Improve TUI layout and increase sparkline height

9 files changed, 41 insertions, 28 deletions

diff --git a/internal/tui/dashboard/files.go b/internal/tui/dashboard/files.go
index 945869e..faade8d 100644
--- a/internal/tui/dashboard/files.go
+++ b/internal/tui/dashboard/files.go
@@ -17,18 +17,19 @@ func renderFilesWithOffset(snap *statsengine.Snapshot, width, height, offset int
 		return "Files: waiting for stats..."
 	}
 
-	rows := fileRows(snap.Files())
+	pathWidth := filePathWidth(width)
+	rows := fileRows(snap.Files(), pathWidth)
 	if len(rows) == 0 {
 		return "Files: no data"
 	}
 
 	columns := []table.Column{
-		{Title: "Path", Width: filePathWidth(width)},
 		{Title: "Accesses", Width: 8},
 		{Title: "Read", Width: 9},
 		{Title: "Write", Width: 9},
 		{Title: "Avg Latency", Width: 11},
 		{Title: "Max Latency", Width: 11},
+		{Title: "Path", Width: pathWidth},
 	}
 
 	tbl := table.New(
@@ -43,16 +44,16 @@ func renderFilesWithOffset(snap *statsengine.Snapshot, width, height, offset int
 	return tbl.View() + fmt.Sprintf("\nRow %d/%d", cursor+1, len(rows))
 }
 
-func fileRows(files []statsengine.FileSnapshot) []table.Row {
+func fileRows(files []statsengine.FileSnapshot, pathWidth int) []table.Row {
 	rows := make([]table.Row, 0, len(files))
 	for _, f := range files {
 		rows = append(rows, table.Row{
-			truncatePathMiddle(f.Path, 48),
 			strconv.FormatUint(f.Accesses, 10),
 			formatBytes(float64(f.BytesRead)),
 			formatBytes(float64(f.BytesWritten)),
 			formatDurationNs(f.AvgLatencyNs),
 			formatDurationUintNs(f.MaxLatencyNs),
+			truncatePathMiddle(f.Path, pathWidth),
 		})
 	}
 	return rows
@@ -62,15 +63,12 @@ func filePathWidth(width int) int {
 	if width <= 0 {
 		return 24
 	}
-	// Reserve enough room for non-path columns and table separators so
-	// latency columns remain visible even on narrower terminals.
-	w := width - 70
+	// Keep fixed metrics visible and let path consume the remaining space.
+	// Fixed columns sum to 48 chars; reserve extra for separators/padding.
+	w := width - 58
 	if w < 14 {
 		return 14
 	}
-	if w > 52 {
-		return 52
-	}
 	return w
 }
 
diff --git a/internal/tui/dashboard/files_test.go b/internal/tui/dashboard/files_test.go
index b0a5dbf..6d73b14 100644
--- a/internal/tui/dashboard/files_test.go
+++ b/internal/tui/dashboard/files_test.go
@@ -49,3 +49,10 @@ func TestTruncatePathMiddle(t *testing.T) {
 		t.Fatalf("expected head and tail preservation, got %q", got)
 	}
 }
+
+func TestFilePathWidthExpandsOnWideTerminal(t *testing.T) {
+	got := filePathWidth(180)
+	if got <= 80 {
+		t.Fatalf("expected wide path column to use remaining space, got %d", got)
+	}
+}
diff --git a/internal/tui/dashboard/histogram.go b/internal/tui/dashboard/histogram.go
index b2bb88e..1e68a7b 100644
--- a/internal/tui/dashboard/histogram.go
+++ b/internal/tui/dashboard/histogram.go
@@ -29,6 +29,15 @@ func renderGapsTab(snap *statsengine.Snapshot, width, height int) string {
 	return strings.Join([]string{hist, spark}, "\n")
 }
 
+func renderLatencyGapsTab(snap *statsengine.Snapshot, width, height int) string {
+	if snap == nil {
+		return common.PanelStyle.Render("Latency+Gaps: waiting for stats...")
+	}
+	lat := renderLatencyTab(snap, width, height)
+	gap := renderGapsTab(snap, width, height)
+	return strings.Join([]string{lat, gap}, "\n")
+}
+
 func renderHistogram(hist statsengine.HistogramSnapshot, title string, width, height int) string {
 	buckets := hist.Buckets()
 	if len(buckets) == 0 {
diff --git a/internal/tui/dashboard/model.go b/internal/tui/dashboard/model.go
index 407802f..78da351 100644
--- a/internal/tui/dashboard/model.go
+++ b/internal/tui/dashboard/model.go
@@ -127,7 +127,7 @@ func (m Model) handleKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 			m.activeTab = TabLatency
 			handled = true
 		case key.Matches(msg, m.keys.Six):
-			m.activeTab = TabGaps
+			m.activeTab = TabStream
 			handled = true
 		case key.Matches(msg, m.keys.Seven):
 			m.activeTab = TabStream
@@ -278,9 +278,7 @@ func renderActiveTab(tab Tab, snap *statsengine.Snapshot, streamModel *eventstre
 	case TabProcesses:
 		return renderProcessesWithOffset(snap, width, height, processesOffset)
 	case TabLatency:
-		return renderLatencyTab(snap, width, height)
-	case TabGaps:
-		return renderGapsTab(snap, width, height)
+		return renderLatencyGapsTab(snap, width, height)
 	default:
 		return common.PanelStyle.Render("Unknown tab")
 	}
diff --git a/internal/tui/dashboard/model_test.go b/internal/tui/dashboard/model_test.go
index b0ce933..29b698d 100644
--- a/internal/tui/dashboard/model_test.go
+++ b/internal/tui/dashboard/model_test.go
@@ -47,6 +47,12 @@ func TestKeySwitchingChangesActiveTab(t *testing.T) {
 	if model.activeTab != TabStream {
 		t.Fatalf("expected stream tab on key 7, got %v", model.activeTab)
 	}
+
+	next, _ = model.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'6'}})
+	model = next.(Model)
+	if model.activeTab != TabStream {
+		t.Fatalf("expected stream tab on key 6, got %v", model.activeTab)
+	}
 }
 
