Invokes platform specific functionality to allocate a new GC handle.
<p>
<b>IMPORTANT:</b> This method is <em>not</em> part of the public
API for <code>Display</code>. It is marked public only so that it
can be shared within the packages provided by SWT. It is not
available on all platforms, and should never be called from
application code.
</p>
@param data the platform specific GC data
@return the platform specific GC handle
@exception SWTException <ul>
<li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
</ul>
@exception SWTError <ul>
<li>ERROR_NO_HANDLES if a handle could not be obtained for gc creation</li>
</ul>
Invokes platform specific functionality to allocate a new GC handle. <p> <b>IMPORTANT:</b> This method is <em>not</em> part of the public API for <code>Display</code>. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code. </p>
@param data the platform specific GC data @return the platform specific GC handle
@exception SWTException <ul> <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li> </ul> @exception SWTError <ul> <li>ERROR_NO_HANDLES if a handle could not be obtained for gc creation</li> </ul>