Extend support for alt key chords

"alt-" with any case-sensitive character is allowed

src/tui/light.go

@@ -1,6 +1,7 @@
 package tui
 
 import (
+	"bytes"
 	"fmt"
 	"os"
 	"regexp"
@@ -230,7 +231,7 @@ func (r *LightRenderer) getBytesInternal(buffer []byte, nonblock bool) []byte {
 	}
 
 	retries := 0
-	if c == ESC || nonblock {
+	if c == ESC.Int() || nonblock {
 		retries = r.escDelay / escPollInterval
 	}
 	buffer = append(buffer, byte(c))
@@ -245,7 +246,7 @@ func (r *LightRenderer) getBytesInternal(buffer []byte, nonblock bool) []byte {
 				continue
 			}
 			break
-		} else if c == ESC && pc != c {
+		} else if c == ESC.Int() && pc != c {
 			retries = r.escDelay / escPollInterval
 		} else {
 			retries = 0
@@ -278,11 +279,11 @@ func (r *LightRenderer) GetChar() Event {
 	}()
 
 	switch r.buffer[0] {
-	case CtrlC:
+	case CtrlC.Byte():
 		return Event{CtrlC, 0, nil}
-	case CtrlG:
+	case CtrlG.Byte():
 		return Event{CtrlG, 0, nil}
-	case CtrlQ:
+	case CtrlQ.Byte():
 		return Event{CtrlQ, 0, nil}
 	case 127:
 		return Event{BSpace, 0, nil}
@@ -296,7 +297,7 @@ func (r *LightRenderer) GetChar() Event {
 		return Event{CtrlCaret, 0, nil}
 	case 31:
 		return Event{CtrlSlash, 0, nil}
-	case ESC:
+	case ESC.Byte():
 		ev := r.escSequence(&sz)
 		// Second chance
 		if ev.Type == Invalid {
@@ -307,8 +308,8 @@ func (r *LightRenderer) GetChar() Event {
 	}
 
 	// CTRL-A ~ CTRL-Z
-	if r.buffer[0] <= CtrlZ {
-		return Event{int(r.buffer[0]), 0, nil}
+	if r.buffer[0] <= CtrlZ.Byte() {
+		return Event{EventType(r.buffer[0]), 0, nil}
 	}
 	char, rsz := utf8.DecodeRune(r.buffer)
 	if char == utf8.RuneError {
@@ -331,26 +332,16 @@ func (r *LightRenderer) escSequence(sz *int) Event {
 
 	*sz = 2
 	if r.buffer[1] >= 1 && r.buffer[1] <= 'z'-'a'+1 {
-		return Event{int(CtrlAltA + r.buffer[1] - 1), 0, nil}
+		return CtrlAltKey(rune(r.buffer[1] + 'a' - 1))
 	}
 	alt := false
-	if len(r.buffer) > 2 && r.buffer[1] == ESC {
+	if len(r.buffer) > 2 && r.buffer[1] == ESC.Byte() {
 		r.buffer = r.buffer[1:]
 		alt = true
 	}
 	switch r.buffer[1] {
-	case ESC:
+	case ESC.Byte():
 		return Event{ESC, 0, nil}
-	case ' ':
-		return Event{AltSpace, 0, nil}
-	case '/':
-		return Event{AltSlash, 0, nil}
-	case 'b':
-		return Event{AltB, 0, nil}
-	case 'd':
-		return Event{AltD, 0, nil}
-	case 'f':
-		return Event{AltF, 0, nil}
 	case 127:
 		return Event{AltBS, 0, nil}
 	case '[', 'O':
@@ -518,11 +509,11 @@ func (r *LightRenderer) escSequence(sz *int) Event {
 			} // r.buffer[2]
 		} // r.buffer[2]
 	} // r.buffer[1]
-	if r.buffer[1] >= 'a' && r.buffer[1] <= 'z' {
-		return Event{AltA + int(r.buffer[1]) - 'a', 0, nil}
-	}
-	if r.buffer[1] >= '0' && r.buffer[1] <= '9' {
-		return Event{Alt0 + int(r.buffer[1]) - '0', 0, nil}
+	rest := bytes.NewBuffer(r.buffer[1:])
+	c, size, err := rest.ReadRune()
+	if err == nil {
+		*sz = 1 + size
+		return AltKey(c)
 	}
 	return Event{Invalid, 0, nil}
 }

