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
* The index of the human-readable name of the parameter itself, in the
	 * parameter values.
	 * 
	 * @deprecated no longer used
	 */
	public static final int INDEX_PARAMETER_NAME = 1;
	/**
	 * The index of the human-readable name of the value of the parameter for
	 * this command.
	 * 
	 * @deprecated no longer used
	 */
	public static final int INDEX_PARAMETER_VALUE_NAME = 2;
	/**
	 * The index of the value of the parameter that the command can understand.
	 * 
	 * @deprecated no longer used
	 */
	public static final int INDEX_PARAMETER_VALUE_VALUE = 3;
	/**
	 * Escapes special characters in the command id, parameter ids and parameter
	 * values for {@link #serialize()}. The special characters
	 * {@link CommandManager#PARAMETER_START_CHAR},
	 * {@link CommandManager#PARAMETER_END_CHAR},
	 * {@link CommandManager#ID_VALUE_CHAR},
	 * {@link CommandManager#PARAMETER_SEPARATOR_CHAR} and
	 * {@link CommandManager#ESCAPE_CHAR} are escaped by prepending a
	 * {@link CommandManager#ESCAPE_CHAR} character.
	 * 
	 * @param rawText