author | darcy |
Wed, 02 Jul 2014 23:03:27 -0700 | |
changeset 25565 | ce603b34c98d |
parent 23697 | e556a715949f |
child 25761 | c408b10ef757 |
permissions | -rw-r--r-- |
/* * Copyright (c) 1998, 2014, 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.plaf.basic; import java.io.*; import java.awt.*; import java.net.URL; import javax.swing.*; import javax.swing.text.*; import javax.swing.text.html.*; import sun.swing.SwingUtilities2; /** * Support for providing html views for the swing components. * This translates a simple html string to a javax.swing.text.View * implementation that can render the html and provide the necessary * layout semantics. * * @author Timothy Prinzing * @since 1.3 */ public class BasicHTML { /** * Create an html renderer for the given component and * string of html. */ public static View createHTMLView(JComponent c, String html) { BasicEditorKit kit = getFactory(); Document doc = kit.createDefaultDocument(c.getFont(), c.getForeground()); Object base = c.getClientProperty(documentBaseKey); if (base instanceof URL) { ((HTMLDocument)doc).setBase((URL)base); } Reader r = new StringReader(html); try { kit.read(r, doc, 0); } catch (Throwable e) { } ViewFactory f = kit.getViewFactory(); View hview = f.create(doc.getDefaultRootElement()); View v = new Renderer(c, f, hview); return v; } /** * Returns the baseline for the html renderer. * * @param view the View to get the baseline for * @param w the width to get the baseline for * @param h the height to get the baseline for * @throws IllegalArgumentException if width or height is < 0 * @return baseline or a value < 0 indicating there is no reasonable * baseline * @see java.awt.FontMetrics * @see javax.swing.JComponent#getBaseline(int,int) * @since 1.6 */ public static int getHTMLBaseline(View view, int w, int h) { if (w < 0 || h < 0) { throw new IllegalArgumentException( "Width and height must be >= 0"); } if (view instanceof Renderer) { return getBaseline(view.getView(0), w, h); } return -1; } /** * Gets the baseline for the specified component. This digs out * the View client property, and if non-null the baseline is calculated * from it. Otherwise the baseline is the value <code>y + ascent</code>. */ static int getBaseline(JComponent c, int y, int ascent, int w, int h) { View view = (View)c.getClientProperty(BasicHTML.propertyKey); if (view != null) { int baseline = getHTMLBaseline(view, w, h); if (baseline < 0) { return baseline; } return y + baseline; } return y + ascent; } /** * Gets the baseline for the specified View. */ static int getBaseline(View view, int w, int h) { if (hasParagraph(view)) { view.setSize(w, h); return getBaseline(view, new Rectangle(0, 0, w, h)); } return -1; } private static int getBaseline(View view, Shape bounds) { if (view.getViewCount() == 0) { return -1; } AttributeSet attributes = view.getElement().getAttributes(); Object name = null; if (attributes != null) { name = attributes.getAttribute(StyleConstants.NameAttribute); } int index = 0; if (name == HTML.Tag.HTML && view.getViewCount() > 1) { // For html on widgets the header is not visible, skip it. index++; } bounds = view.getChildAllocation(index, bounds); if (bounds == null) { return -1; } View child = view.getView(index); if (view instanceof javax.swing.text.ParagraphView) { Rectangle rect; if (bounds instanceof Rectangle) { rect = (Rectangle)bounds; } else { rect = bounds.getBounds(); } return rect.y + (int)(rect.height * child.getAlignment(View.Y_AXIS)); } return getBaseline(child, bounds); } private static boolean hasParagraph(View view) { if (view instanceof javax.swing.text.ParagraphView) { return true; } if (view.getViewCount() == 0) { return false; } AttributeSet attributes = view.getElement().getAttributes(); Object name = null; if (attributes != null) { name = attributes.getAttribute(StyleConstants.NameAttribute); } int index = 0; if (name == HTML.Tag.HTML && view.getViewCount() > 1) { // For html on widgets the header is not visible, skip it. index = 1; } return hasParagraph(view.getView(index)); } /** * Check the given string to see if it should trigger the * html rendering logic in a non-text component that supports * html rendering. */ public static boolean isHTMLString(String s) { if (s != null) { if ((s.length() >= 6) && (s.charAt(0) == '<') && (s.charAt(5) == '>')) { String tag = s.substring(1,5); return tag.equalsIgnoreCase(propertyKey); } } return false; } /** * Stash the HTML render for the given text into the client * properties of the given JComponent. If the given text is * <em>NOT HTML</em> the property will be cleared of any * renderer. * <p> * This method is useful for ComponentUI implementations * that are static (i.e. shared) and get their state * entirely from the JComponent. */ public static void updateRenderer(JComponent c, String text) { View value = null; View oldValue = (View)c.getClientProperty(BasicHTML.propertyKey); Boolean htmlDisabled = (Boolean) c.getClientProperty(htmlDisable); if (htmlDisabled != Boolean.TRUE && BasicHTML.isHTMLString(text)) { value = BasicHTML.createHTMLView(c, text); } if (value != oldValue && oldValue != null) { for (int i = 0; i < oldValue.getViewCount(); i++) { oldValue.getView(i).setParent(null); } } c.putClientProperty(BasicHTML.propertyKey, value); } /** * If this client property of a JComponent is set to Boolean.TRUE * the component's 'text' property is never treated as HTML. */ private static final