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	/*
	* Copyright (c) 1998, 2013, 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.html;

	import java.awt.*;
	import javax.swing.SizeRequirements;
	import javax.swing.event.DocumentEvent;
	import javax.swing.text.Document;
	import javax.swing.text.Element;
	import javax.swing.text.AttributeSet;
	import javax.swing.text.StyleConstants;
	import javax.swing.text.View;
	import javax.swing.text.ViewFactory;
	import javax.swing.text.BadLocationException;
	import javax.swing.text.JTextComponent;

	/**
	* Displays the a paragraph, and uses css attributes for its
	* configuration.
	*
	* @author Timothy Prinzing
	*/

	public class ParagraphView extends javax.swing.text.ParagraphView {

	/**
	* Constructs a ParagraphView for the given element.
	*
	* @param elem the element that this view is responsible for
	*/
	public ParagraphView(Element elem) {
	super(elem);
	}

	/**
	* Establishes the parent view for this view. This is
	* guaranteed to be called before any other methods if the
	* parent view is functioning properly.
	* <p>
	* This is implemented
	* to forward to the superclass as well as call the
	* {@link #setPropertiesFromAttributes setPropertiesFromAttributes}
	* method to set the paragraph properties from the css
	* attributes. The call is made at this time to ensure
	* the ability to resolve upward through the parents
	* view attributes.
	*
	* @param parent the new parent, or null if the view is
	* being removed from a parent it was previously added
	* to
	*/
	public void setParent(View parent) {
	super.setParent(parent);
	if (parent != null) {
	setPropertiesFromAttributes();
	}
	}

	/**
	* Fetches the attributes to use when rendering. This is
	* implemented to multiplex the attributes specified in the
	* model with a StyleSheet.
	*/
	public AttributeSet getAttributes() {
	if (attr == null) {
	StyleSheet sheet = getStyleSheet();
	attr = sheet.getViewAttributes(this);
	}
	return attr;
	}

	/**
	* Sets up the paragraph from css attributes instead of
	* the values found in StyleConstants (i.e. which are used
	* by the superclass). Since
	*/
	protected void setPropertiesFromAttributes() {
	StyleSheet sheet = getStyleSheet();
	attr = sheet.getViewAttributes(this);
	painter = sheet.getBoxPainter(attr);
	if (attr != null) {
	super.setPropertiesFromAttributes();
	setInsets((short) painter.getInset(TOP, this),
	(short) painter.getInset(LEFT, this),
	(short) painter.getInset(BOTTOM, this),
	(short) painter.getInset(RIGHT, this));
	Object o = attr.getAttribute(CSS.Attribute.TEXT_ALIGN);
	if (o != null) {
	// set horizontal alignment
	String ta = o.toString();
	if (ta.equals("left")) {
	setJustification(StyleConstants.ALIGN_LEFT);
	} else if (ta.equals("center")) {
	setJustification(StyleConstants.ALIGN_CENTER);
	} else if (ta.equals("right")) {
	setJustification(StyleConstants.ALIGN_RIGHT);
	} else if (ta.equals("justify")) {
	setJustification(StyleConstants.ALIGN_JUSTIFIED);
	}
	}
	// Get the width/height
	cssWidth = (CSS.LengthValue)attr.getAttribute(
	CSS.Attribute.WIDTH);
	cssHeight = (CSS.LengthValue)attr.getAttribute(
	CSS.Attribute.HEIGHT);
	}
	}

	protected StyleSheet getStyleSheet() {
	HTMLDocument doc = (HTMLDocument) getDocument();
	return doc.getStyleSheet();
	}


	/**
	* Calculate the needs for the paragraph along the minor axis.
	*
	* <p>If size requirements are explicitly specified for the paragraph,
	* use that requirements. Otherwise, use the requirements of the
	* superclass {@link javax.swing.text.ParagraphView}.</p>
	*
	* <p>If the {@code axis} parameter is neither {@code View.X_AXIS} nor
	* {@code View.Y_AXIS}, {@link IllegalArgumentException} is thrown. If the
	* {@code r} parameter is {@code null,} a new {@code SizeRequirements}
	* object is created, otherwise the supplied {@code SizeRequirements}
	* object is returned.</p>
	*
	* @param axis the minor axis
	* @param r the input {@code SizeRequirements} object
	* @return the new or adjusted {@code SizeRequirements} object
	* @throws IllegalArgumentException if the {@code axis} parameter is invalid
	*/
	protected SizeRequirements calculateMinorAxisRequirements(
	int axis, SizeRequirements r) {
	r = super.calculateMinorAxisRequirements(axis, r);

