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
* but disregards characters prefixed with the {@link #ESCAPE_CHAR} escape
	 * character. This is used by {@link #deserialize(String)} and
	 * {@link #getParameterizations(String, IParameter[])} to parse the
	 * serialized parameterized command string.
	 * 
	 * @param escapedText
	 *            the string to search for the index of <code>ch</code> in
	 * @param ch
	 *            a character to search for in <code>escapedText</code>
	 * @return the index of the first unescaped occurrence of the character in
	 *         <code>escapedText</code>, or <code>-1</code> if the
	 *         character does not occur unescaped.
	 * @see String#indexOf(int)
	 */
	private final int unescapedIndexOf(final String escapedText, final char ch) {
		int pos = escapedText.indexOf(ch);
		
		if (pos == 0)
			return pos;
		while (pos != -1) {
			
			if (escapedText.charAt(pos - 1) != ESCAPE_CHAR)
				return pos;
			
			pos = escapedText.indexOf(ch, pos + 1);
		}
		return pos;
	}
}