how to get tooltip text from canvas using selenium webdriver - selenium

Question

It will be a great help if someone help me out with below problem.
Here I am trying to get tooltip text associated with mouse hover on the first gray box in the first row. But still no luck. Please let me know in case of additional details.
Web Link :-https://www.redbus.in/search?fromCityName=Bangalore&fromCityId=122&toCityName=Goa&toCityId=210&onward=25-Aug-2017&opId=0&busType=Any#
public class RedBus {
WebDriver driver;
WebDriverWait wait;
#BeforeTest
public void run() {
System.setProperty("webdriver.gecko.driver", "C:\\geckodriver.exe");
String baseUrl="https://www.redbus.in/";
driver=new FirefoxDriver();
driver.get(baseUrl);
wait=new WebDriverWait(driver,5);
}
#Test
public void testFunctionality() {
try {
driver.findElement(By.id("src")).clear();
driver.findElement(By.id("src")).sendKeys("Bangalore");
wait.until(ExpectedConditions.visibilityOfElementLocated(By.cssSelector("li.selected")));
driver.findElement(By.cssSelector("li.selected")).click();
driver.findElement(By.id("dest")).clear();
driver.findElement(By.id("dest")).sendKeys("Goa");
wait.until(ExpectedConditions.visibilityOfElementLocated(By.cssSelector("li.selected")));
driver.findElement(By.cssSelector("li.selected")).click();
driver.findElement(By.xpath("//div[#id='rb-calendar_onward_cal']/table/tbody/tr[4]/td[3]")).click();
driver.findElement(By.id("search_btn")).click();
String Busname=driver.findElement(By.xpath("//ul//li[2]//div[#class='service-name']")).getText();
String departTime=driver.findElement(By.xpath("//ul//li[2]//div[#class='fl depart']")).getText();
String arrivalTime=driver.findElement(By.xpath("//ul//li[2]//div[#class='fl arrive']")).getText();
String totalSeats=driver.findElement(By.xpath("//ul//li[2]//div[#class='fl seats']//span[#class='tot-seats']")).getText();
String fare=driver.findElement(By.xpath("//ul//li[2]//div[#class='fare']")).getText();
System.out.println(Busname+" "+departTime+" "+arrivalTime+" "+totalSeats+" "+fare );
driver.findElement(By.xpath("//ul//li[2]//button[#class='view-seats button to-be-hidden']")).click();
Actions builder=new Actions(driver);
wait.until(ExpectedConditions.visibilityOfElementLocated(By.xpath("//div[#class='upper-canvas canvas-wrapper']//canvas")));
WebElement Upper=driver.findElement(By.xpath("//div[#class='upper-canvas canvas-wrapper']//canvas"));
Action movetoUpper=builder.moveToElement(Upper).build();
movetoUpper.perform();
System.out.println("tooltip text"+ Upper.getAttribute("title"));
System.out.println("SEAT NO:"+ Upper.getText());
}
catch(NoSuchElementException ex) {
}
}
}