piframe-go/vendor/github.com/gdamore/tcell/key.go

465 lines
11 KiB
Go

// Copyright 2016 The TCell Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use 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 tcell
import (
"fmt"
"strings"
"time"
)
// EventKey represents a key press. Usually this is a key press followed
// by a key release, but since terminal programs don't have a way to report
// key release events, we usually get just one event. If a key is held down
// then the terminal may synthesize repeated key presses at some predefined
// rate. We have no control over that, nor visibility into it.
//
// In some cases, we can have a modifier key, such as ModAlt, that can be
// generated with a key press. (This usually is represented by having the
// high bit set, or in some cases, by sending an ESC prior to the rune.)
//
// If the value of Key() is KeyRune, then the actual key value will be
// available with the Rune() method. This will be the case for most keys.
// In most situations, the modifiers will not be set. For example, if the
// rune is 'A', this will be reported without the ModShift bit set, since
// really can't tell if the Shift key was pressed (it might have been CAPSLOCK,
// or a terminal that only can send capitals, or keyboard with separate
// capital letters from lower case letters).
//
// Generally, terminal applications have far less visibility into keyboard
// activity than graphical applications. Hence, they should avoid depending
// overly much on availability of modifiers, or the availability of any
// specific keys.
type EventKey struct {
t time.Time
mod ModMask
key Key
ch rune
}
// When returns the time when this Event was created, which should closely
// match the time when the key was pressed.
func (ev *EventKey) When() time.Time {
return ev.t
}
// Rune returns the rune corresponding to the key press, if it makes sense.
// The result is only defined if the value of Key() is KeyRune.
func (ev *EventKey) Rune() rune {
return ev.ch
}
// Key returns a virtual key code. We use this to identify specific key
// codes, such as KeyEnter, etc. Most control and function keys are reported
// with unique Key values. Normal alphanumeric and punctuation keys will
// generally return KeyRune here; the specific key can be further decoded
// using the Rune() function.
func (ev *EventKey) Key() Key {
return ev.key
}
// Modifiers returns the modifiers that were present with the key press. Note
// that not all platforms and terminals support this equally well, and some
// cases we will not not know for sure. Hence, applications should avoid
// using this in most circumstances.
func (ev *EventKey) Modifiers() ModMask {
return ev.mod
}
// KeyNames holds the written names of special keys. Useful to echo back a key
// name, or to look up a key from a string value.
var KeyNames = map[Key]string{
KeyEnter: "Enter",
KeyBackspace: "Backspace",
KeyTab: "Tab",
KeyBacktab: "Backtab",
KeyEsc: "Esc",
KeyBackspace2: "Backspace2",
KeyDelete: "Delete",
KeyInsert: "Insert",
KeyUp: "Up",
KeyDown: "Down",
KeyLeft: "Left",
KeyRight: "Right",
KeyHome: "Home",
KeyEnd: "End",
KeyUpLeft: "UpLeft",
KeyUpRight: "UpRight",
KeyDownLeft: "DownLeft",
KeyDownRight: "DownRight",
KeyCenter: "Center",
