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/ExecutionEvent.java
/**
	 * The state of the application at the time the execution was triggered. In
	 * the Eclipse workbench, this might contain information about the active
	 * part of the active selection (for example). This value may be
	 * <code>null</code>.
	 */
	private final Object applicationContext;
	/**
	 * The parameters to qualify the execution. For handlers that normally
	 * prompt for additional information, these can be used to avoid prompting.
	 * This value may be empty, but it is never <code>null</code>.
	 */
	private final Map parameters;
	/**
	 * The object that triggered the execution. In an event-driven architecture,
	 * this is typically just another event. In the Eclipse workbench, this is
	 * typically an SWT event. This value may be <code>null</code>.
	 */