Pause spinner ticks when not refreshing.

Also, add a quick-and-dirty model for displaying basic performance
stats, currently just the number of calls to the root Update() and
View() methods.

tui/tui.go

@@ -6,25 +6,20 @@ import (
 	"code.humancabbage.net/sam/moonmath/coindesk"
 	"code.humancabbage.net/sam/moonmath/config"
 	"code.humancabbage.net/sam/moonmath/tui/asset"
+	"code.humancabbage.net/sam/moonmath/tui/perf"
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
 )
 
 type Model struct {
-	assets []asset.Model
+	assets       []asset.Model
+	stats        perf.Model
+	displayStats bool
 }
 
-func New(assets []coindesk.Asset, cfg config.All) (p *tea.Program) {
-	model := newModel(assets, cfg)
-	p = tea.NewProgram(
-		model,
-		tea.WithAltScreen(),
-		tea.WithFPS(30),
-	)
-	return
-}
-
-func newModel(assets []coindesk.Asset, cfg config.All) (m Model) {
+func New(assets []coindesk.Asset, cfg config.All, displayStats bool) (m Model) {
+	m.stats = perf.New()
+	m.displayStats = displayStats
 	// construct models for each asset, but don't filter out dupes
 	seen := map[coindesk.Asset]struct{}{}
 	for _, a := range assets {
@@ -52,6 +47,7 @@ func (m Model) Init() tea.Cmd {
 }
 
 func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	m.stats.AddUpdate()
 	switch msg := msg.(type) {
 	// handle keys for quitting
 	case tea.KeyMsg:
@@ -78,11 +74,15 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 }
 
 func (m Model) View() string {
+	m.stats.AddView()
 	var ss []string
 	for i := range m.assets {
 		s := m.assets[i].View()
 		ss = append(ss, s)
 	}
+	if m.displayStats {
+		ss = append(ss, m.stats.View())
+	}
 	r := lipgloss.JoinVertical(lipgloss.Center, ss...)
 	return r
 }