ObjectView.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * under the terms of the GNU General Public License version 2 only, as
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 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
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 * 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).
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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packagejavax.swing.text.html;

importjava.awt.*;
importjavax.swing.*;
importjavax.swing.text.*;
importjava.beans.*;
importjava.lang.reflect.*;

importsun.reflect.misc.MethodUtil;

/**
 * Component decorator that implements the view interface
 * for <object> elements.
 * <p>
 * This view will try to load the class specified by the
 * <code>classid</code> attribute. If possible, the Classloader
 * used to load the associated Document is used.
 * This would typically be the same as the ClassLoader
 * used to load the EditorKit. If the document's
 * ClassLoader is null, <code>Class.forName</code> is used.
 * <p>
 * If the class can successfully be loaded, an attempt will
 * be made to create an instance of it by calling
 * <code>Class.newInstance</code>. An attempt will be made
 * to narrow the instance to type <code>java.awt.Component</code>
 * to display the object.
 * <p>
 * This view can also manage a set of parameters with limitations.
 * The parameters to the &lt;object&gt; element are expected to
 * be present on the associated elements attribute set as simple
 * strings. Each bean property will be queried as a key on
 * the AttributeSet, with the expectation that a non-null value
 * (of type String) will be present if there was a parameter
 * specification for the property. Reflection is used to
 * set the parameter. Currently, this is limited to a very
 * simple single parameter of type String.
 * <p>
 * A simple example HTML invocation is:
 * <pre>
 * &lt;object classid="javax.swing.JLabel"&gt;
 * &lt;param name="text" value="sample text"&gt;
 * &lt;/object&gt;
 * </pre>
 *
 * @author Timothy Prinzing
 */
publicclassObjectViewextendsComponentView {

privatebooleancreateComp = true; // default

/**
 * Creates a new ObjectView object.
 *
 * @param elem the element to decorate
 */
publicObjectView(Elementelem) {
super(elem);
 }

ObjectView(Elementelem, booleancreateComp) {
super(elem);
this.createComp = createComp;
 }

/**
 * Create the component. The classid is used
 * as a specification of the classname, which
 * we try to load.
 */
@SuppressWarnings("deprecation")
protectedComponentcreateComponent() {
if (!createComp) {
returngetUnloadableRepresentation();
 }
AttributeSetattr = getElement().getAttributes();
Stringclassname = (String) attr.getAttribute(HTML.Attribute.CLASSID);
try {
Class<?> c = Class.forName(classname, false,Thread.currentThread().
getContextClassLoader());
if (Component.class.isAssignableFrom(c)) {
Objecto = c.newInstance();
if (oinstanceofComponent) {
Componentcomp = (Component) o;
setParameters(comp, attr);
returncomp;
 }
 }
 } catch (Throwablee) {
// couldn't create a component... fall through to the
// couldn't load representation.
 }

returngetUnloadableRepresentation();
 }

/**
 * Fetch a component that can be used to represent the
 * object if it can't be created.
 */
ComponentgetUnloadableRepresentation() {
// PENDING(prinz) get some artwork and return something
// interesting here.
Componentcomp = newJLabel("??");
comp.setForeground(Color.red);
returncomp;
 }

/**
 * Initialize this component according the KEY/VALUEs passed in
 * via the &lt;param&gt; elements in the corresponding
 * &lt;object&gt; element.
 */
privatevoidsetParameters(Componentcomp, AttributeSetattr) {
Class<?> k = comp.getClass();
BeanInfobi;
try {
bi = Introspector.getBeanInfo(k);
 } catch (IntrospectionExceptionex) {
System.err.println("introspector failed, ex: "+ex);
return; // quit for now
 }
PropertyDescriptor[] props = bi.getPropertyDescriptors();
for (inti=0; i < props.length; i++) {
// System.err.println("checking on props[i]: "+props[i].getName());
Objectv = attr.getAttribute(props[i].getName());
if (vinstanceofString) {
// found a property parameter
Stringvalue = (String) v;
Methodwriter = props[i].getWriteMethod();
if (writer == null) {
// read-only property. ignore
return; // for now
 }
Class<?>[] params = writer.getParameterTypes();
if (params.length != 1) {
// zero or more than one argument, ignore
return; // for now
 }
Object [] args = { value };
try {
MethodUtil.invoke(writer, comp, args);
 } catch (Exceptionex) {
System.err.println("Invocation failed");
// invocation code
 }
 }
 }
 }

}