com.gwtplatform.mvp.rebind.TabInfoMethod Maven / Gradle / Ivy

/*
 * Copyright 2011 ArcBees Inc.
 *
 * 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.gwtplatform.mvp.rebind;

import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.core.ext.typeinfo.JClassType;
import com.google.gwt.core.ext.typeinfo.JMethod;
import com.google.gwt.core.ext.typeinfo.JParameter;
import com.google.gwt.user.rebind.SourceWriter;
import com.gwtplatform.mvp.client.TabData;
import com.gwtplatform.mvp.client.annotations.TabInfo;

/**
 * Represents a static method, in the presenter, that returns tab information.
 */
public class TabInfoMethod {
    private final TreeLogger logger;
    private final ClassCollection classCollection;
    private final GinjectorInspector ginjectorInspector;
    private final PresenterInspector presenterInspector;

    private TabInfo annotation;
    private Integer tabPriority;
    private String functionName;
    private JParameter[] parameters;
    private boolean returnString; // Either returns a String or a TabInfo

    public TabInfoMethod(TreeLogger logger,
            ClassCollection classCollection,
            GinjectorInspector ginjectorInspector,
            PresenterInspector presenterInspector) {
        this.logger = logger;
        this.classCollection = classCollection;
        this.ginjectorInspector = ginjectorInspector;
        this.presenterInspector = presenterInspector;
    }

    public void init(JMethod method) throws UnableToCompleteException {
        annotation = method.getAnnotation(TabInfo.class);
        assert annotation != null;
        tabPriority = annotation.priority();
        if (tabPriority < 0) {
            tabPriority = null;
        }

        functionName = method.getName();
        if (!method.isStatic()) {
            logger.log(TreeLogger.ERROR, getErrorPrefix() + " is not static. This is not supported.");
            throw new UnableToCompleteException();
        }

        if (annotation.label().length() != 0) {
            logger.log(TreeLogger.ERROR, getErrorPrefix()
                    + ". The annotation defines a 'label', this is not permitted.", null);
            throw new UnableToCompleteException();
        }

        JClassType classReturnType = method.getReturnType().isClassOrInterface();
        if (classReturnType == classCollection.stringClass) {
            returnString = true;
        } else if (classReturnType.isAssignableFrom(classCollection.tabDataClass)) {
            returnString = false;
        } else {
            logger.log(TreeLogger.ERROR, getErrorPrefix() + " must return either a String or a "
                    + TabData.class.getSimpleName());
            throw new UnableToCompleteException();
        }

        parameters = method.getParameters();
        if (parameters.length > 0) {
            for (JParameter parameter : parameters) {
                final JClassType parameterType = parameter.getType().isClassOrInterface();
                if (!ginjectorInspector.getGinjectorClass().equals(parameterType) &&
                        ginjectorInspector.findGetMethod(parameterType) == null) {
                    logger.log(TreeLogger.ERROR, getErrorPrefix() + " has a parameter that is not provided by "
                            + ginjectorInspector.getGinjectorClassName() + ". This is illegal.");
                    throw new UnableToCompleteException();
                }
            }
        }

        if (tabPriority != null && !returnString) {
            logger.log(TreeLogger.ERROR, getErrorPrefix()
                    + ". The annotation defines a 'tabPriority' but the method returns TabData, "
                    + "this is not permitted.", null);
            throw new UnableToCompleteException();
        }
        if (tabPriority == null && returnString) {
            logger.log(TreeLogger.ERROR, getErrorPrefix()
                    + ". The annotation does not define a 'tabPriority' but the method returns a String, "
                    + "this is not permitted.", null);
            throw new UnableToCompleteException();
        }
    }

    private String getErrorPrefix() {
        return "In presenter " + presenterInspector.getPresenterClassName()
                + ", method " + functionName + " annotated with @" + TabInfo.class.getSimpleName();
    }

    /**
     * Writes the {@code getTabDataInternal} method definition in the generated proxy.
     *
     * @param writer The {@code SourceWriter}
     */
    public void writeGetTabDataInternalMethod(SourceWriter writer) throws UnableToCompleteException {
        if (returnString) {
            // Presenter static method returning a string
            assert tabPriority != null;
            writer.println();
            writer.println("protected TabData getTabDataInternal("
                    + ginjectorInspector.getGinjectorClassName() + " ginjector) {");
            writer.indent();
            writer.print("return new TabDataBasic(");
            writer.print(presenterInspector.getPresenterClassName() + ".");
            writeTabInfoFunctionCall(writer);
            writer.println(", " + tabPriority + ");");
            writer.outdent();
            writer.println("}");
        } else {
            // Presenter static method returning tab data
            writer.println();
            writer.println("protected TabData getTabDataInternal("
                    + ginjectorInspector.getGinjectorClassName() + " ginjector) {");
            writer.indent();
            writer.print("return ");
            writer.print(presenterInspector.getPresenterClassName() + ".");
            writeTabInfoFunctionCall(writer);
            writer.println(";");
            writer.outdent();
            writer.println("}");
        }
    }

    private void writeTabInfoFunctionCall(SourceWriter writer) throws UnableToCompleteException {
        writer.print(functionName + "(");
        for (int i = 0; i < parameters.length; i++) {
            if (i > 0) {
                writer.print(", ");
            }
            writer.print("ginjector");

            JParameter parameter = parameters[i];
            final JClassType returnType = parameter.getType().isClassOrInterface();
            if (!returnType.equals(ginjectorInspector.getGinjectorClass())) {
                writer.print(".");
                writer.print(ginjectorInspector.findGetMethod(returnType));
                writer.print("()");
            }
        }
        writer.print(")");
    }

    public String getTabContainerClassName() {
        return annotation.container().getCanonicalName();
    }

    public String getNameToken() {
        return annotation.nameToken();
    }
}