feat: initial multiline support

readline/instance.go

@@ -47,10 +47,12 @@ type Instance struct {
 
 	// readline operating parameters
 	line  []rune // This is the input line, with entered text: full line = mlnPrompt + line
+	accepted  bool   // Set by 'accept-line' widget, to notify return the line to the caller
 	pos   int
+	hpos  int // The line on which the cursor is (differs from posY, which accounts for wraps)
 	posX  int // Cursor position X
-	fullX int // X coordinate of the full input line, including the prompt if needed.
 	posY  int // Cursor position Y (if multiple lines span)
+	fullX int // X coordinate of the full input line, including the prompt if needed.
 	fullY int // Y offset to the end of input line.
 
 	// Buffer received from host programms
@@ -183,11 +185,12 @@ type Instance struct {
 	// $EDITOR. This will default to os.TempDir()
 	TempDirectory string
 
-	// GetMultiLine is a callback to your host program. Since multiline support
-	// is handled by the application rather than readline itself, this callback
-	// is required when calling $EDITOR. However if this function is not set
-	// then readline will just use the current line.
-	GetMultiLine func([]rune) []rune
+	// AcceptMultiline enables the caller to decide if the shell should keep reading for user input
+	// on a new line (therefore, with the secondary prompt), or if it should return the current
+	// line at the end of the `rl.Readline()` call.
+	// This function should return "true" if the line is deemed complete (thus asking the shell
+	// to return from its Readline() loop), or "false" if the shell should keep reading input.
+	AcceptMultiline func([]rune) bool
 
 	EnableGetCursorPos bool
 
@@ -229,6 +232,9 @@ func NewInstance() *Instance {
 	rl.HintFormatting = "\x1b[2m"
 	rl.evtKeyPress = make(map[string]func(string, []rune, int) *EventReturn)
 	rl.TempDirectory = os.TempDir()
+	rl.AcceptMultiline = func([]rune) bool {
+		return false
+	}
 
 	// Registers
 	rl.initRegisters()

readline/line.go

@@ -1,6 +1,7 @@
 package readline
 
 import (
+	"regexp"
 	"strings"
 )
 
