.getPreferredSpan(axis));
        }
        return super.getPreferredSpan(axis);
    }

    public float getMaximumSpan(int axis) {
        if (axis == View.X_AXIS && isVisible()) {
            // Default to preferred.
            return Math.max(30, super.getMaximumSpan(axis));
        }
        return super.getMaximumSpan(axis);
    }

    // DocumentListener methods
    public void insertUpdate(DocumentEvent e) {
        updateModelFromText();
    }

    public void removeUpdate(DocumentEvent e) {
        updateModelFromText();
    }

    public void changedUpdate(DocumentEvent e) {
        updateModelFromText();
    }

    // View method
    public void changedUpdate(DocumentEvent e, Shape a, ViewFactory f) {
        if (!isSettingAttributes) {
            setTextFromModel();
        }
    }

    // local methods

    @SuppressWarnings("deprecation")
    void updateYAlign(Font font) {
        Container c = getContainer();
        FontMetrics fm = (c != null) ? c.getFontMetrics(font) :
            Toolkit.getDefaultToolkit().getFontMetrics(font);
        float h = fm.getHeight();
        float d = fm.getDescent();
        yAlign = (h > 0) ? (h - d) / h : 0;
    }

    void resetBorder() {
        Component comp = getComponent();

        if (comp != null) {
            if (isEndTag()) {
                ((JPanel)comp).setBorder(EndBorder);
            }
            else {
                ((JPanel)comp).setBorder(StartBorder);
            }
        }
    }

    
This resets the text on the text component we created to match
that of the AttributeSet for the Element we represent.
If this is invoked on the event dispatching thread, this
directly invokes _setTextFromModel, otherwise
SwingUtilities.invokeLater is used to schedule execution
of _setTextFromModel.
/**
     * This resets the text on the text component we created to match
     * that of the AttributeSet for the Element we represent.
     * <p>If this is invoked on the event dispatching thread, this
     * directly invokes <code>_setTextFromModel</code>, otherwise
     * <code>SwingUtilities.invokeLater</code> is used to schedule execution
     * of <code>_setTextFromModel</code>.
     */
    void setTextFromModel() {
        if (SwingUtilities.isEventDispatchThread()) {
            _setTextFromModel();
        }
        else {
            SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    _setTextFromModel();
                }
            });
        }
    }

    
This resets the text on the text component we created to match
that of the AttributeSet for the Element we represent.
/**
     * This resets the text on the text component we created to match
     * that of the AttributeSet for the Element we represent.
     */
    void _setTextFromModel() {
        Document doc = getDocument();
        try {
            isSettingAttributes = true;
            if (doc instanceof AbstractDocument) {
                ((AbstractDocument)doc).readLock();
            }
            JTextComponent text = getTextComponent();
            if (text != null) {
                text.setText(getRepresentedText());
                resetBorder();
                Container host = getContainer();
                if (host != null) {
                    preferenceChanged(this, true, true);
                    host.repaint();
                }
            }
        }
        finally {
            isSettingAttributes = false;
            if (doc instanceof AbstractDocument) {
                ((AbstractDocument)doc).readUnlock();
            }
        }
    }

    
This copies the text from the text component we've created
to the Element's AttributeSet we represent.
If this is invoked on the event dispatching thread, this
directly invokes _updateModelFromText, otherwise
SwingUtilities.invokeLater is used to schedule execution
of _updateModelFromText.
/**
     * This copies the text from the text component we've created
     * to the Element's AttributeSet we represent.
     * <p>If this is invoked on the event dispatching thread, this
     * directly invokes <code>_updateModelFromText</code>, otherwise
     * <code>SwingUtilities.invokeLater</code> is used to schedule execution
     * of <code>_updateModelFromText</code>.
     */
    void updateModelFromText() {
        if (!isSettingAttributes) {
            if (SwingUtilities.isEventDispatchThread()) {
                _updateModelFromText();
            }
            else {
                SwingUtilities.invokeLater(new Runnable() {
                    public void run() {
                        _updateModelFromText();
                    }
                });
            }
        }
    }

