| // Copyright 2014 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; |
| import java.io.OutputStream; |
| import java.nio.charset.StandardCharsets; |
| |
| /** |
| * A class which encapsulates the fancy curses-type stuff that you can do using |
| * standard ANSI terminal control sequences. |
| */ |
| public class AnsiTerminal { |
| /** |
| * An enumeration of all terminal colors, containing the escape sequences for both background and |
| * foreground settings. |
| */ |
| public enum Color { |
| RED("^[31m", "^[41m"), |
| GREEN("^[32m", "^[42m"), |
| YELLOW("^[33m", "^[43m"), |
| BLUE("^[34m", "^[44m"), |
| MAGENTA("^[35m", "^[45m"), |
| CYAN("^[36m", "^[46m"), |
| GRAY("^[37m", "^[47m"), |
| |
| DEFAULT("^[0m", "^[0m"); |
| |
| private final byte[] escapeSeq; |
| private final byte[] backgroundEscapeSeq; |
| |
| private Color(String escapeSeq, String backgroundEscapeSeq) { |
| this.escapeSeq = escapeSeq.replace('^', (char) 27).getBytes(StandardCharsets.US_ASCII); |
| this.backgroundEscapeSeq = |
| backgroundEscapeSeq.replace('^', (char) 27).getBytes(StandardCharsets.US_ASCII); |
| } |
| } |
| |
| private static final byte[] ESC = {27, (byte) '['}; |
| private static final byte BEL = 7; |
| private static final byte UP = (byte) 'A'; |
| private static final byte ERASE_LINE = (byte) 'K'; |
| private static final byte SET_GRAPHICS = (byte) 'm'; |
| private static final byte TEXT_BOLD = (byte) '1'; |
| private static final byte[] SET_TERM_TITLE = {27, (byte) ']', (byte) '0', (byte) ';'}; |
| |
| public static byte[] CR = { 13 }; |
| |
| private final OutputStream out; |
| |
| /** |
| * Creates an AnsiTerminal object wrapping an output stream which is going to |
| * be displayed in an ANSI compatible terminal or shell window. |
| * |
| * @param out the output stream |
| */ |
| public AnsiTerminal(OutputStream out) { |
| this.out = out; |
| } |
| |
| /** |
| * Moves the cursor upwards by a specified number of lines. This will not |
| * cause any scrolling if it tries to move above the top of the terminal |
| * window. |
| */ |
| public void cursorUp(int numLines) throws IOException { |
| writeBytes(ESC, ("" + numLines).getBytes(), new byte[] { UP }); |
| } |
| |
| /** |
| * Clear the current terminal line from the cursor position to the end. |
| */ |
| public void clearLine() throws IOException { |
| writeEscapeSequence(ERASE_LINE); |
| } |
| |
| /** |
| * Makes any text output to the terminal appear in bold. |
| */ |
| public void textBold() throws IOException { |
| writeEscapeSequence(TEXT_BOLD, SET_GRAPHICS); |
| } |
| |
| /** |
| * Set the color of the foreground or background of the terminal. |
| * |
| * @param color one of the foreground or background color constants |
| */ |
| public void setTextColor(Color color) throws IOException { |
| writeBytes(color.escapeSeq); |
| } |
| |
| /** |
| * Resets the terminal colors and fonts to defaults. |
| */ |
| public void resetTerminal() throws IOException { |
| writeEscapeSequence((byte)'0', (byte)'m'); |
| } |
| |
| /** |
| * Makes text print on the terminal in red. |
| */ |
| public void textRed() throws IOException { |
| setTextColor(Color.RED); |
| } |
| |
| /** |
| * Makes text print on the terminal in green. |
| */ |
| public void textGreen() throws IOException { |
| setTextColor(Color.GREEN); |
| } |
| |
| /** |
| * Makes text print on the terminal in magenta. |
| */ |
| public void textMagenta() throws IOException { |
| setTextColor(Color.MAGENTA); |
| } |
| |
| /** |
| * Set the terminal title. |
| */ |
| public void setTitle(String title) throws IOException { |
| writeBytes(SET_TERM_TITLE, title.getBytes(), new byte[] { BEL }); |
| } |
| |
| /** |
| * Writes a string to the terminal using the current font, color and cursor |
| * position settings. |
| * |
| * @param text the text to write |
| */ |
| public void writeString(String text) throws IOException { |
| out.write(text.getBytes()); |
| } |
| |
| /** |
| * Writes a byte sequence to the terminal using the current font, color and cursor position |
| * settings. |
| * |
| * @param bytes the bytes to write |
| */ |
| public void writeBytes(byte[] bytes) throws IOException { |
| out.write(bytes); |
| } |
| |
| /** |
| * Utility method for generating control sequences. Takes a collection of byte arrays, which |
| * contain the components of a control sequence, concatenates them, and prints them to the |
| * terminal. |
| * |
| * @param stuff the byte arrays that make up the sequence to be sent to the terminal |
| */ |
| private void writeBytes(byte[]... stuff) throws IOException { |
| for (byte[] bytes : stuff) { |
| out.write(bytes); |
| } |
| } |
| |
| /** |
| * Utility method which makes it easier to generate the control sequences for the terminal. |
| * |
| * @param bytes bytes which should be prefixed with the terminal escape sequence to produce a |
| * valid control sequence |
| */ |
| private void writeEscapeSequence(byte... bytes) throws IOException { |
| writeBytes(ESC, bytes); |
| } |
| |
| /** Sends a carriage return to the terminal. */ |
| public void cr() throws IOException { |
| writeBytes(CR); |
| } |
| |
| /** |
| * Flushes the underlying stream. This class does not do any buffering of its own, but the |
| * underlying OutputStream may. |
| */ |
| public void flush() throws IOException { |
| out.flush(); |
| } |
| } |