	if (BlockView.spanSetFromAttributes(axis, r, cssWidth, cssHeight)) {
	// Offset by the margins so that pref/min/max return the
	// right value.
	int margin = (axis == X_AXIS) ? getLeftInset() + getRightInset() :
	getTopInset() + getBottomInset();
	r.minimum -= margin;
	r.preferred -= margin;
	r.maximum -= margin;
	}
	return r;
	}


	/**
	* Indicates whether or not this view should be
	* displayed. If none of the children wish to be
	* displayed and the only visible child is the
	* break that ends the paragraph, the paragraph
	* will not be considered visible. Otherwise,
	* it will be considered visible and return true.
	*
	* @return true if the paragraph should be displayed
	*/
	public boolean isVisible() {

	int n = getLayoutViewCount() - 1;
	for (int i = 0; i < n; i++) {
	View v = getLayoutView(i);
	if (v.isVisible()) {
	return true;
	}
	}
	if (n > 0) {
	View v = getLayoutView(n);
	if ((v.getEndOffset() - v.getStartOffset()) == 1) {
	return false;
	}
	}
	// If it's the last paragraph and not editable, it shouldn't
	// be visible.
	if (getStartOffset() == getDocument().getLength()) {
	boolean editable = false;
	Component c = getContainer();
	if (c instanceof JTextComponent) {
	editable = ((JTextComponent)c).isEditable();
	}
	if (!editable) {
	return false;
	}
	}
	return true;
	}

	/**
	* Renders using the given rendering surface and area on that
	* surface. This is implemented to delegate to the superclass
	* after stashing the base coordinate for tab calculations.
	*
	* @param g the rendering surface to use
	* @param a the allocated region to render into
	* @see View#paint
	*/
	public void paint(Graphics g, Shape a) {
	if (a == null) {
	return;
	}

	Rectangle r;
	if (a instanceof Rectangle) {
	r = (Rectangle) a;
	} else {
	r = a.getBounds();
	}
	painter.paint(g, r.x, r.y, r.width, r.height, this);
	super.paint(g, a);
	}

	/**
	* Determines the preferred span for this view. Returns
	* 0 if the view is not visible, otherwise it calls the
	* superclass method to get the preferred span.
	* axis.
	*
	* @param axis may be either View.X_AXIS or View.Y_AXIS
	* @return the span the view would like to be rendered into;
	* typically the view is told to render into the span
	* that is returned, although there is no guarantee;
	* the parent may choose to resize or break the view
	* @see javax.swing.text.ParagraphView#getPreferredSpan
	*/
	public float getPreferredSpan(int axis) {
	if (!isVisible()) {
	return 0;
	}
	return super.getPreferredSpan(axis);
	}

	/**
	* Determines the minimum span for this view along an
	* axis. Returns 0 if the view is not visible, otherwise
	* it calls the superclass method to get the minimum span.
	*
	* @param axis may be either <code>View.X_AXIS</code> or
	* <code>View.Y_AXIS</code>
	* @return the minimum span the view can be rendered into
	* @see javax.swing.text.ParagraphView#getMinimumSpan
	*/
	public float getMinimumSpan(int axis) {
	if (!isVisible()) {
	return 0;
	}
	return super.getMinimumSpan(axis);
	}

	/**
	* Determines the maximum span for this view along an
	* axis. Returns 0 if the view is not visible, otherwise
	* it calls the superclass method ot get the maximum span.
	*
	* @param axis may be either <code>View.X_AXIS</code> or
	* <code>View.Y_AXIS</code>
	* @return the maximum span the view can be rendered into
	* @see javax.swing.text.ParagraphView#getMaximumSpan
	*/
	public float getMaximumSpan(int axis) {
	if (!isVisible()) {
	return 0;
	}
	return super.getMaximumSpan(axis);
	}

	private AttributeSet attr;
	private StyleSheet.BoxPainter painter;
	private CSS.LengthValue cssWidth;
	private CSS.LengthValue cssHeight;
	}

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