src/tui/tcell.go

@@ -226,65 +226,65 @@ func (r *FullscreenRenderer) GetChar() Event {
 		alt := (mods & tcell.ModAlt) > 0
 		shift := (mods & tcell.ModShift) > 0
 		altShift := alt && shift
-		keyfn := func(r rune) int {
+		keyfn := func(r rune) Event {
 			if alt {
-				return CtrlAltA - 'a' + int(r)
+				return CtrlAltKey(r)
 			}
-			return CtrlA - 'a' + int(r)
+			return EventType(CtrlA.Int() - 'a' + int(r)).AsEvent()
 		}
 		switch ev.Key() {
 		case tcell.KeyCtrlA:
-			return Event{keyfn('a'), 0, nil}
+			return keyfn('a')
 		case tcell.KeyCtrlB:
-			return Event{keyfn('b'), 0, nil}
+			return keyfn('b')
 		case tcell.KeyCtrlC:
-			return Event{keyfn('c'), 0, nil}
+			return keyfn('c')
 		case tcell.KeyCtrlD:
-			return Event{keyfn('d'), 0, nil}
+			return keyfn('d')
 		case tcell.KeyCtrlE:
-			return Event{keyfn('e'), 0, nil}
+			return keyfn('e')
 		case tcell.KeyCtrlF:
-			return Event{keyfn('f'), 0, nil}
+			return keyfn('f')
 		case tcell.KeyCtrlG:
-			return Event{keyfn('g'), 0, nil}
+			return keyfn('g')
 		case tcell.KeyCtrlH:
-			return Event{keyfn('h'), 0, nil}
+			return keyfn('h')
 		case tcell.KeyCtrlI:
-			return Event{keyfn('i'), 0, nil}
+			return keyfn('i')
 		case tcell.KeyCtrlJ:
-			return Event{keyfn('j'), 0, nil}
+			return keyfn('j')
 		case tcell.KeyCtrlK:
-			return Event{keyfn('k'), 0, nil}
+			return keyfn('k')
 		case tcell.KeyCtrlL:
-			return Event{keyfn('l'), 0, nil}
+			return keyfn('l')
 		case tcell.KeyCtrlM:
-			return Event{keyfn('m'), 0, nil}
+			return keyfn('m')
 		case tcell.KeyCtrlN:
-			return Event{keyfn('n'), 0, nil}
+			return keyfn('n')
 		case tcell.KeyCtrlO:
-			return Event{keyfn('o'), 0, nil}
+			return keyfn('o')
 		case tcell.KeyCtrlP:
-			return Event{keyfn('p'), 0, nil}
+			return keyfn('p')
 		case tcell.KeyCtrlQ:
-			return Event{keyfn('q'), 0, nil}
+			return keyfn('q')
 		case tcell.KeyCtrlR:
-			return Event{keyfn('r'), 0, nil}
+			return keyfn('r')
 		case tcell.KeyCtrlS:
-			return Event{keyfn('s'), 0, nil}
+			return keyfn('s')
 		case tcell.KeyCtrlT:
-			return Event{keyfn('t'), 0, nil}
+			return keyfn('t')
 		case tcell.KeyCtrlU:
-			return Event{keyfn('u'), 0, nil}
+			return keyfn('u')
 		case tcell.KeyCtrlV:
-			return Event{keyfn('v'), 0, nil}
+			return keyfn('v')
 		case tcell.KeyCtrlW:
-			return Event{keyfn('w'), 0, nil}
+			return keyfn('w')
 		case tcell.KeyCtrlX:
-			return Event{keyfn('x'), 0, nil}
+			return keyfn('x')
 		case tcell.KeyCtrlY:
-			return Event{keyfn('y'), 0, nil}
+			return keyfn('y')
 		case tcell.KeyCtrlZ:
-			return Event{keyfn('z'), 0, nil}
+			return keyfn('z')
 		case tcell.KeyCtrlSpace:
 			return Event{CtrlSpace, 0, nil}
 		case tcell.KeyCtrlBackslash:
@@ -389,18 +389,7 @@ func (r *FullscreenRenderer) GetChar() Event {
 		case tcell.KeyRune:
 			r := ev.Rune()
 			if alt {
-				switch r {
-				case ' ':
-					return Event{AltSpace, 0, nil}
-				case '/':
-					return Event{AltSlash, 0, nil}
-				}
-				if r >= 'a' && r <= 'z' {
-					return Event{AltA + int(r) - 'a', 0, nil}
-				}
-				if r >= '0' && r <= '9' {
-					return Event{Alt0 + int(r) - '0', 0, nil}
-				}
+				return AltKey(r)
 			}
 			return Event{Rune, r, nil}
 

src/tui/tui.go

@@ -8,8 +8,10 @@ import (
 )
 
 // Types of user action
+type EventType int
+
 const (
-	Rune = iota
+	Rune EventType = iota
 
 	CtrlA
 	CtrlB
@@ -89,8 +91,6 @@ const (
 	Change
 	BackwardEOF
 
-	AltSpace
-	AltSlash
 	AltBS
 
 	AltUp
@@ -103,20 +103,38 @@ const (
 	AltSLeft
 	AltSRight
 
-	Alt0
+	Alt
+	CtrlAlt
 )
 
-const ( // Reset iota
-	AltA = Alt0 + 'a' - '0' + iota
-	AltB
-	AltC
-	AltD
-	AltE
-	AltF
-	AltZ     = AltA + 'z' - 'a'
-	CtrlAltA = AltZ + 1
-	CtrlAltM = CtrlAltA + 'm' - 'a'
-)
+func (t EventType) AsEvent() Event {
+	return Event{t, 0, nil}
+}
+
+func (t EventType) Int() int {
+	return int(t)
+}
+
+func (t EventType) Byte() byte {
+	return byte(t)
+}
+
+func (e Event) Comparable() Event {
+	// Ignore MouseEvent pointer
+	return Event{e.Type, e.Char, nil}
+}
+
+func Key(r rune) Event {
+	return Event{Rune, r, nil}
+}
+
+func AltKey(r rune) Event {
+	return Event{Alt, r, nil}
+}
+
+func CtrlAltKey(r rune) Event {
+	return Event{CtrlAlt, r, nil}
+}
 
 const (
 	doubleClickDuration = 500 * time.Millisecond
@@ -251,7 +269,7 @@ type ColorTheme struct {
 }
 
 type Event struct {
-	Type       int
+	Type       EventType
 	Char       rune
 	MouseEvent *MouseEvent
 }