Bug 121709 [Commands] parameters: Add types
I'm going to attach a patch that adds support for typed command parameters. This addresses several issues: - parameter values are strings, but handlers may want to work on objects - multiple handlers of a command should have a consistent way of converting string parameter values to objects - tooling to construct parameterized commands that starts with object parameter values needs a way of producing string parameter values that will work when the command is executed - there should be a way to classify commands by their object parameter types so, given an object, a set of commands that may work with it can be suggested To address these issues, the patch allows parameter types to be declared in the extension-point XML. The example below defines a command for negating integers and a parameter type that works with it. <extension point="org.eclipse.ui.commands"> <command id="org.example.commands.negateInteger" defaultHandler="org.example.commands.NegateIntegerHandler" name="Negate an Integer"> <commandParameter id="param" name="the param" optional="false" typeId="org.example.commands.Integer"/> </command> <commandParameterType id="org.example.commands.Integer" converter="org.example.commands.IntegerConverter" type="java.lang.Integer"/> </extension> In addition to extending the schema for org.eclipse.ui.commands, code has been added to a number of plugins (primarily org.eclipse.core.commands) to support the notion of typed parameters.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/CommandManager.java
}
	/**
	 * Removes an execution listener from this command manager.
	 * 
	 * @param listener
	 *            The listener to be removed; must not be <code>null</code>.
	 */
	public final void removeExecutionListener(final IExecutionListener listener) {
		if (listener == null) {
			throw new NullPointerException("Cannot remove a null listener"); 
		}
		if (executionListeners == null) {
			return;
		}
		executionListeners.remove(listener);
		if (executionListeners.isEmpty()) {
			executionListeners = null;
			
			final Iterator commandItr = handleObjectsById.values().iterator();
			while (commandItr.hasNext()) {
				final Command command = (Command) commandItr.next();
				command.removeExecutionListener(executionListener);
			}
			executionListener = null;
		}
	}
	/**
	 * Block updates all of the handlers for all of the commands. If the handler
	 * is <code>null</code> or the command id does not exist in the map, then
	 * the command becomes unhandled. Otherwise, the handler is set to the