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/Command.java
}
		final Object[] listeners = getListeners();
		for (int i = 0; i < listeners.length; i++) {
			final ICommandListener listener = (ICommandListener) listeners[i];
			listener.commandChanged(commandEvent);
		}
	}
	/**
	 * Notifies the execution listeners for this command that an attempt to
	 * execute has failed because the command is not defined.
	 * 
	 * @param e
	 *            The exception that is about to be thrown; never
	 *            <code>null</code>.
	 * @since 3.2
	 */
	private final void fireNotDefined(final NotDefinedException e) {
		
		if (DEBUG_COMMAND_EXECUTION) {
			Tracing.printTrace("COMMANDS", "execute" + Tracing.SEPARATOR 
					+ "not defined: id=" + getId() + "; exception=" + e); 
		}
		
		if (executionListeners != null) {
			final Object[] listeners = executionListeners.getListeners();
			for (int i = 0; i < listeners.length; i++) {
				final Object object = listeners[i];
				if (object instanceof IExecutionListenerWithChecks) {
					final IExecutionListenerWithChecks listener = (IExecutionListenerWithChecks) object;
					listener.notDefined(getId(), e);