/*
* Copyright 2008 Google 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.google.gwt.resources.rebind.context;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.ext.BadPropertyValueException;
import com.google.gwt.core.ext.Generator;
import com.google.gwt.core.ext.GeneratorContext;
import com.google.gwt.core.ext.PropertyOracle;
import com.google.gwt.core.ext.SelectionProperty;
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.JType;
import com.google.gwt.core.ext.typeinfo.TypeOracle;
import com.google.gwt.dev.generator.NameFactory;
import com.google.gwt.dev.util.Util;
import com.google.gwt.resources.client.ClientBundle;
import com.google.gwt.resources.client.ClientBundleWithLookup;
import com.google.gwt.resources.client.ResourcePrototype;
import com.google.gwt.resources.ext.ClientBundleFields;
import com.google.gwt.resources.ext.ClientBundleRequirements;
import com.google.gwt.resources.ext.ResourceContext;
import com.google.gwt.resources.ext.ResourceGenerator;
import com.google.gwt.resources.ext.ResourceGeneratorType;
import com.google.gwt.resources.rg.BundleResourceGenerator;
import com.google.gwt.user.rebind.ClassSourceFileComposerFactory;
import com.google.gwt.user.rebind.SourceWriter;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* The base class for creating new ClientBundle implementations.
*/
public abstract class AbstractClientBundleGenerator extends Generator {
/**
* An implementation of ClientBundleFields.
*/
protected static class FieldsImpl implements ClientBundleFields {
private final NameFactory factory = new NameFactory();
/**
* It is necessary to maintain order in case one field refers to another.
*/
private final Map<String, String> fieldsToDeclarations = new LinkedHashMap<String, String>();
private final Map<String, String> fieldsToInitializers = new HashMap<String, String>();
public void addName(String name) {
factory.addName(name);
}
public String define(JType type, String name) {
return define(type, name, null, true, false);
}
public String define(JType type, String name, String initializer,
boolean isStatic, boolean isFinal) {
assert Util.isValidJavaIdent(name) : name
+ " is not a valid Java identifier";
String ident = factory.createName(name);
StringBuilder sb = new StringBuilder();
sb.append("private ");
if (isStatic) {
sb.append("static ");
}
if (isFinal) {
sb.append("final ");
}
sb.append(type.getQualifiedSourceName());
sb.append(" ");
sb.append(ident);
fieldsToDeclarations.put(ident, sb.toString());
if (initializer != null) {
fieldsToInitializers.put(ident, initializer);
}
return ident;
}
/**
* This can be called to reset the initializer expression on an
* already-defined field.
*
* @param ident an identifier previously returned by {@link #define}
* @param initializer a Java expression that will be used to initialize the
* field
*/
public void setInitializer(String ident, String initializer) {
assert fieldsToDeclarations.containsKey(ident) : ident + " not defined";
fieldsToInitializers.put(ident, initializer);
}
private String getCode() {
StringBuilder sb = new StringBuilder();
for (Map.Entry<String, String> entry : fieldsToDeclarations.entrySet()) {
String ident = entry.getKey();
sb.append(entry.getValue());
String initializer = fieldsToInitializers.get(ident);
if (initializer != null) {
sb.append(" = ").append(initializer);
}
sb.append(";\n");
}
return sb.toString();
}
}
private static class RequirementsImpl implements ClientBundleRequirements {
private final Set<String> axes = new HashSet<String>();
private final PropertyOracle oracle;
public RequirementsImpl(PropertyOracle oracle) {
this.oracle = oracle;
}
public void addPermutationAxis(String propertyName)
throws BadPropertyValueException {
// Ensure the property exists and add a permutation axis if the
// property is a deferred binding property.
