From bc1b3f0dfd2463481f2e499a8cb39ac319de88a0 Mon Sep 17 00:00:00 2001
From: rrrooommmaaa <rrrooommmaaa@mail.ru>
Date: Mon, 11 Feb 2019 23:26:44 +0300
Subject: [PATCH] Buffer fix (#201)

* bug fix: Save/Restore Cursor mess + some refactoring

* typo fix
---
 buffer/buffer.go | 33 +++++++++++++++------------------
 buffer/line.go   |  4 ++++
 terminal/csi.go  |  2 +-
 3 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/buffer/buffer.go b/buffer/buffer.go
index b5f2a4b..4d21979 100644
--- a/buffer/buffer.go
+++ b/buffer/buffer.go
@@ -10,10 +10,11 @@ import (
 )
 
 type SelectionMode int
+
 const (
-	SelectionChar SelectionMode = iota        // char-by-char selection
-	SelectionWord SelectionMode = iota        // by word selection
-	SelectionLine SelectionMode = iota        // whole line selection
+	SelectionChar SelectionMode = iota // char-by-char selection
+	SelectionWord SelectionMode = iota // by word selection
+	SelectionLine SelectionMode = iota // whole line selection
 )
 
 type Buffer struct {
@@ -214,7 +215,7 @@ func (buffer *Buffer) StartSelection(col uint16, viewRow uint16, mode SelectionM
 		buffer.selectionEnd = nil
 	} else {
 		buffer.selectionEnd = &Position {
-			Col: int(col),
+			Col:  int(col),
 			Line: int(row),
 		}
 	}
@@ -240,7 +241,7 @@ func (buffer *Buffer) ExtendSelection(col uint16, viewRow uint16, complete bool)
 	row := buffer.convertViewLineToRawLine(viewRow) - uint64(buffer.terminalState.scrollLinesFromBottom)
 
 	buffer.selectionEnd = &Position {
-		Col: int(col),
+		Col:  int(col),
 		Line: int(row),
 	}
 
@@ -665,7 +666,7 @@ func (buffer *Buffer) Write(runes ...rune) {
 			}
 
 			for int(buffer.CursorColumn()) >= len(line.cells) {
-				line.cells = append(line.cells, buffer.terminalState.DefaultCell(int(buffer.CursorColumn()) == len(line.cells)))
+				line.Append(buffer.terminalState.DefaultCell(int(buffer.CursorColumn()) == len(line.cells)))
 			}
 			line.cells[buffer.terminalState.cursorX].attr = buffer.terminalState.CursorAttr
 			line.cells[buffer.terminalState.cursorX].setRune(r)
@@ -681,7 +682,7 @@ func (buffer *Buffer) Write(runes ...rune) {
 
 				newLine := buffer.getCurrentLine()
 				if len(newLine.cells) == 0 {
-					newLine.cells = append(newLine.cells, buffer.terminalState.DefaultCell(true))
+					newLine.Append(buffer.terminalState.DefaultCell(true))
 				}
 				cell := &newLine.cells[0]
 				cell.setRune(r)
@@ -696,7 +697,7 @@ func (buffer *Buffer) Write(runes ...rune) {
 		} else {
 
 			for int(buffer.CursorColumn()) >= len(line.cells) {
-				line.cells = append(line.cells, buffer.terminalState.DefaultCell(int(buffer.CursorColumn()) == len(line.cells)))
+				line.Append(buffer.terminalState.DefaultCell(int(buffer.CursorColumn()) == len(line.cells)))
 			}
 
 			cell := &line.cells[buffer.CursorColumn()]
@@ -909,14 +910,12 @@ func (buffer *Buffer) EraseLineFromCursor() {
 			line.cells = line.cells[:buffer.terminalState.cursorX]
 		}
 	}
-
 	max := int(buffer.ViewWidth()) - len(line.cells)
 
-	buffer.SaveCursor()
 	for i := 0; i < max; i++ {
-		buffer.Write(0)
+		line.Append(buffer.terminalState.DefaultCell(true))
 	}
-	buffer.RestoreCursor()
+
 }
 
 func (buffer *Buffer) EraseDisplay() {
@@ -969,11 +968,9 @@ func (buffer *Buffer) EraseDisplayFromCursor() {
 	}
 
 	line.cells = line.cells[:max]
-	for i := buffer.terminalState.cursorY + 1; i < buffer.ViewHeight(); i++ {
-		rawLine := buffer.convertViewLineToRawLine(i)
-		if int(rawLine) < len(buffer.lines) {
-			buffer.lines[int(rawLine)].cells = []Cell{}
-		}
+
+	for rawLine := buffer.convertViewLineToRawLine(buffer.terminalState.cursorY) + 1; int(rawLine) < len(buffer.lines); rawLine++ {
+		buffer.lines[int(rawLine)].cells = []Cell{}
 	}
 }
 
@@ -1061,7 +1058,7 @@ func (buffer *Buffer) ResizeView(width uint16, height uint16) {
 				if moveCount > len(nextLine.cells) {
 					moveCount = len(nextLine.cells)
 				}
-				line.cells = append(line.cells, nextLine.cells[:moveCount]...)
+				line.Append(nextLine.cells[:moveCount]...)
 				if moveCount == len(nextLine.cells) {
 
 					if i+offset <= int(buffer.terminalState.cursorY) {
diff --git a/buffer/line.go b/buffer/line.go
index 3099b3b..270b26f 100644
--- a/buffer/line.go
+++ b/buffer/line.go
@@ -75,4 +75,8 @@ func (line *Line) CutCellsFromEnd(n int) []Cell {
 	return cut
 }
 
+func (line *Line) Append(cells ...Cell) {
+	line.cells = append(line.cells, cells...)
+}
+
 // -------------------------------------------------------
diff --git a/terminal/csi.go b/terminal/csi.go
index f0e69a4..bac472b 100644
--- a/terminal/csi.go
+++ b/terminal/csi.go
@@ -37,7 +37,7 @@ var csiSequences = []csiMapping{
 	{id: 'D', handler: csiCursorBackwardHandler, description: "Cursor Backward Ps Times (default = 1) (CUB)"},
 	{id: 'E', handler: csiCursorNextLineHandler, description: "Cursor Next Line Ps Times (default = 1) (CNL)"},
 	{id: 'F', handler: csiCursorPrecedingLineHandler, description: "Cursor Preceding Line Ps Times (default = 1) (CPL)"},
-	{id: 'G', handler: csiCursorCharacterAbsoluteHandler, description: "Cursor Character Absolute  [column] (default = [row,1]) (CHA)"},
+	{id: 'G', handler: csiCursorCharacterAbsoluteHandler, description: "Cursor Horizontal Absolute  [column] (default = [row,1]) (CHA)"},
 	{id: 'H', handler: csiCursorPositionHandler, description: "Cursor Position [row;column] (default = [1,1]) (CUP)"},
 	{id: 'J', handler: csiEraseInDisplayHandler, description: "Erase in Display (ED), VT100"},
 	{id: 'K', handler: csiEraseInLineHandler, description: "Erase in Line (EL), VT100"},