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	/*
	* Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.
	* 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.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package javax.swing.text;

	import java.awt.*;
	import javax.swing.event.*;

	/**
	* A <code>LabelView</code> is a styled chunk of text
	* that represents a view mapped over an element in the
	* text model. It caches the character level attributes
	* used for rendering.
	*
	* @author Timothy Prinzing
	*/
	public class LabelView extends GlyphView implements TabableView {

	/**
	* Constructs a new view wrapped on an element.
	*
	* @param elem the element
	*/
	public LabelView(Element elem) {
	super(elem);
	}

	/**
	* Synchronize the view's cached values with the model.
	* This causes the font, metrics, color, etc to be
	* re-cached if the cache has been invalidated.
	*/
	final void sync() {
	if (font == null) {
	setPropertiesFromAttributes();
	}
	}

	/**
	* Sets whether or not the view is underlined.
	* Note that this setter is protected and is really
	* only meant if you need to update some additional
	* state when set.
	*
	* @param u true if the view is underlined, otherwise
	* false
	* @see #isUnderline
	*/
	protected void setUnderline(boolean u) {
	underline = u;
	}

	/**
	* Sets whether or not the view has a strike/line
	* through it.
	* Note that this setter is protected and is really
	* only meant if you need to update some additional
	* state when set.
	*
	* @param s true if the view has a strike/line
	* through it, otherwise false
	* @see #isStrikeThrough
	*/
	protected void setStrikeThrough(boolean s) {
	strike = s;
	}


	/**
	* Sets whether or not the view represents a
	* superscript.
	* Note that this setter is protected and is really
	* only meant if you need to update some additional
	* state when set.
	*
	* @param s true if the view represents a
	* superscript, otherwise false
	* @see #isSuperscript
	*/
	protected void setSuperscript(boolean s) {
	superscript = s;
	}

	/**
	* Sets whether or not the view represents a
	* subscript.
	* Note that this setter is protected and is really
	* only meant if you need to update some additional
	* state when set.
	*
	* @param s true if the view represents a
	* subscript, otherwise false
	* @see #isSubscript
	*/
	protected void setSubscript(boolean s) {
	subscript = s;
	}

	/**
	* Sets the background color for the view. This method is typically
	* invoked as part of configuring this <code>View</code>. If you need
	* to customize the background color you should override
	* <code>setPropertiesFromAttributes</code> and invoke this method. A
	* value of null indicates no background should be rendered, so that the
	* background of the parent <code>View</code> will show through.
	*
	* @param bg background color, or null
	* @see #setPropertiesFromAttributes
	* @since 1.5
	*/
	protected void setBackground(Color bg) {
	this.bg = bg;
	}

	/**
	* Sets the cached properties from the attributes.
	*/
	protected void setPropertiesFromAttributes() {
	AttributeSet attr = getAttributes();
	if (attr != null) {
	Document d = getDocument();
	if (d instanceof StyledDocument) {
	StyledDocument doc = (StyledDocument) d;
	font = doc.getFont(attr);
	fg = doc.getForeground(attr);
	if (attr.isDefined(StyleConstants.Background)) {
	bg = doc.getBackground(attr);
	} else {
	bg = null;
	}
	setUnderline(StyleConstants.isUnderline(attr));
	setStrikeThrough(StyleConstants.isStrikeThrough(attr));
	setSuperscript(StyleConstants.isSuperscript(attr));
	setSubscript(StyleConstants.isSubscript(attr));
	} else {
	throw new StateInvariantError("LabelView needs StyledDocument");
	}
	}
	}

	/**
	* Fetches the <code>FontMetrics</code> used for this view.
	* @deprecated FontMetrics are not used for glyph rendering
	* when running in the JDK.
	*/
	@Deprecated
	protected FontMetrics getFontMetrics() {
	sync();
	Container c = getContainer();
	return (c != null) ? c.getFontMetrics(font) :
	Toolkit.getDefaultToolkit().getFontMetrics(font);
	}

	/**
	* Fetches the background color to use to render the glyphs.
	* This is implemented to return a cached background color,
	* which defaults to <code>null</code>.
	*
	* @return the cached background color
	* @since 1.3
	*/
	public Color getBackground() {
	sync();
	return bg;
	}

	/**
	* Fetches the foreground color to use to render the glyphs.
	* This is implemented to return a cached foreground color,
	* which defaults to <code>null</code>.
	*
	* @return the cached foreground color
	* @since 1.3
	*/
	public Color getForeground() {
	sync();
	return fg;
	}

	/**
	* Fetches the font that the glyphs should be based upon.
	* This is implemented to return a cached font.
	*
	* @return the cached font
	*/
	public Font getFont() {
	sync();
	return font;
	}

	/**
	* Determines if the glyphs should be underlined. If true,
	* an underline should be drawn through the baseline. This
	* is implemented to return the cached underline property.
	*
	* <p>When you request this property, <code>LabelView</code>
	* re-syncs its state with the properties of the
	* <code>Element</code>'s <code>AttributeSet</code>.
	* If <code>Element</code>'s <code>AttributeSet</code>
	* does not have this property set, it will revert to false.
	*
	* @return the value of the cached
	* <code>underline</code> property
	* @since 1.3
	*/
	public boolean isUnderline() {
	sync();
	return underline;
	}

	/**
	* Determines if the glyphs should have a strikethrough
	* line. If true, a line should be drawn through the center
	* of the glyphs. This is implemented to return the
	* cached <code>strikeThrough</code> property.
	*
	* <p>When you request this property, <code>LabelView</code>
	* re-syncs its state with the properties of the
	* <code>Element</code>'s <code>AttributeSet</code>.
	* If <code>Element</code>'s <code>AttributeSet</code>
	* does not have this property set, it will revert to false.
	*
	* @return the value of the cached
	* <code>strikeThrough</code> property
	* @since 1.3
	*/
	public boolean isStrikeThrough() {
	sync();
	return strike;
	}

	/**
	* Determines if the glyphs should be rendered as superscript.
	* @return the value of the cached subscript property
	*
	* <p>When you request this property, <code>LabelView</code>
	* re-syncs its state with the properties of the
	* <code>Element</code>'s <code>AttributeSet</code>.
	* If <code>Element</code>'s <code>AttributeSet</code>
	* does not have this property set, it will revert to false.
	*
	* @return the value of the cached
	* <code>subscript</code> property
	* @since 1.3
	*/
	public boolean isSubscript() {
	sync();
	return subscript;
	}

	/**
	* Determines if the glyphs should be rendered as subscript.
	*
	* <p>When you request this property, <code>LabelView</code>
	* re-syncs its state with the properties of the
	* <code>Element</code>'s <code>AttributeSet</code>.
	* If <code>Element</code>'s <code>AttributeSet</code>
	* does not have this property set, it will revert to false.
	*
	* @return the value of the cached
	* <code>superscript</code> property
	* @since 1.3
	*/
	public boolean isSuperscript() {
	sync();
	return superscript;
	}

	// --- View methods ---------------------------------------------

	/**
	* Gives notification from the document that attributes were changed
	* in a location that this view is responsible for.
	*
	* @param e the change information from the associated document
	* @param a the current allocation of the view
	* @param f the factory to use to rebuild if the view has children
	* @see View#changedUpdate
	*/
	public void changedUpdate(DocumentEvent e, Shape a, ViewFactory f) {
	font = null;
	super.changedUpdate(e, a, f);
	}

	// --- variables ------------------------------------------------

	private Font font;
	private Color fg;
	private Color bg;
	private boolean underline;
	private boolean strike;
	private boolean superscript;
	private boolean subscript;

	}

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