Sets the echo character.
<p>
The echo character is the character that is
displayed when the user enters text or the
text is changed by the programmer. Setting
the echo character to '\0' clears the echo
character and redraws the original text.
If for any reason the echo character is invalid,
or if the platform does not allow modification
of the echo character, the default echo character
for the platform is used.
</p>
@param echo the new echo character
@exception SWTException <ul>
<li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
<li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
</ul>
Sets the echo character. <p> The echo character is the character that is displayed when the user enters text or the text is changed by the programmer. Setting the echo character to '\0' clears the echo character and redraws the original text. If for any reason the echo character is invalid, or if the platform does not allow modification of the echo character, the default echo character for the platform is used. </p>
@param echo the new echo character
@exception SWTException <ul> <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> </ul>