Merge "Add wrapping support to IndentingPrintWriter." (ed1ad7fa) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/util/IndentingPrintWriter.java

+59 −18

Original line number	Diff line number	Diff line
		@@ -21,29 +21,47 @@ import java.io.Writer;

		/**
		* Lightweight wrapper around {@link PrintWriter} that automatically indents
		* newlines based on internal state. Delays writing indent until first actual
		* write on a newline, enabling indent modification after newline.
		* newlines based on internal state. It also automatically wraps long lines
		* based on given line length.
		* <p>
		* Delays writing indent until first actual write on a newline, enabling indent
		* modification after newline.
		*/
		public class IndentingPrintWriter extends PrintWriter {
		private final String mIndent;
		private final String mSingleIndent;
		private final int mWrapLength;

		private StringBuilder mBuilder = new StringBuilder();
		private char[] mCurrent;
		/** Mutable version of current indent */
		private StringBuilder mIndentBuilder = new StringBuilder();
		/** Cache of current {@link #mIndentBuilder} value */
		private char[] mCurrentIndent;
		/** Length of current line being built, excluding any indent */
		private int mCurrentLength;

		/**
		* Flag indicating if we're currently sitting on an empty line, and that
		* next write should be prefixed with the current indent.
		*/
		private boolean mEmptyLine = true;

		public IndentingPrintWriter(Writer writer, String indent) {
		public IndentingPrintWriter(Writer writer, String singleIndent) {
		this(writer, singleIndent, -1);
		}

		public IndentingPrintWriter(Writer writer, String singleIndent, int wrapLength) {
		super(writer);
		mIndent = indent;
		mSingleIndent = singleIndent;
		mWrapLength = wrapLength;
		}

		public void increaseIndent() {
		mBuilder.append(mIndent);
		mCurrent = null;
		mIndentBuilder.append(mSingleIndent);
		mCurrentIndent = null;
		}

		public void decreaseIndent() {
		mBuilder.delete(0, mIndent.length());
		mCurrent = null;
		mIndentBuilder.delete(0, mSingleIndent.length());
		mCurrentIndent = null;
		}

		public void printPair(String key, Object value) {
		@@ -52,33 +70,56 @@ public class IndentingPrintWriter extends PrintWriter {

		@Override
		public void write(char[] buf, int offset, int count) {
		final int indentLength = mIndentBuilder.length();
		final int bufferEnd = offset + count;
		int lineStart = offset;
		int lineEnd = offset;

		// March through incoming buffer looking for newlines
		while (lineEnd < bufferEnd) {
		char ch = buf[lineEnd++];
		mCurrentLength++;
		if (ch == '\n') {
		writeIndent();
		maybeWriteIndent();
		super.write(buf, lineStart, lineEnd - lineStart);
		lineStart = lineEnd;
		mEmptyLine = true;
		mCurrentLength = 0;
		}

		// Wrap if we've pushed beyond line length
		if (mWrapLength > 0 && mCurrentLength >= mWrapLength - indentLength) {
		if (!mEmptyLine) {
		// Give ourselves a fresh line to work with
		super.write('\n');
		mEmptyLine = true;
		mCurrentLength = lineEnd - lineStart;
		} else {
		// We need more than a dedicated line, slice it hard
		maybeWriteIndent();
		super.write(buf, lineStart, lineEnd - lineStart);
		super.write('\n');
		mEmptyLine = true;
		lineStart = lineEnd;
		mCurrentLength = 0;
		}
		}
		}

		if (lineStart != lineEnd) {
		writeIndent();
		maybeWriteIndent();
		super.write(buf, lineStart, lineEnd - lineStart);
		}
		}

		private void writeIndent() {
		private void maybeWriteIndent() {
		if (mEmptyLine) {
		mEmptyLine = false;
		if (mBuilder.length() != 0) {
		if (mCurrent == null) {
		mCurrent = mBuilder.toString().toCharArray();
		if (mIndentBuilder.length() != 0) {
		if (mCurrentIndent == null) {
		mCurrentIndent = mIndentBuilder.toString().toCharArray();
		}
		super.write(mCurrent, 0, mCurrent.length);
		super.write(mCurrentIndent, 0, mCurrentIndent.length);
		}
		}
		}

core/tests/coretests/src/com/android/internal/util/IndentingPrintWriterTest.java

0 → 100644

+132 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2013 The Android Open Source Project
		*
		* 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.android.internal.util;

		import junit.framework.TestCase;

		import java.io.ByteArrayOutputStream;
		import java.io.PrintWriter;