KeyPgDn: "PgDn",
KeyPgUp: "PgUp",
KeyClear: "Clear",
KeyExit: "Exit",
KeyCancel: "Cancel",
KeyPause: "Pause",
KeyPrint: "Print",
KeyF1: "F1",
KeyF2: "F2",
KeyF3: "F3",
KeyF4: "F4",
KeyF5: "F5",
KeyF6: "F6",
KeyF7: "F7",
KeyF8: "F8",
KeyF9: "F9",
KeyF10: "F10",
KeyF11: "F11",
KeyF12: "F12",
KeyF13: "F13",
KeyF14: "F14",
KeyF15: "F15",
KeyF16: "F16",
KeyF17: "F17",
KeyF18: "F18",
KeyF19: "F19",
KeyF20: "F20",
KeyF21: "F21",
KeyF22: "F22",
KeyF23: "F23",
KeyF24: "F24",
KeyF25: "F25",
KeyF26: "F26",
KeyF27: "F27",
KeyF28: "F28",
KeyF29: "F29",
KeyF30: "F30",
KeyF31: "F31",
KeyF32: "F32",
KeyF33: "F33",
KeyF34: "F34",
KeyF35: "F35",
KeyF36: "F36",
KeyF37: "F37",
KeyF38: "F38",
KeyF39: "F39",
KeyF40: "F40",
KeyF41: "F41",
KeyF42: "F42",
KeyF43: "F43",
KeyF44: "F44",
KeyF45: "F45",
KeyF46: "F46",
KeyF47: "F47",
KeyF48: "F48",
KeyF49: "F49",
KeyF50: "F50",
KeyF51: "F51",
KeyF52: "F52",
KeyF53: "F53",
KeyF54: "F54",
KeyF55: "F55",
KeyF56: "F56",
KeyF57: "F57",
KeyF58: "F58",
KeyF59: "F59",
KeyF60: "F60",
KeyF61: "F61",
KeyF62: "F62",
KeyF63: "F63",
KeyF64: "F64",
KeyCtrlA: "Ctrl-A",
KeyCtrlB: "Ctrl-B",
KeyCtrlC: "Ctrl-C",
KeyCtrlD: "Ctrl-D",
KeyCtrlE: "Ctrl-E",
KeyCtrlF: "Ctrl-F",
KeyCtrlG: "Ctrl-G",
KeyCtrlJ: "Ctrl-J",
KeyCtrlK: "Ctrl-K",
KeyCtrlL: "Ctrl-L",
KeyCtrlN: "Ctrl-N",
KeyCtrlO: "Ctrl-O",
KeyCtrlP: "Ctrl-P",
KeyCtrlQ: "Ctrl-Q",
KeyCtrlR: "Ctrl-R",
KeyCtrlS: "Ctrl-S",
KeyCtrlT: "Ctrl-T",
KeyCtrlU: "Ctrl-U",
KeyCtrlV: "Ctrl-V",
KeyCtrlW: "Ctrl-W",
KeyCtrlX: "Ctrl-X",
KeyCtrlY: "Ctrl-Y",
KeyCtrlZ: "Ctrl-Z",
KeyCtrlSpace: "Ctrl-Space",
KeyCtrlUnderscore: "Ctrl-_",
KeyCtrlRightSq: "Ctrl-]",
KeyCtrlBackslash: "Ctrl-\\",
KeyCtrlCarat: "Ctrl-^",
}
// Name returns a printable value or the key stroke. This can be used
// when printing the event, for example.
func (ev *EventKey) Name() string {
s := ""
m := []string{}
if ev.mod&ModShift != 0 {
m = append(m, "Shift")
}
if ev.mod&ModAlt != 0 {
m = append(m, "Alt")
}
if ev.mod&ModMeta != 0 {
m = append(m, "Meta")
}
if ev.mod&ModCtrl != 0 {
m = append(m, "Ctrl")
}
ok := false
if s, ok = KeyNames[ev.key]; !ok {
if ev.key == KeyRune {
s = "Rune[" + string(ev.ch) + "]"
} else {
s = fmt.Sprintf("Key[%d,%d]", ev.key, int(ev.ch))
}
}
if len(m) != 0 {
if ev.mod&ModCtrl != 0 && strings.HasPrefix(s, "Ctrl-") {
s = s[5:]
}
return fmt.Sprintf("%s+%s", strings.Join(m, "+"), s)
}
return s
}
// NewEventKey attempts to create a suitable event. It parses the various
// ASCII control sequences if KeyRune is passed for Key, but if the caller
// has more precise information it should set that specifically. Callers
// that aren't sure about modifier state (most) should just pass ModNone.
func NewEventKey(k Key, ch rune, mod ModMask) *EventKey {
if k == KeyRune && (ch < ' ' || ch == 0x7f) {
// Turn specials into proper key codes. This is for
// control characters and the DEL.
k = Key(ch)
if mod == ModNone && ch < ' ' {
switch Key(ch) {
case KeyBackspace, KeyTab, KeyEsc, KeyEnter:
// these keys are directly typeable without CTRL
default:
// most likely entered with a CTRL keypress
mod = ModCtrl
}
}
}
return &EventKey{t: time.Now(), key: k, ch: ch, mod: mod}
}
// ModMask is a mask of modifier keys. Note that it will not always be
// possible to report modifier keys.
