github.com/gop9/olt@v0.0.0-20200202132135-d956aad50b08/gio/io/key/key.go

// SPDX-License-Identifier: Unlicense OR MIT

/*
Package key implements key and text events and operations.

The InputOp operations is used for declaring key input handlers. Use
an implementation of the Queue interface from package ui to receive
events.
*/
package key

import (
	"strings"

	"github.com/gop9/olt/gio/internal/opconst"
	"github.com/gop9/olt/gio/io/event"
	"github.com/gop9/olt/gio/op"
)

// InputOp declares a handler ready for key events.
// Key events are in general only delivered to the
// focused key handler. Set the Focus flag to request
// the focus.
type InputOp struct {
	Key   event.Key
	Focus bool
}

// HideInputOp request that any on screen text input
// be hidden.
type HideInputOp struct{}

// A FocusEvent is generated when a handler gains or loses
// focus.
type FocusEvent struct {
	Focus bool
}

// An Event is generated when a key is pressed. For text input
// use EditEvent.
type Event struct {
	// Rune is the meaning of the key event as determined by the
	// operating system. The mapping is determined by system-dependent
	// current layout, modifiers, lock-states, etc.
	//
	// If non-negative, it is a Unicode codepoint: pressing the 'a' key
	// generates different Runes 'a' or 'A' (but the same Code) depending on
	// the state of the shift key.
	//
	// If -1, the key does not generate a Unicode codepoint. To distinguish
	// them, look at Code.
	Rune rune

	// Code is the identity of the physical key relative to a notional
	// "standard" keyboard, independent of current layout, modifiers,
	// lock-states, etc
	//
	// For standard key codes, its value matches USB HID key codes.
	// Compare its value to uint32-typed constants in this package, such
	// as CodeLeftShift and CodeEscape.
	//
	// Pressing the regular '2' key and number-pad '2' key (with Num-Lock)
	// generate different Codes (but the same Rune).
	Code Code
	// Name of the key. For letters, the upper case form is used, via
	// unicode.ToUpper. The shift modifier is taken into account, all other
	// modifiers are ignored. For example, the "shift-1" and "ctrl-shift-1"
	// combinations both give the Name "!" with the US keyboard layout.
	Name string
	// Modifiers is the set of active modifiers when the key was pressed.
	Modifiers Modifiers

	// Direction is the direction of the key event: DirPress, DirRelease,
	// or DirNone (for key repeats).
	Direction Direction
}

// An EditEvent is generated when text is input.
type EditEvent struct {
	Text string
}

// Direction is the direction of the key event.
type Direction uint8

const (
	DirNone    Direction = 0
	DirPress   Direction = 1
	DirRelease Direction = 2
)

// Modifiers
type Modifiers uint32

// Code is the identity of a key relative to a notional "standard" keyboard.
type Code uint32

// Physical key codes.
//
// For standard key codes, its value matches USB HID key codes.
// TODO: add missing codes.
const (
	CodeUnknown Code = 0

	CodeA Code = 4
	CodeB Code = 5
	CodeC Code = 6
	CodeD Code = 7
	CodeE Code = 8
	CodeF Code = 9
	CodeG Code = 10
	CodeH Code = 11
	CodeI Code = 12
	CodeJ Code = 13
	CodeK Code = 14
	CodeL Code = 15
	CodeM Code = 16
	CodeN Code = 17
	CodeO Code = 18
	CodeP Code = 19
	CodeQ Code = 20
	CodeR Code = 21
	CodeS Code = 22
	CodeT Code = 23
	CodeU Code = 24
	CodeV Code = 25
	CodeW Code = 26
	CodeX Code = 27
	CodeY Code = 28
	CodeZ Code = 29

	Code1 Code = 30
	Code2 Code = 31
	Code3 Code = 32
	Code4 Code = 33
	Code5 Code = 34
	Code6 Code = 35
	Code7 Code = 36
	Code8 Code = 37
	Code9 Code = 38
	Code0 Code = 39

	CodeReturnEnter        Code = 40
	CodeEscape             Code = 41
	CodeDeleteBackspace    Code = 42
	CodeTab                Code = 43
	CodeSpacebar           Code = 44
	CodeHyphenMinus        Code = 45 // -
	CodeEqualSign          Code = 46 // =
	CodeLeftSquareBracket  Code = 47 // [
	CodeRightSquareBracket Code = 48 // ]
	CodeBackslash          Code = 49 // \
	CodeSemicolon          Code = 51 // ;
	CodeApostrophe         Code = 52 // '
	CodeGraveAccent        Code = 53 // `
	CodeComma              Code = 54 // ,
	CodeFullStop           Code = 55 // .
	CodeSlash              Code = 56 // /
	CodeCapsLock           Code = 57

	CodeF1  Code = 58
	CodeF2  Code = 59
	CodeF3  Code = 60
	CodeF4  Code = 61
	CodeF5  Code = 62
	CodeF6  Code = 63
	CodeF7  Code = 64
	CodeF8  Code = 65
	CodeF9  Code = 66
	CodeF10 Code = 67
	CodeF11 Code = 68
	CodeF12 Code = 69

