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/ParameterizedCommand.java
*            a <code>String</code> to escape special characters in for
	 *            serialization.
	 * @return a <code>String</code> representing <code>rawText</code> with
	 *         special serialization characters escaped
	 * @see CommandManager#unescape(String)
	 * @since 3.2
	 */
	private static final String escape(final String rawText) {
		
		StringBuffer buffer = null;
		for (int i = 0; i < rawText.length(); i++) {
			char c = rawText.charAt(i);
			switch (c) {
			case CommandManager.PARAMETER_START_CHAR:
			case CommandManager.PARAMETER_END_CHAR:
			case CommandManager.ID_VALUE_CHAR:
			case CommandManager.PARAMETER_SEPARATOR_CHAR:
			case CommandManager.ESCAPE_CHAR:
				if (buffer == null)
					buffer = new StringBuffer(rawText.substring(0, i));
				buffer.append(CommandManager.ESCAPE_CHAR);
				buffer.append(c);
				break;
			default:
				if (buffer != null)
					buffer.append(c);
				break;
			}
		}
		if (buffer == null)