feat(loader): add styled loader to the status bar

Closes #82

app/ui/screen.go

@@ -17,8 +17,9 @@ type Screen struct {
 	status    commander.StatusReporter
 	view      commander.View
 	theme     commander.ThemeManager
-	title     *views.BoxLayout
-	titleBar  *views.TextBar
+	// TODO: separate title widget
+	title    *views.BoxLayout
+	titleBar *views.TextBar
 }
 
 func (s *Screen) View() commander.View {
@@ -39,6 +40,10 @@ func (s *Screen) Init(status commander.StatusReporter, theme commander.ThemeMana
 	s.SetTitle(s.title)
 }
 
+func (s *Screen) Status() commander.StatusReporter {
+	return s.status
+}
+
 func (s *Screen) UpdateScreen() {
 	if s.app != nil {
 		s.app.Update()

app/ui/status/loader.go

@@ -0,0 +1,85 @@
+package status
+
+import (
+	"fmt"
+	"github.com/AnatolyRugalev/kube-commander/commander"
+	"github.com/gdamore/tcell"
+	"github.com/gdamore/tcell/views"
+	"go.uber.org/atomic"
+	"sync"
+)
+
+const (
+	lastPhase   = 3
+	loadingIcon = rune('☸')
+)
+
+type loader struct {
+	views.WidgetWatchers
+	sync.Mutex
+	view   views.View
+	screen commander.ScreenHandler
+
+	stack *atomic.Int32
+	phase *atomic.Int32
+}
+
+func NewLoader(screen commander.ScreenHandler) *loader {
+	return &loader{
+		screen: screen,
+		stack:  atomic.NewInt32(0),
+		phase:  atomic.NewInt32(0),
+	}
+}
+
+func (l *loader) Start() {
+	l.stack.Inc()
+}
+
+func (l *loader) Finish() {
+	l.stack.Dec()
+}
+
+func (l *loader) Tick() {
+	if !l.phase.CAS(lastPhase, 0) {
+		l.phase.Inc()
+	}
+	if l.stack.Load() != 0 {
+		l.screen.UpdateScreen()
+	}
+}
+
+func (l *loader) Draw() {
+	l.Lock()
+	defer l.Unlock()
+	if l.view == nil {
+		return
+	}
+	if l.stack.Load() == 0 {
+		style := l.screen.Theme().GetStyle("status-loader-idle")
+		l.view.SetContent(0, 0, ' ', nil, style)
+		l.view.SetContent(1, 0, ' ', nil, style)
+	} else {
+		phase := l.phase.Load()
+		style := l.screen.Theme().GetStyle(fmt.Sprintf("status-loader-phase-%d", phase))
+		l.view.SetContent(0, 0, loadingIcon, nil, style)
+		l.view.SetContent(1, 0, ' ', nil, style)
+	}
+}
+
+func (l *loader) Resize() {
+}
+
+func (l *loader) HandleEvent(_ tcell.Event) bool {
+	return false
+}
+
+func (l *loader) SetView(view views.View) {
+	l.Lock()
+	l.view = view
+	l.Unlock()
+}
+
+func (l *loader) Size() (int, int) {
+	return 2, 1
+}

app/ui/status/status.go

@@ -10,9 +10,16 @@ import (
 )
 
 type Status struct {
+	views.WidgetWatchers
 	*focus.Focusable
-	*views.Text
-	mu     sync.Mutex
+	mu sync.Mutex
+
+	view    views.View
+	loaderV *views.ViewPort
+	loader  *loader
+	textV   *views.ViewPort
+	text    *views.Text
+
 	screen commander.ScreenHandler
 	events chan *tcell.EventKey
 
@@ -21,8 +28,33 @@ type Status struct {
 	clearIn time.Time
 }
 
+func (s *Status) LoadingStarted() {
+	s.loader.Start()
+}
+
+func (s *Status) LoadingFinished() {
+	s.loader.Finish()
+}
+
+func (s *Status) Resize() {
+	w, h := s.view.Size()
+	s.loaderV.Resize(0, 0, 2, h)
+	s.textV.Resize(2, 0, w-2, h)
+}
+
+func (s *Status) SetView(view views.View) {
+	s.mu.Lock()
+	s.view = view
+	w, h := view.Size()
+	s.loaderV = views.NewViewPort(view, 0, 0, 2, h)
+	s.loader.SetView(s.loaderV)
+	s.textV = views.NewViewPort(view, 2, 0, w-2, h)
+	s.text.SetView(s.textV)
+	s.mu.Unlock()
+}
+
 func (s *Status) watch() {
-	ticker := time.NewTicker(time.Millisecond * 100)
+	ticker := time.NewTicker(time.Millisecond * 200)
 	for {
 		t := <-ticker.C
 		s.mu.Lock()
@@ -31,6 +63,7 @@ func (s *Status) watch() {
 		if clear {
 			s.Clear()
 		}
+		s.loader.Tick()
 	}
 }
 
