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
* 
	 * @return The defined categories; this value may be empty, but it is never
	 *         <code>null</code>.
	 * @since 3.2
	 */
	public final Category[] getDefinedCategories() {
		final Category[] categories = new Category[definedCategoryIds.size()];
		final Iterator categoryIdItr = definedCategoryIds.iterator();
		int i = 0;
		while (categoryIdItr.hasNext()) {
			String categoryId = (String) categoryIdItr.next();
			categories[i++] = getCategory(categoryId);
		}
		return categories;
	}
	/**
	 * Returns the set of identifiers for those category that are defined.
	 * 
	 * @return The set of defined category identifiers; this value may be empty,
	 *         but it is never <code>null</code>.
	 */
	public final Set getDefinedCategoryIds() {
		return Collections.unmodifiableSet(definedCategoryIds);
	}
	/**
	 * Returns the set of identifiers for those commands that are defined.
	 * 
	 * @return The set of defined command identifiers; this value may be empty,
	 *         but it is never <code>null</code>.
	 */