Java tutorial
/* * Copyright (c) 2002-2016 Gargoyle Software Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.gargoylesoftware.htmlunit.javascript; import static com.gargoylesoftware.htmlunit.BrowserVersionFeatures.HTMLIMAGE_HTMLELEMENT; import static com.gargoylesoftware.htmlunit.BrowserVersionFeatures.HTMLIMAGE_HTMLUNKNOWNELEMENT; import java.lang.reflect.Method; import java.util.Stack; import net.sourceforge.htmlunit.corejs.javascript.Context; import net.sourceforge.htmlunit.corejs.javascript.ScriptRuntime; import net.sourceforge.htmlunit.corejs.javascript.Scriptable; import net.sourceforge.htmlunit.corejs.javascript.ScriptableObject; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import com.gargoylesoftware.htmlunit.BrowserVersion; import com.gargoylesoftware.htmlunit.WebAssert; import com.gargoylesoftware.htmlunit.WebWindow; import com.gargoylesoftware.htmlunit.html.DomNode; import com.gargoylesoftware.htmlunit.html.HtmlElement; import com.gargoylesoftware.htmlunit.html.HtmlImage; import com.gargoylesoftware.htmlunit.javascript.configuration.CanSetReadOnly; import com.gargoylesoftware.htmlunit.javascript.configuration.JsxGetter; import com.gargoylesoftware.htmlunit.javascript.host.Window; import com.gargoylesoftware.htmlunit.javascript.host.html.HTMLElement; import com.gargoylesoftware.htmlunit.javascript.host.html.HTMLUnknownElement; /** * Base class for Rhino host objects in HtmlUnit. * * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a> * @author David K. Taylor * @author Marc Guillemot * @author Chris Erskine * @author Daniel Gredler * @author Ahmed Ashour * @author Ronald Brill */ public class SimpleScriptable extends HtmlUnitScriptable implements Cloneable { private static final Log LOG = LogFactory.getLog(SimpleScriptable.class); private DomNode domNode_; private boolean caseSensitive_ = true; /** * Gets a named property from the object. * Normally HtmlUnit objects don't need to overwrite this method as properties are defined * on the prototypes from the XML configuration. In some cases where "content" of object * has priority compared to the properties consider using utility {@link #getWithPreemption(String)}. * For fallback case just implement {@link ScriptableWithFallbackGetter}. * {@inheritDoc} */ @Override public Object get(String name, final Scriptable start) { // If this object is not case-sensitive about property names, transform the property name accordingly. if (!caseSensitive_) { for (final Object o : getAllIds()) { final String objectName = Context.toString(o); if (name.equalsIgnoreCase(objectName)) { name = objectName; break; } } } // Try to get property configured on object itself. final Object response = super.get(name, start); if (response != NOT_FOUND) { return response; } if (this == start) { return getWithPreemption(name); } return NOT_FOUND; } /** * <p>Called by {@link #get(String, Scriptable)} to allow retrieval of the property before the prototype * chain is searched.</p> * * <p>IMPORTANT: This method is invoked *very* often by Rhino. If you override this method, the implementation * needs to be as fast as possible!</p> * * @param name the property name * @return {@link Scriptable#NOT_FOUND} if not found */ protected Object getWithPreemption(final String name) { return NOT_FOUND; } /** * Returns the DOM node that corresponds to this JavaScript object or throw * an exception if one cannot be found. * @return the DOM node * @exception IllegalStateException If the DOM node could not be found. */ public DomNode getDomNodeOrDie() throws IllegalStateException { if (domNode_ == null) { final String clazz = getClass().getName(); throw new IllegalStateException("DomNode has not been set for this SimpleScriptable: " + clazz); } return domNode_; } /** * Returns the DOM node that corresponds to this JavaScript object * or null if a node hasn't been set. * @return the DOM node or null */ public DomNode getDomNodeOrNull() { return domNode_; } /** * Sets the DOM node that corresponds to this JavaScript object. * @param domNode the DOM node */ public void setDomNode(final DomNode domNode) { setDomNode(domNode, true); } /** * Sets the DOM node that corresponds to