fix: windows: enable mouse mode on demand (#1340)

Since we added native Windows API input events support, we always enable
mouse events even if the user doesn't want them. This is a problem because
it breaks applications that don't expect mouse events and selection
stops working without any modifier key.

Fixes: #1313

Author: aymanbagabas

inputreader_other.go

@@ -9,6 +9,6 @@ import (
 	"github.com/muesli/cancelreader"
 )
 
-func newInputReader(r io.Reader) (cancelreader.CancelReader, error) {
+func newInputReader(r io.Reader, _ bool) (cancelreader.CancelReader, error) {
 	return cancelreader.NewReader(r)
 }

inputreader_windows.go

@@ -25,7 +25,7 @@ type conInputReader struct {
 
 var _ cancelreader.CancelReader = &conInputReader{}
 
-func newInputReader(r io.Reader) (cancelreader.CancelReader, error) {
+func newInputReader(r io.Reader, enableMouse bool) (cancelreader.CancelReader, error) {
 	fallback := func(io.Reader) (cancelreader.CancelReader, error) {
 		return cancelreader.NewReader(r)
 	}
@@ -38,11 +38,21 @@ func newInputReader(r io.Reader) (cancelreader.CancelReader, error) {
 		return fallback(r)
 	}
 
-	originalMode, err := prepareConsole(conin,
-		windows.ENABLE_MOUSE_INPUT,
+	modes := []uint32{
 		windows.ENABLE_WINDOW_INPUT,
 		windows.ENABLE_EXTENDED_FLAGS,
-	)
+	}
+
+	// Since we have options to enable mouse events, [WithMouseCellMotion],
+	// [WithMouseAllMotion], and [EnableMouseCellMotion],
+	// [EnableMouseAllMotion], and [DisableMouse], we need to check if the user
+	// has enabled mouse events and add the appropriate mode accordingly.
+	// Otherwise, mouse events will be enabled all the time.
+	if enableMouse {
+		modes = append(modes, windows.ENABLE_MOUSE_INPUT)
+	}
+
+	originalMode, err := prepareConsole(conin, modes...)
 	if err != nil {
 		return nil, fmt.Errorf("failed to prepare console input: %w", err)
 	}

tea.go

@@ -16,6 +16,7 @@ import (
 	"io"
 	"os"
 	"os/signal"
+	"runtime"
 	"runtime/debug"
 	"sync"
 	"sync/atomic"
@@ -183,6 +184,9 @@ type Program struct {
 	// fps is the frames per second we should set on the renderer, if
 	// applicable,
 	fps int
+
+	// mouseMode is true if the program should enable mouse mode on Windows.
+	mouseMode bool
 }
 
 // Quit is a special command that tells the Bubble Tea program to exit.
@@ -413,9 +417,25 @@ func (p *Program) eventLoop(model Model, cmds chan Cmd) (Model, error) {
 				// mouse mode (1006) is a no-op if the terminal doesn't support it.
 				p.renderer.enableMouseSGRMode()
 
+				// XXX: This is used to enable mouse mode on Windows. We need
+				// to reinitialize the cancel reader to get the mouse events to
+				// work.
+				if runtime.GOOS == "windows" && !p.mouseMode {
+					p.mouseMode = true
+					p.initCancelReader(true) //nolint:errcheck
+				}
+
 			case disableMouseMsg:
 				p.disableMouse()
 
+				// XXX: On Windows, mouse mode is enabled on the input reader
+				// level. We need to instruct the input reader to stop reading
+				// mouse events.
+				if runtime.GOOS == "windows" && p.mouseMode {
+					p.mouseMode = false
+					p.initCancelReader(true) //nolint:errcheck
+				}
+
 			case showCursorMsg:
 				p.renderer.showCursor()
 
@@ -579,6 +599,11 @@ func (p *Program) Run() (Model, error) {
 		p.renderer.enableMouseAllMotion()
 		p.renderer.enableMouseSGRMode()
 	}
+
+	// XXX: Should we enable mouse mode on Windows?
+	// This needs to happen before initializing the cancel and input reader.
+	p.mouseMode = p.startupOptions&withMouseCellMotion != 0 || p.startupOptions&withMouseAllMotion != 0
+
 	if p.startupOptions&withReportFocus != 0 {
 		p.renderer.enableReportFocus()
 	}
@@ -607,7 +632,7 @@ func (p *Program) Run() (Model, error) {
 
 	// Subscribe to user input.
 	if p.input != nil {
-		if err := p.initCancelReader(); err != nil {
+		if err := p.initCancelReader(false); err != nil {
 			return model, err
 		}
 	}
@@ -763,7 +788,7 @@ func (p *Program) RestoreTerminal() error {
 	if err := p.initTerminal(); err != nil {
 		return err
 	}
-	if err := p.initCancelReader(); err != nil {
+	if err := p.initCancelReader(false); err != nil {
 		return err
 	}
 	if p.altScreenWasActive {

tty.go

@@ -75,9 +75,14 @@ func (p *Program) restoreInput() error {
 }
 
 // initCancelReader (re)commences reading inputs.
-func (p *Program) initCancelReader() error {
+func (p *Program) initCancelReader(cancel bool) error {
+	if cancel && p.cancelReader != nil {
+		p.cancelReader.Cancel()
+		p.waitForReadLoop()
+	}
+
 	var err error
-	p.cancelReader, err = newInputReader(p.input)
+	p.cancelReader, err = newInputReader(p.input, p.mouseMode)
 	if err != nil {
 		return fmt.Errorf("error creating cancelreader: %w", err)
 	}