content: /**
   * Copyright (C) 2010-2016 eBusiness Information, Excilys Group
   *
   * 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 org.androidannotations.internal.core.handler;
  
  import static com.helger.jcodemodel.JExpr._new;
  import static com.helger.jcodemodel.JExpr.lit;
  
  import javax.lang.model.element.Element;
  import javax.lang.model.element.ExecutableElement;
  
  import org.androidannotations.AndroidAnnotationsEnvironment;
  import org.androidannotations.ElementValidation;
  import org.androidannotations.annotations.UiThread;
  import org.androidannotations.api.UiThreadExecutor;
  import org.androidannotations.holder.EComponentHolder;
  
  import com.helger.jcodemodel.AbstractJClass;
  import com.helger.jcodemodel.IJExpression;
  import com.helger.jcodemodel.JBlock;
  import com.helger.jcodemodel.JClassAlreadyExistsException;
  import com.helger.jcodemodel.JConditional;
  import com.helger.jcodemodel.JDefinedClass;
  import com.helger.jcodemodel.JMethod;
  import com.helger.jcodemodel.JOp;
  
  public class UiThreadHandler extends AbstractRunnableHandler {
  
  	private static final String METHOD_CUR_THREAD = "currentThread";
  	private static final String METHOD_MAIN_LOOPER = "getMainLooper";
  	private static final String METHOD_GET_THREAD = "getThread";
  	private static final String METHOD_RUN_TASK = "runTask";
  
  	public UiThreadHandler(AndroidAnnotationsEnvironment environment) {
  		super(UiThread.class, environment);
  	}
  
  	@Override
  	public void validate(Element element, ElementValidation valid) {
  		super.validate(element, valid);
  
  		coreValidatorHelper.usesEnqueueIfHasId(element, valid);
  
  		UiThread annotation = element.getAnnotation(UiThread.class);
  		long delay = annotation.delay();
  		UiThread.Propagation propagation = annotation.propagation();
  		if (delay != 0 && propagation == UiThread.Propagation.REUSE) {
  			valid.addWarning("propagation=REUSE is ignored when using a delay");
  		}
  	}
  
  	@Override
  	public void process(Element element, EComponentHolder holder) throws Exception {
  		ExecutableElement executableElement = (ExecutableElement) element;
  		JMethod delegatingMethod = codeModelHelper.overrideAnnotatedMethod(executableElement, holder);
  		JBlock previousBody = codeModelHelper.removeBody(delegatingMethod);
  		JDefinedClass anonymousRunnableClass = codeModelHelper.createDelegatingAnonymousRunnableClass(previousBody);
  
  		UiThread annotation = element.getAnnotation(UiThread.class);
  		long delay = annotation.delay();
  		UiThread.Propagation propagation = annotation.propagation();
  
  		if (delay == 0 && propagation == UiThread.Propagation.REUSE) {
  			// Put in the check for the UI thread.
  			addUIThreadCheck(delegatingMethod, previousBody, holder);
  		}
  		delegatingMethod.body().add(getJClass(UiThreadExecutor.class).staticInvoke(METHOD_RUN_TASK) //
  				.arg(annotation.id()) //
  				.arg(_new(anonymousRunnableClass)) //
  				.arg(lit(delay)));
  	}
  
  	/**
  	 * Add the pre-check to see if we are already in the UI thread.
  	 *
  	 * @param delegatingMethod
  	 * @param holder
  	 * @throws JClassAlreadyExistsException
  	 */
  	private void addUIThreadCheck(JMethod delegatingMethod, JBlock previousBody, EComponentHolder holder) throws JClassAlreadyExistsException {
  		// Get the Thread and Looper class.
  		AbstractJClass tClass = getClasses().THREAD;
  		AbstractJClass lClass = getClasses().LOOPER;
  
  		// invoke the methods.
  		IJExpression lhs = tClass.staticInvoke(METHOD_CUR_THREAD);
  		IJExpression rhs = lClass.staticInvoke(METHOD_MAIN_LOOPER).invoke(METHOD_GET_THREAD);
  
  		// create the conditional and the block.
  		JConditional con = delegatingMethod.body()._if(JOp.eq(lhs, rhs));
  		JBlock thenBlock = con._then().add(previousBody);
  		thenBlock._return();
  	}
  
  }
  