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/Command.java
&& ((DEBUG_HANDLERS_COMMAND_ID == null) || (DEBUG_HANDLERS_COMMAND_ID
						.equals(id)))) {
			final StringBuffer buffer = new StringBuffer("Command('"); 
			buffer.append(id);
			buffer.append("') has changed to "); 
			if (handler == null) {
				buffer.append("no handler"); 
			} else {
				buffer.append('\'');
				buffer.append(handler);
				buffer.append("' as its handler"); 
			}
			Tracing.printTrace("HANDLERS", buffer.toString());  
		}
		
		fireCommandChanged(new CommandEvent(this, false, false, false, true,
				false, false));
		return true;
	}
	/**
	 * The string representation of this command -- for debugging purposes only.
	 * This string should not be shown to an end user.
	 * 
	 * @return The string representation; never <code>null</code>.
	 */
	public final String toString() {
		if (string == null) {
			final StringBuffer stringBuffer = new StringBuffer();
			stringBuffer.append("Command("); 
			stringBuffer.append(id);