basic editor skeleton now uses the buffer

editor.nim

@@ -4,6 +4,8 @@ import terminal
 import strformat
 import posix
 
+import termBuffer/buffer
+
 import keycodes
 
 type
@@ -21,6 +23,7 @@ type
     y: int # which row are we editing
     size: int # size of the row being edited in characters
     buffer: seq[string] # current text
+    screenBuffer: Buffer
     history: seq[seq[string]] # past texts
     historyIndex: int # where are we in history
     cols: int # number of columns in the terminal
@@ -41,6 +44,7 @@ proc newEditor*(prompt: string = "> ", multiline: bool = true): EditorState =
   result.prompt = prompt
   result.maxRowsGoal = if multiline: 0 else: 1
   result.buffer.add("")
+  result.screenBuffer = newBuffer(0, 0, terminalWidth(), terminalHeight(), stdout)
   editors.add(result)
 
 proc destroyEditor*(oldEditor: EditorState) =
@@ -51,15 +55,17 @@ proc destroyEditor*(oldEditor: EditorState) =
       return
 
 proc render(ed: EditorState) =
-  eraseLine()
-  setCursorXPos(0)
-  write stdout, ed.prompt
-  write stdout, ed.buffer[ed.y]
+  ed.screenBuffer.clearLine()
+  ed.screenBuffer.write(ed.prompt)
+  ed.screenBuffer.write(ed.buffer[ed.y])
+  ed.screenBuffer.redraw()
 
 template cline(ed: EditorState): var string =
   ed.buffer[ed.y]
 
-
+proc print*(ed: EditorState, text: string) =
+  ed.screenBuffer.print(text)
+  ed.screenBuffer.redraw()
 
 proc read*(ed: EditorState): (EditorResult, string) =
 
@@ -76,6 +82,7 @@ proc read*(ed: EditorState): (EditorResult, string) =
       if ed.x == 0:
         discard # merge two lines TODO
       elif ed.x > ed.cline().high():
+        # TODO UTF8
         ed.cline() = ed.cline[0..ed.cline().high()-1]
         dec ed.x
         dec ed.bx
@@ -84,6 +91,15 @@ proc read*(ed: EditorState): (EditorResult, string) =
         ed.cline() = ed.cline[0..ed.x-1] & ed.cline[ed.x+1..ed.cline().high()]
         dec ed.x
         dec ed.bx
+    of jkDelete.int:
+      if ed.x > ed.cline.high():
+        discard # merge two lines TODO
+      elif ed.x == 0:
+        # TODO UTF8
+        ed.cline() = ed.cline[1..ed.cline.high()]
+      else:
+        # TODO UTF8
+        discard # TODO implement
     of 3: # ctrl+c
       editorResult = erCtrlC
       break
@@ -110,7 +126,6 @@ proc read*(ed: EditorState): (EditorResult, string) =
   result = (editorResult, ed.buffer.join("\n"))
 
   # cleanup
-  write(stdout, "\n")
   ed.history.add(ed.buffer)
   ed.buffer = @[""]
   ed.y = 0

example.nim

@@ -5,5 +5,6 @@ let e = newEditor("> ", false)
 while true:
   let (res, text) = e.read()
   if res in {erCtrlC, erCtrlD} or text == "quit":
+    e.print("")
     break
-  echo text
+  e.print(text)

termBuffer/buffer.nim

@@ -1,5 +1,6 @@
 import unicode
 import escapeSequences
+import sequtils
 
 type
   Buffer* = ref object
@@ -40,6 +41,7 @@ type
     attributes: seq[uint8]
     text: Rune
 
+
 func getCursorPos*(buf: Buffer): (int, int) =
   (buf.bufferX, buf.bufferY)
 
@@ -57,7 +59,6 @@ proc setCursorXPos*(buf: Buffer, x: int) =
     raise newException(ValueError, "Provided x is out of bounds.")
   buf.bufferX = x
 
-
 proc setAttributes*(buf: Buffer, attributes: seq[uint8]) =
   buf.cursorAttributes = attributes
 
@@ -99,24 +100,56 @@ proc write*(buf: Buffer, text: string) =
   for i in fromPos..toPos:
     buf.buffered[i] = Cell(text: runes[i-fromPos], attributes: buf.cursorAttributes)
   
+  buf.bufferX += runes.len()
 
-proc redraw*(buf: Buffer) =
+proc print*(buf: Buffer, text: string) =
+  # write, but makes sure it's on its own line
+  if buf.bufferX > 0:
+    # TODO scroll implementation
+    buf.bufferX = 0
+    if buf.bufferY < buf.height - 1:
+      buf.bufferY += 1
+  
+  buf.write(text)
+
+  # TODO scroll implementation
+  if text.len() > 0 and buf.bufferY < buf.height - 1:
+      buf.bufferY += 1
+    
+
+proc redraw*(buf: Buffer, force: bool = false) =
   var toPrint = ""
-  # save cursor state
-  let oldDisplayX = buf.displayX
-  let oldDisplayY = buf.displayY
 
   # go over display and buffer to find any differences
   for i in 0..buf.buffered.high():
     let cellBuffer = buf.buffered[i]
     let cellDisplay = buf.displayed[i]
-    # TODO continue here :)
-
-
 
+    # TODO: this is a spot for obvious optimization
+    if cellBuffer != cellDisplay or force:
+      let y = i div buf.width
+      let x = i mod buf.width
+      # go to given place
+      toPrint &= escCursorPos(x+buf.positionX, y+buf.positionY)
+      
+      # get the right attributes
+      # first reset
+      toPrint &= escAttributes(@[fsReset.uint8])
+      # set cell attributes
+      toPrint &= escAttributes(cellBuffer.attributes)
+      # write the character if it's a non null
+      if cellBuffer.text != Rune(0):
+        toPrint &= $cellBuffer.text
+      else:
+        # erase a character since it's a null
+        toPrint &= escEraseCharacters(1)
+      
+      # update displayed buffer
+      buf.displayed[i] = cellBuffer
 
   # finish
-  toPrint &= escCursorPos(oldDisplayX, oldDisplayY)
+  toPrint &= escAttributes(@[fsReset.uint8])
+  toPrint &= escCursorPos(buf.bufferX + buf.positionX, buf.bufferY + buf.positionY)
   buf.stdout.write(toPrint)
   
 
@@ -131,4 +164,22 @@ func getPosition*(buf: Buffer): (int, int) =
 
 proc setPosition*(buf: Buffer, x, y: int) =
   buf.positionX = x
-  buf.positionY = y
+  buf.positionY = y
+
+proc newBuffer*(x, y, w, h: int, stdout: File): Buffer =
+  new(result)
+  result.positionX = x
+  result.positionY = y
+  result.width = w
+  result.height = h
+  result.stdout = stdout
+  let length = w * h
+  result.buffered = repeat(Cell(text: Rune(0)), length)
+  result.displayed = repeat(Cell(text: Rune(0)), length)
+  result.bufferX = 0
+  result.bufferY = 0
+  result.displayX = 0
+  result.displayY = 0
+  result.cursorAttributes = @[]
+  result.redraw(force = true)
+  

termBuffer/escapeSequences.nim

@@ -4,7 +4,7 @@ import strformat
 import strutils
 
 func escCursorPos*(x, y: int): string =
-  &"\e[{x+1};{y+1}H"
+  &"\e[{y+1};{x+1}H"
 
 func escAttributes*(attributes: seq[uint8]): string =
   let joined = attributes.join(";")