Export $FZF_KEY environment variable to child processes

It's the name of the last key pressed.

Related #3412

3 files changed, 230 insertions, 67 deletions

diff --git a/src/tui/eventtype_string.go b/src/tui/eventtype_string.go
new file mode 100644
index 00000000..ce34d36e
--- /dev/null
+++ b/src/tui/eventtype_string.go
@@ -0,0 +1,120 @@
+// Code generated by "stringer -type=EventType"; DO NOT EDIT.
+
+package tui
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[Rune-0]
+	_ = x[CtrlA-1]
+	_ = x[CtrlB-2]
+	_ = x[CtrlC-3]
+	_ = x[CtrlD-4]
+	_ = x[CtrlE-5]
+	_ = x[CtrlF-6]
+	_ = x[CtrlG-7]
+	_ = x[CtrlH-8]
+	_ = x[Tab-9]
+	_ = x[CtrlJ-10]
+	_ = x[CtrlK-11]
+	_ = x[CtrlL-12]
+	_ = x[CtrlM-13]
+	_ = x[CtrlN-14]
+	_ = x[CtrlO-15]
+	_ = x[CtrlP-16]
+	_ = x[CtrlQ-17]
+	_ = x[CtrlR-18]
+	_ = x[CtrlS-19]
+	_ = x[CtrlT-20]
+	_ = x[CtrlU-21]
+	_ = x[CtrlV-22]
+	_ = x[CtrlW-23]
+	_ = x[CtrlX-24]
+	_ = x[CtrlY-25]
+	_ = x[CtrlZ-26]
+	_ = x[Esc-27]
+	_ = x[CtrlSpace-28]
+	_ = x[CtrlDelete-29]
+	_ = x[CtrlBackSlash-30]
+	_ = x[CtrlRightBracket-31]
+	_ = x[CtrlCaret-32]
+	_ = x[CtrlSlash-33]
+	_ = x[ShiftTab-34]
+	_ = x[Backspace-35]
+	_ = x[Delete-36]
+	_ = x[PageUp-37]
+	_ = x[PageDown-38]
+	_ = x[Up-39]
+	_ = x[Down-40]
+	_ = x[Left-41]
+	_ = x[Right-42]
+	_ = x[Home-43]
+	_ = x[End-44]
+	_ = x[Insert-45]
+	_ = x[ShiftUp-46]
+	_ = x[ShiftDown-47]
+	_ = x[ShiftLeft-48]
+	_ = x[ShiftRight-49]
+	_ = x[ShiftDelete-50]
+	_ = x[F1-51]
+	_ = x[F2-52]
+	_ = x[F3-53]
+	_ = x[F4-54]
+	_ = x[F5-55]
+	_ = x[F6-56]
+	_ = x[F7-57]
+	_ = x[F8-58]
+	_ = x[F9-59]
+	_ = x[F10-60]
+	_ = x[F11-61]
+	_ = x[F12-62]
+	_ = x[AltBackspace-63]
+	_ = x[AltUp-64]
+	_ = x[AltDown-65]
+	_ = x[AltLeft-66]
+	_ = x[AltRight-67]
+	_ = x[AltShiftUp-68]
+	_ = x[AltShiftDown-69]
+	_ = x[AltShiftLeft-70]
+	_ = x[AltShiftRight-71]
+	_ = x[Alt-72]
+	_ = x[CtrlAlt-73]
+	_ = x[Invalid-74]
+	_ = x[Mouse-75]
+	_ = x[DoubleClick-76]
+	_ = x[LeftClick-77]
+	_ = x[RightClick-78]
+	_ = x[SLeftClick-79]
+	_ = x[SRightClick-80]
+	_ = x[ScrollUp-81]
+	_ = x[ScrollDown-82]
+	_ = x[SScrollUp-83]
+	_ = x[SScrollDown-84]
+	_ = x[PreviewScrollUp-85]
+	_ = x[PreviewScrollDown-86]
+	_ = x[Resize-87]
+	_ = x[Change-88]
+	_ = x[BackwardEOF-89]
+	_ = x[Start-90]
+	_ = x[Load-91]
+	_ = x[Focus-92]
+	_ = x[One-93]
+	_ = x[Zero-94]
+	_ = x[Result-95]
+	_ = x[Jump-96]
+	_ = x[JumpCancel-97]
+}
+
+const _EventType_name = "RuneCtrlACtrlBCtrlCCtrlDCtrlECtrlFCtrlGCtrlHTabCtrlJCtrlKCtrlLCtrlMCtrlNCtrlOCtrlPCtrlQCtrlRCtrlSCtrlTCtrlUCtrlVCtrlWCtrlXCtrlYCtrlZEscCtrlSpaceCtrlDeleteCtrlBackSlashCtrlRightBracketCtrlCaretCtrlSlashShiftTabBackspaceDeletePageUpPageDownUpDownLeftRightHomeEndInsertShiftUpShiftDownShiftLeftShiftRightShiftDeleteF1F2F3F4F5F6F7F8F9F10F11F12AltBackspaceAltUpAltDownAltLeftAltRightAltShiftUpAltShiftDownAltShiftLeftAltShiftRightAltCtrlAltInvalidMouseDoubleClickLeftClickRightClickSLeftClickSRightClickScrollUpScrollDownSScrollUpSScrollDownPreviewScrollUpPreviewScrollDownResizeChangeBackwardEOFStartLoadFocusOneZeroResultJumpJumpCancel"
+
+var _EventType_index = [...]uint16{0, 4, 9, 14, 19, 24, 29, 34, 39, 44, 47, 52, 57, 62, 67, 72, 77, 82, 87, 92, 97, 102, 107, 112, 117, 122, 127, 132, 135, 144, 154, 167, 183, 192, 201, 209, 218, 224, 230, 238, 240, 244, 248, 253, 257, 260, 266, 273, 282, 291, 301, 312, 314, 316, 318, 320, 322, 324, 326, 328, 330, 333, 336, 339, 351, 356, 363, 370, 378, 388, 400, 412, 425, 428, 435, 442, 447, 458, 467, 477, 487, 498, 506, 516, 525, 536, 551, 568, 574, 580, 591, 596, 600, 605, 608, 612, 618, 622, 632}
+
+func (i EventType) String() string {
+	if i < 0 || i >= EventType(len(_EventType_index)-1) {
+		return "EventType(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _EventType_name[_EventType_index[i]:_EventType_index[i+1]]
+}
diff --git a/src/tui/light.go b/src/tui/light.go
index e42d398b..244891a9 100644
--- a/src/tui/light.go
+++ b/src/tui/light.go
@@ -245,7 +245,7 @@ func (r *LightRenderer) getBytesInternal(buffer []byte, nonblock bool) []byte {
 	}
 
