Add more --border options

Instead of drawing the window border in Vim using an extra window,
extend the --border option so that we do can it natively.

Close #2223
Fix #2184

src/options.go

@@ -58,7 +58,8 @@ const usage = `usage: fzf [options]
                           (default: 10)
     --layout=LAYOUT       Choose layout: [default|reverse|reverse-list]
     --border[=STYLE]      Draw border around the finder
-                          [rounded|sharp|horizontal] (default: rounded)
+                          [rounded|sharp|horizontal|vertical|
+                           top|bottom|left|right] (default: rounded)
     --margin=MARGIN       Screen margin (TRBL / TB,RL / T,RL,B / T,R,B,L)
     --info=STYLE          Finder info style [default|inline|hidden]
     --prompt=STR          Input prompt (default: '> ')
@@ -421,11 +422,21 @@ func parseBorder(str string, optional bool) tui.BorderShape {
 		return tui.BorderSharp
 	case "horizontal":
 		return tui.BorderHorizontal
+	case "vertical":
+		return tui.BorderVertical
+	case "top":
+		return tui.BorderTop
+	case "bottom":
+		return tui.BorderBottom
+	case "left":
+		return tui.BorderLeft
+	case "right":
+		return tui.BorderRight
 	default:
 		if optional && str == "" {
 			return tui.BorderRounded
 		}
-		errorExit("invalid border style (expected: rounded|sharp|horizontal)")
+		errorExit("invalid border style (expected: rounded|sharp|horizontal|vertical|top|bottom|left|right)")
 	}
 	return tui.BorderNone
 }

src/terminal.go

@@ -670,7 +670,7 @@ func calculateSize(base int, size sizeSpec, occupied int, minSize int, pad int)
 func (t *Terminal) resizeWindows() {
 	screenWidth := t.tui.MaxX()
 	screenHeight := t.tui.MaxY()
-	marginInt := [4]int{}
+	marginInt := [4]int{} // TRBL
 	t.prevLines = make([]itemLine, screenHeight)
 	for idx, sizeSpec := range t.margin {
 		if sizeSpec.percent {
@@ -687,6 +687,24 @@ func (t *Terminal) resizeWindows() {
 		switch t.borderShape {
 		case tui.BorderHorizontal:
 			marginInt[idx] += 1 - idx%2
+		case tui.BorderVertical:
+			marginInt[idx] += 2 * (idx % 2)
+		case tui.BorderTop:
+			if idx == 0 {
+				marginInt[idx]++
+			}
+		case tui.BorderRight:
+			if idx == 1 {
+				marginInt[idx] += 2
+			}
+		case tui.BorderBottom:
+			if idx == 2 {
+				marginInt[idx]++
+			}
+		case tui.BorderLeft:
+			if idx == 3 {
+				marginInt[idx] += 2
+			}
 		case tui.BorderRounded, tui.BorderSharp:
 			marginInt[idx] += 1 + idx%2
 		}
@@ -735,17 +753,31 @@ func (t *Terminal) resizeWindows() {
 	switch t.borderShape {
 	case tui.BorderHorizontal:
 		t.border = t.tui.NewWindow(
-			marginInt[0]-1,
-			marginInt[3],
-			width,
-			height+2,
+			marginInt[0]-1, marginInt[3], width, height+2,
 			false, tui.MakeBorderStyle(tui.BorderHorizontal, t.unicode))
+	case tui.BorderVertical:
+		t.border = t.tui.NewWindow(
+			marginInt[0], marginInt[3]-2, width+4, height,
+			false, tui.MakeBorderStyle(tui.BorderVertical, t.unicode))
+	case tui.BorderTop:
+		t.border = t.tui.NewWindow(
+			marginInt[0]-1, marginInt[3], width, height+1,
+			false, tui.MakeBorderStyle(tui.BorderTop, t.unicode))
+	case tui.BorderBottom:
+		t.border = t.tui.NewWindow(
+			marginInt[0], marginInt[3], width, height+1,
+			false, tui.MakeBorderStyle(tui.BorderBottom, t.unicode))
+	case tui.BorderLeft:
+		t.border = t.tui.NewWindow(
+			marginInt[0], marginInt[3]-2, width+2, height,
+			false, tui.MakeBorderStyle(tui.BorderLeft, t.unicode))
+	case tui.BorderRight:
+		t.border = t.tui.NewWindow(
+			marginInt[0], marginInt[3], width+2, height,
+			false, tui.MakeBorderStyle(tui.BorderRight, t.unicode))
 	case tui.BorderRounded, tui.BorderSharp:
 		t.border = t.tui.NewWindow(
-			marginInt[0]-1,
-			marginInt[3]-2,
-			width+4,
-			height+2,
+			marginInt[0]-1, marginInt[3]-2, width+4, height+2,
 			false, tui.MakeBorderStyle(t.borderShape, t.unicode))
 	}
 	noBorder := tui.MakeBorderStyle(tui.BorderNone, t.unicode)

