How to use DefaultDecorated class of org.openqa.selenium.support.decorators package

I solved that converting a mp4 file to mjpeg, which is a format that also can be used, and setting my chromedriver same as you did, but using a relative path to the file.

options.addArguments("--use-fake-ui-for-media-stream",
                     "--use-fake-device-for-media-stream",
                     "--use-file-for-fake-video-capture=src/test/resources/sample_640x360.mjpeg"); 

This thread helped me to get there: https://stackoverflow.com/a/52188760/1843429

After calling driver.close() the value of driver is set to

FirefoxDriver: firefox on WINDOWS(4b4ffb1e-7c02-4d9c-b37b-310c771492ac)

But if you call driver.quit() then it sets the value of driver to

FirefoxDriver: firefox on WINDOWS (null)

So if you're checking the browser window after calling driver.quit() then you will be able to know by below implementation.

WebDriver driver = new FirefoxDriver();
driver.get("http://www.google.com");
driver.quit();              
if(driver.toString().contains("null"))
{

System.out.print("All Browser windows are closed ");
}
else
{
//open a new Browser
}

I also got the same exception:

I tried the following steps:

1. In Eclipse> Project > Clean. (The Exception remained)

2. I ran another project(The testng.xml ran successfully)

After running another project, I ran the project in which I was getting the Exception, and fortunately it worked for me, with no errors.

To work with Selenium 3.x, Mozila Firefox 52.x you need to download the latest gecko driver from here and provide the absolute path of gecko driver as follows:

//Mozila Firefox
System.setProperty("webdriver.gecko.driver", "C:\\your_directory\\geckodriver.exe");
WebDriver driver =  new FirefoxDriver();
driver.manage().window().maximize();
driver.get("http:\\gmail.com");
driver.manage().timeouts().implicitlyWait(5, TimeUnit.SECONDS);
driver.findElement(By.id("Email")).sendKeys("your_id");

You can control how the Firefox driver chooses the profile. Set the webdriver.firefox.profile property to the name of the profile you want to use. Most folks think this is a bad idea, because you'll inherit all the cookies, cache contents, etc. of the previous uses of the profile, but it's allowed if you really want to do it.

For example:

System.setProperty("webdriver.firefox.profile", "MySeleniumProfile");
WebDriver driver = new FirefoxDriver(...);

UPDATE - From Ranhiru

How I handled it for Java

FirefoxProfile profile = new FirefoxProfile(new File("D:\\Selenium Profile"));                  
WebDriver driver = new FirefoxDriver(profile);

Then I changed settings in Firefox to clear all cookies and cache when exiting. Look here on how to do it.

disable-infobars flag has been removed in latest Chrome => https://chromium.googlesource.com/chromium/src/+/d869ab3350d8ebd95222b4a47adf87ce3d3214b1

Maybe the span element is hidden. If that's the case then use the innerHtml property:

By.css:

String kk = wd.findElement(By.cssSelector("#customSelect_3 span.selectLabel"))
              .getAttribute("innerHTML");

By.xpath:

String kk = wd.findElement(By.xpath(
                   "//*[@id='customSelect_3']/.//span[contains(@class,'selectLabel')]"))
              .getAttribute("innerHTML");

"/.//" means "look under the selected element".

Answering your first question:

Have a look at the Selenium API docs for ExpectedConditon.

I quote:

public interface ExpectedCondition<T>
extends com.google.common.base.Function<WebDriver,T>

You see, that ExpectedCondition inherited from google's Function interface, thus you can use it as an argument for the until() method.

As for your second question:

I don't think you can hand over a lambda just like that. Until method is waiting for a Predicate or Function (as you correctly mentioned).

Regarding the differences between Predicates and lambdas, have a look for example here

So you can try something like this instead, still using your lambda-expressions:

Predicate<WebDriver> myPredicate = x ->x.findElement(By.id("id")).isDisplayed();

WebDriverWait wait = (WebDriverWait)new WebDriverWait(driver, 10);
wait.until(myPredicate);

To display the device in landscape mode you can use the following line of code:

descap.setCapability("--main-frame-resizes-are-orientation-changes", "landscape");

Note: Ensure that descap is an instance of ChromeOptions() class.