[news.eclipse.platform] enabledWhen for handlers and editors

[Karl Koster <klkoster@xxxxxxxxxxxxx>]

I am having a heck of a time trying to get a the main toolbar state to 
change when state in an editor changes. I have the same handler being 
used in the editor's context menu and it works fine (probably because 
the enabledWhen expression is evaluated every time the context menu is 
displayed.

This is the fragment from the plugin.xml for this particular menu/handler:

      <menuContribution 
locationURI="toolbar:org.eclipse.ui.main.toolbar?after=additions">
         <toolbar
               id="org.kdr.portfolio.toolbar">
            <command
                  commandId="org.kdr.risk.command.portfolio.save"
                  icon="icons/save.gif"
                  id="org.kdr.risk.toolbar.main.portfolio.save"
                  mnemonic="%action.save.mnemonic"
                  style="push"
                  tooltip="%portfolio.save.tooltip">
               <visibleWhen
                     checkEnabled="false">
                  <and>
                     <reference 
definitionId="org.kdr.risk.definition.portfolio.editor">
                     </reference>
                  </and>
               </visibleWhen>
            </command>
         </toolbar>
      </menuContribution>

----------------------------------------------------------------------------

      <handler
            class="org.kdr.ui.handler.SaveHandler"
            commandId="org.kdr.risk.command.portfolio.save">
         <activeWhen>
            <or>
               <reference
                     definitionId="org.kdr.risk.definition.portfolio.view">
               </reference>
               <reference

definitionId="org.kdr.risk.definition.portfolio.editor">
               </reference>
            </or>
         </activeWhen>
         <enabledWhen>
            <and>
               <reference

definitionId="org.kdr.risk.definition.portfolio.security.delete">
               </reference>
               <reference
                  definitionId="org.kdr.risk.definition.portfolio.editor">
               </reference>
               <reference
                  definitionId="org.kdr.risk.definition.portfolio.dirty">
                </reference>
            </and>
         </enabledWhen>
      </handler>

All conditions used referenced expressions so the can (and are) reused. 
All of the expressions are firing correctly (i.e. initial state of the 
toolbar button is correct for the possible state scenarios). However, 
when the state of the editor changes, it appears that the handler 
expressions are not being re-evaluated. All controls on the editor (an 
RCP form) have listeners registered to invoke comparison of the control 
state vs. the model's state. No state is saved to the model until the 
"Save" button is pressed. Hence the need for the toolbar button. If a 
difference between the model and control is found a property change 
event is fired (i.e. 
firePropertyChange(IWorkbenchPartConstants.PROP_DIRTY)). Is there some 
other notification mechanism I should be using to cause the handler's 
enabledWhen expression to re-evaluate?

Any and all help would be appreciated.

Thanks,
Karl