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Utilities helping with various *nix console topics. Mostly geared
toward expressive and interactive command line applications.
/*
* Copyright (c) 2016, Stein Eldar Johnsen
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 net.morimekta.console;
import net.morimekta.console.chr.Char;
import net.morimekta.console.chr.CharReader;
import net.morimekta.console.chr.Control;
import net.morimekta.console.util.STTY;
import net.morimekta.console.util.STTYMode;
import net.morimekta.console.util.STTYModeSwitcher;
import com.google.common.annotations.VisibleForTesting;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UncheckedIOException;
import java.nio.charset.StandardCharsets;
/**
* Terminal interface. It sets proper TTY mode and reads complex characters
* from the input, and writes lines dependent on terminal mode.
*/
public class Terminal extends CharReader implements Closeable, LinePrinter {
private final STTY tty;
/**
* Construct a default RAW terminal.
*
* @throws UncheckedIOException If unable to set TTY mode.
*/
public Terminal() {
this(new STTY());
}
/**
* Construct a default RAW terminal.
*
* @param tty The terminal device.
* @throws UncheckedIOException If unable to set TTY mode.
*/
public Terminal(STTY tty) {
this(tty, STTYMode.RAW, null);
}
/**
* Construct a terminal with given mode.
*
* @param tty The terminal device.
* @param mode The terminal mode.
* @throws UncheckedIOException If unable to set TTY mode.
*/
public Terminal(STTY tty, STTYMode mode) {
this(tty, mode, null);
}
/**
* Construct a terminal with a custom line printer.
*
* @param tty The terminal device.
* @param lp The line printer.
* @throws UncheckedIOException If unable to set TTY mode.
*/
public Terminal(STTY tty, LinePrinter lp) {
this(tty, STTYMode.RAW, lp);
}
/**
* Construct a terminal with a terminal mode and custom line printer.
*
* @param tty The terminal device.
* @param mode The terminal mode.
* @param lp The line printer.
* @throws UncheckedIOException If unable to set TTY mode.
*/
public Terminal(STTY tty, STTYMode mode, LinePrinter lp) {
this(tty, System.in, System.out, lp, tty.setSTTYMode(mode));
}
/**
* Constructor visible for testing.
*
* @param tty The terminal device.
* @param in The input stream.
* @param out The output stream.
* @param lp The line printer or null.
* @throws UncheckedIOException If unable to set TTY mode.
*/
@VisibleForTesting
public Terminal(STTY tty, InputStream in, OutputStream out, LinePrinter lp, STTYModeSwitcher switcher) {
super(in);
this.tty = tty;
this.lp = lp == null ? this::printlnInternal : lp;
this.out = out;
this.switcher = switcher;
this.lineCount = 0;
try {
if (switcher.didChangeMode() && switcher.getBefore() == STTYMode.RAW) {
this.out.write('\n');
this.out.flush();
}
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
/**
* @return Get the terminal device.
*/
public STTY getTTY() {
return tty;
}
/**
* Make a user confirmation. E.g.:
*
* boolean really = term.confirm("Do you o'Really?");
*
* Will print out "Do you o'Really? [Y/n]: ". If the user press
* 'y' and 'enter' will pass (return true), if 'n', and 'backspace' will return
* false. Invalid characters will print a short error message.
*
* @param what What to confirm. Basically the message before '[Y/n]'.
* @return Confirmation result.
*/
public boolean confirm(String what) {
return confirm(what, true);
}
/**
* Make a user confirmation. E.g.:
*
* boolean really = term.confirm("Do you o'Really?", false);
*
* Will print out "Do you o'Really? [y/N]: ". If the user press
* 'y' will pass (return true), if 'n', 'enter' and 'backspace' will return
* false. Invalid characters will print a short error message.
*
* @param what What to confirm. Basically the message before '[Y/n]'.
* @param def the default response on 'enter'.
* @return Confirmation result.
*/
public boolean confirm(String what, boolean def) {
String yn = def ? "Y/n" : "y/N";
formatln("%s [%s]:", what, yn);
try {
for (;;) {
Char c = read();
if (c == null) {
throw new IOException("End of stream.");
}
int cp = c.asInteger();
if (cp == Char.CR) {
print(def ? " Yes." : " No.");
return def;
}
if (cp == 'y' || cp == 'Y') {
print(" Yes.");
return true;
}
if (cp == 'n' || cp == 'N' || cp == Char.DEL) {
print(" No.");
return false;
}
if (cp == Char.ESC || cp == Char.ABR || cp == Char.EOF) {
throw new IOException("User interrupted: " + c.asString());
}
if (cp == ' ' || cp == '\t') {
continue;
}
format("\r%s%s [%s]: %s is not valid input.",
Control.CURSOR_ERASE,
what, yn, c.asString());
}
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
public void format(String format, Object... args) {
print(String.format(format, args));
}
public void formatln(String format, Object... args) {
println(String.format(format, args));
}
public void print(Char ch) {
print(ch.toString());
}
public void print(String message) {
try {
out.write(message.getBytes(StandardCharsets.UTF_8));
out.flush();
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
@Override
public void println(String message) {
lp.println(message);
}
public void println() {
lp.println(null);
}
/**
* Finish the current set of lines and continue below.
*/
public void finish() {
try {
if (switcher.getCurrentMode() == STTYMode.RAW && lineCount > 0) {
out.write('\r');
out.write('\n');
out.flush();
}
lineCount = 0;
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
@Override
public void close() throws IOException {
try {
if (switcher.didChangeMode() && switcher.getBefore() == STTYMode.COOKED) {
finish();
}
} catch (UncheckedIOException e) {
// Ignore.
}
switcher.close();
}
private void printlnInternal(String message) {
try {
if (switcher.getCurrentMode() == STTYMode.RAW) {
lnBefore(message);
} else {
lnAfter(message);
}
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
private void lnAfter(String message) throws IOException {
if (message != null) {
out.write('\r');
out.write(message.getBytes(StandardCharsets.UTF_8));
}
out.write('\r');
out.write('\n');
out.flush();
++lineCount;
}
private void lnBefore(String message) throws IOException {
if (lineCount > 0) {
out.write('\r');
out.write('\n');
}
if (message != null) {
out.write(message.getBytes(StandardCharsets.UTF_8));
}
out.flush();
++lineCount;
}
private final STTYModeSwitcher switcher;
private final OutputStream out;
private final LinePrinter lp;
private int lineCount;
}
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