src/tui/light.go

@@ -653,15 +653,46 @@ func (w *LightWindow) drawBorder() {
 	case BorderRounded, BorderSharp:
 		w.drawBorderAround()
 	case BorderHorizontal:
-		w.drawBorderHorizontal()
+		w.drawBorderHorizontal(true, true)
+	case BorderVertical:
+		w.drawBorderVertical(true, true)
+	case BorderTop:
+		w.drawBorderHorizontal(true, false)
+	case BorderBottom:
+		w.drawBorderHorizontal(false, true)
+	case BorderLeft:
+		w.drawBorderVertical(true, false)
+	case BorderRight:
+		w.drawBorderVertical(false, true)
 	}
 }
 
-func (w *LightWindow) drawBorderHorizontal() {
-	w.Move(0, 0)
-	w.CPrint(ColBorder, repeat(w.border.horizontal, w.width))
-	w.Move(w.height-1, 0)
-	w.CPrint(ColBorder, repeat(w.border.horizontal, w.width))
+func (w *LightWindow) drawBorderHorizontal(top, bottom bool) {
+	if top {
+		w.Move(0, 0)
+		w.CPrint(ColBorder, repeat(w.border.horizontal, w.width))
+	}
+	if bottom {
+		w.Move(w.height-1, 0)
+		w.CPrint(ColBorder, repeat(w.border.horizontal, w.width))
+	}
+}
+
+func (w *LightWindow) drawBorderVertical(left, right bool) {
+	width := w.width - 2
+	if !left || !right {
+		width++
+	}
+	for y := 0; y < w.height; y++ {
+		w.Move(y, 0)
+		if left {
+			w.CPrint(ColBorder, string(w.border.vertical))
+		}
+		w.CPrint(ColBorder, repeat(' ', width))
+		if right {
+			w.CPrint(ColBorder, string(w.border.vertical))
+		}
+	}
 }
 
 func (w *LightWindow) drawBorderAround() {

src/tui/tcell.go

@@ -583,7 +583,8 @@ func (w *TcellWindow) CFill(fg Color, bg Color, a Attr, str string) FillReturn {
 }
 
 func (w *TcellWindow) drawBorder() {
-	if w.borderStyle.shape == BorderNone {
+	shape := w.borderStyle.shape
+	if shape == BorderNone {
 		return
 	}
 
@@ -603,17 +604,32 @@ func (w *TcellWindow) drawBorder() {
 		style = w.normal.style()
 	}
 
-	for x := left; x < right; x++ {
-		_screen.SetContent(x, top, w.borderStyle.horizontal, nil, style)
-		_screen.SetContent(x, bot-1, w.borderStyle.horizontal, nil, style)
+	switch shape {
+	case BorderRounded, BorderSharp, BorderHorizontal, BorderTop:
+		for x := left; x < right; x++ {
+			_screen.SetContent(x, top, w.borderStyle.horizontal, nil, style)
+		}
 	}
-
-	if w.borderStyle.shape != BorderHorizontal {
+	switch shape {
+	case BorderRounded, BorderSharp, BorderHorizontal, BorderBottom:
+		for x := left; x < right; x++ {
+			_screen.SetContent(x, bot-1, w.borderStyle.horizontal, nil, style)
+		}
+	}
+	switch shape {
+	case BorderRounded, BorderSharp, BorderVertical, BorderLeft:
 		for y := top; y < bot; y++ {
 			_screen.SetContent(left, y, w.borderStyle.vertical, nil, style)
+		}
+	}
+	switch shape {
+	case BorderRounded, BorderSharp, BorderVertical, BorderRight:
+		for y := top; y < bot; y++ {
 			_screen.SetContent(right-1, y, w.borderStyle.vertical, nil, style)
 		}
-
+	}
+	switch shape {
+	case BorderRounded, BorderSharp:
 		_screen.SetContent(left, top, w.borderStyle.topLeft, nil, style)
 		_screen.SetContent(right-1, top, w.borderStyle.topRight, nil, style)
 		_screen.SetContent(left, bot-1, w.borderStyle.bottomLeft, nil, style)

src/tui/tui.go

@@ -259,6 +259,11 @@ const (
 	BorderRounded
 	BorderSharp
 	BorderHorizontal
+	BorderVertical
+	BorderTop
+	BorderBottom
+	BorderLeft
+	BorderRight
 )
 
 type BorderStyle struct {