From be60c1d053e550af970df1ce8b26981577e921dc Mon Sep 17 00:00:00 2001
From: Liam Galvin <liam@liam-galvin.co.uk>
Date: Sat, 1 Sep 2018 21:19:13 +0100
Subject: [PATCH] fix background renderinf

---
 buffer/buffer.go      | 15 ++++++++-------
 buffer/buffer_test.go | 12 +++++-------
 buffer/cell.go        |  4 ----
 buffer/line.go        |  6 +++++-
 gui/gui.go            |  8 ++++----
 gui/renderer.go       |  1 -
 6 files changed, 22 insertions(+), 24 deletions(-)

diff --git a/buffer/buffer.go b/buffer/buffer.go
index 447942a..cd0da94 100644
--- a/buffer/buffer.go
+++ b/buffer/buffer.go
@@ -227,7 +227,7 @@ func (buffer *Buffer) Write(runes ...rune) {
 		} else {
 
 			for int(buffer.CursorColumn()) >= len(line.cells) {
-				line.cells = append(line.cells, newCell())
+				line.cells = append(line.cells, NewBackgroundCell(buffer.cursorAttr.BgColour))
 			}
 
 			cell := &line.cells[buffer.CursorColumn()]
@@ -383,14 +383,15 @@ func (buffer *Buffer) EraseLineFromCursor() {
 	defer buffer.emitDisplayChange()
 	line := buffer.getCurrentLine()
 
-	max := int(buffer.cursorX)
-	if max > len(line.cells) {
-		max = len(line.cells)
-	}
+	line.cells = line.cells[:buffer.cursorX]
 
-	for c := int(buffer.cursorX); c < len(line.cells); c++ {
-		line.cells[c].erase()
+	max := int(buffer.ViewWidth()) - len(line.cells)
+
+	buffer.SaveCursor()
+	for i := 0; i < max; i++ {
+		buffer.Write(0)
 	}
+	buffer.RestoreCursor()
 }
 
 func (buffer *Buffer) EraseDisplay() {
diff --git a/buffer/buffer_test.go b/buffer/buffer_test.go
index 8fb97e5..9b864e5 100644
--- a/buffer/buffer_test.go
+++ b/buffer/buffer_test.go
@@ -255,7 +255,7 @@ func TestCarriageReturnOnOverWrappedLine(t *testing.T) {
 	b.Write([]rune("hello there!\rsecret sauce")...)
 	lines := b.GetVisibleLines()
 	require.Equal(t, 3, len(lines))
-	assert.Equal(t, "hello ", lines[0].String())
+	assert.Equal(t, "hello", lines[0].String())
 	assert.Equal(t, "secret", lines[1].String())
 	assert.True(t, b.lines[1].wrapped)
 	assert.Equal(t, " sauce", lines[2].String())
@@ -289,8 +289,6 @@ func TestGetCellWithBadCursor(t *testing.T) {
 	b := NewBuffer(80, 2, CellAttributes{})
 	b.Write([]rune("Hello\r\nthere\r\nsomething...")...)
 	require.Nil(t, b.GetCell(8, 3))
-	require.Nil(t, b.GetCell(8, -1))
-	require.Nil(t, b.GetCell(-8, 1))
 	require.Nil(t, b.GetCell(90, 0))
 
 }
@@ -365,7 +363,7 @@ func TestEraseLineAfterCursor(t *testing.T) {
 	b.MovePosition(-3, 0)
 	b.EraseLineFromCursor()
 	assert.Equal(t, "hello, this is a test", b.lines[0].String())
-	assert.Equal(t, "dele\x00\x00\x00", b.lines[1].String())
+	assert.Equal(t, "dele", b.lines[1].String())
 }
 func TestEraseDisplay(t *testing.T) {
 	b := NewBuffer(80, 5, CellAttributes{})
@@ -404,9 +402,9 @@ func TestBackspace(t *testing.T) {
 	b.Write([]rune("hello")...)
 	b.Backspace()
 	b.Backspace()
-	b.Write([]rune("l")...)
+	b.Write([]rune("p")...)
 	lines := b.GetVisibleLines()
-	assert.Equal(t, "hell\x00", lines[0].String())
+	assert.Equal(t, "helpo", lines[0].String())
 }
 
 func TestBackspaceWithWrap(t *testing.T) {
@@ -424,7 +422,7 @@ func TestBackspaceWithWrap(t *testing.T) {
 	b.Backspace()
 	b.EraseLineFromCursor()
 	lines := b.GetVisibleLines()
-	assert.Equal(t, "hello\x00\x00\x00\x00\x00", lines[0].String())
+	assert.Equal(t, "hello", lines[0].String())
 }
 
 func TestHorizontalResizeView(t *testing.T) {
diff --git a/buffer/cell.go b/buffer/cell.go
index b3a0867..b07cbea 100644
--- a/buffer/cell.go
+++ b/buffer/cell.go
@@ -16,10 +16,6 @@ type CellAttributes struct {
 	Hidden    bool
 }
 
-func newCell() Cell {
-	return Cell{}
-}
-
 func (cell *Cell) Attr() CellAttributes {
 	return cell.attr
 }
diff --git a/buffer/line.go b/buffer/line.go
index 763b1ad..e86e059 100644
--- a/buffer/line.go
+++ b/buffer/line.go
@@ -1,5 +1,9 @@
 package buffer
 
+import (
+	"strings"
+)
+
 type Line struct {
 	wrapped bool // whether line was wrapped onto from the previous one
 	cells   []Cell
@@ -40,7 +44,7 @@ func (line *Line) String() string {
 	for _, cell := range line.cells {
 		runes = append(runes, cell.r)
 	}
-	return string(runes)
+	return strings.TrimRight(string(runes), "\x00 ")
 }
 
 // @todo test these (ported from legacy) ------------------
diff --git a/gui/gui.go b/gui/gui.go
index 408963c..06d0950 100644
--- a/gui/gui.go
+++ b/gui/gui.go
@@ -219,9 +219,9 @@ func (gui *GUI) Render() error {
 						cells := lines[y].Cells()
 						if x < len(cells) {
 							cell = cells[x]
-							if cell.Rune() == 0 {
-								cell = defaultCell
-							}
+							//if cell.Rune() == 0 {
+							//	cell = defaultCell
+							//}
 						}
 					}
 
@@ -240,7 +240,7 @@ func (gui *GUI) Render() error {
 						if x < len(cells) {
 							cell = cells[x]
 							if cell.Rune() == 0 {
-								cell = defaultCell
+								continue
 							}
 						}
 					}
diff --git a/gui/renderer.go b/gui/renderer.go
index 26a2844..9f7c3b1 100644
--- a/gui/renderer.go
+++ b/gui/renderer.go
@@ -215,7 +215,6 @@ func (r *OpenGLRenderer) DrawCellBg(cell buffer.Cell, col uint, row uint) {
 		rect.setColour(bg)
 		rect.Draw()
 	}
-
 }
 
 func (r *OpenGLRenderer) DrawCellText(cell buffer.Cell, col uint, row uint) {