From 85511af2a512912c909d940ee1392ef6575e52a4 Mon Sep 17 00:00:00 2001
From: Pavel Vojtechovsky <p.vojtechovsky@post.cz>
Date: Thu, 28 Sep 2017 22:15:04 +0200
Subject: [PATCH] next mandatory PTW of DJPP -> AutoWriteTabsPrinterTokenWriter

---
 .../AutoWriteTabsPrinterTokenWriter.java      | 63 +++++++++++++++++++
 .../visitor/DefaultJavaPrettyPrinter.java     |  9 ++-
 2 files changed, 69 insertions(+), 3 deletions(-)
 create mode 100644 src/main/java/spoon/reflect/visitor/AutoWriteTabsPrinterTokenWriter.java

diff --git a/src/main/java/spoon/reflect/visitor/AutoWriteTabsPrinterTokenWriter.java b/src/main/java/spoon/reflect/visitor/AutoWriteTabsPrinterTokenWriter.java
new file mode 100644
index 00000000000..8666fa9a357
--- /dev/null
+++ b/src/main/java/spoon/reflect/visitor/AutoWriteTabsPrinterTokenWriter.java
@@ -0,0 +1,63 @@
+/**
+ * Copyright (C) 2006-2017 INRIA and contributors
+ * Spoon - http://spoon.gforge.inria.fr/
+ *
+ * This software is governed by the CeCILL-C License under French law and
+ * abiding by the rules of distribution of free software. You can use, modify
+ * and/or redistribute the software under the terms of the CeCILL-C license as
+ * circulated by CEA, CNRS and INRIA at http://www.cecill.info.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the CeCILL-C License for more details.
+ *
+ * The fact that you are presently reading this means that you have had
+ * knowledge of the CeCILL-C license and that you accept its terms.
+ */
+package spoon.reflect.visitor;
+
+/**
+ * The special {@link PrinterTokenWriter} implementation,
+ * ignores all writeTabs tokens produced by {@link DefaultJavaPrettyPrinter}.
+ * This implementation automatically correctly writes tabs at places where they belongs to.
+ * - calling writeTabs is no more responsibility of developer of {@link DefaultJavaPrettyPrinter}
+ */
+class AutoWriteTabsPrinterTokenWriter extends PrinterTokenWriterDelegate<AutoWriteTabsPrinterTokenWriter> {
+
+	boolean shouldWriteTabs = true;
+
+	AutoWriteTabsPrinterTokenWriter(PrinterTokenWriter next) {
+		super(next);
+	}
+
+	@Override
+	public AutoWriteTabsPrinterTokenWriter writeTabs() {
+		//ignore that call. DJPP does not have to call it now at all - we can remove all these calls from DJPP sources -> easier maintenance
+		return this;
+	}
+
+	@Override
+	protected void onToken(spoon.reflect.visitor.PrinterTokenWriterDelegate.TokenType tokenType, Object token) {
+		if (tokenType == TokenType.NEW_LINE) {
+			//mark that it should write tabs after new line
+			shouldWriteTabs = true;
+		} else if (shouldWriteTabs && isTabCounterChangingToken(tokenType) == false) {
+			/*
+			 * the last token was new line. Now it is going to write some text. Write tabs to have text aligned by expected number of tabs.
+			 * Note that tabs are not written if there is more empty new lines
+			 */
+			next.writeTabs();
+			shouldWriteTabs = false;
+		}
+	}
+
+	private boolean isTabCounterChangingToken(TokenType tokenType) {
+		return tokenType == TokenType.INCREMENT_TABS || tokenType == TokenType.DECREMENT_TABS;
+	}
+
+	@Override
+	public void reset() {
+		shouldWriteTabs = true;
+		super.reset();
+	}
+}
diff --git a/src/main/java/spoon/reflect/visitor/DefaultJavaPrettyPrinter.java b/src/main/java/spoon/reflect/visitor/DefaultJavaPrettyPrinter.java
index a68111e8d5f..745b9777390 100644
--- a/src/main/java/spoon/reflect/visitor/DefaultJavaPrettyPrinter.java
+++ b/src/main/java/spoon/reflect/visitor/DefaultJavaPrettyPrinter.java
@@ -187,6 +187,7 @@ public class DefaultJavaPrettyPrinter implements CtVisitor, PrettyPrinter {
 	 * Token detector, which delegates tokens to {@link PrinterTokenWriter}
 	 */
 	private SnapshotPrinterTokenWriter printer;
+	private PrinterTokenWriterDelegate<?> lastInternalPrinter;
 
 	/**
 	 * Element printer helper.
@@ -203,7 +204,9 @@ public class DefaultJavaPrettyPrinter implements CtVisitor, PrettyPrinter {
 	 */
 	public DefaultJavaPrettyPrinter(Environment env) {
 		this.env = env;
-		printer = new SnapshotPrinterTokenWriter(new SimplePrinterTokenWriter(new PrinterHelper(env)));
+		lastInternalPrinter = new AutoWriteTabsPrinterTokenWriter(new SimplePrinterTokenWriter(new PrinterHelper(env)));
+		printer = new SnapshotPrinterTokenWriter(lastInternalPrinter);
+
 		elementPrinterHelper = new ElementPrinterHelper(printer, this, env);
 		if (env.isAutoImports()) {
 			this.importsContext = new ImportScannerImpl();
@@ -1809,13 +1812,13 @@ public Map<Integer, Integer> getLineNumberMapping() {
 	 * @return implementation of {@link PrinterTokenWriter}, which is used to print tokens
 	 */
 	public PrinterTokenWriter getPrinterTokenWriter() {
-		return printer.getNext();
+		return lastInternalPrinter.getNext();
 	}
 	/**
 	 * Set {@link PrinterTokenWriter}, which has to be used to print tokens
 	 */
 	public DefaultJavaPrettyPrinter setPrinterTokenWriter(PrinterTokenWriter tokenWriter) {
-		printer.setNext(tokenWriter);
+		lastInternalPrinter.setNext(tokenWriter);
 		return this;
 	}