Returns the receiver's alpha value. The alpha value is between 0 (transparent) and 255 (opaque).
@return the alpha value
@exception SWTException <ul> <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> </ul>
@since 3.1
See Implementation
Returns the receiver's alpha value. The alpha value is between 0 (transparent) and 255 (opaque).
@return the alpha value
@exception SWTException <ul> <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> </ul>
@since 3.1