Make preview renderer suspend early on line wrap

src/tui/light.go

@@ -730,23 +730,29 @@ func wrapLine(input string, prefixLength int, max int, tabstop int) []wrappedLin
 	return lines
 }
 
-func (w *LightWindow) fill(str string, onMove func()) bool {
+func (w *LightWindow) fill(str string, onMove func()) FillReturn {
 	allLines := strings.Split(str, "\n")
 	for i, line := range allLines {
 		lines := wrapLine(line, w.posx, w.width, w.tabstop)
 		for j, wl := range lines {
+			if w.posx >= w.Width()-1 && wl.displayWidth == 0 {
+				if w.posy < w.height-1 {
+					w.MoveAndClear(w.posy+1, 0)
+				}
+				return FillNextLine
+			}
 			w.stderr(wl.text)
 			w.posx += wl.displayWidth
 			if j < len(lines)-1 || i < len(allLines)-1 {
 				if w.posy+1 >= w.height {
-					return false
+					return FillSuspend
 				}
 				w.MoveAndClear(w.posy+1, 0)
 				onMove()
 			}
 		}
 	}
-	return true
+	return FillContinue
 }
 
 func (w *LightWindow) setBg() {
@@ -755,13 +761,13 @@ func (w *LightWindow) setBg() {
 	}
 }
 
-func (w *LightWindow) Fill(text string) bool {
+func (w *LightWindow) Fill(text string) FillReturn {
 	w.MoveAndClear(w.posy, w.posx)
 	w.setBg()
 	return w.fill(text, w.setBg)
 }
 
-func (w *LightWindow) CFill(fg Color, bg Color, attr Attr, text string) bool {
+func (w *LightWindow) CFill(fg Color, bg Color, attr Attr, text string) FillReturn {
 	w.MoveAndClear(w.posy, w.posx)
 	if bg == colDefault {
 		bg = w.bg

src/tui/ncurses.go

@@ -282,11 +282,14 @@ func (r *FullscreenRenderer) DoesAutoWrap() bool {
 	return true
 }
 
-func (w *CursesWindow) Fill(str string) bool {
-	return C.waddstr(w.impl, C.CString(str)) == C.OK
+func (w *CursesWindow) Fill(str string) FillReturn {
+	if C.waddstr(w.impl, C.CString(str)) == C.OK {
+		return FillContinue
+	}
+	return FillSuspend
 }
 
-func (w *CursesWindow) CFill(fg Color, bg Color, attr Attr, str string) bool {
+func (w *CursesWindow) CFill(fg Color, bg Color, attr Attr, str string) FillReturn {
 	index := ColorPair{fg, bg, -1}.index()
 	C.wcolor_set(w.impl, C.short(index), nil)
 	C.wattron(w.impl, C.int(attr))

src/tui/tcell.go

@@ -477,7 +477,7 @@ func (w *TcellWindow) CPrint(pair ColorPair, attr Attr, text string) {
 	w.printString(text, pair, attr)
 }
 
-func (w *TcellWindow) fillString(text string, pair ColorPair, a Attr) bool {
+func (w *TcellWindow) fillString(text string, pair ColorPair, a Attr) FillReturn {
 	lx := 0
 
 	var style tcell.Style
@@ -511,7 +511,7 @@ func (w *TcellWindow) fillString(text string, pair ColorPair, a Attr) bool {
 			var yPos = w.top + w.lastY
 
 			if yPos >= (w.top + w.height) {
-				return false
+				return FillSuspend
 			}
 
 			_screen.SetContent(xPos, yPos, r, nil, style)
@@ -520,14 +520,14 @@ func (w *TcellWindow) fillString(text string, pair ColorPair, a Attr) bool {
 	}
 	w.lastX += lx
 
-	return true
+	return FillContinue
 }
 
-func (w *TcellWindow) Fill(str string) bool {
+func (w *TcellWindow) Fill(str string) FillReturn {
 	return w.fillString(str, ColDefault, 0)
 }
 
-func (w *TcellWindow) CFill(fg Color, bg Color, a Attr, str string) bool {
+func (w *TcellWindow) CFill(fg Color, bg Color, a Attr, str string) FillReturn {
 	return w.fillString(str, ColorPair{fg, bg, -1}, a)
 }
 

src/tui/tui.go

@@ -117,6 +117,14 @@ const (
 	colWhite
 )
 
+type FillReturn int
+
+const (
+	FillContinue FillReturn = iota
+	FillNextLine
+	FillSuspend
+)
+
 type ColorPair struct {
 	fg Color
 	bg Color
@@ -216,8 +224,8 @@ type Window interface {
 	MoveAndClear(y int, x int)
 	Print(text string)
 	CPrint(color ColorPair, attr Attr, text string)
-	Fill(text string) bool
-	CFill(fg Color, bg Color, attr Attr, text string) bool
+	Fill(text string) FillReturn
+	CFill(fg Color, bg Color, attr Attr, text string) FillReturn
 	Erase()
 }