More line edititng

lib/line_editor.go

@@ -3,6 +3,7 @@
 package mop
 
 import (
+"fmt"
 	"github.com/nsf/termbox-go"
 )
 
@@ -42,17 +43,48 @@ func (self *LineEditor) Handle(ev termbox.Event) bool {
         case termbox.KeyBackspace, termbox.KeyBackspace2:
 		if len(self.input) > 0 {
 			self.input = self.input[:len(self.input)-1]
+			self.cursor -= 1
 			DrawLine(len(self.prompt), 3, self.input + " ")
-		     termbox.SetCursor(len(self.prompt)+len(self.input), 3)
+			termbox.SetCursor(len(self.prompt) + self.cursor, 3)
 			termbox.Flush()
 		}
+	case termbox.KeyCtrlB, termbox.KeyArrowLeft:
+		if self.cursor > 0 {
+			self.cursor -= 1
+			termbox.SetCursor(len(self.prompt) + self.cursor, 3)
+			termbox.Flush()
+		}
+	case termbox.KeyCtrlF, termbox.KeyArrowRight:
+		if self.cursor < len(self.input) {
+			self.cursor += 1
+			termbox.SetCursor(len(self.prompt) + self.cursor, 3)
+			termbox.Flush()
+		}
+	case termbox.KeyCtrlA: // Jump to the beginning of line.
+		self.cursor = 0
+		termbox.SetCursor(len(self.prompt) + self.cursor, 3)
+		termbox.Flush()
+	case termbox.KeyCtrlE: // Jump to the end of line.
+		self.cursor = len(self.input)
+		termbox.SetCursor(len(self.prompt) + self.cursor, 3)
+		termbox.Flush()
+	case termbox.KeySpace:
+		self.append_character(' ')
 	default:
 		if ev.Ch != 0 {
-			self.input += string(ev.Ch)
+			self.append_character(ev.Ch)
-			DrawLine(len(self.prompt), 3, self.input)
-			termbox.SetCursor(len(self.prompt)+len(self.input), 3)
-			termbox.Flush()
 		}
 	}
+	DrawLine(20,20, fmt.Sprintf("cursor: %02d [%s] %08d", self.cursor, self.input, ev.Ch))
 	return false
 }
+
+//-----------------------------------------------------------------------------
+func (self *LineEditor) append_character(ch rune) {
+	self.input += string(ch)
+	self.cursor += 1
+	DrawLine(len(self.prompt), 3, self.input)
+	termbox.SetCursor(len(self.prompt) + self.cursor, 3)
+	termbox.Flush()
+}
+