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
*            The name of the category for uncategorized commands; must not
	 *            be <code>null</code>.
	 * @param description
	 *            The description of the category for uncategorized commands;
	 *            may be <code>null</code>.
	 * @since 3.2
	 */
	public final void defineUncategorizedCategory(final String name,
			final String description) {
		final Category category = getCategory(AUTOGENERATED_CATEGORY_ID);
		category.define(name, description);
	}
	/**
	 * <p>
	 * Returns a {@link ParameterizedCommand} with a command and
	 * parameterizations as specified in the provided
	 * <code>serializedParameterizedCommand</code> string. The
	 * <code>serializedParameterizedCommand</code> must use the format
	 * returned by {@link ParameterizedCommand#serialize()} and described in the
	 * Javadoc for that method.
	 * </p>
	 * <p>
	 * If a parameter id encoded in the
	 * <code>serializedParameterizedCommand</code> does not exist in the
	 * encoded command, that parameter id and value are ignored. A given
	 * parameter id should not be used more than once in
	 * <code>serializedParameterizedCommand</code>. This will not result in
	 * an exception, but in this case the value of the parameter when the
	 * command is executed is unspecified.
	 * </p>