/*
* Copyright 2011, The gwtquery team.
*
* 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.query.rebind;
import com.google.gwt.core.ext.Generator;
import com.google.gwt.core.ext.GeneratorContext;
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.core.ext.typeinfo.JTypeParameter;
import com.google.gwt.core.ext.typeinfo.TypeOracle;
import com.google.gwt.user.rebind.ClassSourceFileComposerFactory;
import com.google.gwt.user.rebind.SourceWriter;
import java.io.PrintWriter;
/**
* Generate lazy implementations for interface delegated to parameterized type.
* The originating type implements Lazy<T> where T extends LazyBase<OriginType>.
* The generator generates an implementation of T where each method returns type
* T and queues up a closure which delegates execution of the method to the
* OriginType.
*/
public class LazyGenerator extends Generator {
private JClassType lazyType = null;
private JClassType lazyBaseType = null;
public String generate(TreeLogger treeLogger,
GeneratorContext generatorContext, String requestedClass)
throws UnableToCompleteException {
TypeOracle oracle = generatorContext.getTypeOracle();
lazyType = oracle.findType("com.google.gwt.query.client.Lazy");
lazyBaseType = oracle.findType("com.google.gwt.query.client.LazyBase");
assert lazyType != null : "Can't find Lazy interface type";
assert lazyBaseType != null : "Can't find LazyBase interface type";
JClassType requestedType = oracle.findType(requestedClass);
JClassType targetType = null;
JClassType nonLazyType = null;
for (JClassType inf : requestedType.getImplementedInterfaces()) {
if (inf.isAssignableTo(lazyType)) {
nonLazyType = inf.isParameterized().getTypeArgs()[0];
targetType = inf.isParameterized().getTypeArgs()[1];
break;
}
}
if (targetType == null) return null;
assert targetType != null : "Parameter of Lazy<T> not found";
String genClass = targetType.getPackage().getName() + "."
+ targetType.getSimpleSourceName() + getImplSuffix();
SourceWriter sw = getSourceWriter(treeLogger, generatorContext,
requestedType.getPackage().getName(),
targetType.getSimpleSourceName() + getImplSuffix(),
targetType.getQualifiedSourceName());
if (sw != null) {
generatePreamble(sw, nonLazyType.getQualifiedSourceName(), treeLogger);
sw.indent();
for (JMethod method : targetType.getMethods()) {
generateMethod(sw, method, nonLazyType.getQualifiedSourceName(),
genClass, treeLogger);
}
sw.outdent();
generateDoneMethod(sw, nonLazyType, treeLogger);
sw.commit(treeLogger);
}
return genClass;
}
private void generatePreamble(SourceWriter sw, String nonLazyClass,
TreeLogger treeLogger) {
sw.indent();
sw.println(
"private JsArray<JsClosure> closures = JsArray.createArray().cast();");
sw.println("private " + nonLazyClass + " ctx;");
sw.outdent();
}
public String getJSNIParams(JMethod method) {
String reference = "(";
JParameter[] params = method.getParameters();
for (int i = 0; i < params.length; i++) {
reference += params[i].getType().getJNISignature();
}
reference += ")";
return reference;
}
public void generateMethod(SourceWriter sw, JMethod method,
String nonLazyClass, String genClass, TreeLogger logger)
throws UnableToCompleteException {
JParameter[] params = method.getParameters();
JTypeParameter gType = method.getReturnType().isTypeParameter();
String retType = method.getReturnType()
.getParameterizedQualifiedSourceName();
if (gType != null) {
retType = "<" + gType.getParameterizedQualifiedSourceName() + " extends "
+ gType.getFirstBound().getQualifiedSourceName() + "> " + retType;
}
sw.print("public final native " + retType + " " + method.getName());
sw.print("(");
int argNum = 0;
for (JParameter param : params) {
sw.print((argNum == 0 ? "" : ", ")
+ param.getType().getParameterizedQualifiedSourceName() + " arg"
+ argNum);
argNum++;
}
sw.println(") /*-{");
sw.indent();
sw.println("var self=this;");
sw.println("this.@" + genClass + "::closures.push(");
sw.indent();
sw.println("function() {");
sw.indent();
sw.print("self.@" + genClass + "::ctx=self.@" + genClass + "::ctx.@"
+ nonLazyClass + "::" + method.getName());
sw.print(getJSNIParams(method));
sw.print("(");
for (int i = 0; i < argNum; i++) {
sw.print("arg" + i + (i < argNum - 1 ? "," : ""));
}
sw.print(")");
// special case, as() needs to invoke createLazy()
if ("as".equals(method.getName())) {
sw.print(".createLazy()");
}
sw.println(";");
sw.outdent();
sw.println("}");
sw.outdent();
sw.println(");");
sw.println("return this;");
sw.outdent();
sw.println("}-*/;");
}
protected String getImplSuffix() {
return "Impl";
}
protected SourceWriter getSourceWriter(TreeLogger logger,
GeneratorContext context, String packageName, String className,
String... interfaceNames) {
PrintWriter printWriter = context.tryCreate(logger, packageName, className);
if (printWriter == null) {
return null;
}
ClassSourceFileComposerFactory composerFactory
= new ClassSourceFileComposerFactory(packageName, className);
composerFactory.addImport("com.google.gwt.core.client.*");
composerFactory.addImport("com.google.gwt.query.client.*");
composerFactory.addImport("com.google.gwt.dom.client.Element");
composerFactory.addImport("com.google.gwt.user.client.Event");
composerFactory.addImport("com.google.gwt.query.client.Function");
composerFactory.addImport("com.google.gwt.query.client.js.JsClosure");
for (String interfaceName : interfaceNames) {
composerFactory.addImplementedInterface(interfaceName);
}
return composerFactory.createSourceWriter(context, printWriter);
}
// used by benchmark harness
private void generateDoneMethod(SourceWriter sw, JClassType nonLazyType,
TreeLogger treeLogger) {
sw.indent();
sw.println("public Function done() {");
sw.indent();
sw.println("return new Function() {");
sw.indent();
sw.println("public void f() {");
sw.indent();
String classID = nonLazyType.getSimpleSourceName();
if ("GQuery".equals(classID)) {
classID = "GQUERY";
}
sw.println(
"ctx = GQuery.$(getElement()).as(" + nonLazyType.getQualifiedSourceName() + "."
+ classID + ");");
sw.println("for (int i = 0; i < closures.length(); i++) {");
sw.indent();
sw.println("closures.get(i).invoke();");
sw.outdent();
sw.println("}");
sw.outdent();
sw.println("}");
sw.outdent();
sw.println("};");
sw.outdent();
sw.println("}");
}
}