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
* corresponding value in the map.
	 * 
	 * @param handlersByCommandId
	 *            A map of command identifiers (<code>String</code>) to
	 *            handlers (<code>IHandler</code>). This map may be
	 *            <code>null</code> if all handlers should be cleared.
	 *            Similarly, if the map is empty, then all commands will become
	 *            unhandled.
	 */
	public final void setHandlersByCommandId(final Map handlersByCommandId) {
		
		final Iterator commandIdItr = handlersByCommandId.keySet().iterator();
		while (commandIdItr.hasNext()) {
			getCommand((String) commandIdItr.next());
		}
		
		final Iterator commandItr = handleObjectsById.values().iterator();
		while (commandItr.hasNext()) {
			final Command command = (Command) commandItr.next();
			final String commandId = command.getId();
			final Object value = handlersByCommandId.get(commandId);
			if (value instanceof IHandler) {
				command.setHandler((IHandler) value);
			} else {
				command.setHandler(null);
			}
		}
	}
	/**
	 * Searches for the index of a <code>char</code> in a <code>String</code>