String htmlDisable = "html.disable"; /** * Key to use for the html renderer when stored as a * client property of a JComponent. */ public static final String propertyKey = "html"; /** * Key stored as a client property to indicate the base that relative * references are resolved against. For example, lets say you keep * your images in the directory resources relative to the code path, * you would use the following the set the base: * <pre> * jComponent.putClientProperty(documentBaseKey, * xxx.class.getResource("resources/")); * </pre> */ public static final String documentBaseKey = "html.base"; static BasicEditorKit getFactory() { if (basicHTMLFactory == null) { basicHTMLViewFactory = new BasicHTMLViewFactory(); basicHTMLFactory = new BasicEditorKit(); } return basicHTMLFactory; } /** * The source of the html renderers */ private static BasicEditorKit basicHTMLFactory; /** * Creates the Views that visually represent the model. */ private static ViewFactory basicHTMLViewFactory; /** * Overrides to the default stylesheet. Should consider * just creating a completely fresh stylesheet. */ private static final String styleChanges = "p { margin-top: 0; margin-bottom: 0; margin-left: 0; margin-right: 0 }" + "body { margin-top: 0; margin-bottom: 0; margin-left: 0; margin-right: 0 }"; /** * The views produced for the ComponentUI implementations aren't * going to be edited and don't need full html support. This kit * alters the HTMLEditorKit to try and trim things down a bit. * It does the following: * <ul> * <li>It doesn't produce Views for things like comments, * head, title, unknown tags, etc. * <li>It installs a different set of css settings from the default * provided by HTMLEditorKit. * </ul> */ @SuppressWarnings("serial") // JDK-implementation class static class BasicEditorKit extends HTMLEditorKit { /** Shared base style for all documents created by us use. */ private static StyleSheet defaultStyles; /** * Overriden to return our own slimmed down style sheet. */ public StyleSheet getStyleSheet() { if (defaultStyles == null) { defaultStyles = new StyleSheet(); StringReader r = new StringReader(styleChanges); try { defaultStyles.loadRules(r, null); } catch (Throwable e) { // don't want to die in static initialization... // just display things wrong. } r.close(); defaultStyles.addStyleSheet(super.getStyleSheet()); } return defaultStyles; } /** * Sets the async policy to flush everything in one chunk, and * to not display unknown tags. */ public Document createDefaultDocument(Font defaultFont, Color foreground) { StyleSheet styles = getStyleSheet(); StyleSheet ss = new StyleSheet(); ss.addStyleSheet(styles); BasicDocument doc = new BasicDocument(ss, defaultFont, foreground); doc.setAsynchronousLoadPriority(Integer.MAX_VALUE); doc.setPreservesUnknownTags(false); return doc; } /** * Returns the ViewFactory that is used to make sure the Views don't * load in the background. */ public ViewFactory getViewFactory() { return basicHTMLViewFactory; } } /** * BasicHTMLViewFactory extends HTMLFactory to force images to be loaded * synchronously. */ static class BasicHTMLViewFactory extends HTMLEditorKit.HTMLFactory { public View create(Element elem) { View view = super.create(elem); if (view instanceof ImageView) { ((ImageView)view).setLoadsSynchronously(true); } return view; } } /** * The subclass of HTMLDocument that is used as the model. getForeground * is overridden to return the foreground property from the Component this * was created for. */ @SuppressWarnings("serial") // Superclass is not serializable across versions static class BasicDocument extends HTMLDocument { /** The host, that is where we are rendering. */ // private JComponent host; BasicDocument(StyleSheet s, Font defaultFont, Color foreground) { super(s); setPreservesUnknownTags(false); setFontAndColor(defaultFont, foreground); } /** * Sets the default font and default color. These are set by * adding a rule for the body that specifies the font and color. * This allows the html to override these should it wish to have * a custom font or color. */ private void setFontAndColor(Font font, Color fg) { getStyleSheet().addRule(sun.swing.SwingUtilities2. displayPropertiesToCSS(font,fg)); } } /** * Root text view that acts as an HTML renderer. */ static class Renderer extends View { Renderer(JComponent c, ViewFactory f, View v) { super(null); host = c; factory = f; view = v; view.setParent(this); // initially layout to the preferred size setSize(view.getPreferredSpan(X_AXIS), view.getPreferredSpan(Y_AXIS)); } /** * Fetches the attributes to use when rendering. At the root * level there are no attributes. If an attribute is resolved * up the view hierarchy this is the end of the line. */ public AttributeSet getAttributes() { return null; } /** * Determines the preferred span for this view along an axis. * * @param axis may be either X_AXIS or 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. */ public float getPreferredSpan(int axis) { if (axis == X_AXIS) { // width currently laid out to return width; } return view.getPreferredSpan(axis); } /** * Determines the minimum span for this view along an axis. * * @param axis may be either X_AXIS or 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. */ public float getMinimumSpan(int axis) { return view.getMinimumSpan(axis); } /** * Determines the maximum span for this view along an axis. * * @param axis may be either X_AXIS or 