/* * Copyright (c) 1998, 2011, 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 delgate 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;}