feat: add panic handler and kill the program from the outside

* Add Kill() to force kill the program from the outside
* Allow passing a custom panic handler when CatchPanics is enabled

options.go

@@ -130,3 +130,11 @@ func WithANSICompressor() ProgramOption {
 		p.startupOptions |= withANSICompressor
 	}
 }
+
+// WithPanicHandler sets the program's panic handler. This won't have any effect
+// if the WithoutCatchPanics option was enabled.
+func WithPanicHandler(f func(*Program)) ProgramOption {
+	return func(p *Program) {
+		p.panicHandler = f
+	}
+}

tea.go

@@ -97,6 +97,9 @@ type Program struct {
 	// is on by default.
 	CatchPanics bool
 
+	panicHandler func(*Program)
+	killc        chan bool
+
 	console console.Console
 
 	// Stores the original reference to stdin for cases where input is not a
@@ -248,6 +251,8 @@ func NewProgram(model Model, opts ...ProgramOption) *Program {
 		input:        os.Stdin,
 		msgs:         make(chan Msg),
 		CatchPanics:  true,
+		panicHandler: defaultPanicHandler(),
+		killc:        make(chan bool, 1),
 	}
 
 	// Apply all options to the program.
@@ -349,14 +354,7 @@ func (p *Program) StartReturningModel() (Model, error) {
 	}()
 
 	if p.CatchPanics {
-		defer func() {
-			if r := recover(); r != nil {
-				p.shutdown(true)
-				fmt.Printf("Caught panic:\n\n%s\n\nRestoring terminal...\n\n", r)
-				debug.PrintStack()
-				return
-			}
-		}()
+		defer p.panicHandler(p)
 	}
 
 	// Check if output is a TTY before entering raw mode, hiding the cursor and
@@ -486,6 +484,8 @@ func (p *Program) StartReturningModel() (Model, error) {
 	// Handle updates and draw.
 	for {
 		select {
+		case <-p.killc:
+			return nil, nil
 		case err := <-errs:
 			cancelContext()
 			waitForGoroutines(cancelReader.Cancel())
@@ -577,6 +577,16 @@ func (p *Program) Quit() {
 	p.Send(Quit())
 }
 
+// Kill stops the program immediately and restores the former terminal state.
+// This final render than you would normally see when quitting will be skipped.
+//
+// This method is currently provisional. The method signature may alter
+// slightly, or it may be removed in a future version of this package.
+func (p *Program) Kill() {
+	p.killc <- true
+	p.shutdown(true)
+}
+
 // shutdown performs operations to free up resources and restore the terminal
 // to its original state.
 func (p *Program) shutdown(kill bool) {
@@ -671,3 +681,14 @@ func (p *Program) DisableMouseAllMotion() {
 	defer p.mtx.Unlock()
 	fmt.Fprintf(p.output, te.CSI+te.DisableMouseAllMotionSeq)
 }
+
+func defaultPanicHandler() func(*Program) {
+	return func(p *Program) {
+		if r := recover(); r != nil {
+			p.shutdown(true)
+			fmt.Printf("Caught panic:\n\n%s\n\nRestoring terminal...\n\n", r)
+			debug.PrintStack()
+			return
+		}
+	}
+}