 	retries := 0
-	if c == ESC.Int() || nonblock {
+	if c == Esc.Int() || nonblock {
 		retries = r.escDelay / escPollInterval
 	}
 	buffer = append(buffer, byte(c))
@@ -260,7 +260,7 @@ func (r *LightRenderer) getBytesInternal(buffer []byte, nonblock bool) []byte {
 				continue
 			}
 			break
-		} else if c == ESC.Int() && pc != c {
+		} else if c == Esc.Int() && pc != c {
 			retries = r.escDelay / escPollInterval
 		} else {
 			retries = 0
@@ -300,7 +300,7 @@ func (r *LightRenderer) GetChar() Event {
 	case CtrlQ.Byte():
 		return Event{CtrlQ, 0, nil}
 	case 127:
-		return Event{BSpace, 0, nil}
+		return Event{Backspace, 0, nil}
 	case 0:
 		return Event{CtrlSpace, 0, nil}
 	case 28:
@@ -311,7 +311,7 @@ func (r *LightRenderer) GetChar() Event {
 		return Event{CtrlCaret, 0, nil}
 	case 31:
 		return Event{CtrlSlash, 0, nil}
-	case ESC.Byte():
+	case Esc.Byte():
 		ev := r.escSequence(&sz)
 		// Second chance
 		if ev.Type == Invalid {
@@ -327,7 +327,7 @@ func (r *LightRenderer) GetChar() Event {
 	}
 	char, rsz := utf8.DecodeRune(r.buffer)
 	if char == utf8.RuneError {
-		return Event{ESC, 0, nil}
+		return Event{Esc, 0, nil}
 	}
 	sz = rsz
 	return Event{Rune, char, nil}
@@ -335,7 +335,7 @@ func (r *LightRenderer) GetChar() Event {
 
 func (r *LightRenderer) escSequence(sz *int) Event {
 	if len(r.buffer) < 2 {
-		return Event{ESC, 0, nil}
+		return Event{Esc, 0, nil}
 	}
 