try {
oracle.getSelectionProperty(TreeLogger.NULL, propertyName).getCurrentValue();
axes.add(propertyName);
} catch (BadPropertyValueException e) {
oracle.getConfigurationProperty(propertyName).getValues();
}
}
}
public final String generate(TreeLogger logger,
GeneratorContext generatorContext, String typeName)
throws UnableToCompleteException {
// The TypeOracle knows about all types in the type system
TypeOracle typeOracle = generatorContext.getTypeOracle();
// Get a reference to the type that the generator should implement
JClassType sourceType = typeOracle.findType(typeName);
// Ensure that the requested type exists
if (sourceType == null) {
logger.log(TreeLogger.ERROR, "Could not find requested typeName");
throw new UnableToCompleteException();
} else if (sourceType.isInterface() == null) {
// The incoming type wasn't a plain interface, we don't support
// abstract base classes
logger.log(TreeLogger.ERROR, sourceType.getQualifiedSourceName()
+ " is not an interface.", null);
throw new UnableToCompleteException();
}
/*
* This associates the methods to implement with the ResourceGenerator class
* that will generate the implementations of those methods.
*/
Map<Class<? extends ResourceGenerator>, List<JMethod>> taskList = createTaskList(
logger, typeOracle, sourceType);
/*
* Additional objects that hold state during the generation process.
*/
AbstractResourceContext resourceContext = createResourceContext(logger,
generatorContext, sourceType);
FieldsImpl fields = new FieldsImpl();
RequirementsImpl requirements = new RequirementsImpl(
generatorContext.getPropertyOracle());
doAddFieldsAndRequirements(logger, generatorContext, fields, requirements);
/*
* Initialize the ResourceGenerators and prepare them for subsequent code
* generation.
*/
Map<ResourceGenerator, List<JMethod>> generators = initAndPrepare(logger,
taskList, resourceContext, requirements);
/*
* Now that the ResourceGenerators have been initialized and prepared, we
* can compute the actual name of the implementation class in order to
* ensure that we use a distinct name between permutations.
*/
String generatedSimpleSourceName = generateSimpleSourceName(logger,
resourceContext, requirements);
String packageName = sourceType.getPackage().getName();
String createdClassName = packageName + "." + generatedSimpleSourceName;
PrintWriter out = generatorContext.tryCreate(logger, packageName,
generatedSimpleSourceName);
// If an implementation already exists, we don't need to do any work
if (out != null) {
// There is actual work to do
doCreateBundleForPermutation(logger, generatorContext, fields,
generatedSimpleSourceName);
// Begin writing the generated source.
ClassSourceFileComposerFactory f = new ClassSourceFileComposerFactory(
packageName, generatedSimpleSourceName);
// The generated class needs to be able to determine the module base URL
f.addImport(GWT.class.getName());
// Used by the map methods
f.addImport(ResourcePrototype.class.getName());
// The whole point of this exercise
f.addImplementedInterface(sourceType.getQualifiedSourceName());
// All source gets written through this Writer
SourceWriter sw = f.createSourceWriter(generatorContext, out);
// Set the now-calculated simple source name
resourceContext.setSimpleSourceName(generatedSimpleSourceName);
// Write the generated code to disk
createFieldsAndAssignments(logger, sw, generators, resourceContext,
fields);
// Print the accumulated field definitions
sw.println(fields.getCode());
/*
* The map-accessor methods use JSNI and need a fully-qualified class
* name, but should not include any sub-bundles.
*/
taskList.remove(BundleResourceGenerator.class);
writeMapMethods(logger, createdClassName, sw, taskList);
sw.commit(logger);
}
finish(logger, resourceContext, generators.keySet());
doFinish(logger);
// Return the name of the concrete class
return createdClassName;
}
/**
* Create the ResourceContext object that will be used by
* {@link ResourceGenerator} subclasses. This is the primary way to implement
* custom logic in the resource generation pass.
*/
protected abstract AbstractResourceContext createResourceContext(
TreeLogger logger, GeneratorContext context, JClassType resourceBundleType)
throws UnableToCompleteException;
/**
* Provides a hook for subtypes to add additional fields or requirements to
* the bundle.
