1579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/* 2579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Copyright (C) 2007 The Android Open Source Project 3579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * 4579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Licensed under the Apache License, Version 2.0 (the "License"); 5579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * you may not use this file except in compliance with the License. 6579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * You may obtain a copy of the License at 7579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * 8579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * http://www.apache.org/licenses/LICENSE-2.0 9579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * 10579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Unless required by applicable law or agreed to in writing, software 11579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * distributed under the License is distributed on an "AS IS" BASIS, 12579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * See the License for the specific language governing permissions and 14579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * limitations under the License. 15579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 16579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 17579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonpackage com.android.dx.util; 18579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 19579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonimport java.io.IOException; 20579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonimport java.io.OutputStream; 21579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonimport java.io.OutputStreamWriter; 22579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonimport java.io.StringWriter; 23579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonimport java.io.Writer; 24579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 25579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson/** 26579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Class that takes a combined output destination and provides two 27579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * output writers, one of which ends up writing to the left column and 28579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * one which goes on the right. 29579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 30579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilsonpublic final class TwoColumnOutput { 31579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** {@code non-null;} underlying writer for final output */ 32579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson private final Writer out; 33579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 34579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** {@code > 0;} the left column width */ 35579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson private final int leftWidth; 36579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 37579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** {@code non-null;} pending left column output */ 38579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson private final StringBuffer leftBuf; 39579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 40579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** {@code non-null;} pending right column output */ 41579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson private final StringBuffer rightBuf; 42579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 43579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** {@code non-null;} left column writer */ 44579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson private final IndentingWriter leftColumn; 45579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 46579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** {@code non-null;} right column writer */ 47579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson private final IndentingWriter rightColumn; 48579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 49579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** 50579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Turns the given two strings (with widths) and spacer into a formatted 51579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * two-column string. 52579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * 53579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param s1 {@code non-null;} first string 54579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param width1 {@code > 0;} width of the first column 55579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param spacer {@code non-null;} spacer string 56579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param s2 {@code non-null;} second string 57579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param width2 {@code > 0;} width of the second column 58579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @return {@code non-null;} an appropriately-formatted string 59579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 60579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson public static String toString(String s1, int width1, String spacer, 61579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson String s2, int width2) { 62579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson int len1 = s1.length(); 63579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson int len2 = s2.length(); 64579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 65579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson StringWriter sw = new StringWriter((len1 + len2) * 3); 66579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson TwoColumnOutput twoOut = 67579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson new TwoColumnOutput(sw, width1, width2, spacer); 68579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 69579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson try { 70579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson twoOut.getLeft().write(s1); 71579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson twoOut.getRight().write(s2); 72579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } catch (IOException ex) { 73579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson throw new RuntimeException("shouldn't happen", ex); 74579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 75579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 76579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson twoOut.flush(); 77579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return sw.toString(); 78579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 79579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 80579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** 81579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Constructs an instance. 82579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * 83579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param out {@code non-null;} writer to send final output to 84579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param leftWidth {@code > 0;} width of the left column, in characters 85579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param rightWidth {@code > 0;} width of the right column, in characters 86579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param spacer {@code non-null;} spacer string to sit between the two columns 87579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 88579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson public TwoColumnOutput(Writer out, int leftWidth, int rightWidth, 89579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson String spacer) { 90579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (out == null) { 91579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson throw new NullPointerException("out == null"); 92579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 93579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 94579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (leftWidth < 1) { 95579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson throw new IllegalArgumentException("leftWidth < 1"); 96579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 97579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 98579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (rightWidth < 1) { 99579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson throw new IllegalArgumentException("rightWidth < 1"); 100579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 101579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 102579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (spacer == null) { 103579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson throw new NullPointerException("spacer == null"); 104579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 105579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 106579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson StringWriter leftWriter = new StringWriter(1000); 107579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson StringWriter rightWriter = new StringWriter(1000); 108579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 109579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson this.out = out; 110579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson this.leftWidth = leftWidth; 111579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson this.leftBuf = leftWriter.getBuffer(); 112579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson this.rightBuf = rightWriter.getBuffer(); 113579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson this.leftColumn = new IndentingWriter(leftWriter, leftWidth); 114579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson this.rightColumn = 115579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson new IndentingWriter(rightWriter, rightWidth, spacer); 116579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 117579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 118579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** 119579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Constructs an instance. 