 	loc := offsetRegexpBegin.FindIndex(r.buffer)
@@ -349,15 +349,15 @@ func (r *LightRenderer) escSequence(sz *int) Event {
 		return CtrlAltKey(rune(r.buffer[1] + 'a' - 1))
 	}
 	alt := false
-	if len(r.buffer) > 2 && r.buffer[1] == ESC.Byte() {
+	if len(r.buffer) > 2 && r.buffer[1] == Esc.Byte() {
 		r.buffer = r.buffer[1:]
 		alt = true
 	}
 	switch r.buffer[1] {
-	case ESC.Byte():
-		return Event{ESC, 0, nil}
+	case Esc.Byte():
+		return Event{Esc, 0, nil}
 	case 127:
-		return Event{AltBS, 0, nil}
+		return Event{AltBackspace, 0, nil}
 	case '[', 'O':
 		if len(r.buffer) < 3 {
 			return Event{Invalid, 0, nil}
@@ -386,7 +386,7 @@ func (r *LightRenderer) escSequence(sz *int) Event {
 			}
 			return Event{Up, 0, nil}
 		case 'Z':
-			return Event{BTab, 0, nil}
+			return Event{ShiftTab, 0, nil}
 		case 'H':
 			return Event{Home, 0, nil}
 		case 'F':
@@ -434,7 +434,7 @@ func (r *LightRenderer) escSequence(sz *int) Event {
 				return Event{Invalid, 0, nil} // INS
 			case '3':
 				if r.buffer[3] == '~' {
-					return Event{Del, 0, nil}
+					return Event{Delete, 0, nil}
 				}
 				if len(r.buffer) == 6 && r.buffer[5] == '~' {
 					*sz = 6
@@ -442,16 +442,16 @@ func (r *LightRenderer) escSequence(sz *int) Event {
 					case '5':
 						return Event{CtrlDelete, 0, nil}
 					case '2':
-						return Event{SDelete, 0, nil}
+						return Event{ShiftDelete, 0, nil}
 					}
 				}
 				return Event{Invalid, 0, nil}
 			case '4':
 				return Event{End, 0, nil}
 			case '5':
-				return Event{PgUp, 0, nil}
+				return Event{PageUp, 0, nil}
 			case '6':
-				return Event{PgDn, 0, nil}
+				return Event{PageDown, 0, nil}
 			case '7':
 				return Event{Home, 0, nil}
 			case '8':
@@ -489,16 +489,29 @@ func (r *LightRenderer) escSequence(sz *int) Event {
 					}
 					*sz = 6
 					switch r.buffer[4] {
-					case '1', '2', '3', '5':
+					case '1', '2', '3', '4', '5':
+						//                   Kitty      iTerm2     WezTerm
+						// SHIFT-ARROW       "\e[1;2D"
+						// ALT-SHIFT-ARROW   "\e[1;4D"  "\e[1;10D" "\e[1;4D"
+						// CTRL-SHIFT-ARROW  "\e[1;6D"             N/A
+						// CMD-SHIFT-ARROW   "\e[1;10D" N/A        N/A ("\e[1;2D")
 						alt := r.buffer[4] == '3'
-						altShift := r.buffer[4] == '1' && r.buffer[5] == '0'
 						char := r.buffer[5]
-						if altShift {
+						altShift := false
+						if r.buffer[4] == '1' && r.buffer[5] == '0' {
+							altShift = true
 							if len(r.buffer) < 7 {
 								return Event{Invalid, 0, nil}
 							}
 							*sz = 7
 							char = r.buffer[6]
+						} else if r.buffer[4] == '4' {
+							altShift = true
+							if len(r.buffer) < 6 {
+								return Event{Invalid, 0, nil}
+							}
+							*sz = 6
+							char = r.buffer[5]
 						}
 						switch char {
 						case 'A':
@@ -506,33 +519,33 @@ func (r *LightRenderer) escSequence(sz *int) Event {
 								return Event{AltUp, 0, nil}
 							}
 							if altShift {
-								return Event{AltSUp, 0, nil}
+								return Event{AltShiftUp, 0, nil}
 							}
-							return Event{SUp, 0, nil}
+							return Event{ShiftUp, 0, nil}
 						case 'B':
 							if alt {
 								return Event{AltDown, 0, nil}
 							}
 							if altShift {
-								return Event{AltSDown, 0, nil}
+								return Event{AltShiftDown, 0, nil}
 							}
-							return Event{SDown, 0, nil}
+							return Event{ShiftDown, 0, nil}
 						case 'C':
 							if alt {
 								return Event{AltRight, 0, nil}
 							}
 							if altShift {
-								return Event{AltSRight, 0, nil}
+								return Event{AltShiftRight, 0, nil}
 							}
-							return Event{SRight, 0, nil}
+							return Event{ShiftRight, 0, nil}
 						case 'D':
 							if alt {
 								return Event{AltLeft, 0, nil}
 							}
 							if altShift {
-								return Event{AltSLeft, 0, nil}
+								return Event{AltShiftLeft, 0, nil}
 							}
-							return Event{SLeft, 0, nil}
+							return Event{ShiftLeft, 0, nil}
 						}
 					} // r.buffer[4]
 				} // r.buffer[3]
diff --git a/src/tui/tui.go b/src/tui/tui.go
index 729146cc..ad65e92f 100644
--- a/src/tui/tui.go
+++ b/src/tui/tui.go
@@ -6,10 +6,13 @@ import (
 	"strconv"
 	"time"
 
