feat: WithoutEmptyRenders

options.go

@@ -166,6 +166,16 @@ func WithANSICompressor() ProgramOption {
 	}
 }
 
+// WithoutEmptyRenders makes bubbletea do nothing when the View method return
+// an empty string.
+//
+// By default, it will render a space instead.
+func WithoutEmptyRenders() ProgramOption {
+	return func(p *Program) {
+		p.startupOptions |= withoutEmptyRenders
+	}
+}
+
 // WithFilter supplies an event filter that will be invoked before Bubble Tea
 // processes a tea.Msg. The event filter can return any tea.Msg which will then
 // get handled by Bubble Tea instead of the original event. If the event filter

options_test.go

@@ -65,7 +65,6 @@ func TestOptions(t *testing.T) {
 			var b bytes.Buffer
 			exercise(t, WithInput(&b), customInput)
 		})
-
 	})
 
 	t.Run("startup options", func(t *testing.T) {
@@ -92,6 +91,10 @@ func TestOptions(t *testing.T) {
 			exercise(t, WithoutSignalHandler(), withoutSignalHandler)
 		})
 
+		t.Run("without empty renders", func(t *testing.T) {
+			exercise(t, WithoutEmptyRenders(), withoutEmptyRenders)
+		})
+
 		t.Run("mouse cell motion", func(t *testing.T) {
 			p := NewProgram(nil, WithMouseAllMotion(), WithMouseCellMotion())
 			if !p.startupOptions.has(withMouseCellMotion) {

standard_renderer.go

@@ -37,6 +37,7 @@ type standardRenderer struct {
 	lastRender         string
 	linesRendered      int
 	useANSICompressor  bool
+	renderEmpty        bool
 	once               sync.Once
 
 	// cursor visibility state
@@ -55,7 +56,7 @@ type standardRenderer struct {
 
 // newRenderer creates a new renderer. Normally you'll want to initialize it
 // with os.Stdout as the first argument.
-func newRenderer(out *termenv.Output, useANSICompressor bool, fps int) renderer {
+func newRenderer(out *termenv.Output, useANSICompressor, renderEmpty bool, fps int) renderer {
 	if fps < 1 {
 		fps = defaultFPS
 	} else if fps > maxFPS {
@@ -67,6 +68,7 @@ func newRenderer(out *termenv.Output, useANSICompressor bool, fps int) renderer
 		done:               make(chan struct{}),
 		framerate:          time.Second / time.Duration(fps),
 		useANSICompressor:  useANSICompressor,
+		renderEmpty:        renderEmpty,
 		queuedMessageLines: []string{},
 	}
 	if r.useANSICompressor {
@@ -271,7 +273,7 @@ func (r *standardRenderer) write(s string) {
 	// rendering nothing. Rather than introduce additional state to manage
 	// this, we render a single space as a simple (albeit less correct)
 	// solution.
-	if s == "" {
+	if s == "" && r.renderEmpty {
 		s = " "
 	}
 

tea.go

@@ -98,6 +98,8 @@ const (
 	// recover from panics, print the stack trace, and disable raw mode. This
 	// feature is on by default.
 	withoutCatchPanics
+
+	withoutEmptyRenders
 )
 
 // handlers manages series of channels returned by various processes. It allows
@@ -470,7 +472,12 @@ func (p *Program) Run() (Model, error) {
 
 	// If no renderer is set use the standard one.
 	if p.renderer == nil {
-		p.renderer = newRenderer(p.output, p.startupOptions.has(withANSICompressor), p.fps)
+		p.renderer = newRenderer(
+			p.output,
+			p.startupOptions.has(withANSICompressor),
+			!p.startupOptions.has(withoutEmptyRenders),
+			p.fps,
+		)
 	}
 
 	// Check if output is a TTY before entering raw mode, hiding the cursor and