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
for (int i = 0; i < parameterizationCount; i++) {
				final Parameterization parameterization = (Parameterization) parameterizations
						.get(i);
				final List combination = new ArrayList(1);
				combination.add(parameterization);
				parameterizations.set(i, combination);
			}
			return parameterizations;
		}
		final Collection returnValue = new ArrayList();
		final Iterator suffixItr = suffixes.iterator();
		while (suffixItr.hasNext()) {
			final List combination = (List) suffixItr.next();
			final int combinationSize = combination.size();
			for (int i = 0; i < parameterizationCount; i++) {
				final Parameterization parameterization = (Parameterization) parameterizations
						.get(i);
				final List newCombination = new ArrayList(combinationSize + 1);
				newCombination.add(parameterization);
				newCombination.addAll(combination);
				returnValue.add(newCombination);
			}
		}
		return returnValue;
	}
	/**
	 * <p>
	 * Generates all the possible combinations of command parameterizations for
	 * the given command. If the command has no parameters, then this is simply
	 * a parameterized version of that command. If a parameter is optional, both