dagger.hilt.processor.internal.root.RootFileFormatter Maven / Gradle / Ivy
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/*
* Copyright (C) 2020 The Dagger Authors.
*
* 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 dagger.hilt.processor.internal.root;
import com.squareup.javapoet.JavaFile;
import java.io.IOException;
import java.io.Writer;
import java.util.regex.MatchResult;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.annotation.processing.Filer;
import javax.lang.model.element.Element;
import javax.tools.JavaFileObject;
/**
* Typically we would just use {@code JavaFile#writeTo()} to write files. However, this formatter
* exists to add new lines inbetween interfaces. This can be important for classes with many
* interfaces (e.g. Dagger components) to avoid spamming the entire list of interfaces when
* reporting errors to the user.
*
* See b/33108646.
*/
final class RootFileFormatter {
private static final Pattern CLASS_PATERN = Pattern.compile("(\\h*)(.*class.*implements)(.*\\{)");
/** Formats the {@link JavaFile} java source file. */
static void write(JavaFile javaFile, Filer filer) throws IOException {
String fileName =
javaFile.packageName.isEmpty()
? javaFile.typeSpec.name
: javaFile.packageName + "." + javaFile.typeSpec.name;
Element[] originatingElements = javaFile.typeSpec.originatingElements.toArray(new Element[0]);
StringBuilder sb = new StringBuilder("");
javaFile.writeTo(sb);
String fileContent = formatInterfaces(sb.toString(), CLASS_PATERN);
JavaFileObject filerSourceFile = filer.createSourceFile(fileName, originatingElements);
try (Writer writer = filerSourceFile.openWriter()) {
writer.write(fileContent);
} catch (Exception e) {
try {
filerSourceFile.delete();
} catch (Exception ignored) {
// Nothing to do.
}
throw e;
}
}
private static String formatInterfaces(String content, Pattern pattern) {
Matcher matcher = pattern.matcher(content);
StringBuffer sb = new StringBuffer(content.length());
while (matcher.find()) {
MatchResult result = matcher.toMatchResult();
String spaces = result.group(1);
String prefix = result.group(2);
String interfaces = result.group(3);
String formattedInterfaces = formatInterfaces(spaces, interfaces);
matcher.appendReplacement(
sb, Matcher.quoteReplacement(spaces + prefix + formattedInterfaces));
}
matcher.appendTail(sb);
return sb.toString();
}
private static String formatInterfaces(String prefixSpaces, String interfaces) {
StringBuilder sb = new StringBuilder(interfaces);
String newLine = String.format("\n%s ", prefixSpaces);
// Add a line break after each interface so that there's only 1 interface per line.
int i = 0;
int bracketCount = 0;
while (i >= 0 && i < sb.length()) {
char c = sb.charAt(i++);
if (c == '<') {
bracketCount++;
} else if (c == '>') {
bracketCount--;
} else if (c == ',' && bracketCount == 0) {
sb.insert(i++, newLine);
}
}
return sb.toString();
}
private RootFileFormatter() {}
}