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
private final void fireCommandManagerChanged(final CommandManagerEvent event) {
		if (event == null)
			throw new NullPointerException();
		final Object[] listeners = getListeners();
		for (int i = 0; i < listeners.length; i++) {
			final ICommandManagerListener listener = (ICommandManagerListener) listeners[i];
			listener.commandManagerChanged(event);
		}
	}
	/**
	 * Gets the category with the given identifier. If no such category
	 * currently exists, then the category will be created (but be undefined).
	 * 
	 * @param categoryId
	 *            The identifier to find; must not be <code>null</code>. If
	 *            the category is <code>null</code>, then a category suitable
	 *            for uncategorized items is defined and returned.
	 * @return The category with the given identifier; this value will never be
	 *         <code>null</code>, but it might be undefined.
	 * @see Category
	 */
	public final Category getCategory(final String categoryId) {
		if (categoryId == null) {
			return getCategory(AUTOGENERATED_CATEGORY_ID);
		}
		checkId(categoryId);
		Category category = (Category) categoriesById.get(categoryId);
		if (category == null) {
			category = new Category(categoryId);
			categoriesById.put(categoryId, category);