Refactor input mapping

editor/editor.go

@@ -80,6 +80,13 @@ func (e *editor) SetStatusMessage(template string, a ...interface{}) {
 func (e *editor) ProcessKeypress() bool {
 	ch, _ := terminal.ReadKey()
 
+	return e.processKeypressChar(ch)
+}
+
+/**
+ * Determine what to do with an individual character of input
+ */
+func (e *editor) processKeypressChar(ch rune) bool {
 	switch ch {
 	case key.Ctrl('q'):
 		if e.document.dirty && e.quitTimes > 0 {
@@ -106,7 +113,34 @@ func (e *editor) ProcessKeypress() bool {
 		// Modifier keys that return ANSI escape sequences
 		str := parseEscapeSequence()
 
-		switch str {
+		// Don't swallow a character after ESC if it doesn't
+		// start an ANSI escape sequence
+		if len(str) == 1 {
+			return e.processKeypressChar(rune(str[0]))
+		}
+
+		e.processKeypressStr(str)
+
+	default:
+		e.insertChar(ch)
+	}
+
+	// Clear the quit message and restart the
+	// confirmation count if confirmation is not
+	// completed
+	if e.quitTimes != KiloQuitTimes {
+		e.quitTimes = KiloQuitTimes
+		e.SetStatusMessage("")
+	}
+
+	return true
+}
+
+/**
+ * Determine what do do with a parsed ANSI escape sequence
+ */
+func (e *editor) processKeypressStr(key string) {
+	switch key {
 	case keyUp,
 		keyDown,
 		keyLeft,
@@ -116,22 +150,12 @@ func (e *editor) ProcessKeypress() bool {
 		keyHome,
 		keyEnd:
 
-			e.moveCursor(str)
+		e.moveCursor(key)
 
 	case keyDelete:
 		e.moveCursor(keyRight)
 		e.delChar()
 	}
-
-	default:
-		e.insertChar(ch)
-	}
-
-	if e.quitTimes != KiloQuitTimes {
-		e.quitTimes = KiloQuitTimes
-	}
-
-	return true
 }
 
 func (e *editor) moveCursor(key string) {
@@ -229,28 +253,51 @@ func (e *editor) delChar() {
 
 // Convert the raw ANSI escape sequences to the type of key input
 func parseEscapeSequence() string {
-	var runes []rune
+	// If we aren't starting an escape sequence,
+	// return the character
+	startChar, _ := terminal.ReadKey()
+	if startChar != '[' && startChar != 'O' {
+		return string(startChar)
+	}
 
-	for i := 0; i < 3; i++ {
+	// Read one or two characters after
+	// \e[ or \eO, which is the end of the
+	// handled escape sequences
+	runes := [2]rune{'\000', '\000'}
+	for i := 0; i < 2; i++ {
 		ch, size := terminal.ReadKey()
 		if size == 0 {
-			return "\x1b"
+			return string(rune(key.Esc))
 		}
-		runes = append(runes, ch)
+		runes[i] = ch
 
-		if i == 1 && runes[1] >= 'A' {
-			// \eOH \eOF
-			if runes[0] == 'O' {
-				switch runes[1] {
+		if i == 0 && runes[0] >= 'A' && runes[0] <= 'Z' {
+			return escSeqToKey([]rune{startChar, runes[0]})
+		}
+
+		// \e[*~
+		if i == 1 && startChar == '[' && runes[1] == '~' {
+			return escSeqToKey([]rune{startChar, runes[0], runes[1]})
+		}
+	}
+
+	return string(rune(key.Esc))
+}
+
+func escSeqToKey (seq []rune) string {
+	// \eO*
+	// \e[*
+	if len(seq) == 2 {
+		startChar, cmd := seq[0], seq[1]
+		if startChar == 'O' {
+			switch cmd {
 			case 'H':
 				return keyHome
 			case 'F':
 				return keyEnd
 			}
-			}
-			// \e[A
-			if runes[0] == '[' {
-				switch runes[1] {
+		} else if startChar == '[' {
+			switch cmd {
 			case 'A':
 				return keyUp
 			case 'B':
@@ -265,11 +312,9 @@ func parseEscapeSequence() string {
 				return keyEnd
 			}
 		}
-		}
-
-		// \e[1~
-		if i == 2 && runes[0] == '[' && runes[2] == '~' {
-			switch runes[1] {
+	} else if len(seq) == 3 { // \e[*~
+		cmd := seq[1]
+		switch cmd {
 		case '1':
 			return keyHome
 		case '3':
@@ -286,7 +331,6 @@ func parseEscapeSequence() string {
 			return keyEnd
 		}
 	}
-	}
 
-	return string('\x1b')
+	return string(rune(key.Esc))
 }