Add more preview window options and reduce vertical padding on noborder

Fix #2138
Fix #2029

src/options.go

@@ -81,6 +81,7 @@ const usage = `usage: fzf [options]
     --preview=COMMAND     Command to preview highlighted line ({})
     --preview-window=OPT  Preview window layout (default: right:50%)
                           [up|down|left|right][:SIZE[%]][:wrap][:hidden][:+SCROLL[-OFFSET]]
+                          [:rounded|sharp|noborder]
 
   Scripting
     -q, --query=STR       Start the finder with the given query
@@ -162,7 +163,7 @@ type previewOpts struct {
 	scroll   string
 	hidden   bool
 	wrap     bool
-	border   bool
+	border   tui.BorderShape
 }
 
 // Options stores the values of command-line options
@@ -261,7 +262,7 @@ func defaultOptions() *Options {
 		ToggleSort:  false,
 		Expect:      make(map[int]string),
 		Keymap:      make(map[int][]action),
-		Preview:     previewOpts{"", posRight, sizeSpec{50, true}, "", false, false, true},
+		Preview:     previewOpts{"", posRight, sizeSpec{50, true}, "", false, false, tui.BorderRounded},
 		PrintQuery:  false,
 		ReadZero:    false,
 		Printer:     func(str string) { fmt.Println(str) },
@@ -1011,10 +1012,12 @@ func parsePreviewWindow(opts *previewOpts, input string) {
 			opts.position = posLeft
 		case "right":
 			opts.position = posRight
-		case "border":
-			opts.border = true
+		case "rounded", "border":
+			opts.border = tui.BorderRounded
+		case "sharp":
+			opts.border = tui.BorderSharp
 		case "noborder":
-			opts.border = false
+			opts.border = tui.BorderNone
 		default:
 			if sizeRegex.MatchString(token) {
 				opts.size = parseSize(token, 99, "window size")
@@ -1274,7 +1277,7 @@ func parseOptions(opts *Options, allArgs []string) {
 			opts.Preview.command = ""
 		case "--preview-window":
 			parsePreviewWindow(&opts.Preview,
-				nextString(allArgs, &i, "preview window layout required: [up|down|left|right][:SIZE[%]][:noborder][:wrap][:hidden][:+SCROLL[-OFFSET]]"))
+				nextString(allArgs, &i, "preview window layout required: [up|down|left|right][:SIZE[%]][:rounded|sharp|noborder][:wrap][:hidden][:+SCROLL[-OFFSET]]"))
 		case "--height":
 			opts.Height = parseHeight(nextString(allArgs, &i, "height required: HEIGHT[%]"))
 		case "--min-height":

src/terminal.go

@@ -676,6 +676,8 @@ func (t *Terminal) resizeWindows() {
 	}
 	if t.pborder != nil {
 		t.pborder.Close()
+	}
+	if t.pwindow != nil {
 		t.pwindow.Close()
 	}
 
@@ -700,19 +702,28 @@ func (t *Terminal) resizeWindows() {
 	noBorder := tui.MakeBorderStyle(tui.BorderNone, t.unicode)
 	if previewVisible {
 		createPreviewWindow := func(y int, x int, w int, h int) {
-			previewBorder := tui.MakeBorderStyle(tui.BorderRounded, t.unicode)
-			if !t.preview.border {
-				previewBorder = tui.MakeTransparentBorder()
+			pwidth := w
+			pheight := h
+			if t.preview.border != tui.BorderNone {
+				previewBorder := tui.MakeBorderStyle(t.preview.border, t.unicode)
+				t.pborder = t.tui.NewWindow(y, x, w, h, true, previewBorder)
+				pwidth -= 4
+				pheight -= 2
+				x += 2
+				y += 1
+			} else {
+				previewBorder := tui.MakeTransparentBorder()
+				t.pborder = t.tui.NewWindow(y, x, w, h, true, previewBorder)
+				pwidth -= 2
+				x += 1
 			}
-			t.pborder = t.tui.NewWindow(y, x, w, h, true, previewBorder)
-			pwidth := w - 4
 			// ncurses auto-wraps the line when the cursor reaches the right-end of
 			// the window. To prevent unintended line-wraps, we use the width one
 			// column larger than the desired value.
 			if !t.preview.wrap && t.tui.DoesAutoWrap() {
 				pwidth += 1
 			}
-			t.pwindow = t.tui.NewWindow(y+1, x+2, pwidth, h-2, true, noBorder)
+			t.pwindow = t.tui.NewWindow(y, x, pwidth, pheight, true, noBorder)
 		}
 		switch t.preview.position {
 		case posUp:
@@ -1210,7 +1221,10 @@ func (t *Terminal) refresh() {
 			windows = append(windows, t.border)
 		}
 		if t.hasPreviewWindow() {
-			windows = append(windows, t.pborder, t.pwindow)
+			if t.pborder != nil {
+				windows = append(windows, t.pborder)
+			}
+			windows = append(windows, t.pwindow)
 		}
 		windows = append(windows, t.window)
 		t.tui.RefreshWindows(windows)