feat: make signal handler optional

You can now initialize a tea app without a signal handler:

p := NewProgram(model, WithoutSignalHandler())

options.go

@@ -38,6 +38,14 @@ func WithInputTTY() ProgramOption {
 	}
 }
 
+// WithoutSignalHandler disables the signal handler that Bubble Tea sets up for
+// Programs. This is useful if you want to handle signals yourself.
+func WithoutSignalHandler() ProgramOption {
+	return func(p *Program) {
+		p.startupOptions |= withoutSignalHandler
+	}
+}
+
 // WithoutCatchPanics disables the panic catching that Bubble Tea does by
 // default. If panic catching is disabled the terminal will be in a fairly
 // unusable state after a panic because Bubble Tea will not perform its usual

options_test.go

@@ -62,6 +62,10 @@ func TestOptions(t *testing.T) {
 			exercise(t, WithANSICompressor(), withANSICompressor)
 		})
 
+		t.Run("without signal handler", func(t *testing.T) {
+			exercise(t, WithoutSignalHandler(), withoutSignalHandler)
+		})
+
 		t.Run("mouse cell motion", func(t *testing.T) {
 			p := NewProgram(nil, WithMouseAllMotion(), WithMouseCellMotion())
 			if !p.startupOptions.has(withMouseCellMotion) {

tea.go

@@ -71,6 +71,7 @@ const (
 	withInputTTY
 	withCustomInput
 	withANSICompressor
+	withoutSignalHandler
 )
 
 // Program is a terminal user interface.
@@ -375,7 +376,12 @@ func (p *Program) StartReturningModel() (Model, error) {
 	}
 
 	// Handle signals.
-	sigintLoopDone := p.handleSignals()
+	sigintLoopDone := make(chan struct{})
+	if !p.startupOptions.has(withoutSignalHandler) {
+		sigintLoopDone = p.handleSignals()
+	} else {
+		close(sigintLoopDone)
+	}
 
 	if p.CatchPanics {
 		defer func() {