Event structure meta-definition

Event Structures defined in the meta-definition specify EventStructure blocks used in Server => Client runtime communication.

Note that event blocks are defined for each widget, but it is better to have only one definition shared by all events of the same type, as for the parameter structure definitions.

Examples

Simple example

An empty EventStructure block Definition:

 <eventBlock id="empty">
   <pad size="16bit"/>
 </eventBlock>

Here (as specified in the standard), the ParameterStructure block contains only :

• One Padding of 16 bits

Another example

An EventStructure block Definition containing only one uchar data:

 <eventBlock id="uchar">
   <blockData size="8bit"/>
   <pad size="8bit"/>
 </eventBlock>

Here the EventStructure block contains only :

• One Padding of 16 bits
• One parameter of a 8 bit size (can be a bool, a char, an uchar)

Example for a String

Another ParameterStructure block Definition, specifying the A661_ParameterStructure_String message structure as specified in the standard:

 <eventBlock id="string">>
   <blockMetaData size="16bit" type="length"/>
   <blockData size="32bitArray" type="string cplxString" />
 </eventBlock>

Here the EventStructure block contains:

• An 16 bits field containing the length of the String (including the last \0 character)
• The parameter, whose size is an array of 32bit. To specify that we only want to have a String parameter, the type attribute specifies that the type of the data can only be a string or cplxString