Warn about useless handler property redefinitions

When polymorphism or a priority is defined at listener-level and then
identically defined for a specific handler, a warning is issued.

This does not affect redefinitions of default values.
This commit is contained in:
Kai S. K. Engelbart 2021-03-14 14:38:43 +01:00
parent 32dfe64c0f
commit 7357198d45
Signed by: kske
GPG Key ID: 8BEB13EC5DF7EF13

View File

@ -84,8 +84,44 @@ public class EventProcessor extends AbstractProcessor {
} }
} }
// Get the listener containing this handler
TypeElement listener = (TypeElement) eventHandler.getEnclosingElement();
// Default properties
boolean defPolymorphic = false;
int defPriority = 100;
// Listener-level polymorphism
Polymorphic listenerPolymorphic = listener.getAnnotation(Polymorphic.class);
boolean hasListenerPolymorphic = listenerPolymorphic != null;
// Listener-level priority
Priority listenerPriority = listener.getAnnotation(Priority.class);
boolean hasListenerPriority = listenerPriority != null;
// Effective polymorphism
boolean polymorphic =
hasListenerPolymorphic ? listenerPolymorphic.value() : defPolymorphic;
boolean hasHandlerPolymorphic = eventHandler.getAnnotation(Polymorphic.class) != null;
if (hasHandlerPolymorphic)
polymorphic = eventHandler.getAnnotation(Polymorphic.class).value();
// Effective priority
int priority = hasListenerPriority ? listenerPriority.value() : defPriority;
boolean hasHandlerPriority = eventHandler.getAnnotation(Priority.class) != null;
if (hasHandlerPriority)
priority = eventHandler.getAnnotation(Priority.class).value();
// Detect useless polymorphism redefinition
if (hasListenerPolymorphic && hasHandlerPolymorphic
&& listenerPolymorphic.value() == polymorphic)
warning(eventHandler, "@Polymorphism is already defined at listener level");
// Detect useless priority redefinition
if (hasListenerPriority && hasHandlerPriority && listenerPriority.value() == priority)
warning(eventHandler, "@Priority is already defined at the listener level");
// Detect missing or useless @Polymorphic // Detect missing or useless @Polymorphic
boolean polymorphic = eventHandler.getAnnotation(Polymorphic.class) != null;
Element eventElement = ((DeclaredType) eventType).asElement(); Element eventElement = ((DeclaredType) eventType).asElement();
// Check for handlers for abstract types that aren't polymorphic // Check for handlers for abstract types that aren't polymorphic