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/CommandManager.java
case ESCAPE_CHAR:
						buffer.append(c);
						break;
					default:
						throw new SerializationException(
								"Invalid character '" + c + "' in escape sequence"); 
					}
				} else {
					throw new SerializationException(
							"Unexpected termination of escape sequence"); 
				}
			}
		}
		if (buffer == null)
			return escapedText;
		return buffer.toString();
	}
	/**
	 * The map of category identifiers (<code>String</code>) to categories (
	 * <code>Category</code>). This collection may be empty, but it is never
	 * <code>null</code>.
	 */
	private final Map categoriesById = new HashMap();
	/**
	 * The set of identifiers for those categories that are defined. This value
	 * may be empty, but it is never <code>null</code>.
	 */
	private final Set definedCategoryIds = new HashSet();
	/**
	 * The execution listener for this command manager. This just forwards