@@ -25,6 +26,118 @@ func (rl *Instance) GetLine() []rune {
 	return rl.line
 }
 
+func (rl *Instance) lineSuggested() (line []rune, cpos int) {
+	//rl.checkCursorBounds()
+
+	if len(rl.currentComp) > 0 {
+		line = rl.lineComp
+		cpos = len(rl.lineComp[:rl.pos])
+	} else {
+		line = rl.line
+		cpos = len(rl.line[:rl.pos])
+	}
+
+	/*
+	if len(rl.histSuggested) > 0 {
+		line = append(line, rl.histSuggested...)
+	}
+	*/
+
+	return line, cpos
+}
+
+// computeLinePos determines the X and Y coordinates of the cursor.
+func (rl *Instance) computeLinePos() {
+	// Use the line including any completion or line suggestion,
+	// and compute buffer/cursor length. Only add a newline when
+	// the current buffer does not end with one.
+	line, cpos := rl.lineSuggested()
+	line = append(line, '\n')
+
+	// Get the index of each newline in the buffer.
+	nl := regexp.MustCompile("\n")
+	newlinesIdx := nl.FindAllStringIndex(string(line), -1)
+
+	rl.posY = 0
+	rl.fullY = 0
+	startLine := 0
+	cursorSet := false
+
+	for pos, newline := range newlinesIdx {
+		// Compute any adjustment in case this line must be wrapped.
+		// Here, compute if line must be wrapped, to adjust posY.
+		lineY := rl.realLineLen(line[startLine:newline[0]], pos)
+
+		// All lines add to the global offset.
+		rl.fullY += lineY
+
+		switch {
+		case newline[0] < cpos:
+			// If we are not on the cursor line yet.
+			rl.posY += lineY
+		case !cursorSet:
+			// We are on the cursor line, since we didn't catch
+			// the first case, and that our cursor X coordinate
+			// has not been set yet.
+			rl.computeCursorPos(startLine, cpos, pos)
+			cursorSet = true
+			rl.hpos = pos
+		}
+
+		startLine = newline[1]
+	}
+}
+
+// computeCursorPos computes the X/Y coordinates of the cursor on a given line.
+func (rl *Instance) computeCursorPos(startLine, cpos, lineIdx int) {
+	termWidth := GetTermWidth()
+	cursorStart := cpos - startLine
+	//cursorStart += rl.Prompt.inputAt(rl)
+
+	cursorY := cursorStart / termWidth
+	cursorX := cursorStart % termWidth
+
+	// The very first (unreal) line counts for nothing,
+	// so by opposition all others count for one more.
+	if lineIdx == 0 {
+		cursorY--
+	}
+
+	// Any excess wrap means a newline.
+	if cursorX > 0 {
+		cursorY++
+	}
+
+	rl.posY += cursorY
+	rl.posX = cursorX
+}
+
+func (rl *Instance) realLineLen(line []rune, idx int) (lineY int) {
+	lineLen := getRealLength(string(line))
+	termWidth := GetTermWidth()
+	//lineLen += rl.Prompt.inputAt(rl)
+
+	lineY = lineLen / termWidth
+	restY := lineLen % termWidth
+
+	// The very first line counts for nothing.
+	if idx == 0 {
+		lineY--
+	}
+
+	// Any excess wrap means a newline.
+	if restY > 0 {
+		lineY++
+	}
+
+	// Empty lines are still considered a line.
+	if lineY == 0 && idx != 0 {
+		lineY++
+	}
+
+	return
+}
+
 // echo - refresh the current input line, either virtually completed or not.
 // also renders the current completions and hints. To be noted, the updateReferences()
 // function is only ever called once, and after having moved back to prompt position
@@ -42,7 +155,6 @@ func (rl *Instance) echo() {
 		// Go back to prompt position, and clear everything below
 		moveCursorBackwards(GetTermWidth())
 		moveCursorUp(rl.posY)
-		print(seqClearScreenBelow)
 
 		// Print the prompt
 		print(string(rl.realPrompt))
@@ -55,23 +167,19 @@ func (rl *Instance) echo() {
 			line = rl.line
 		}
 
+		printed := string(line)
 		// Print the input line with optional syntax highlighting
 		if rl.SyntaxHighlighter != nil {
-			print(rl.SyntaxHighlighter(line))
-		} else {
-			print(string(line))
+			printed = (rl.SyntaxHighlighter(line))
 		}
+
+		rl.computeLinePos()
+		print(printed)
 	}
 
 	// Update references with new coordinates only now, because
 	// the new line may be longer/shorter than the previous one.
-	rl.updateReferences()
-
-	// Go back to the current cursor position, with new coordinates
-	moveCursorBackwards(GetTermWidth())
-	moveCursorUp(rl.fullY)
-	moveCursorDown(rl.posY)
-	moveCursorForwards(rl.posX)
+	//rl.updateReferences()
 }
 
 func (rl *Instance) insert(r []rune) {
@@ -107,6 +215,49 @@ func (rl *Instance) insert(r []rune) {
 	rl.updateHelpers()
 }
 
+// lineSlice returns a subset of the current input line.
+func (rl *Instance) lineSlice(adjust int) (slice string) {
+	switch {
+	case rl.pos+adjust > len(rl.line):
+		slice = string(rl.line[rl.pos:])
+	case adjust < 0:
+		if rl.pos+adjust < 0 {
+			slice = string(rl.line[:rl.pos])
+		} else {
+			slice = string(rl.line[rl.pos+adjust : rl.pos])
+		}
+	default:
+		slice = string(rl.line[rl.pos : rl.pos+adjust])
+	}
+
+	return
+}
+
+func (rl *Instance) lineCarriageReturn() {
+	//rl.histSuggested = []rune{}
+
+	// Ask the caller if the line should be accepted as is.
+	if rl.AcceptMultiline(rl.GetLine()) {
+		// Clear the tooltip prompt if any,
+		// then go down and clear hints/completions.
+		//rl.moveToLineEnd()
+		//rl.Prompt.clearRprompt(rl, false)
+		print("\r\n")
+		print(seqClearScreenBelow)
+
+		// Save the command line and accept it.
+		//rl.writeHistoryLine()
+		rl.accepted = true
+		return
+	}
+
+	// If not, we should start editing another line,
+	// and insert a newline where our cursor value is.
+	// This has the nice advantage of being able to work
+	// in multiline mode even in the middle of the buffer.
+	rl.insert([]rune{'\n'})
+}
+
 func (rl *Instance) Insert(t string) {
 	rl.insert([]rune(t))
 }

