Get the width and height in pixels for the specified image.
The values of width and height are returned as -1 if the values cannot be obtained (for instance, if the
object is not onscreen).
If the size can not be obtained (e.g. missing support), x and y are set to -1.
| this |
a Object instance that implements AtkImageIface |
| width |
filled with the image width, or -1 if the value cannot be obtained. |
| height |
filled with the image height, or -1 if the value cannot be obtained. |