		/**
		* Tests for {@link IndentingPrintWriter}.
		*/
		public class IndentingPrintWriterTest extends TestCase {

		private ByteArrayOutputStream mStream;
		private PrintWriter mWriter;

		@Override
		protected void setUp() throws Exception {
		super.setUp();

		mStream = new ByteArrayOutputStream();
		mWriter = new PrintWriter(mStream);
		}

		public void testMultipleIndents() throws Exception {
		final IndentingPrintWriter pw = new IndentingPrintWriter(mWriter, " ");

		pw.print("Hello");
		pw.increaseIndent();
		pw.println();
		pw.print("World");
		pw.increaseIndent();
		pw.println();
		pw.print("And");
		pw.decreaseIndent();
		pw.println();
		pw.print("Goodbye");
		pw.decreaseIndent();
		pw.println();
		pw.print("World");
		pw.println();

		pw.flush();
		assertEquals("Hello\n World\n And\n Goodbye\nWorld\n", mStream.toString());
		}

		public void testAdjustIndentAfterNewline() throws Exception {
		final IndentingPrintWriter pw = new IndentingPrintWriter(mWriter, " ");

		pw.println("Hello");
		pw.increaseIndent();
		pw.println("World");

		pw.flush();
		assertEquals("Hello\n World\n", mStream.toString());
		}

		public void testWrapping() throws Exception {
		final IndentingPrintWriter pw = new IndentingPrintWriter(mWriter, "", 10);

		pw.print("dog ");
		pw.print("cat ");
		pw.print("cow ");
		pw.print("meow ");

		pw.flush();
		assertEquals("dog cat \ncow meow ", mStream.toString());
		}

		public void testWrappingIndented() throws Exception {
		final IndentingPrintWriter pw = new IndentingPrintWriter(mWriter, " ", 10);

		pw.increaseIndent();
		pw.print("dog ");
		pw.print("meow ");
		pw.print("a ");
		pw.print("b ");
		pw.print("cow ");

		pw.flush();
		assertEquals(" dog \n meow \n a b \n cow ", mStream.toString());
		}

		public void testWrappingEmbeddedNewlines() throws Exception {
		final IndentingPrintWriter pw = new IndentingPrintWriter(mWriter, " ", 10);

		pw.increaseIndent();
		pw.print("Lorem ipsum \ndolor sit \namet, consectetur \nadipiscing elit.");

		pw.flush();
		assertEquals(" Lorem ip\n sum \n dolor si\n t \n amet, co\n"
		+ " nsectetu\n r \n adipisci\n ng elit.\n", mStream.toString());
		}

		public void testWrappingSingleGiant() throws Exception {
		final IndentingPrintWriter pw = new IndentingPrintWriter(mWriter, " ", 10);

		pw.increaseIndent();
		pw.print("Lorem ipsum dolor sit amet, consectetur adipiscing elit.");

		pw.flush();
		assertEquals(" Lorem ip\n sum dolo\n r sit am\n et, cons\n"
		+ " ectetur \n adipisci\n ng elit.\n", mStream.toString());
		}

		public void testWrappingPrefixedGiant() throws Exception {
		final IndentingPrintWriter pw = new IndentingPrintWriter(mWriter, " ", 10);

		pw.increaseIndent();
		pw.print("foo");
		pw.print("Lorem ipsum dolor sit amet, consectetur adipiscing elit.");

		pw.flush();
		assertEquals(" foo\n Lorem ip\n sum dolo\n r sit am\n et, cons\n"
		+ " ectetur \n adipisci\n ng elit.\n", mStream.toString());
		}
		}