/*
* This file is part of lanterna (http://code.google.com/p/lanterna/).
*
* lanterna is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright (C) 2010-2017 Martin Berglund
*/
package com.googlecode.lanterna.input;
import static com.googlecode.lanterna.input.KeyDecodingProfile.ESC_CODE;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* This implementation of CharacterPattern matches two similar patterns
* of Escape sequences, that many terminals produce for special keys.<p>
*
* These sequences all start with Escape, followed by either an open bracket
* or a capital letter O (these two are treated as equivalent).<p>
*
* Then follows a list of zero or up to two decimals separated by a
* semicolon, and a non-digit last character.<p>
*
* If the last character is a tilde (~) then the first number defines
* the key (through stdMap), otherwise the last character itself defines
* the key (through finMap).<p>
*
* The second number, if provided by the terminal, specifies the modifier
* state (shift,alt,ctrl). The value is 1 + sum(modifiers), where shift is 1,
* alt is 2 and ctrl is 4.<p>
*
* The two maps stdMap and finMap can be customized in subclasses to add,
* remove or replace keys - to support non-standard Terminals.<p>
*
* Examples: (on a gnome terminal)<br>
* ArrowUp is "Esc [ A"; Alt-ArrowUp is "Esc [ 1 ; 3 A"<br>
* both are handled by finMap mapping 'A' to ArrowUp <br><br>
* F6 is "Esc [ 1 7 ~"; Ctrl-Shift-F6 is "Esc [ 1 7 ; 6 R"<br>
* both are handled by stdMap mapping 17 to F6 <br><br>
*
* @author Andreas
*
*/
public class EscapeSequenceCharacterPattern implements CharacterPattern {
// state machine used to match key sequence:
private enum State {
START, INTRO, NUM1, NUM2, DONE
}
// bit-values for modifier keys: only used internally
public static final int SHIFT = 1, ALT = 2, CTRL = 4;
/**
* Map of recognized "standard pattern" sequences:<br>
* e.g.: 24 -> F12 : "Esc [ <b>24</b> ~"
*/
protected final Map<Integer, KeyType> stdMap = new HashMap<Integer, KeyType>();
/**
* Map of recognized "finish pattern" sequences:<br>
* e.g.: 'A' -> ArrowUp : "Esc [ <b>A</b>"
*/
protected final Map<Character, KeyType> finMap = new HashMap<Character, KeyType>();
/**
* A flag to control, whether an Esc-prefix for an Esc-sequence is to be treated
* as Alt-pressed. Some Terminals (e.g. putty) report the Alt-modifier like that.<p>
* If the application is e.g. more interested in seeing separate Escape and plain
* Arrow keys, then it should replace this class by a subclass that sets this flag
* to false. (It might then also want to remove the CtrlAltAndCharacterPattern.)
*/
protected boolean useEscEsc = true;
/**
* Create an instance with a standard set of mappings.
*/
public EscapeSequenceCharacterPattern() {
finMap.put('A', KeyType.ArrowUp);
finMap.put('B', KeyType.ArrowDown);
finMap.put('C', KeyType.ArrowRight);
finMap.put('D', KeyType.ArrowLeft);
finMap.put('E', KeyType.Unknown); // gnome-terminal center key on numpad
finMap.put('G', KeyType.Unknown); // putty center key on numpad
finMap.put('H', KeyType.Home);
finMap.put('F', KeyType.End);
finMap.put('P', KeyType.F1);
finMap.put('Q', KeyType.F2);
finMap.put('R', KeyType.F3);
finMap.put('S', KeyType.F4);
finMap.put('Z', KeyType.ReverseTab);
stdMap.put(1, KeyType.Home);
stdMap.put(2, KeyType.Insert);
stdMap.put(3, KeyType.Delete);
stdMap.put(4, KeyType.End);
stdMap.put(5, KeyType.PageUp);
stdMap.put(6, KeyType.PageDown);
stdMap.put(11, KeyType.F1);
stdMap.put(12, KeyType.F2);
stdMap.put(13, KeyType.F3);
stdMap.put(14, KeyType.F4);
stdMap.put(15, KeyType.F5);
stdMap.put(16, KeyType.F5);
stdMap.put(17, KeyType.F6);
stdMap.put(18, KeyType.F7);
stdMap.put(19, KeyType.F8);
stdMap.put(20, KeyType.F9);
stdMap.put(21, KeyType.F10);
stdMap.put(23, KeyType.F11);
stdMap.put(24, KeyType.F12);
stdMap.put(25, KeyType.F13);
stdMap.put(26, KeyType.F14);
stdMap.put(28, KeyType.F15);
stdMap.put(29, KeyType.F16);
stdMap.put(31, KeyType.F17);
stdMap.put(32, KeyType.F18);
stdMap.put(33, KeyType.F19);
}
/**
* combines a KeyType and modifiers into a KeyStroke.