*
* @param logger a TreeLogger
* @param context the GeneratorContext
* @param fields ClentBundle fields
* @param requirements ClientBundleRequirements
*
* @throws UnableToCompleteException if an error occurs.
*/
protected void doAddFieldsAndRequirements(TreeLogger logger,
GeneratorContext context, FieldsImpl fields,
ClientBundleRequirements requirements) throws UnableToCompleteException {
}
/**
* This method is called after the ClientBundleRequirements have been
* evaluated and a new ClientBundle implementation is being created.
*
* @param logger a TreeLogger
* @param generatorContext the GeneratoContext
* @param fields ClientBundle fields
* @param generatedSimpleSourceName a String
*
* @throws UnableToCompleteException if an error occurs.
*/
protected void doCreateBundleForPermutation(TreeLogger logger,
GeneratorContext generatorContext, FieldsImpl fields,
String generatedSimpleSourceName) throws UnableToCompleteException {
}
/**
* Provides a hook for finalizing generated resources.
*
* @param logger a TreeLogger
*
* @throws UnableToCompleteException if an error occurs.
*/
protected void doFinish(TreeLogger logger) throws UnableToCompleteException {
}
/**
* Create fields and assignments for a single ResourceGenerator.
*/
private boolean createFieldsAndAssignments(TreeLogger logger,
AbstractResourceContext resourceContext, ResourceGenerator rg,
List<JMethod> generatorMethods, SourceWriter sw, ClientBundleFields fields) {
// Defer failure until this phase has ended
boolean fail = false;
resourceContext.setCurrentResourceGenerator(rg);
// Write all field values
try {
rg.createFields(logger.branch(TreeLogger.DEBUG, "Creating fields"),
resourceContext, fields);
} catch (UnableToCompleteException e) {
return false;
}
// Create the instance variables in the IRB subclass by calling
// writeAssignment() on the ResourceGenerator
for (JMethod m : generatorMethods) {
String rhs;
try {
rhs = rg.createAssignment(logger.branch(TreeLogger.DEBUG,
"Creating assignment for " + m.getName() + "()"), resourceContext,
m);
} catch (UnableToCompleteException e) {
fail = true;
continue;
}
String ident = fields.define(m.getReturnType().isClassOrInterface(),
m.getName(), null, true, false);
// Strip off all but the access modifiers
sw.print(m.getReadableDeclaration(false, true, true, true, true));
sw.println(" {");
sw.indent();
sw.println("if (" + ident + " == null) {");
sw.indent();
sw.println(ident + " = " + rhs + ";");
sw.outdent();
sw.println("}");
sw.println("return " + ident + ";");
sw.outdent();
sw.println("}");
}
if (fail) {
return false;
}
return true;
}
/**
* Create fields and assignments for multiple ResourceGenerators.
*/
private void createFieldsAndAssignments(TreeLogger logger, SourceWriter sw,
Map<ResourceGenerator, List<JMethod>> generators,
AbstractResourceContext resourceContext, ClientBundleFields fields)
throws UnableToCompleteException {
// Try to provide as many errors as possible before failing.
boolean success = true;
// Run the ResourceGenerators to generate implementations of the methods
for (Map.Entry<ResourceGenerator, List<JMethod>> entry : generators.entrySet()) {
success &= createFieldsAndAssignments(logger, resourceContext,
entry.getKey(), entry.getValue(), sw, fields);
}
if (!success) {
throw new UnableToCompleteException();
}
}
/**
* Given a ClientBundle subtype, compute which ResourceGenerators should
* implement which methods. The data returned from this method should be
* stable across identical modules.