readline/readline.go

@@ -52,22 +52,6 @@ func (rl *Instance) Readline() (string, error) {
 	rl.histOffset = 0
 	rl.viUndoHistory = []undoItem{{line: "", pos: 0}}
 
-	// Multisplit
-	if len(rl.multisplit) > 0 {
-		r := []rune(rl.multisplit[0])
-		if len(r) >= 1 {
-			rl.editorInput(r)
-		}
-
-		rl.carridgeReturn()
-		if len(rl.multisplit) > 1 {
-			rl.multisplit = rl.multisplit[1:]
-		} else {
-			rl.multisplit = []string{}
-		}
-		return string(rl.line), nil
-	}
-
 	// Finally, print any info or completions
 	// if the TabCompletion engines so desires
 	rl.renderHelpers()
@@ -98,33 +82,6 @@ func (rl *Instance) Readline() (string, error) {
 			rl.RawInputCallback(r[:i])
 		}
 
-		if isMultiline(r[:i]) || len(rl.multiline) > 0 {
-			rl.multiline = append(rl.multiline, b[:i]...)
-			if i == len(b) {
-				continue
-			}
-
-			if !rl.allowMultiline(rl.multiline) {
-				rl.multiline = []byte{}
-				continue
-			}
-
-			s := string(rl.multiline)
-			rl.multisplit = rxMultiline.Split(s, -1)
-
-			r = []rune(rl.multisplit[0])
-			rl.modeViMode = VimInsert
-			rl.editorInput(r)
-			rl.carridgeReturn()
-			rl.multiline = []byte{}
-			if len(rl.multisplit) > 1 {
-				rl.multisplit = rl.multisplit[1:]
-			} else {
-				rl.multisplit = []string{}
-			}
-			return string(rl.line), nil
-		}
-
 		s := string(r[:i])
 		if rl.evtKeyPress[s] != nil {
 			rl.clearHelpers()
@@ -448,7 +405,7 @@ func (rl *Instance) Readline() (string, error) {
 				completion := cur.getCurrentCell(rl)
 				prefix := len(rl.tcPrefix)
 				if prefix > len(completion) {
-					rl.carridgeReturn()
+					rl.lineCarriageReturn()
 					return string(rl.line), nil
 				}
 
@@ -459,7 +416,7 @@ func (rl *Instance) Readline() (string, error) {
 
 				// If we were in history completion, immediately execute the line.
 				if rl.modeAutoFind && rl.searchMode == HistoryFind {
-					rl.carridgeReturn()
+					rl.lineCarriageReturn()
 					return string(rl.line), nil
 				}
 
@@ -470,8 +427,10 @@ func (rl *Instance) Readline() (string, error) {
 
 				continue
 			}
-			rl.carridgeReturn()
-			return string(rl.line), nil
+			rl.lineCarriageReturn()
+			if rl.accepted {
+				return string(rl.line), nil
+			}
 
 		// Vim --------------------------------------------------------------------------------------
 		case charEscape:

readline/vim.go

@@ -238,11 +238,11 @@ func (rl *Instance) vi(r rune) {
 	case 'v':
 		rl.clearHelpers()
 		var multiline []rune
-		if rl.GetMultiLine == nil {
+		/*if rl.GetMultiLine == nil {
 			multiline = rl.line
 		} else {
 			multiline = rl.GetMultiLine(rl.line)
-		}
+		}*/
 
 		// Keep the previous cursor position
 		//prev := rl.pos