diff options
| -rw-r--r-- | core/java/com/android/internal/util/IndentingPrintWriter.java | 77 | ||||
| -rw-r--r-- | core/tests/coretests/src/com/android/internal/util/IndentingPrintWriterTest.java | 132 |
2 files changed, 191 insertions, 18 deletions
diff --git a/core/java/com/android/internal/util/IndentingPrintWriter.java b/core/java/com/android/internal/util/IndentingPrintWriter.java index dd5918b..d01a817 100644 --- a/core/java/com/android/internal/util/IndentingPrintWriter.java +++ b/core/java/com/android/internal/util/IndentingPrintWriter.java @@ -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); } } } diff --git a/core/tests/coretests/src/com/android/internal/util/IndentingPrintWriterTest.java b/core/tests/coretests/src/com/android/internal/util/IndentingPrintWriterTest.java new file mode 100644 index 0000000..6773612 --- /dev/null +++ b/core/tests/coretests/src/com/android/internal/util/IndentingPrintWriterTest.java @@ -0,0 +1,132 @@ +/* + * 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()); + } +} |