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/ParameterizedCommand.java
* A command that has had one or more of its parameters specified. This class
 * serves as a utility class for developers that need to manipulate commands
 * with parameters. It handles the behaviour of generating a parameter map and a
 * human-readable name.
 * </p>
 * 
 * @since 3.1
 */
public final class ParameterizedCommand implements Comparable {
	/**
	 * The constant integer hash code value meaning the hash code has not yet
	 * been computed.
	 */
	private static final int HASH_CODE_NOT_COMPUTED = -1;
	/**
	 * A factor for computing the hash code for all parameterized commands.
	 */
	private static final int HASH_FACTOR = 89;
	/**
	 * The seed for the hash code for all parameterized commands.
	 */
	private static final int HASH_INITIAL = ParameterizedCommand.class
			.getName().hashCode();
	/**
	 * The index of the parameter id in the parameter values.
	 * 
	 * @deprecated no longer used
	 */
	public static final int INDEX_PARAMETER_ID = 0;
	/**