Bug 118429 [DataBinding] Validation should use IStatus, not just Strings
In order to use data binding in Workbench or IDE dialogs and preference pages, we need validation in terms of IStatus objects. Using strings is too simplistic. For example, look at the wizard for creating a new class. You will get a warning if the class name does not start with an uppercase letter, or if you don't provide a package name, but you will still be able to click "Finish" to proceed anyway. (Note that IStatus is currently not on the classpath, we need to re-introduce the dependency on org.eclipse.equinox.common, which contains IStatus etc.)
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/DefaultBindSupportFactory.java
private static final String INTEGER_TYPE = "java.lang.Integer.TYPE"; 
	private static final String BYTE_TYPE = "java.lang.Byte.TYPE"; 
	private static final String DOUBLE_TYPE = "java.lang.Double.TYPE"; 
	private static final String BOOLEAN_TYPE = "java.lang.Boolean.TYPE"; 
	private static final String FLOAT_TYPE = "java.lang.Float.TYPE"; 
	private static final String LONG_TYPE = "java.lang.Long.TYPE"; 
	private static final String SHORT_TYPE = "java.lang.Short.TYPE"; 
	private ValidatorRegistry validatorRegistry = new ValidatorRegistry();
	private Map converterMap;
	public IValidator createValidator(Object fromType, Object toType) {
		if (fromType == null || toType == null) {
			return new IValidator() {
				public ValidationError isPartiallyValid(Object value) {
					return null;
				}
				public ValidationError isValid(Object value) {
					return null;