* Subclasses can override this for customization purposes.
*
* @param key the KeyType as determined by parsing the sequence.
* It will be null, if the pattern looked like a key sequence but wasn't
* identified.
* @param mods the bitmask of the modifer keys pressed along with the key.
* @return either null (to report mis-match), or a valid KeyStroke.
*/
protected KeyStroke getKeyStroke(KeyType key, int mods) {
boolean bShift = false, bCtrl = false, bAlt = false;
if (key == null) { return null; } // alternative: key = KeyType.Unknown;
if (mods >= 0) { // only use when non-negative!
bShift = (mods & SHIFT) != 0;
bAlt = (mods & ALT) != 0;
bCtrl = (mods & CTRL) != 0;
}
return new KeyStroke( key , bCtrl, bAlt, bShift);
}
/**
* combines the raw parts of the sequence into a KeyStroke.
* This method does not check the first char, but overrides may do so.
*
* @param first the char following after Esc in the sequence (either [ or O)
* @param num1 the first decimal, or 0 if not in the sequence
* @param num2 the second decimal, or 0 if not in the sequence
* @param last the terminating char.
* @param bEsc whether an extra Escape-prefix was found.
* @return either null (to report mis-match), or a valid KeyStroke.
*/
protected KeyStroke getKeyStrokeRaw(char first,int num1,int num2,char last,boolean bEsc) {
KeyType kt;
boolean bPuttyCtrl = false;
if (last == '~' && stdMap.containsKey(num1)) {
kt = stdMap.get(num1);
} else if (finMap.containsKey(last)) {
kt = finMap.get(last);
// Putty sends ^[OA for ctrl arrow-up, ^[[A for plain arrow-up:
// but only for A-D -- other ^[O... sequences are just plain keys
if (first == 'O' && last >= 'A' && last <= 'D') { bPuttyCtrl = true; }
// if we ever stumble into "keypad-mode", then it will end up inverted.
} else {
kt = null; // unknown key.
}
int mods = num2 - 1;
if (bEsc) {
if (mods >= 0) { mods |= ALT; }
else { mods = ALT; }
}
if (bPuttyCtrl) {
if (mods >= 0) { mods |= CTRL; }
else { mods = CTRL; }
}
return getKeyStroke( kt, mods );
}
@Override
public Matching match(List<Character> cur) {
State state = State.START;
int num1 = 0, num2 = 0;
char first = '\0', last = '\0';
boolean bEsc = false;
for (char ch : cur) {
switch (state) {
case START:
if (ch != ESC_CODE) {
return null; // nope
}
state = State.INTRO;
continue;
case INTRO:
// Recognize a second Escape to mean "Alt is pressed".
// (at least putty sends it that way)
if (useEscEsc && ch == ESC_CODE && ! bEsc) {
bEsc = true; continue;
}
// Key sequences supported by this class must
// start either with Esc-[ or Esc-O
if (ch != '[' && ch != 'O') {
return null; // nope
}
first = ch; state = State.NUM1;
continue;
case NUM1:
if (ch == ';') {
state = State.NUM2;
} else if (Character.isDigit(ch)) {
num1 = num1 * 10 + Character.digit(ch, 10);
} else {
last = ch; state = State.DONE;
}
continue;
case NUM2:
if (Character.isDigit(ch)) {
num2 = num2 * 10 + Character.digit(ch, 10);
} else {
last = ch; state = State.DONE;
}
continue;
case DONE: // once done, extra characters spoil it
return null; // nope
}
}
if (state == State.DONE) {
KeyStroke ks = getKeyStrokeRaw(first,num1,num2,last,bEsc);
return ks != null ? new Matching( ks ) : null; // depends
} else {
return Matching.NOT_YET; // maybe later
}
}
}