Add pane-widths { text } to limit the max line width

Fixes: https://todo.sr.ht/~taiite/senpai/87

5 files changed, 36 insertions, 8 deletions

diff --git a/app.go b/app.go
index 4d5e5b3..2aaa486 100644
--- a/app.go
+++ b/app.go
@@ -127,6 +127,7 @@ func NewApp(cfg Config) (app *App, err error) {
 		ChanColEnabled:   cfg.ChanColEnabled,
 		MemberColWidth:   cfg.MemberColWidth,
 		MemberColEnabled: cfg.MemberColEnabled,
+		TextMaxWidth:     cfg.TextMaxWidth,
 		AutoComplete: func(cursorIdx int, text []rune) []ui.Completion {
 			return app.completions(cursorIdx, text)
 		},
diff --git a/config.go b/config.go
index 5ac2a8a..7823ae7 100644
--- a/config.go
+++ b/config.go
@@ -68,6 +68,7 @@ type Config struct {
 	ChanColEnabled   bool
 	MemberColWidth   int
 	MemberColEnabled bool
+	TextMaxWidth     int
 
 	Colors ConfigColors
 
@@ -100,6 +101,7 @@ func Defaults() (cfg Config, err error) {
 		ChanColEnabled:   true,
 		MemberColWidth:   16,
 		MemberColEnabled: true,
+		TextMaxWidth:     0,
 		Colors: ConfigColors{
 			Prompt: tcell.ColorDefault,
 			Unread: tcell.ColorDefault,
@@ -241,6 +243,15 @@ func unmarshal(filename string, cfg *Config) (err error) {
 					} else {
 						cfg.MemberColWidth = members
 					}
+				case "text":
+					var text string
+					if err := child.ParseParams(&text); err != nil {
+						return err
+					}
+
+					if cfg.TextMaxWidth, err = strconv.Atoi(text); err != nil {
+						return err
+					}
 				default:
 					return fmt.Errorf("unknown directive %q", child.Name)
 				}
diff --git a/doc/senpai.5.scd b/doc/senpai.5.scd
index ec6bea5..a8bd9c3 100644
--- a/doc/senpai.5.scd
+++ b/doc/senpai.5.scd
@@ -125,6 +125,11 @@ pane-widths {
 		If the value is negative, the member list will be disabled by default
 		and will take the positive (opposite) width value when toggled with F8.
 
+	*text*
+		The maximum message text line width for messages, in number of cells.
+		By default, the value is zero, which means that there is no maximum.
+		Useful for keeping a readable line width on large screens.
+
 *tls*
 	Enable TLS encryption.  Defaults to true.
 
diff --git a/ui/buffers.go b/ui/buffers.go
index f1f71b3..915a1c8 100644
--- a/ui/buffers.go
+++ b/ui/buffers.go
@@ -205,6 +205,7 @@ type BufferList struct {
 
 	tlInnerWidth int
 	tlHeight     int
+	textWidth    int
 
 	showBufferNumbers bool
 
@@ -222,9 +223,10 @@ func NewBufferList(colors ConfigColors, mergeLine func(*Line, Line)) BufferList
 	}
 }
 
-func (bs *BufferList) ResizeTimeline(tlInnerWidth, tlHeight int) {
+func (bs *BufferList) ResizeTimeline(tlInnerWidth, tlHeight, textWidth int) {
 	bs.tlInnerWidth = tlInnerWidth
 	bs.tlHeight = tlHeight - 2
+	bs.textWidth = textWidth
 }
 
 func (bs *BufferList) OpenOverlay() {
@@ -374,7 +376,7 @@ func (bs *BufferList) AddLine(netID, title string, notify NotifyType, line Line)
 		line.computeSplitPoints()
 		b.lines = append(b.lines, line)
 		if b == current && 0 < b.scrollAmt {
-			b.scrollAmt += len(line.NewLines(bs.tlInnerWidth)) + 1
+			b.scrollAmt += len(line.NewLines(bs.textWidth)) + 1
 		}
 	}
 
@@ -451,7 +453,7 @@ func (bs *BufferList) UpdateRead() (netID, title string, timestamp time.Time) {
 		if y >= b.scrollAmt && line.Readable {
 			break
 		}
-		y += len(line.NewLines(bs.tlInnerWidth)) + 1
+		y += len(line.NewLines(bs.textWidth)) + 1
 	}
 	if line != nil && line.At.After(b.read) {
 		b.read = line.At
@@ -492,7 +494,7 @@ func (bs *BufferList) ScrollUpHighlight() bool {
 			b.scrollAmt = y - bs.tlHeight + 1
 			return true
 		}
-		y += len(line.NewLines(bs.tlInnerWidth)) + 1
+		y += len(line.NewLines(bs.textWidth)) + 1
 	}
 	return false
 }
@@ -506,7 +508,7 @@ func (bs *BufferList) ScrollDownHighlight() bool {
 		if line.Highlight {
 			yLastHighlight = y
 		}
-		y += len(line.NewLines(bs.tlInnerWidth)) + 1
+		y += len(line.NewLines(bs.textWidth)) + 1
 	}
 	b.scrollAmt = yLastHighlight
 	return b.scrollAmt != 0
@@ -722,6 +724,10 @@ func (bs *BufferList) DrawTimeline(screen tcell.Screen, x0, y0, nickColWidth int
 	}
 	y0++
 
+	if bs.textWidth < bs.tlInnerWidth {
+		x0 += (bs.tlInnerWidth - bs.textWidth) / 2
+	}
+
 	yi := b.scrollAmt + y0 + bs.tlHeight
 	for i := len(b.lines) - 1; 0 <= i; i-- {
 		if yi < y0 {
@@ -731,7 +737,7 @@ func (bs *BufferList) DrawTimeline(screen tcell.Screen, x0, y0, nickColWidth int
 		x1 := x0 + 9 + nickColWidth
 
 		line := &b.lines[i]
-		nls := line.NewLines(bs.tlInnerWidth)
+		nls := line.NewLines(bs.textWidth)
 		yi -= len(nls) + 1
 		if y0+bs.tlHeight <= yi {
 			continue
diff --git a/ui/ui.go b/ui/ui.go
index 5533633..7ae13e2 100644
--- a/ui/ui.go
+++ b/ui/ui.go
@@ -16,6 +16,7 @@ type Config struct {
 	ChanColEnabled   bool
 	MemberColWidth   int
 	MemberColEnabled bool
+	TextMaxWidth     int
 	AutoComplete     func(cursorIdx int, text []rune) []Completion
 	Mouse            bool
 	MergeLine        func(former *Line, addition Line)
@@ -404,10 +405,14 @@ func (ui *UI) Resize() {
 		innerWidth = 1 // will break display somewhat, but this is an edge case
 	}
 	ui.e.Resize(innerWidth)
+	textWidth := innerWidth
+	if ui.config.TextMaxWidth > 0 && ui.config.TextMaxWidth < textWidth {
+		textWidth = ui.config.TextMaxWidth
+	}
 	if ui.channelWidth == 0 {
-		ui.bs.ResizeTimeline(innerWidth, h-3)
+		ui.bs.ResizeTimeline(innerWidth, h-3, textWidth)
 	} else {
-		ui.bs.ResizeTimeline(innerWidth, h-2)
+		ui.bs.ResizeTimeline(innerWidth, h-2, textWidth)
 	}
 	ui.screen.Sync()
 }