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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* 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,
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*
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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 y + ascent
.
*/
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
* NOT HTML the property will be cleared of any
* renderer.
*
* 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: *
* jComponent.putClientProperty(documentBaseKey, * xxx.class.getResource("resources/")); **/ 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: *
* 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; } }