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/Command.java
stringBuffer.append(',');
			stringBuffer.append(name);
			stringBuffer.append(',');
			stringBuffer.append(description);
			stringBuffer.append(',');
			stringBuffer.append(category);
			stringBuffer.append(',');
			stringBuffer.append(handler);
			stringBuffer.append(',');
			stringBuffer.append(parameters);
			stringBuffer.append(',');
			stringBuffer.append(defined);
			stringBuffer.append(')');
			string = stringBuffer.toString();
		}
		return string;
	}
	/**
	 * Makes this command become undefined. This has the side effect of changing
	 * the name and description to <code>null</code>. This also removes all
	 * state and disposes of it. Notification is sent to all listeners.
	 */
	public final void undefine() {
		string = null;
		final boolean definedChanged = defined;
		defined = false;
		final boolean nameChanged = name != null;
		name = null;
		final boolean descriptionChanged = description != null;
		description = null;