Description Brian de Alwis 2011-11-17 12:57:40 EST

In seeking to extend "padding" support (bug XXXXXX), I realized I had no idea what the "composite" attribute meant when defining a property handler in a plugin.xml.  The schema definition has no details, and the code in CSSSWTEngineImpl#initializeCSSPropertyHandlers() seems to have a subtle bug:

			for (IConfigurationElement ce : e.getConfigurationElements()) {  // line 100
				if (ce.getName().equals("handler")) {
					String name = ce.getAttribute("composite");
					String adapter = ce.getAttribute("adapter");
//					if (className.equals(adapter)) {
						IConfigurationElement[] children = ce.getChildren();
						String[] names = new String[children.length];
						for (int i = 0; i < children.length; i++) {
							if (children[i].getName().equals("property-name"))
								names[i] =  children[i].getAttribute("name");
						}
						try {
							if (handlersMap.containsKey(adapter)) {
								HashMap adapterMap = (HashMap) handlersMap.get(adapter);
								if (!adapterMap.containsKey(name)){ // 114

"composite" is defined (and used) as an optional boolean value — not a name as on line 102.  On line 114, this "composite" boolean value (possibly blank, or "true" or "false") is looked up in the adapterMap, which is actually keyed by adapter class names, and so this conditional expression is always true.

Some of the handlers defined in org.eclipse.e4.ui.css.swt do set composite=false.  I suspect it was an attempt to define a composite property using other property handlers?