IF element is not visible, or either width or height=0 this method will fail

comment updated as pe suggestion from aaltat:
Because it is not defined anywhere. I would just say:
The element width and height is returned.

An update for tests. In case element is doesn't have width or height  method must fail. Example for a <div></> which does not contain anything

Empty div will have height=0, and width will be equal to screen size.

Empty div will have height=0, and width will be equal to screen size.

Updates advised by Tatu Aalto

Forgot to update test

Author: SergiuTudos

src/Selenium2Library/keywords/_element.py

@@ -297,6 +297,16 @@ def get_horizontal_position(self, locator):
             raise AssertionError("Could not determine position for '%s'" % (locator))
         return element.location['x']
 
+    def get_element_size(self, locator):
+        """Returns width and height of element identified by `locator`.
+
+        The element width and height is returned.
+        Fails if a matching element is not found.
+        """
+        element = self._element_find(locator, True, True)
+
+        return element.size['width'], element.size['height']
+
     def get_value(self, locator):
         """Returns the value attribute of element identified by `locator`.
 

test/acceptance/keywords/elements.robot

@@ -69,3 +69,14 @@ Get Vertical Position
     Should Be True    ${pos} > ${0}
     Run Keyword And Expect Error    Could not determine position for 'non-existent'
     ...    Get Horizontal Position    non-existent
+
+
+Get Element Size
+	${width}  ${height}=  Get Element Size  link=Link
+	Should be True  ${height} > ${0}
+	Should be True  ${width} > ${0}
+	Run Keyword And Expect Error  ValueError: Element locator 'non-existent' did not match any elements.  Get Element Size  non-existent
+
+Get Empty Element Size
+    ${width}  ${height}=  Get Element Size  id=emptyDiv
+  	Should be True  ${height} == 0

test/resources/html/links.html

@@ -35,6 +35,7 @@
       <a href="target/second.html"><img src="robot.png" alt="Image"/></a>
       <a href="target/second.html">Link</a>
     </div>
+    <div id="emptyDiv"></div>
     <a href="index.html" target="_blank">Target opens in new window</a>
   </body>
 </html>