type ModMask int16
// These are the modifiers keys that can be sent either with a key press,
// or a mouse event. Note that as of now, due to the confusion associated
// with Meta, and the lack of support for it on many/most platforms, the
// current implementations never use it. Instead, they use ModAlt, even for
// events that could possibly have been distinguished from ModAlt.
const (
ModShift ModMask = 1 << iota
ModCtrl
ModAlt
ModMeta
ModNone ModMask = 0
)
// Key is a generic value for representing keys, and especially special
// keys (function keys, cursor movement keys, etc.) For normal keys, like
// ASCII letters, we use KeyRune, and then expect the application to
// inspect the Rune() member of the EventKey.
type Key int16
// This is the list of named keys. KeyRune is special however, in that it is
// a place holder key indicating that a printable character was sent. The
// actual value of the rune will be transported in the Rune of the associated
// EventKey.
const (
KeyRune Key = iota + 256
KeyUp
KeyDown
KeyRight
KeyLeft
KeyUpLeft
KeyUpRight
KeyDownLeft
KeyDownRight
KeyCenter
KeyPgUp
KeyPgDn
KeyHome
KeyEnd
KeyInsert
KeyDelete
KeyHelp
KeyExit
KeyClear
KeyCancel
KeyPrint
KeyPause
KeyBacktab
KeyF1
KeyF2
KeyF3
KeyF4
KeyF5
KeyF6
KeyF7
KeyF8
KeyF9
KeyF10
KeyF11
KeyF12
KeyF13
KeyF14
KeyF15
KeyF16
KeyF17
KeyF18
KeyF19
KeyF20
KeyF21
KeyF22
KeyF23
KeyF24
KeyF25
KeyF26
KeyF27
KeyF28
KeyF29
KeyF30
KeyF31
KeyF32
KeyF33
KeyF34
KeyF35
KeyF36
KeyF37
KeyF38
KeyF39
KeyF40
KeyF41
KeyF42
KeyF43
KeyF44
KeyF45
KeyF46
KeyF47
KeyF48
KeyF49
KeyF50
KeyF51
KeyF52
KeyF53
KeyF54
KeyF55
KeyF56
KeyF57
KeyF58
KeyF59
KeyF60
KeyF61
KeyF62
KeyF63
KeyF64
)
// These are the control keys. Note that they overlap with other keys,
// perhaps. For example, KeyCtrlH is the same as KeyBackspace.
const (
KeyCtrlSpace Key = iota
KeyCtrlA
KeyCtrlB
KeyCtrlC
KeyCtrlD
KeyCtrlE
KeyCtrlF
KeyCtrlG
KeyCtrlH
KeyCtrlI
KeyCtrlJ
KeyCtrlK
KeyCtrlL
KeyCtrlM
KeyCtrlN
KeyCtrlO
KeyCtrlP
KeyCtrlQ
KeyCtrlR
KeyCtrlS
KeyCtrlT
KeyCtrlU
KeyCtrlV
KeyCtrlW
KeyCtrlX
KeyCtrlY
KeyCtrlZ
KeyCtrlLeftSq // Escape
KeyCtrlBackslash
KeyCtrlRightSq
KeyCtrlCarat
KeyCtrlUnderscore
)
// Special values - these are fixed in an attempt to make it more likely
// that aliases will encode the same way.
// These are the defined ASCII values for key codes. They generally match
// with KeyCtrl values.
const (
KeyNUL Key = iota
KeySOH
KeySTX
KeyETX
KeyEOT
KeyENQ
KeyACK
KeyBEL
KeyBS
KeyTAB
KeyLF
KeyVT
KeyFF
KeyCR
KeySO
KeySI
KeyDLE
KeyDC1
KeyDC2
KeyDC3
KeyDC4
KeyNAK
KeySYN
KeyETB
KeyCAN
KeyEM
KeySUB
KeyESC
KeyFS
KeyGS
KeyRS
KeyUS
KeyDEL Key = 0x7F
)
// These keys are aliases for other names.
const (
KeyBackspace = KeyBS
KeyTab = KeyTAB
KeyEsc = KeyESC
KeyEscape = KeyESC
KeyEnter = KeyCR
KeyBackspace2 = KeyDEL
)