Add shift+tab to switch to previous tab

Author: alexandre-daubois

internal/ui/app.go

@@ -131,6 +131,15 @@ func (a *App) nextTab() {
 	}
 }
 
+func (a *App) prevTab() {
+	for i, t := range a.tabs {
+		if t == a.activeTab {
+			a.switchTab(a.tabs[(i-1+len(a.tabs))%len(a.tabs)])
+			return
+		}
+	}
+}
+
 type tickMsg struct{}
 type fetchMsg struct {
 	snap *fetcher.Snapshot
@@ -432,6 +441,9 @@ func (a *App) handleListKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 	case "tab":
 		a.nextTab()
 		return a, nil
+	case "shift+tab":
+		a.prevTab()
+		return a, nil
 	case "1":
 		if len(a.tabs) > 0 {
 			a.switchTab(a.tabs[0])

internal/ui/app_test.go

@@ -557,6 +557,41 @@ func TestTabSwitch_TabKey(t *testing.T) {
 	assert.Equal(t, tabFrankenPHP, app.activeTab)
 }
 
+func TestTabSwitch_ShiftTabKey(t *testing.T) {
+	app := newAppWithThreads([]fetcher.ThreadDebugState{{Index: 0, IsWaiting: true}})
+	assert.Equal(t, tabFrankenPHP, app.activeTab)
+
+	app.handleListKey(tea.KeyMsg{Type: tea.KeyShiftTab})
+	assert.Equal(t, tabCaddy, app.activeTab)
+
+	app.handleListKey(tea.KeyMsg{Type: tea.KeyShiftTab})
+	assert.Equal(t, tabFrankenPHP, app.activeTab)
+}
+
+func TestTabSwitch_ShiftTabReversesTab(t *testing.T) {
+	app := newAppWithThreads([]fetcher.ThreadDebugState{{Index: 0, IsWaiting: true}})
+	assert.Equal(t, tabFrankenPHP, app.activeTab)
+
+	app.handleListKey(tea.KeyMsg{Type: tea.KeyTab})
+	assert.Equal(t, tabCaddy, app.activeTab)
+
+	app.handleListKey(tea.KeyMsg{Type: tea.KeyShiftTab})
+	assert.Equal(t, tabFrankenPHP, app.activeTab, "Shift+Tab should reverse Tab direction")
+}
+
+func TestTabSwitch_ShiftTabPreservesCursorPerTab(t *testing.T) {
+	app := newAppWithThreads([]fetcher.ThreadDebugState{
+		{Index: 0}, {Index: 1}, {Index: 2},
+	})
+	app.cursor = 2
+
+	app.handleListKey(tea.KeyMsg{Type: tea.KeyShiftTab})
+	assert.Equal(t, 0, app.cursor, "Caddy tab should start at cursor 0")
+
+	app.handleListKey(tea.KeyMsg{Type: tea.KeyShiftTab})
+	assert.Equal(t, 2, app.cursor, "FrankenPHP tab should restore cursor")
+}
+
 func TestTabSwitch_NumberKeys(t *testing.T) {
 	app := newAppWithThreads([]fetcher.ThreadDebugState{{Index: 0, IsWaiting: true}})
 

internal/ui/help.go

@@ -37,7 +37,7 @@ func renderHelp(sortBy model.SortField, hostSortBy model.HostSortField, paused b
 	bindings = append(bindings,
 		binding{"g", "graphs"},
 		binding{"/", "filter"},
-		binding{"Tab", "switch"},
+		binding{"Tab/S-Tab", "switch"},
 		binding{"q", "quit"},
 	)
 
@@ -60,7 +60,7 @@ func renderHelpOverlay(base string, width, height int, hasFrankenPHP bool) strin
 		{"↑/↓ j/k", "Move cursor"},
 		{"Enter", "Open detail panel"},
 		{"Esc", "Close / go back"},
-		{"Tab", "Switch tab"},
+		{"Tab/S-Tab", "Switch tab"},
 		{"1/2", "Jump to tab"},
 		{"Home/End", "Jump to first/last"},
 		{"PgUp/PgDn", "Page up/down"},