Scroll horizontal channel list with the mouse wheel

This is inspired by a patch by mooff.

The horizontal channel list can now be scrolled with the mouse wheel.

2 files changed, 23 insertions, 4 deletions

diff --git a/ui/buffers.go b/ui/buffers.go
index 69d1aa0..021ddb1 100644
--- a/ui/buffers.go
+++ b/ui/buffers.go
@@ -593,10 +593,29 @@ func (bs *BufferList) DrawVerticalBufferList(screen tcell.Screen, x0, y0, width,
 	}
 }
 
-func (bs *BufferList) DrawHorizontalBufferList(screen tcell.Screen, x0, y0, width int) {
-	x := x0
+func (bs *BufferList) DrawHorizontalBufferList(screen tcell.Screen, x0, y0, width int, offset *int) {
+	x := width
+	for i := len(bs.list) - 1; i >= 0; i-- {
+		b := &bs.list[i]
+		x--
+		if b.title == "" {
+			x -= stringWidth(b.netName)
+		} else {
+			x -= stringWidth(b.title)
+		}
+		if 0 < b.highlights {
+			x -= 2 + len(fmt.Sprintf("%d", b.highlights))
+		}
+		if x <= 10 {
+			break
+		}
+		if *offset > i {
+			*offset = i
+		}
+	}
+	x = x0
 
-	for i, b := range bs.list {
+	for i, b := range bs.list[*offset:] {
 		if width <= x-x0 {
 			break
 		}
diff --git a/ui/ui.go b/ui/ui.go
index 1498949..6a9979a 100644
--- a/ui/ui.go
+++ b/ui/ui.go
@@ -415,7 +415,7 @@ func (ui *UI) Draw(members []irc.Member) {
 
 	ui.bs.DrawTimeline(ui.screen, ui.channelWidth, 0, ui.config.NickColWidth)
 	if ui.channelWidth == 0 {
-		ui.bs.DrawHorizontalBufferList(ui.screen, 0, h-1, w-ui.memberWidth)
+		ui.bs.DrawHorizontalBufferList(ui.screen, 0, h-1, w-ui.memberWidth, &ui.channelOffset)
 	} else {
 		ui.bs.DrawVerticalBufferList(ui.screen, 0, 0, ui.channelWidth, h, &ui.channelOffset)
 	}