DelegatingWebDriver.java

package ch.vorburger.webdriver.runner.core.providers;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.internal.WrapsDriver;
import org.openqa.selenium.internal.WrapsElement;
import org.openqa.selenium.support.events.WebDriverEventListener;

/**
 * WebDriver Delegate helper.
 * 
 * Implementation for the correct handling for the various WebDriver extension
 * interfaces (JavascriptExecutor, TakesScreenshot, HasInputDevices, HasTouchScreen; 
 * Rotatable, BrowserConnection, WebStorage, LocationContext, LocationListener,
 * ApplicationCache; FindsBy* etc.) is "strongly inspired" (erm, mostly 
 * copy/pasted) from the EventFiringWebDriver.
 * 
 * Shame such a helper/util class is not already included in WebDriver core.
 * @see https://code.google.com/p/selenium/issues/detail?id=2512
 * 
 * @author Michael Vorburger
 */
public abstract class DelegatingWebDriver implements WebDriver, WrapsDriver {
	
	// intentionally private and not protected, because all code should go through getWrappedDriver() 
	private final WebDriver delegate;

	protected DelegatingWebDriver(final WebDriver delegate) {
		// copy/pasted from EventFiringWebDriver
		Class<?>[] allInterfaces = extractInterfaces(delegate);
		this.delegate = (WebDriver) Proxy.newProxyInstance(
				WebDriverEventListener.class.getClassLoader(), allInterfaces,
				new InvocationHandler() {
					public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
						if ("getWrappedDriver".equals(method.getName())) {
							return delegate;
						}

						try {
							return method.invoke(delegate, args);
						} catch (InvocationTargetException e) {
							onExceptionFromAdditionalInterfaceProxyInvocation(e);
							throw e.getTargetException();
						}
					}
				});
	}

	// copy/pasted from EventFiringWebDriver
	protected Class<?>[] extractInterfaces(Object object) {
		Set<Class<?>> allInterfaces = new HashSet<Class<?>>();
		allInterfaces.add(WrapsDriver.class);
		if (object instanceof WebElement) {
			allInterfaces.add(WrapsElement.class);
		}
		extractInterfaces(allInterfaces, object.getClass());

		return allInterfaces.toArray(new Class<?>[allInterfaces.size()]);
	}

	// copy/pasted from EventFiringWebDriver
	protected void extractInterfaces(Set<Class<?>> addTo, Class<?> clazz) {
		if (Object.class.equals(clazz)) {
			return; // Done
		}

		Class<?>[] classes = clazz.getInterfaces();
		addTo.addAll(Arrays.asList(classes));
		extractInterfaces(addTo, clazz.getSuperclass());
	}
	
	protected void onExceptionFromAdditionalInterfaceProxyInvocation(InvocationTargetException e) {
        // dispatcher.onException(e.getTargetException(), driver);
	}
	
	@Override public WebDriver getWrappedDriver() {
		return delegate;
	}

	public void get(String url) {
		getWrappedDriver().get(url);
	}

	public String getCurrentUrl() {
		return getWrappedDriver().getCurrentUrl();
	}

	public String getTitle() {
		return getWrappedDriver().getTitle();
	}

	public List<WebElement> findElements(By by) {
		return getWrappedDriver().findElements(by);
	}

	public WebElement findElement(By by) {
		return getWrappedDriver().findElement(by);
	}

	public String getPageSource() {
		return getWrappedDriver().getPageSource();
	}

	public void close() {
		getWrappedDriver().close();
	}

	public void quit() {
		getWrappedDriver().quit();
	}

	public Set<String> getWindowHandles() {
		return getWrappedDriver().getWindowHandles();
	}

	public String getWindowHandle() {
		return getWrappedDriver().getWindowHandle();
	}

	public TargetLocator switchTo() {
		return getWrappedDriver().switchTo();
	}

	public Navigation navigate() {
		return getWrappedDriver().navigate();
	}

	public Options manage() {
		return getWrappedDriver().manage();
	}
	
}