this JavaScript object. * @param domNode the DOM node * @param assignScriptObject If true, call <code>setScriptObject</code> on domNode */ protected void setDomNode(final DomNode domNode, final boolean assignScriptObject) { WebAssert.notNull("domNode", domNode); domNode_ = domNode; if (assignScriptObject) { domNode_.setScriptableObject(this); } } /** * Sets the HTML element that corresponds to this JavaScript object. * @param htmlElement the HTML element */ public void setHtmlElement(final HtmlElement htmlElement) { setDomNode(htmlElement); } /** * Returns the JavaScript object that corresponds to the specified object. * New JavaScript objects will be created as needed. If a JavaScript object * cannot be created for a domNode then NOT_FOUND will be returned. * * @param object a {@link DomNode} or a {@link WebWindow} * @return the JavaScript object or NOT_FOUND */ protected SimpleScriptable getScriptableFor(final Object object) { if (object instanceof WebWindow) { return (SimpleScriptable) ((WebWindow) object).getScriptableObject(); } final DomNode domNode = (DomNode) object; final Object scriptObject = domNode.getScriptableObject(); if (scriptObject != null) { return (SimpleScriptable) scriptObject; } return makeScriptableFor(domNode); } /** * Builds a new the JavaScript object that corresponds to the specified object. * @param domNode the DOM node for which a JS object should be created * @return the JavaScript object */ @SuppressWarnings("unchecked") public SimpleScriptable makeScriptableFor(final DomNode domNode) { // Get the JS class name for the specified DOM node. // Walk up the inheritance chain if necessary. Class<? extends SimpleScriptable> javaScriptClass = null; if (domNode instanceof HtmlImage && "image".equals(((HtmlImage) domNode).getOriginalQualifiedName()) && ((HtmlImage) domNode).wasCreatedByJavascript()) { if (domNode.hasFeature(HTMLIMAGE_HTMLELEMENT)) { javaScriptClass = HTMLElement.class; } else if (domNode.hasFeature(HTMLIMAGE_HTMLUNKNOWNELEMENT)) { javaScriptClass = HTMLUnknownElement.class; } } if (javaScriptClass == null) { final JavaScriptEngine javaScriptEngine = getWindow().getWebWindow().getWebClient() .getJavaScriptEngine(); for (Class<?> c = domNode.getClass(); javaScriptClass == null && c != null; c = c.getSuperclass()) { javaScriptClass = (Class<? extends SimpleScriptable>) javaScriptEngine.getJavaScriptClass(c); } } final SimpleScriptable scriptable; if (javaScriptClass == null) { // We don't have a specific subclass for this element so create something generic. scriptable = new HTMLElement(); if (LOG.isDebugEnabled()) { LOG.debug( "No JavaScript class found for element <" + domNode.getNodeName() + ">. Using HTMLElement"); } } else { try { scriptable = javaScriptClass.newInstance(); } catch (final Exception e) { throw Context.throwAsScriptRuntimeEx(e); } } initParentScope(domNode, scriptable); scriptable.setPrototype(getPrototype(javaScriptClass)); scriptable.setDomNode(domNode); return scriptable; } /** * Initialize the parent scope of a newly created scriptable. * @param domNode the DOM node for the script object * @param scriptable the script object to initialize */ protected void initParentScope(final DomNode domNode, final SimpleScriptable scriptable) { final WebWindow enclosingWindow = domNode.getPage().getEnclosingWindow(); if (enclosingWindow.getEnclosedPage() == domNode.getPage()) { scriptable.setParentScope(enclosingWindow.getScriptableObject()); } else { scriptable.setParentScope(ScriptableObject.getTopLevelScope(domNode.getPage().getScriptableObject())); } } /** * Gets the prototype object for the given host class. * @param javaScriptClass the host class * @return the prototype */ @SuppressWarnings("unchecked") public Scriptable getPrototype(final Class<? extends SimpleScriptable> javaScriptClass) { final Scriptable prototype = getWindow().getPrototype(javaScriptClass); if (prototype == null && javaScriptClass != SimpleScriptable.class) { return getPrototype((Class<? extends SimpleScriptable>) javaScriptClass.getSuperclass()); } return prototype; } /** * Returns the JavaScript default value of this object. This is the JavaScript equivalent of a toString() in Java. * * @param hint a hint as to the format of the default value (ignored in this case) * @return the default value */ @Override public Object getDefaultValue(final Class<?