BindingPropertySetCreateHandler.java

package com.googlecode.gwt.test.gxt3.internal.handlers;

import com.googlecode.gwt.test.GwtCreateHandler;
import com.googlecode.gwt.test.exceptions.GwtTestException;
import com.googlecode.gwt.test.internal.GwtConfig;
import com.googlecode.gwt.test.utils.JavassistUtils;
import com.sencha.gxt.core.client.BindingPropertySet;
import com.sencha.gxt.core.client.BindingPropertySet.PropertyName;
import com.sencha.gxt.core.client.BindingPropertySet.PropertyValue;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

/**
 * Custom {@link GwtCreateHandler} implementation for {@link BindingPropertySet}
 * subtype instanciation.<strong>For internal use only.</strong>
 *
 * @author Gael Lazzari
 */
public class BindingPropertySetCreateHandler implements GwtCreateHandler {

    private static final class BindingPropertySetInvocationHandler implements
            InvocationHandler {

        private final String propertyName;
        private final Class<?> proxiedClass;

        private BindingPropertySetInvocationHandler(Class<?> proxiedClass) {
            this.proxiedClass = proxiedClass;
            this.propertyName = JavassistUtils.getInvisibleAnnotationStringValue(
                    proxiedClass, PropertyName.class, "value");
            if (propertyName == null) {
                throw new GwtTestException(proxiedClass.getName()
                        + " must be annotated with @" + PropertyName.class.getSimpleName());
            }
        }

        public Object invoke(Object proxy, Method method, Object[] args)
                throws Throwable {
            String propertyValue = JavassistUtils.getInvisibleAnnotationStringValue(
                    method, PropertyValue.class, "value");
            if (propertyValue == null) {
                throw new GwtTestException(method.toString()
                        + " must be annotated with @" + PropertyValue.class.getSimpleName());
            }

            if (method.getReturnType() != Boolean.TYPE
                    && method.getReturnType() != Boolean.class) {
                throw new GwtTestException(proxiedClass.getName()
                        + " must return a boolean");
            }

            return propertyValue.equals(GwtConfig.get().getModuleRunner().getClientProperty(
                    propertyName));
        }

    }

    /*
     * (non-Javadoc)
     *
     * @see com.googlecode.gwt.test.GwtCreateHandler#create(java.lang.Class)
     */
    public Object create(Class<?> classLiteral) throws Exception {
        if (!BindingPropertySet.class.isAssignableFrom(classLiteral)) {
            return null;
        }

        InvocationHandler ih = new BindingPropertySetInvocationHandler(classLiteral);
        return Proxy.newProxyInstance(classLiteral.getClassLoader(),
                new Class<?>[]{classLiteral}, ih);
    }

}