*/
private Map<Class<? extends ResourceGenerator>, List<JMethod>> createTaskList(
TreeLogger logger, TypeOracle typeOracle, JClassType sourceType)
throws UnableToCompleteException {
Map<Class<? extends ResourceGenerator>, List<JMethod>> toReturn = new LinkedHashMap<Class<? extends ResourceGenerator>, List<JMethod>>();
JClassType bundleType = typeOracle.findType(ClientBundle.class.getName());
assert bundleType != null;
JClassType bundleWithLookupType = typeOracle.findType(ClientBundleWithLookup.class.getName());
assert bundleWithLookupType != null;
JClassType resourcePrototypeType = typeOracle.findType(ResourcePrototype.class.getName());
assert resourcePrototypeType != null;
// Accumulate as many errors as possible before failing
boolean throwException = false;
// Using overridable methods allows composition of interface types
for (JMethod m : sourceType.getOverridableMethods()) {
JClassType returnType = m.getReturnType().isClassOrInterface();
if (m.getEnclosingType().equals(bundleType)
|| m.getEnclosingType().equals(bundleWithLookupType)) {
// Methods that we must generate, but that are not resources
continue;
} else if (!m.isAbstract()) {
// Covers the case of an abstract class base type
continue;
} else if (returnType == null
|| !(returnType.isAssignableTo(resourcePrototypeType) || returnType.isAssignableTo(bundleType))) {
// Primitives and random other abstract methods
logger.log(TreeLogger.ERROR, "Unable to implement " + m.getName()
+ " because it does not derive from "
+ resourcePrototypeType.getQualifiedSourceName() + " or "
+ bundleType.getQualifiedSourceName());
throwException = true;
continue;
}
try {
Class<? extends ResourceGenerator> clazz = findResourceGenerator(
logger, m);
List<JMethod> generatorMethods;
if (toReturn.containsKey(clazz)) {
generatorMethods = toReturn.get(clazz);
} else {
generatorMethods = new ArrayList<JMethod>();
toReturn.put(clazz, generatorMethods);
}
generatorMethods.add(m);
} catch (UnableToCompleteException e) {
throwException = true;
}
}
if (throwException) {
throw new UnableToCompleteException();
}
return toReturn;
}
/**
* Given a JMethod, find the a ResourceGenerator class that will be able to
* provide an implementation of the method.
*/
private Class<? extends ResourceGenerator> findResourceGenerator(
TreeLogger logger, JMethod method) throws UnableToCompleteException {
JClassType resourceType = method.getReturnType().isClassOrInterface();
assert resourceType != null;
ResourceGeneratorType annotation = resourceType.findAnnotationInTypeHierarchy(ResourceGeneratorType.class);
if (annotation == null) {
logger.log(TreeLogger.ERROR, "No @"
+ ResourceGeneratorType.class.getName() + " was specifed for type "
+ resourceType.getQualifiedSourceName() + " or its supertypes");
throw new UnableToCompleteException();
}
return annotation.value();
}
/**
* Call finish() on several ResourceGenerators.
*/
private void finish(TreeLogger logger, AbstractResourceContext context,
Collection<ResourceGenerator> generators)
throws UnableToCompleteException {
boolean fail = false;
// Finalize the ResourceGenerator
for (ResourceGenerator rg : generators) {
context.setCurrentResourceGenerator(rg);
try {
rg.finish(
logger.branch(TreeLogger.DEBUG, "Finishing ResourceGenerator"),
context);
} catch (UnableToCompleteException e) {
fail = true;
}
}
if (fail) {
throw new UnableToCompleteException();
}
}
/**
* Given a user-defined type name, determine the type name for the generated
* class based on accumulated requirements.
*
* @throws UnableToCompleteException if an error occurs.
