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
return Collections.EMPTY_MAP;
		}
		final Map parameterMap = new HashMap();
		for (int i = 0; i < parameterizations.length; i++) {
			final Parameterization parameterization = parameterizations[i];
			parameterMap.put(parameterization.getParameter().getId(),
					parameterization.getValue());
		}
		return parameterMap;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see java.lang.Object#hashCode()
	 */
	public final int hashCode() {
		if (hashCode == HASH_CODE_NOT_COMPUTED) {
			hashCode = HASH_INITIAL * HASH_FACTOR + Util.hashCode(command);
			hashCode = hashCode * HASH_FACTOR
					+ Util.hashCode(parameterizations);
			if (hashCode == HASH_CODE_NOT_COMPUTED) {
				hashCode++;
			}
		}
		return hashCode;
	}
	/**
	 * Returns a {@link String} containing the command id, parameter ids and
	 * parameter values for this {@link ParameterizedCommand}. The returned
	 * {@link String} can be stored by a client and later used to recontruct an