120579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * 121579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param out {@code non-null;} stream to send final output to 122579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param leftWidth {@code >= 1;} width of the left column, in characters 123579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param rightWidth {@code >= 1;} width of the right column, in characters 124579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param spacer {@code non-null;} spacer string to sit between the two columns 125579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 126579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson public TwoColumnOutput(OutputStream out, int leftWidth, int rightWidth, 127579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson String spacer) { 128579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson this(new OutputStreamWriter(out), leftWidth, rightWidth, spacer); 129579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 130579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 131579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** 132579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Gets the writer to use to write to the left column. 133579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * 134579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @return {@code non-null;} the left column writer 135579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 136579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson public Writer getLeft() { 137579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return leftColumn; 138579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 139579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 140579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** 141579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Gets the writer to use to write to the right column. 142579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * 143579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @return {@code non-null;} the right column writer 144579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 145579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson public Writer getRight() { 146579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return rightColumn; 147579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 148579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 149579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** 150579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Flushes the output. If there are more lines of pending output in one 151579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * column, then the other column will get filled with blank lines. 152579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 153579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson public void flush() { 154579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson try { 155579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson appendNewlineIfNecessary(leftBuf, leftColumn); 156579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson appendNewlineIfNecessary(rightBuf, rightColumn); 157579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson outputFullLines(); 158579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson flushLeft(); 159579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson flushRight(); 160579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } catch (IOException ex) { 161579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson throw new RuntimeException(ex); 162579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 163579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 164579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 165579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** 166579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Outputs to the final destination as many full line pairs as 167579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * there are in the pending output, removing those lines from 168579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * their respective buffers. This method terminates when at 169579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * least one of the two column buffers is empty. 170579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 171579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson private void outputFullLines() throws IOException { 172579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson for (;;) { 173579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson int leftLen = leftBuf.indexOf("\n"); 174579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (leftLen < 0) { 175579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return; 176579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 177579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 178579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson int rightLen = rightBuf.indexOf("\n"); 179579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (rightLen < 0) { 180579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson return; 181579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 182579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 183579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (leftLen != 0) { 184579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson out.write(leftBuf.substring(0, leftLen)); 185579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 186579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 187579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if (rightLen != 0) { 188579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson writeSpaces(out, leftWidth - leftLen); 189579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson out.write(rightBuf.substring(0, rightLen)); 190579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 191579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 192579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson out.write('\n'); 193579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 194579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson leftBuf.delete(0, leftLen + 1); 195579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson rightBuf.delete(0, rightLen + 1); 196579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 197579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 198579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 199579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** 200579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Flushes the left column buffer, printing it and clearing the buffer. 201579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * If the buffer is already empty, this does nothing. 202579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 203579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson private void flushLeft() throws IOException { 204579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson appendNewlineIfNecessary(leftBuf, leftColumn); 205579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 206579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson while (leftBuf.length() != 0) { 207579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson rightColumn.write('\n'); 208579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson outputFullLines(); 209579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 210579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 211579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 212579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** 213579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Flushes the right column buffer, printing it and clearing the buffer. 214579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * If the buffer is already empty, this does nothing. 215579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 216579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson private void flushRight() throws IOException { 217579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson appendNewlineIfNecessary(rightBuf, rightColumn); 218579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 219579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson while (rightBuf.length() != 0) { 220579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson leftColumn.write('\n'); 221579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson outputFullLines(); 222579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 223579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 224579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 225579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** 226579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Appends a newline to the given buffer via the given writer, but 227579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * only if it isn't empty and doesn't already end with one. 228579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * 229579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param buf {@code non-null;} the buffer in question 230579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param out {@code non-null;} the writer to use 231579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 232579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson private static void appendNewlineIfNecessary(StringBuffer buf, 233579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson Writer out) 234579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson throws IOException { 235579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson int len = buf.length(); 236579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 237579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson if ((len != 0) && (buf.charAt(len - 1) != '\n')) { 238579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson out.write('\n'); 239579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 240579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 241579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson 242579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson /** 243579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * Writes the given number of spaces to the given writer. 244579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * 245579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param out {@code non-null;} where to write 246579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson * @param amt {@code >= 0;} the number of spaces to write 247579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson */ 248579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson private static void writeSpaces(Writer out, int amt) throws IOException { 249579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson while (amt > 0) { 250579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson out.write(' '); 251579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson amt--; 252579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 253579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson } 254579d7739c53a2707ad711a2d2cae46d7d782f06Jesse Wilson} 255