| // Copyright 2016 The Bazel Authors. All rights reserved. |
| // |
| // 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.google.devtools.build.lib.util.io; |
| |
| import java.io.IOException; |
| |
| /** |
| * Wrap an {@link AnsiTerminalWriter} into one that breaks lines to use |
| * at most a first given number of columns of the terminal. In this way, |
| * all line breaks are predictable, even if we only have a lower bound |
| * on the number of columns of the underlying terminal. To simplify copy |
| * and paste of the terminal output, a continuation character is written |
| * into the last usable column when we break a line. Additionally, newline |
| * characters are translated into calls to the {@link AnsiTerminalWriter#newline()} |
| * method. |
| */ |
| public class LineWrappingAnsiTerminalWriter implements AnsiTerminalWriter { |
| |
| private final AnsiTerminalWriter terminalWriter; |
| private final int width; |
| private final char continuationCharacter; |
| private int position; |
| |
| public LineWrappingAnsiTerminalWriter( |
| AnsiTerminalWriter terminalWriter, int width, char continuationCharacter) { |
| this.terminalWriter = terminalWriter; |
| this.width = width; |
| this.continuationCharacter = continuationCharacter; |
| this.position = 0; |
| } |
| |
| public LineWrappingAnsiTerminalWriter(AnsiTerminalWriter terminalWriter, int width) { |
| this(terminalWriter, width, '\\'); |
| } |
| |
| private void appendChar(char c) throws IOException { |
| if (c == '\n') { |
| terminalWriter.newline(); |
| position = 0; |
| } else if (position + 1 < width) { |
| terminalWriter.append(Character.toString(c)); |
| position++; |
| } else { |
| // The last usable character of the line was already been written, |
| // hence we have to start a continuation before writing the symbol. |
| terminalWriter.append(Character.toString(continuationCharacter)); |
| terminalWriter.newline(); |
| terminalWriter.append(Character.toString(c)); |
| position = 1; |
| } |
| } |
| |
| @Override |
| public AnsiTerminalWriter append(String text) throws IOException { |
| for (int i = 0; i < text.length(); i++) { |
| appendChar(text.charAt(i)); |
| } |
| return this; |
| } |
| |
| @Override |
| public AnsiTerminalWriter newline() throws IOException { |
| terminalWriter.newline(); |
| position = 0; |
| return this; |
| } |
| |
| @Override |
| public AnsiTerminalWriter okStatus() throws IOException { |
| terminalWriter.okStatus(); |
| return this; |
| } |
| |
| @Override |
| public AnsiTerminalWriter failStatus() throws IOException { |
| terminalWriter.failStatus(); |
| return this; |
| } |
| |
| @Override |
| public AnsiTerminalWriter normal() throws IOException { |
| terminalWriter.normal(); |
| return this; |
| } |
| } |