 func TestArrowAndViKeysCycleTabs(t *testing.T) {
diff --git a/internal/tui/dashboard/overview.go b/internal/tui/dashboard/overview.go
index 1bdb64f..9feafab 100644
--- a/internal/tui/dashboard/overview.go
+++ b/internal/tui/dashboard/overview.go
@@ -214,8 +214,5 @@ func sparklineWidth(width int) int {
 	if w < 8 {
 		return 8
 	}
-	if w > 80 {
-		return 80
-	}
 	return w
 }
diff --git a/internal/tui/dashboard/sparkline.go b/internal/tui/dashboard/sparkline.go
index 1531ca6..9c1f2c4 100644
--- a/internal/tui/dashboard/sparkline.go
+++ b/internal/tui/dashboard/sparkline.go
@@ -11,8 +11,10 @@ func renderSparkline(data []float64, width int) string {
 
 	samples := sampleForWidth(data, width)
 	min, max := minMax(samples)
+	line := ""
 	if min == max {
-		return repeatRune('▄', len(samples))
+		line = repeatRune('▄', len(samples))
+		return line + "\n" + line
 	}
 
 	out := make([]rune, len(samples))
@@ -28,7 +30,8 @@ func renderSparkline(data []float64, width int) string {
 		}
 		out[i] = sparkChars[idx]
 	}
-	return string(out)
+	line = string(out)
+	return line + "\n" + line
 }
 
 func sampleForWidth(data []float64, width int) []float64 {
diff --git a/internal/tui/dashboard/tabs.go b/internal/tui/dashboard/tabs.go
index 9aae218..a2fe366 100644
--- a/internal/tui/dashboard/tabs.go
+++ b/internal/tui/dashboard/tabs.go
@@ -22,8 +22,6 @@ const (
 	TabProcesses
 	// TabLatency is the latency histogram tab.
 	TabLatency
-	// TabGaps is the inter-syscall gap tab.
-	TabGaps
 	// TabStream is the live event stream tab.
 	TabStream
 )
@@ -34,7 +32,6 @@ var allTabs = []Tab{
 	TabFiles,
 	TabProcesses,
 	TabLatency,
-	TabGaps,
 	TabStream,
 }
 
@@ -49,9 +46,7 @@ func (t Tab) String() string {
 	case TabProcesses:
 		return "Processes"
 	case TabLatency:
-		return "Latency"
-	case TabGaps:
-		return "Gaps"
+		return "Latency+Gaps"
 	case TabStream:
 		return "Stream"
 	default:
diff --git a/internal/tui/dashboard/tabs_test.go b/internal/tui/dashboard/tabs_test.go
index d40cc68..0fc36f2 100644
--- a/internal/tui/dashboard/tabs_test.go
+++ b/internal/tui/dashboard/tabs_test.go
@@ -6,8 +6,8 @@ import (
 )
 
 func TestTabNavigationWraps(t *testing.T) {
-	if got := nextTab(TabGaps); got != TabStream {
-		t.Fatalf("expected next after gaps to be stream, got %v", got)
+	if got := nextTab(TabLatency); got != TabStream {
+		t.Fatalf("expected next after latency+gaps to be stream, got %v", got)
 	}
 	if got := nextTab(TabStream); got != TabOverview {
 		t.Fatalf("expected wrap to overview from stream, got %v", got)
@@ -19,7 +19,7 @@ func TestTabNavigationWraps(t *testing.T) {
 
 func TestRenderTabBarContainsLabels(t *testing.T) {
 	out := renderTabBar(TabOverview, 80)
-	for _, label := range []string{"Overview", "Syscalls", "Files", "Processes", "Latency", "Gaps", "Stream"} {
+	for _, label := range []string{"Overview", "Syscalls", "Files", "Processes", "Latency+Gaps", "Stream"} {
 		if !strings.Contains(out, label) {
 			t.Fatalf("expected tab label %q in tab bar", label)
 		}