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. */ public float getMaximumSpan(int axis) { return Integer.MAX_VALUE; } /** * Specifies that a preference has changed. * Child views can call this on the parent to indicate that * the preference has changed. The root view routes this to * invalidate on the hosting component. * <p> * This can be called on a different thread from the * event dispatching thread and is basically unsafe to * propagate into the component. To make this safe, * the operation is transferred over to the event dispatching * thread for completion. It is a design goal that all view * methods be safe to call without concern for concurrency, * and this behavior helps make that true. * * @param child the child view * @param width true if the width preference has changed * @param height true if the height preference has changed */ public void preferenceChanged(View child, boolean width, boolean height) { host.revalidate(); host.repaint(); } /** * Determines the desired alignment for this view along an axis. * * @param axis may be either X_AXIS or Y_AXIS * @return the desired alignment, where 0.0 indicates the origin * and 1.0 the full span away from the origin */ public float getAlignment(int axis) { return view.getAlignment(axis); } /** * Renders the view. * * @param g the graphics context * @param allocation the region to render into */ public void paint(Graphics g, Shape allocation) { Rectangle alloc = allocation.getBounds(); view.setSize(alloc.width, alloc.height); view.paint(g, allocation); } /** * Sets the view parent. * * @param parent the parent view */ public void setParent(View parent) { throw new Error("Can't set parent on root view"); } /** * Returns the number of views in this view. Since * this view simply wraps the root of the view hierarchy * it has exactly one child. * * @return the number of views * @see #getView */ public int getViewCount() { return 1; } /** * Gets the n-th view in this container. * * @param n the number of the view to get * @return the view */ public View getView(int n) { return view; } /** * Provides a mapping from the document model coordinate space * to the coordinate space of the view mapped to it. * * @param pos the position to convert * @param a the allocated region to render into * @return the bounding box of the given position */ public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException { return view.modelToView(pos, a, b); } /** * Provides a mapping from the document model coordinate space * to the coordinate space of the view mapped to it. * * @param p0 the position to convert >= 0 * @param b0 the bias toward the previous character or the * next character represented by p0, in case the * position is a boundary of two views. * @param p1 the position to convert >= 0 * @param b1 the bias toward the previous character or the * next character represented by p1, in case the * position is a boundary of two views. * @param a the allocated region to render into * @return the bounding box of the given position is returned * @exception BadLocationException if the given position does * not represent a valid location in the associated document * @exception IllegalArgumentException for an invalid bias argument * @see View#viewToModel */ public Shape modelToView(int p0, Position.Bias b0, int p1, Position.Bias b1, Shape a) throws BadLocationException { return view.modelToView(p0, b0, p1, b1, a); } /** * Provides a mapping from the view coordinate space to the logical * coordinate space of the model. * * @param x x coordinate of the view location to convert * @param y y coordinate of the view location to convert * @param a the allocated region to render into * @return the location within the model that best represents the * given point in the view */ public int viewToModel(float x, float y, Shape a, Position.Bias[] bias) { return view.viewToModel(x, y, a, bias); } /** * Returns the document model underlying the view. * * @return the model */ public Document getDocument() { return view.getDocument(); } /** * Returns the starting offset into the model for this view. * * @return the starting offset */ public int getStartOffset() { return view.getStartOffset(); } /** * Returns the ending offset into the model for this view. * * @return the ending offset */ public int getEndOffset() { return view.getEndOffset(); } /** * Gets the element that this view is mapped to. * * @return the view */ public Element getElement() { return view.getElement(); } /** * Sets the view size. * * @param width the width * @param height the height */ public void setSize(float width, float height) { this.width = (int) width; view.setSize(width, height); } /** * Fetches the container hosting the view. This is useful for * things like scheduling a repaint, finding out the host * components font, etc. The default implementation * of this is to forward the query to the parent view. * * @return the container */ public Container getContainer() { return host; } /** * Fetches the factory to be used for building the * various view fragments that make up the view that * represents the model. This is what determines * how the model will be represented. This is implemented * to fetch the factory provided by the associated * EditorKit. * * @return the factory */ public ViewFactory getViewFactory() { return factory; } private int width; private View view; private ViewFactory factory; private JComponent host; } }