@@ -41,8 +74,8 @@ func (s *Status) setMessage(text string, style tcell.Style, clearIn time.Duratio
 	} else {
 		s.clearIn = time.Now().Add(clearIn)
 	}
-	s.SetText(text)
-	s.SetStyle(style)
+	s.text.SetStyle(style)
+	s.text.SetText(text)
 	s.mu.Unlock()
 	s.screen.UpdateScreen()
 }
@@ -87,11 +120,12 @@ func (s *Status) Confirm(msg string) bool {
 func (s *Status) Draw() {
 	s.once.Do(func() {
 		s.mu.Lock()
-		s.SetStyle(s.screen.Theme().GetStyle("status-bar"))
+		s.text.SetStyle(s.screen.Theme().GetStyle("status-bar"))
 		s.mu.Unlock()
 	})
 	s.mu.Lock()
-	s.Text.Draw()
+	s.loader.Draw()
+	s.text.Draw()
 	s.mu.Unlock()
 }
 
@@ -102,7 +136,8 @@ func (s *Status) Size() (int, int) {
 func NewStatus(screen commander.ScreenHandler) *Status {
 	s := &Status{
 		Focusable: focus.NewFocusable(),
-		Text:      views.NewText(),
+		loader:    NewLoader(screen),
+		text:      views.NewText(),
 		screen:    screen,
 		events:    make(chan *tcell.EventKey),
 	}

app/ui/theme/themes/themes.go

@@ -135,5 +135,29 @@ func BaseStyles() []*pb.Style {
 			Fg:   "confirm-fg",
 			Bg:   "confirm-bg",
 		},
+		{
+			Name: "status-loader-idle",
+			Bg:   "status-bar",
+		},
+		{
+			Name: "status-loader-phase-0",
+			Bg:   "selection-bg",
+			Fg:   "selection-fg",
+		},
+		{
+			Name: "status-loader-phase-1",
+			Bg:   "confirm-bg",
+			Fg:   "confirm-fg",
+		},
+		{
+			Name: "status-loader-phase-2",
+			Bg:   "error-bg",
+			Fg:   "error-fg",
+		},
+		{
+			Name: "status-loader-phase-3",
+			Bg:   "unfocused-bg",
+			Fg:   "unfocused-fg",
+		},
 	}
 }

app/ui/widgets/listTable/resource.go

@@ -186,6 +186,9 @@ func (r *ResourceListTable) extractRows(addNamespace bool, event watch.Event) ([
 }
 
 func (r *ResourceListTable) loadResourceRows() ([]string, []commander.Row, error) {
+	r.screen.Status().LoadingStarted()
+	defer r.screen.Status().LoadingFinished()
+
 	namespace := r.container.CurrentNamespace()
 	table, err := r.container.Client().ListAsTable(context.TODO(), r.resource, namespace)
 	if err != nil {

commander/screen.go

@@ -15,9 +15,12 @@ type StatusReporter interface {
 	Warning(msg string)
 	Info(msg string)
 	Confirm(msg string) bool
+	LoadingStarted()
+	LoadingFinished()
 }
 
 type ScreenHandler interface {
+	Status() StatusReporter
 	UpdateScreen()
 	Resize()
 	Theme() ThemeManager

go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/mattn/go-runewidth v0.0.9
 	github.com/spf13/cast v1.3.1
 	github.com/spf13/cobra v0.0.7
+	go.uber.org/atomic v1.4.0
 	golang.org/x/crypto v0.0.0-20200220183623-bac4c82f6975
 	google.golang.org/appengine v1.6.1 // indirect
 	google.golang.org/protobuf v1.25.0

go.sum

@@ -311,6 +311,7 @@ github.com/xlab/handysort v0.0.0-20150421192137-fb3537ed64a1/go.mod h1:QcJo0QPSf
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 go.etcd.io/bbolt v1.3.2/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
+go.uber.org/atomic v1.4.0 h1:cxzIVoETapQEqDhQu3QfnvXAV4AlzcvUCxkVUFw3+EU=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
 go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=