title: Unable to locate the Element on Canvas using Selenium WebDriver
body: <p>I have an application developed by using Vaadin Framework, Now i need to click on the rectangular polygon which is on the Canvas.following is the html code 
  here i am providing the Html code</p>
  
  <pre><code>&lt;canvas width="1920" height="524" class="ol-unselectable" style="width: 100%; height: 100%;"&gt;&lt;/canvas&gt;
  </code></pre>
  
  <p>and i tried by using Actions which makes the mouse move over the Polygon and click .</p>
  
  <pre><code>int x = (int) 5638326.333511386;
  int y = (int)  2580101.9711508946;
  driver.get("http://localhost:8080/internship");
  
  WebElement ele = driver.findElement(By.xpath("//canvas[@class='ol-unselectable']"));
          //  driver.findElement(By.tagName("canvas"));
          //driver.findElemet(By.className("ol-unselectable"));
  try {
      Actions builder = new Actions(driver);
      builder.moveToElement(ele, x, y);
      builder.clickAndHold();
      builder.release();
      builder.perform();
      } catch (Exception e) {
          // do nothing
      }
  </code></pre>
  
  <p>i am getting the foloowing error </p>
  
  <blockquote>
    <p>org.openqa.selenium.NoSuchElementException: Unable to locate element:
    //canvas[@class='ol-unselectable'].</p>
  </blockquote>
  
  <p>can anyone suggest some samples how to find polygon on canvas with co-ordinates and make click on it.</p>