    
This copies the text from the text component we've created
to the Element's AttributeSet we represent.
/**
     * This copies the text from the text component we've created
     * to the Element's AttributeSet we represent.
     */
    void _updateModelFromText() {
        Document doc = getDocument();
        Object name = getElement().getAttributes().getAttribute
            (StyleConstants.NameAttribute);
        if ((name instanceof HTML.UnknownTag) &&
            (doc instanceof StyledDocument)) {
            SimpleAttributeSet sas = new SimpleAttributeSet();
            JTextComponent textComponent = getTextComponent();
            if (textComponent != null) {
                String text = textComponent.getText();
                isSettingAttributes = true;
                try {
                    sas.addAttribute(StyleConstants.NameAttribute,
                                     new HTML.UnknownTag(text));
                    ((StyledDocument)doc).setCharacterAttributes
                        (getStartOffset(), getEndOffset() -
                         getStartOffset(), sas, false);
                }
                finally {
                    isSettingAttributes = false;
                }
            }
        }
    }

    JTextComponent getTextComponent() {
        Component comp = getComponent();

        return (comp == null) ? null : (JTextComponent)((Container)comp).
                                       getComponent(0);
    }

    String getRepresentedText() {
        String retValue = getElement().getName();
        return (retValue == null) ? "" : retValue;
    }

    boolean isEndTag() {
        AttributeSet as = getElement().getAttributes();
        if (as != null) {
            Object end = as.getAttribute(HTML.Attribute.ENDTAG);
            if (end != null && (end instanceof String) &&
                ((String)end).equals("true")) {
                return true;
            }
        }
        return false;
    }

    
Alignment along the y axis, based on the font of the textfield. /** Alignment along the y axis, based on the font of the textfield. */
    float yAlign;
    
Set to true when setting attributes. /** Set to true when setting attributes. */
    boolean isSettingAttributes;


    // Following are for Borders that used for Unknown tags and comments.
    //
    // Border defines
    static final int circleR = 3;
    static final int circleD = circleR * 2;
    static final int tagSize = 6;
    static final int padding = 3;
    static final Color UnknownTagBorderColor = Color.black;
    static final Border StartBorder = new StartTagBorder();
    static final Border EndBorder = new EndTagBorder();

    @SuppressWarnings("serial") // Same-version serialization only
    static class StartTagBorder implements Border, Serializable {
        public void paintBorder(Component c, Graphics g, int x, int y,
                                int width, int height) {
            g.setColor(UnknownTagBorderColor);
            x += padding;
            width -= (padding * 2);
            g.drawLine(x, y + circleR,
                       x, y + height - circleR);
            g.drawArc(x, y + height - circleD - 1,
                      circleD, circleD, 180, 90);
            g.drawArc(x, y, circleD, circleD, 90, 90);
            g.drawLine(x + circleR, y, x + width - tagSize, y);
            g.drawLine(x + circleR, y + height - 1,
                       x + width - tagSize, y + height - 1);

            g.drawLine(x + width - tagSize, y,
                       x + width - 1, y + height / 2);
            g.drawLine(x + width - tagSize, y + height,
                       x + width - 1, y + height / 2);
        }

        public Insets getBorderInsets(Component c) {
            return new Insets(2, 2 + padding, 2, tagSize + 2 + padding);
        }

        public boolean isBorderOpaque() {
            return false;
        }
    } // End of class HiddenTagView.StartTagBorder

    @SuppressWarnings("serial") // Same-version serialization only
    static class EndTagBorder implements Border, Serializable {
        public void paintBorder(Component c, Graphics g, int x, int y,
                                int width, int height) {
            g.setColor(UnknownTagBorderColor);
            x += padding;
            width -= (padding * 2);
            g.drawLine(x + width - 1, y + circleR,
                       x + width - 1, y + height - circleR);
            g.drawArc(x + width - circleD - 1, y + height - circleD - 1,
                      circleD, circleD, 270, 90);
            g.drawArc(x + width - circleD - 1, y, circleD, circleD, 0, 90);
            g.drawLine(x + tagSize, y, x + width - circleR, y);
            g.drawLine(x + tagSize, y + height - 1,
                       x + width - circleR, y + height - 1);

            g.drawLine(x + tagSize, y,
                       x, y + height / 2);
            g.drawLine(x + tagSize, y + height,
                       x, y + height / 2);
        }

        public Insets getBorderInsets(Component c) {
            return new Insets(2, tagSize + 2 + padding, 2, 2 + padding);
        }

        public boolean isBorderOpaque() {
            return false;
        }
    } // End of class HiddenTagView.EndTagBorder


} // End of HiddenTagView