	CodePause         Code = 72
	CodeInsert        Code = 73
	CodeHome          Code = 74
	CodePageUp        Code = 75
	CodeDeleteForward Code = 76
	CodeEnd           Code = 77
	CodePageDown      Code = 78

	CodeRightArrow Code = 79
	CodeLeftArrow  Code = 80
	CodeDownArrow  Code = 81
	CodeUpArrow    Code = 82

	CodeKeypadNumLock     Code = 83
	CodeKeypadSlash       Code = 84 // /
	CodeKeypadAsterisk    Code = 85 // *
	CodeKeypadHyphenMinus Code = 86 // -
	CodeKeypadPlusSign    Code = 87 // +
	CodeKeypadEnter       Code = 88
	CodeKeypad1           Code = 89
	CodeKeypad2           Code = 90
	CodeKeypad3           Code = 91
	CodeKeypad4           Code = 92
	CodeKeypad5           Code = 93
	CodeKeypad6           Code = 94
	CodeKeypad7           Code = 95
	CodeKeypad8           Code = 96
	CodeKeypad9           Code = 97
	CodeKeypad0           Code = 98
	CodeKeypadFullStop    Code = 99  // .
	CodeKeypadEqualSign   Code = 103 // =

	CodeF13 Code = 104
	CodeF14 Code = 105
	CodeF15 Code = 106
	CodeF16 Code = 107
	CodeF17 Code = 108
	CodeF18 Code = 109
	CodeF19 Code = 110
	CodeF20 Code = 111
	CodeF21 Code = 112
	CodeF22 Code = 113
	CodeF23 Code = 114
	CodeF24 Code = 115

	CodeHelp Code = 117

	CodeMute       Code = 127
	CodeVolumeUp   Code = 128
	CodeVolumeDown Code = 129

	CodeLeftControl  Code = 224
	CodeLeftShift    Code = 225
	CodeLeftAlt      Code = 226
	CodeLeftGUI      Code = 227
	CodeRightControl Code = 228
	CodeRightShift   Code = 229
	CodeRightAlt     Code = 230
	CodeRightGUI     Code = 231

	// The following codes are not part of the standard USB HID Usage IDs for
	// keyboards. See http://www.usb.org/developers/hidpage/Hut1_12v2.pdf
	//
	// Usage IDs are uint16s, so these non-standard values start at 0x10000.

	// CodeCompose is the Code for a compose key, sometimes called a multi key,
	// used to input non-ASCII characters such as ñ being composed of n and ~.
	//
	// See https://en.wikipedia.org/wiki/Compose_key
	CodeCompose Code = 0x10000
)

const (
	// ModCtrl is the ctrl modifier key.
	ModCtrl Modifiers = 1 << iota
	// ModCommand is the command modifier key
	// found on Apple keyboards.
	ModCommand
	// ModShift is the shift modifier key.
	//ModShift
	// ModAlt is the alt modifier key, or the option
	// key on Apple keyboards.
	//ModAlt
	// ModSuper is the "logo" modifier key, often
	// represented by a Windows logo.
	ModSuper

	ModShift   Modifiers = 1 << 0
	ModControl Modifiers = 1 << 1
	ModAlt     Modifiers = 1 << 2
	ModMeta    Modifiers = 1 << 3 // called "Command" on OS X
)

const (
	// Names for special keys.
	NameLeftArrow      = "←"
	NameRightArrow     = "→"
	NameUpArrow        = "↑"
	NameDownArrow      = "↓"
	NameReturn         = "⏎"
	NameEnter          = "⌤"
	NameEscape         = "⎋"
	NameHome           = "⇱"
	NameEnd            = "⇲"
	NameDeleteBackward = "⌫"
	NameDeleteForward  = "⌦"
	NamePageUp         = "⇞"
	NamePageDown       = "⇟"
	NameTab            = "⇥"
)

// Contain reports whether m contains all modifiers
// in m2.
func (m Modifiers) Contain(m2 Modifiers) bool {
	return m&m2 == m2
}

func (h InputOp) Add(o *op.Ops) {
	data := o.Write(opconst.TypeKeyInputLen, h.Key)
	data[0] = byte(opconst.TypeKeyInput)
	if h.Focus {
		data[1] = 1
	}
}

func (h HideInputOp) Add(o *op.Ops) {
	data := o.Write(opconst.TypeHideInputLen)
	data[0] = byte(opconst.TypeHideInput)
}

func (EditEvent) ImplementsEvent()  {}
func (Event) ImplementsEvent()      {}
func (FocusEvent) ImplementsEvent() {}

func (e Event) String() string {
	return "{" + string(e.Name) + " " + e.Modifiers.String() + "}"
}

func (m Modifiers) String() string {
	var strs []string
	if m.Contain(ModCtrl) {
		strs = append(strs, "ModCtrl")
	}
	if m.Contain(ModCommand) {
		strs = append(strs, "ModCommand")
	}
	if m.Contain(ModShift) {
		strs = append(strs, "ModShift")
	}
	if m.Contain(ModAlt) {
		strs = append(strs, "ModAlt")
	}
	if m.Contain(ModSuper) {
		strs = append(strs, "ModSuper")
	}
	return strings.Join(strs, "|")
}