Package com.googlecode.lanterna.input

Class EscapeSequenceCharacterPattern

java.lang.Object

com.googlecode.lanterna.input.EscapeSequenceCharacterPattern

All Implemented Interfaces:

CharacterPattern

Direct Known Subclasses:

ScreenInfoCharacterPattern

public class EscapeSequenceCharacterPattern
extends Object
implements CharacterPattern

This implementation of CharacterPattern matches two similar patterns of Escape sequences, that many terminals produce for special keys.

These sequences all start with Escape, followed by either an open bracket or a capital letter O (these two are treated as equivalent).

Then follows a list of zero or up to two decimals separated by a semicolon, and a non-digit last character.

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).

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.

The two maps stdMap and finMap can be customized in subclasses to add, remove or replace keys - to support non-standard Terminals.

Examples: (on a gnome terminal)
ArrowUp is "Esc [ A"; Alt-ArrowUp is "Esc [ 1 ; 3 A"
both are handled by finMap mapping 'A' to ArrowUp

F6 is "Esc [ 1 7 ~"; Ctrl-Shift-F6 is "Esc [ 1 7 ; 6 R"
both are handled by stdMap mapping 17 to F6

Author:

Andreas

Nested Class Summary

Nested classes/interfaces inherited from interface com.googlecode.lanterna.input.CharacterPattern

CharacterPattern.Matching

Field Summary

Fields

Modifier and Type	Field	Description
static int	ALT
static int	CTRL
protected Map<Character,KeyType>	finMap	Map of recognized "finish pattern" sequences: e.g.: 'A' -> ArrowUp : "Esc [ A"
static int	SHIFT
protected Map<Integer,KeyType>	stdMap	Map of recognized "standard pattern" sequences: e.g.: 24 -> F12 : "Esc [ 24 ~"
protected boolean	useEscEsc	A flag to control, whether an Esc-prefix for an Esc-sequence is to be treated as Alt-pressed.

Constructor Summary

Constructors

Constructor	Description
EscapeSequenceCharacterPattern()	Create an instance with a standard set of mappings.

Method Summary

Modifier and Type	Method	Description
protected KeyStroke	getKeyStroke(KeyType key, int mods)	combines a KeyType and modifiers into a KeyStroke.
protected KeyStroke	getKeyStrokeRaw(char first, int num1, int num2, char last, boolean bEsc)	combines the raw parts of the sequence into a KeyStroke.
CharacterPattern.Matching	match(List<Character> cur)	Given a list of characters, determine whether it exactly matches any known KeyStroke, and whether a longer sequence can possibly match.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SHIFT

public static final int SHIFT

See Also:

Constant Field Values

ALT

public static final int ALT

See Also:

Constant Field Values

CTRL

public static final int CTRL

See Also:

Constant Field Values

stdMap

protected final Map<Integer,KeyType> stdMap

Map of recognized "standard pattern" sequences:
e.g.: 24 -> F12 : "Esc [ 24 ~"

finMap

protected final Map<Character,KeyType> finMap

Map of recognized "finish pattern" sequences:
e.g.: 'A' -> ArrowUp : "Esc [ A"

useEscEsc

protected boolean useEscEsc

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.

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.)

Constructor Detail

EscapeSequenceCharacterPattern

public EscapeSequenceCharacterPattern()

Create an instance with a standard set of mappings.

Method Detail

getKeyStroke

protected KeyStroke getKeyStroke(KeyType key,
                                 int mods)

combines a KeyType and modifiers into a KeyStroke. Subclasses can override this for customization purposes.

Parameters:

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.

mods - the bitmask of the modifer keys pressed along with the key.

Returns:

either null (to report mis-match), or a valid KeyStroke.

getKeyStrokeRaw

protected KeyStroke getKeyStrokeRaw(char first,
                                    int num1,
                                    int num2,
                                    char last,
                                    boolean bEsc)

combines the raw parts of the sequence into a KeyStroke. This method does not check the first char, but overrides may do so.

Parameters:

first - the char following after Esc in the sequence (either [ or O)

num1 - the first decimal, or 0 if not in the sequence

num2 - the second decimal, or 0 if not in the sequence

last - the terminating char.

bEsc - whether an extra Escape-prefix was found.

Returns:

either null (to report mis-match), or a valid KeyStroke.

match

public CharacterPattern.Matching match(List<Character> cur)

Description copied from interface: CharacterPattern

Given a list of characters, determine whether it exactly matches any known KeyStroke, and whether a longer sequence can possibly match.

Specified by:

match in interface CharacterPattern

Parameters:

cur - of characters to check

Returns:

see Matching