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com.github.nalukit.nalu.processor.scanner.EventHandlerAnnotationScanner Maven / Gradle / Ivy
/*
* Copyright (c) 2018 - Frank Hossfeld
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.github.nalukit.nalu.processor.scanner;
import com.github.nalukit.nalu.client.event.annotation.EventHandler;
import com.github.nalukit.nalu.processor.ProcessorException;
import com.github.nalukit.nalu.processor.ProcessorUtils;
import com.github.nalukit.nalu.processor.model.MetaModel;
import com.github.nalukit.nalu.processor.model.intern.ClassNameModel;
import com.github.nalukit.nalu.processor.model.intern.EventHandlerModel;
import com.github.nalukit.nalu.processor.model.intern.EventModel;
import org.gwtproject.event.shared.Event;
import javax.annotation.processing.ProcessingEnvironment;
import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.element.VariableElement;
import javax.lang.model.type.ArrayType;
import javax.lang.model.type.DeclaredType;
import javax.lang.model.type.ErrorType;
import javax.lang.model.type.PrimitiveType;
import javax.lang.model.type.TypeMirror;
import javax.lang.model.type.TypeVariable;
import javax.lang.model.util.SimpleTypeVisitor8;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
public class EventHandlerAnnotationScanner {
private final ProcessingEnvironment processingEnvironment;
private final MetaModel metaModel;
private final Element parentElement;
private ProcessorUtils processorUtils;
@SuppressWarnings("unused")
private EventHandlerAnnotationScanner(Builder builder) {
super();
this.processingEnvironment = builder.processingEnvironment;
this.metaModel = builder.metaModel;
this.parentElement = builder.parentElement;
setUp();
}
public static Builder builder() {
return new Builder();
}
private void setUp() {
this.processorUtils = ProcessorUtils.builder()
.processingEnvironment(this.processingEnvironment)
.build();
}
public EventMetaData scan()
throws ProcessorException {
EventMetaData eventMetaData = new EventMetaData();
List eventHandlerElement = this.processorUtils.getMethodFromTypeElementAnnotatedWith(this.processingEnvironment,
(TypeElement) this.parentElement,
EventHandler.class);
for (Element element : eventHandlerElement) {
if (!(element instanceof ExecutableElement)) {
throw new ProcessorException("NaluProcessor: element >>" +
this.parentElement.getSimpleName()
.toString() +
"<< is not of type ExecutableElement");
}
ExecutableElement executableElement = (ExecutableElement) element;
String methodName = executableElement.getSimpleName()
.toString();
// check number of paraemters --> should be 1!
if (executableElement.getParameters()
.size() == 0 ||
executableElement.getParameters()
.size() > 1) {
throw new ProcessorException("NaluProcessor: @EventHandler -> method >> " +
methodName +
"<< should have only one parameter and that should be an event");
}
VariableElement variableElement = executableElement.getParameters()
.get(0);
TypeElement eventElement = (TypeElement) this.processingEnvironment.getTypeUtils()
.asElement(variableElement.asType());
this.validateEvent(eventElement,
methodName);
TypeElement parentTypeElement = (TypeElement) this.parentElement;
EventHandlerModel eventHandlerModel = new EventHandlerModel(new ClassNameModel(parentTypeElement.getQualifiedName()
.toString()),
new ClassNameModel(eventElement.getQualifiedName()
.toString()),
methodName);
Optional optional = eventMetaData.getEventModels()
.stream()
.filter(e -> e.getEvent()
.getClassName()
.equals(eventElement.getQualifiedName()
.toString()))
.findFirst();
if (!optional.isPresent()) {
EventModel eventModel = this.scanEvent(eventElement,
methodName);
eventMetaData.getEventModels()
.add(eventModel);
}
eventMetaData.getEventHandlerModels()
.add(eventHandlerModel);
}
return eventMetaData;
}
private void validateEvent(TypeElement eventElement,
String methodName)
throws ProcessorException {
ProcessorUtils processorUtils = ProcessorUtils.builder()
.processingEnvironment(this.processingEnvironment)
.build();
if (!processorUtils.supertypeHasGeneric(this.processingEnvironment.getTypeUtils(),
eventElement.asType(),
this.processorUtils.getElements()
.getTypeElement(Event.class.getCanonicalName())
.asType())) {
