| /* |
| * 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.rg; |
| |
| import com.google.gwt.core.ext.Generator; |
| import com.google.gwt.core.ext.TreeLogger; |
| import com.google.gwt.core.ext.UnableToCompleteException; |
| import com.google.gwt.core.ext.typeinfo.JMethod; |
| import com.google.gwt.dev.util.Util; |
| import com.google.gwt.resources.client.TextResource; |
| import com.google.gwt.resources.ext.AbstractResourceGenerator; |
| import com.google.gwt.resources.ext.ResourceContext; |
| import com.google.gwt.resources.ext.ResourceGeneratorUtil; |
| import com.google.gwt.resources.ext.SupportsGeneratorResultCaching; |
| import com.google.gwt.user.rebind.SourceWriter; |
| import com.google.gwt.user.rebind.StringSourceWriter; |
| |
| import java.net.URL; |
| |
| /** |
| * Provides implementations of TextResource. |
| */ |
| public final class TextResourceGenerator extends AbstractResourceGenerator |
| implements SupportsGeneratorResultCaching { |
| /** |
| * Java compiler has a limit of 2^16 bytes for encoding string constants in a |
| * class file. Since the max size of a character is 4 bytes, we'll limit the |
| * number of characters to (2^14 - 1) to fit within one record. |
| */ |
| private static final int MAX_STRING_CHUNK = 16383; |
| |
| @Override |
| public String createAssignment(TreeLogger logger, ResourceContext context, |
| JMethod method) throws UnableToCompleteException { |
| URL[] resources = ResourceGeneratorUtil.findResources(logger, context, |
| method); |
| |
| if (resources.length != 1) { |
| logger.log(TreeLogger.ERROR, "Exactly one resource must be specified", |
| null); |
| throw new UnableToCompleteException(); |
| } |
| |
| URL resource = resources[0]; |
| |
| SourceWriter sw = new StringSourceWriter(); |
| // Write the expression to create the subtype. |
| sw.println("new " + TextResource.class.getName() + "() {"); |
| sw.indent(); |
| |
| if (!AbstractResourceGenerator.STRIP_COMMENTS) { |
| // Convenience when examining the generated code. |
| sw.println("// " + resource.toExternalForm()); |
| } |
| |
| sw.println("public String getText() {"); |
| sw.indent(); |
| |
| String toWrite = Util.readURLAsString(resource); |
| |
| if (toWrite.length() > MAX_STRING_CHUNK) { |
| writeLongString(sw, toWrite); |
| } else { |
| sw.println("return \"" + Generator.escape(toWrite) + "\";"); |
| } |
| sw.outdent(); |
| sw.println("}"); |
| |
| sw.println("public String getName() {"); |
| sw.indent(); |
| sw.println("return \"" + method.getName() + "\";"); |
| sw.outdent(); |
| sw.println("}"); |
| |
| sw.outdent(); |
| sw.println("}"); |
| |
| return sw.toString(); |
| } |
| |
| /** |
| * A single constant that is too long will crash the compiler with an out of |
| * memory error. Break up the constant and generate code that appends using a |
| * buffer. |
| */ |
| private void writeLongString(SourceWriter sw, String toWrite) { |
| sw.println("StringBuilder builder = new StringBuilder();"); |
| int offset = 0; |
| int length = toWrite.length(); |
| while (offset < length - 1) { |
| int subLength = Math.min(MAX_STRING_CHUNK, length - offset); |
| sw.print("builder.append(\""); |
| sw.print(Generator.escape(toWrite.substring(offset, offset + subLength))); |
| sw.println("\");"); |
| offset += subLength; |
| } |
| sw.println("return builder.toString();"); |
| } |
| } |