*/
private String generateSimpleSourceName(TreeLogger logger,
ResourceContext context, RequirementsImpl requirements)
throws UnableToCompleteException {
StringBuilder toReturn = new StringBuilder(
context.getClientBundleType().getQualifiedSourceName().replaceAll(
"[.$]", "_"));
Set<String> permutationAxes = new HashSet<String>(requirements.axes);
permutationAxes.add("locale");
try {
PropertyOracle oracle = context.getGeneratorContext().getPropertyOracle();
for (String property : permutationAxes) {
SelectionProperty prop = oracle.getSelectionProperty(logger, property);
String value = prop.getCurrentValue();
toReturn.append("_" + value);
}
} catch (BadPropertyValueException e) {
}
toReturn.append("_" + getClass().getSimpleName());
return toReturn.toString();
}
private boolean initAndPrepare(TreeLogger logger,
AbstractResourceContext resourceContext, ResourceGenerator rg,
List<JMethod> generatorMethods, ClientBundleRequirements requirements) {
try {
resourceContext.setCurrentResourceGenerator(rg);
rg.init(
logger.branch(TreeLogger.DEBUG, "Initializing ResourceGenerator"),
resourceContext);
} catch (UnableToCompleteException e) {
return false;
}
boolean fail = false;
// Prepare the ResourceGenerator by telling it all methods that it is
// expected to produce.
for (JMethod m : generatorMethods) {
try {
rg.prepare(logger.branch(TreeLogger.DEBUG, "Preparing method "
+ m.getName()), resourceContext, requirements, m);
} catch (UnableToCompleteException e) {
fail = true;
}
}
return !fail;
}
private Map<ResourceGenerator, List<JMethod>> initAndPrepare(
TreeLogger logger,
Map<Class<? extends ResourceGenerator>, List<JMethod>> taskList,
AbstractResourceContext resourceContext,
ClientBundleRequirements requirements) throws UnableToCompleteException {
// Try to provide as many errors as possible before failing.
boolean success = true;
Map<ResourceGenerator, List<JMethod>> toReturn = new LinkedHashMap<ResourceGenerator, List<JMethod>>();
// Run the ResourceGenerators to generate implementations of the methods
for (Map.Entry<Class<? extends ResourceGenerator>, List<JMethod>> entry : taskList.entrySet()) {
ResourceGenerator rg = instantiateResourceGenerator(logger,
entry.getKey());
toReturn.put(rg, entry.getValue());
success &= initAndPrepare(logger, resourceContext, rg, entry.getValue(),
requirements);
}
if (!success) {
throw new UnableToCompleteException();
}
return toReturn;
}
/**
* Utility method to construct a ResourceGenerator that logs errors.
*/
private <T extends ResourceGenerator> T instantiateResourceGenerator(
TreeLogger logger, Class<T> generatorClass)
throws UnableToCompleteException {
try {
return generatorClass.newInstance();
} catch (InstantiationException e) {
logger.log(TreeLogger.ERROR, "Unable to initialize ResourceGenerator", e);
} catch (IllegalAccessException e) {
logger.log(TreeLogger.ERROR, "Unable to instantiate ResourceGenerator. "
+ "Does it have a public default constructor?", e);
}
throw new UnableToCompleteException();
}
// FIXME - document
/**
* @param logger
* @param createdClassName
* @param sw
* @param taskList
*
* @throws UnableToCompleteException if an error occurs
*/
private void writeMapMethods(TreeLogger logger, String createdClassName,
SourceWriter sw,
Map<Class<? extends ResourceGenerator>, List<JMethod>> taskList)
throws UnableToCompleteException {
// Complete the IRB contract
sw.println("public ResourcePrototype[] getResources() {");
sw.indent();
sw.println("return new ResourcePrototype[] {");
sw.indent();
for (List<JMethod> methods : taskList.values()) {
for (JMethod m : methods) {
sw.println(m.getName() + "(), ");
}
}
sw.outdent();
sw.println("};");
sw.outdent();
sw.println("}");
// Use a switch statement as a fast map
sw.println("public native ResourcePrototype "
+ "getResource(String name) /*-{");
sw.indent();
sw.println("switch (name) {");
sw.indent();
for (List<JMethod> list : taskList.values()) {
for (JMethod m : list) {
sw.println("case '" + m.getName() + "': return this."
+ m.getJsniSignature() + "();");
}
}
sw.outdent();
sw.println("}");
sw.println("return null;");
sw.outdent();
sw.println("}-*/;");
}
}