throw new ProcessorException("NaluProcessor: class >>" +
eventElement.getQualifiedName()
.toString() +
"<< - method >>" +
methodName +
"<< has wrong data type. Parameter needs to extend org.gwtproject.event.shared.Event");
}
TypeMirror gwtEventHandlerTypeMirror = this.getGwtEventHandlerType(eventElement.asType());
if (Objects.isNull(gwtEventHandlerTypeMirror)) {
throw new ProcessorException("NaluProcessor: class >> " +
eventElement.getQualifiedName() +
"<< does not have a generic EventHandler defined");
}
}
private EventModel scanEvent(TypeElement eventElement,
String methodName)
throws ProcessorException {
ProcessorUtils processorUtils = ProcessorUtils.builder()
.processingEnvironment(this.processingEnvironment)
.build();
TypeMirror gwtEventMirror = processorUtils.getFlattenedSupertype(this.processingEnvironment.getTypeUtils(),
eventElement.asType(),
this.processorUtils.getElements()
.getTypeElement(Event.class.getCanonicalName())
.asType());
if (Objects.isNull(gwtEventMirror)) {
throw new ProcessorException("NaluProcessor: class >> " +
eventElement.getQualifiedName() +
"<< does not extend org.gwtproject.event.shared.Event");
}
if (!processorUtils.supertypeHasGeneric(this.processingEnvironment.getTypeUtils(),
gwtEventMirror,
this.processorUtils.getElements()
.getTypeElement(Event.class.getCanonicalName())
.asType())) {
throw new ProcessorException("NaluProcessor: class >>" +
eventElement.getQualifiedName()
.toString() +
"<< - method >>" +
methodName +
"<< has wrong data type. Parameter needs to extend org.gwtproject.event.shared.Event");
}
TypeMirror gwtEventHandlerTypeMirror = this.getGwtEventHandlerType(eventElement.asType());
if (Objects.isNull(gwtEventHandlerTypeMirror)) {
throw new ProcessorException("NaluProcessor: class >> " +
eventElement.getQualifiedName() +
"<< does not have a generic EventHandler defined");
}
TypeElement gwtEventHandlerElement = (TypeElement) this.processingEnvironment.getTypeUtils()
.asElement(gwtEventHandlerTypeMirror);
// Save to MetaModel
return new EventModel(new ClassNameModel(eventElement.getQualifiedName()
.toString()),
new ClassNameModel(gwtEventHandlerElement.getQualifiedName()
.toString()),
methodName);
}
private TypeMirror getGwtEventHandlerType(final TypeMirror typeMirror) {
final TypeMirror[] result = { null };
TypeMirror type = this.processorUtils.getFlattenedSupertype(this.processingEnvironment.getTypeUtils(),
typeMirror,
this.processorUtils.getElements()
.getTypeElement(Event.class.getCanonicalName())
.asType());
if (type == null) {
return result[0];
}
type.accept(new SimpleTypeVisitor8() {
@Override
protected Void defaultAction(TypeMirror typeMirror,
Void v) {
throw new UnsupportedOperationException();
}
@Override
public Void visitPrimitive(PrimitiveType primitiveType,
Void v) {
return null;
}
@Override
public Void visitArray(ArrayType arrayType,
Void v) {
return null;
}
@Override
public Void visitDeclared(DeclaredType declaredType,
Void v) {
List typeArguments = declaredType.getTypeArguments();
if (!typeArguments.isEmpty()) {
if (typeArguments.size() == 1) {
result[0] = typeArguments.get(0);
}
}
return null;
}
@Override
public Void visitError(ErrorType errorType,
Void v) {
return null;
}
@Override
public Void visitTypeVariable(TypeVariable typeVariable,
Void v) {
return null;
}
},
null);
return result[0];
}
public static class Builder {
ProcessingEnvironment processingEnvironment;
MetaModel metaModel;
Element parentElement;
public Builder processingEnvironment(ProcessingEnvironment processingEnvironment) {
this.processingEnvironment = processingEnvironment;
return this;
}
public Builder metaModel(MetaModel metaModel) {
this.metaModel = metaModel;
return this;
}
public Builder parentElement(Element parentElement) {
this.parentElement = parentElement;
return this;
}
public EventHandlerAnnotationScanner build() {
return new EventHandlerAnnotationScanner(this);
}
}
public class EventMetaData {
private final List eventHandlerModels;
private final List eventModels;
public EventMetaData() {
this.eventHandlerModels = new ArrayList<>();
this.eventModels = new ArrayList<>();
}
public List getEventHandlerModels() {
return eventHandlerModels;
}
public List getEventModels() {
return eventModels;
}
}
}
