Difference between revisions of "Menu Contributions/Radio Button Command"

Revision as of 14:09, 10 October 2007

You can create a command with a required parameter. The parameter will be passed during every execution.

Command Definition

You want to create a command that will be executed with a paramter. The parameter in this example matches which of the radio buttons is selected.

<command
      categoryId="org.eclipse.ui.category.help"
      defaultHandler="z.ex.dropdown.internal.RadioHandler"
      id="z.ex.dropdown.radio"
      name="Radio Example">
   <commandParameter
         id="z.ex.dropdown.radio.info"
         name="Radio Name"
         optional="false">
   </commandParameter>
</command>

Handler

The handler will receive the parameter. It can then update its model (in my example my model is a local variable, but that might not be appropriate in command that can have multiple handlers).

package com.example.handlers.internal;

import java.util.Map;
import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.ui.commands.ICommandService;
import org.eclipse.ui.commands.IElementUpdater;
import org.eclipse.ui.handlers.HandlerUtil;
import org.eclipse.ui.menus.UIElement;

public class RadioHandler extends AbstractHandler implements IElementUpdater {

 private static final String PARM_INFO = "z.ex.dropdown.radio.info";
 private String fCurrentValue;

 public Object execute(ExecutionEvent event) throws ExecutionException {
   String parm = event.getParameter(PARM_INFO);
   if (parm.equals(fCurrentValue)) {
     return null; // in theory, we're already in the correct state
   }
   
   // do whatever having "parm" active implies
   fCurrentValue = parm;
   
   
   // update our radio button states ... get the service from
   // a place that's most appropriate
   ICommandService service = (ICommandService) HandlerUtil
       .getActiveWorkbenchWindowChecked(event).getService(
           ICommandService.class);
   service.refreshElements(event.getCommand().getId(), null);
   return null;
 }

 public void updateElement(UIElement element, Map parameters) {
   String parm = (String) parameters.get(PARM_INFO);
   if (parm != null) {
     if (fCurrentValue != null && fCurrentValue.equals(parm)) {
       element.setChecked(true);
     } else {
       element.setChecked(false);
     }
   }
 }
}

Menu Contribution

Then you add menu contributions with the specific parameters that you want:

     <menuContribution
           locationURI="menu:help?after=additions">
        <separator
              name="z.ex.dropdown.menu.separator1"
              visible="true">
        </separator>
        <command
              commandId="z.ex.dropdown.radio"
              id="z.ex.dropdown.menu.radio1"
              label="Moe"
              style="radio">
           <parameter
                 name="z.ex.dropdown.radio.info"
                 value="Moe">
           </parameter>
        </command>
        <command
              commandId="z.ex.dropdown.radio"
              id="z.ex.dropdown.menu.radio2"
              label="Larry"
              style="radio">
           <parameter
                 name="z.ex.dropdown.radio.info"
                 value="Larry">
           </parameter>
        </command>
        <command
              commandId="z.ex.dropdown.radio"
              id="z.ex.dropdown.menu.radio3"
              label="Curly"
              style="radio">
           <parameter
                 name="z.ex.dropdown.radio.info"
                 value="Curly">
           </parameter>
        </command>
        <separator
              name="z.ex.dropdown.menu.separator2"
              visible="true">
        </separator>
     </menuContribution>
  </extension>