From 119144e78c09d4763ea57e33e45f3c63b3b368d1 Mon Sep 17 00:00:00 2001
From: Christian Rocha <christian@rocha.is>
Date: Sat, 30 Oct 2021 12:29:30 -0400
Subject: [PATCH] ANSI compression is now opt-in via the WithANSICompressor
 program option

---
 options.go           | 11 +++++++++++
 standard_renderer.go | 39 +++++++++++++++++++++++++--------------
 tea.go               |  3 ++-
 3 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/options.go b/options.go
index 944c1e5..09e5ecb 100644
--- a/options.go
+++ b/options.go
@@ -119,3 +119,14 @@ func WithoutRenderer() ProgramOption {
 		m.renderer = &nilRenderer{}
 	}
 }
+
+// WithANSICompressor removes redundant ANSI sequences to produce potentially
+// smaller output, at the cost of some processing overhead.
+//
+// This feature is provisional, and may be changed removed in a future version
+// of this package.
+func WithANSICompressor() ProgramOption {
+	return func(p *Program) {
+		p.startupOptions |= withANSICompressor
+	}
+}
diff --git a/standard_renderer.go b/standard_renderer.go
index c24db99..dbd1aa3 100644
--- a/standard_renderer.go
+++ b/standard_renderer.go
@@ -23,14 +23,15 @@ const (
 // In cases where very high performance is needed the renderer can be told
 // to exclude ranges of lines, allowing them to be written to directly.
 type standardRenderer struct {
-	out           io.WriteCloser
-	buf           bytes.Buffer
-	framerate     time.Duration
-	ticker        *time.Ticker
-	mtx           *sync.Mutex
-	done          chan struct{}
-	lastRender    string
-	linesRendered int
+	out               io.Writer
+	buf               bytes.Buffer
+	framerate         time.Duration
+	ticker            *time.Ticker
+	mtx               *sync.Mutex
+	done              chan struct{}
+	lastRender        string
+	linesRendered     int
+	useANSICompressor bool
 
 	// essentially whether or not we're using the full size of the terminal
 	altScreenActive bool
@@ -45,12 +46,17 @@ 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 io.Writer, mtx *sync.Mutex) renderer {
-	return &standardRenderer{
-		out:       &compressor.Writer{Forward: out},
-		mtx:       mtx,
-		framerate: defaultFramerate,
+func newRenderer(out io.Writer, mtx *sync.Mutex, useANSICompressor bool) renderer {
+	r := &standardRenderer{
+		out:               out,
+		mtx:               mtx,
+		framerate:         defaultFramerate,
+		useANSICompressor: useANSICompressor,
 	}
+	if r.useANSICompressor {
+		r.out = &compressor.Writer{Forward: out}
+	}
+	return r
 }
 
 // start starts the renderer.
@@ -67,7 +73,12 @@ func (r *standardRenderer) stop() {
 	r.flush()
 	clearLine(r.out)
 	close(r.done)
-	r.out.Close()
+
+	if r.useANSICompressor {
+		if w, ok := r.out.(io.WriteCloser); ok {
+			_ = w.Close()
+		}
+	}
 }
 
 // kill halts the renderer. The final frame will not be rendered.
diff --git a/tea.go b/tea.go
index 8c9c9db..7c9b901 100644
--- a/tea.go
+++ b/tea.go
@@ -71,6 +71,7 @@ const (
 	withMouseAllMotion
 	withInputTTY
 	withCustomInput
+	withANSICompressor
 )
 
 // Program is a terminal user interface.
@@ -360,7 +361,7 @@ func (p *Program) StartReturningModel() (Model, error) {
 
 	// If no renderer is set use the standard one.
 	if p.renderer == nil {
-		p.renderer = newRenderer(p.output, p.mtx)
+		p.renderer = newRenderer(p.output, p.mtx, p.startupOptions.has(withANSICompressor))
 	}
 
 	// Honor program startup options.