+	"github.com/junegunn/fzf/src/util"
 	"github.com/rivo/uniseg"
 )
 
 // Types of user action
+//
+//go:generate stringer -type=EventType
 type EventType int
 
 const (
@@ -41,7 +44,7 @@ const (
 	CtrlX
 	CtrlY
 	CtrlZ
-	ESC
+	Esc
 	CtrlSpace
 	CtrlDelete
 
@@ -51,27 +54,12 @@ const (
 	CtrlCaret
 	CtrlSlash
 
-	Invalid
-	Resize
-	Mouse
-	DoubleClick
-	LeftClick
-	RightClick
-	SLeftClick
-	SRightClick
-	ScrollUp
-	ScrollDown
-	SScrollUp
-	SScrollDown
-	PreviewScrollUp
-	PreviewScrollDown
-
-	BTab
-	BSpace
+	ShiftTab
+	Backspace
 
-	Del
-	PgUp
-	PgDn
+	Delete
+	PageUp
+	PageDown
 
 	Up
 	Down
@@ -81,11 +69,11 @@ const (
 	End
 	Insert
 
-	SUp
-	SDown
-	SLeft
-	SRight
-	SDelete
+	ShiftUp
+	ShiftDown
+	ShiftLeft
+	ShiftRight
+	ShiftDelete
 
 	F1
 	F2
@@ -100,6 +88,38 @@ const (
 	F11
 	F12
 
+	AltBackspace
+
+	AltUp
+	AltDown
+	AltLeft
+	AltRight
+
+	AltShiftUp
+	AltShiftDown
+	AltShiftLeft
+	AltShiftRight
+
+	Alt
+	CtrlAlt
+
+	Invalid
+
+	Mouse
+	DoubleClick
+	LeftClick
+	RightClick
+	SLeftClick
+	SRightClick
+	ScrollUp
+	ScrollDown
+	SScrollUp
+	SScrollDown
+	PreviewScrollUp
+	PreviewScrollDown
+
+	// Events
+	Resize
 	Change
 	BackwardEOF
 	Start
@@ -110,21 +130,6 @@ const (
 	Result
 	Jump
 	JumpCancel
-
-	AltBS
-
-	AltUp
-	AltDown
-	AltLeft
-	AltRight
-
-	AltSUp
-	AltSDown
-	AltSLeft
-	AltSRight
-
-	Alt
-	CtrlAlt
 )
 
 func (t EventType) AsEvent() Event {
@@ -144,6 +149,31 @@ func (e Event) Comparable() Event {
 	return Event{e.Type, e.Char, nil}
 }
 
+func (e Event) KeyName() string {
+	if e.Type >= Invalid {
+		return ""
+	}
+
+	switch e.Type {
+	case Rune:
+		return string(e.Char)
+	case Alt:
+		return "alt-" + string(e.Char)
+	case CtrlAlt:
+		return "ctrl-alt-" + string(e.Char)
+	case CtrlBackSlash:
+		return "ctrl-\\"
+	case CtrlRightBracket:
+		return "ctrl-]"
+	case CtrlCaret:
+		return "ctrl-^"
+	case CtrlSlash:
+		return "ctrl-/"
+	}
+
+	return util.ToKebabCase(e.Type.String())
+}
+
 func Key(r rune) Event {
 	return Event{Rune, r, nil}
 }