> hint) { if (String.class.equals(hint) || hint == null) { return "[object " + getClassName() + "]"; } return super.getDefaultValue(hint); } /** * Gets the window that is the top scope for this object. * @return the window associated with this object * @throws RuntimeException if the window cannot be found, which should never occur */ public Window getWindow() throws RuntimeException { return getWindow(this); } /** * Gets the window that is the top scope for the specified object. * @param s the JavaScript object whose associated window is to be returned * @return the window associated with the specified JavaScript object * @throws RuntimeException if the window cannot be found, which should never occur */ protected static Window getWindow(final Scriptable s) throws RuntimeException { final Scriptable top = ScriptableObject.getTopLevelScope(s); if (top instanceof Window) { return (Window) top; } throw new RuntimeException("Unable to find window associated with " + s); } /** * Gets the scriptable used at starting scope for the execution of current script. * @return the scope as defined in {@link JavaScriptEngine#callFunction} * or {@link JavaScriptEngine#execute}. */ protected Scriptable getStartingScope() { @SuppressWarnings("unchecked") final Stack<Scriptable> stack = (Stack<Scriptable>) Context.getCurrentContext() .getThreadLocal(JavaScriptEngine.KEY_STARTING_SCOPE); if (null == stack) { return null; } return stack.peek(); } /** * Gets the browser version currently used. * @return the browser version */ public BrowserVersion getBrowserVersion() { final DomNode node = getDomNodeOrNull(); if (node != null) { return node.getPage().getWebClient().getBrowserVersion(); } return getWindow().getWebWindow().getWebClient().getBrowserVersion(); } /** * {@inheritDoc} */ @Override public boolean hasInstance(final Scriptable instance) { if (getPrototype() == null) { // to handle cases like "x instanceof HTMLElement", // but HTMLElement is not in the prototype chain of any element final Object prototype = get("prototype", this); if (!(prototype instanceof ScriptableObject)) { Context.throwAsScriptRuntimeEx(new Exception("Null prototype")); } return ((ScriptableObject) prototype).hasInstance(instance); } return super.hasInstance(instance); } /** * {@inheritDoc} */ @Override protected Object equivalentValues(Object value) { if (value instanceof SimpleScriptableProxy<?>) { value = ((SimpleScriptableProxy<?>) value).getDelegee(); } return super.equivalentValues(value); } /** * {@inheritDoc} */ @Override public SimpleScriptable clone() { try { return (SimpleScriptable) super.clone(); } catch (final Exception e) { throw new IllegalStateException("Clone not supported"); } } /** * Sets case sensitivity of all properties of this scriptable. * @param caseSensitive case sensitive or no */ public void setCaseSensitive(final boolean caseSensitive) { caseSensitive_ = caseSensitive; final Scriptable prototype = getPrototype(); if (prototype instanceof SimpleScriptable) { ((SimpleScriptable) prototype).setCaseSensitive(caseSensitive); } } @Override protected boolean isReadOnlySettable(final String name, final Object value) { for (final Method m : getClass().getMethods()) { final JsxGetter jsxGetter = m.getAnnotation(JsxGetter.class); if (jsxGetter != null) { String methodProperty; if (jsxGetter.propertyName().isEmpty()) { final int prefix = m.getName().startsWith("is") ? 2 : 3; methodProperty = m.getName().substring(prefix); methodProperty = Character.toLowerCase(methodProperty.charAt(0)) + methodProperty.substring(1); } else { methodProperty = jsxGetter.propertyName(); } if (methodProperty.equals(name)) { final CanSetReadOnly canSetReadOnly = m.getAnnotation(CanSetReadOnly.class); if (canSetReadOnly != null) { switch (canSetReadOnly.value()) { case YES: return true; case IGNORE: return false; case EXCEPTION: throw ScriptRuntime.typeError3("msg.set.prop.no.setter", name, getClassName(), Context.toString(value)); default: } } } } } return true; } }