Revert "Update dependencies"

vendor/github.com/rivo/tview/application.go

@@ -1,34 +1,25 @@
 package tview
 
 import (
+	"fmt"
+	"os"
 	"sync"
 
 	"github.com/gdamore/tcell"
 )
 
-// The size of the event/update/redraw channels.
-const queueSize = 100
-
 // Application represents the top node of an application.
 //
 // It is not strictly required to use this class as none of the other classes
 // depend on it. However, it provides useful tools to set up an application and
 // plays nicely with all widgets.
-//
-// The following command displays a primitive p on the screen until Ctrl-C is
-// pressed:
-//
-//   if err := tview.NewApplication().SetRoot(p, true).Run(); err != nil {
-//       panic(err)
-//   }
 type Application struct {
 	sync.RWMutex
 
 	// The application's screen.
 	screen tcell.Screen
 
-	// Indicates whether the application's screen is currently active. This is
-	// false during suspended mode.
+	// Indicates whether the application's screen is currently active.
 	running bool
 
 	// The primitive which currently has the keyboard focus.
@@ -53,23 +44,13 @@ type Application struct {
 	// was drawn.
 	afterDraw func(screen tcell.Screen)
 
-	// Used to send screen events from separate goroutine to main event loop
-	events chan tcell.Event
-
-	// Functions queued from goroutines, used to serialize updates to primitives.
-	updates chan func()
-
-	// A channel which signals the end of the suspended mode.
-	suspendToken chan struct{}
+	// Halts the event loop during suspended mode.
+	suspendMutex sync.Mutex
 }
 
 // NewApplication creates and returns a new application.
 func NewApplication() *Application {
-	return &Application{
-		events:       make(chan tcell.Event, queueSize),
-		updates:      make(chan func(), queueSize),
-		suspendToken: make(chan struct{}, 1),
-	}
+	return &Application{}
 }
 
 // SetInputCapture sets a function which captures all key events before they are
@@ -153,105 +134,65 @@ func (a *Application) Run() error {
 
 	// Draw the screen for the first time.
 	a.Unlock()
-	a.draw()
-
-	// Separate loop to wait for screen events.
-	var wg sync.WaitGroup
-	wg.Add(1)
-	a.suspendToken <- struct{}{} // We need this to get started.
-	go func() {
-		defer wg.Done()
-		for range a.suspendToken {
-			for {
-				a.RLock()
-				screen := a.screen
-				a.RUnlock()
-				if screen == nil {
-					// We have no screen. We might need to stop.
-					break
-				}
-
-				// Wait for next event and queue it.
-				event := screen.PollEvent()
-				if event != nil {
-					// Regular event. Queue.
-					a.QueueEvent(event)
-					continue
-				}
-
-				// A screen was finalized (event is nil).
-				a.RLock()
-				running := a.running
-				a.RUnlock()
-				if running {
-					// The application was stopped. End the event loop.
-					a.QueueEvent(nil)
-					return
-				}
-
-				// We're in suspended mode (running is false). Pause and wait for new
-				// token.
-				break
-			}
-		}
-	}()
+	a.Draw()
 
 	// Start event loop.
-EventLoop:
 	for {
-		select {
-		case event := <-a.events:
-			if event == nil {
-				break EventLoop
+		// Do not poll events during suspend mode
+		a.suspendMutex.Lock()
+		a.RLock()
+		screen := a.screen
+		a.RUnlock()
+		if screen == nil {
+			a.suspendMutex.Unlock()
+			break
+		}
+
+		// Wait for next event.
+		event := a.screen.PollEvent()
+		a.suspendMutex.Unlock()
+		if event == nil {
+			// The screen was finalized. Exit the loop.
+			break
+		}
+
+		switch event := event.(type) {
+		case *tcell.EventKey:
+			a.RLock()
+			p := a.focus
+			a.RUnlock()
+
+			// Intercept keys.
+			if a.inputCapture != nil {
+				event = a.inputCapture(event)
+				if event == nil {
+					break // Don't forward event.
+				}
 			}
 
-			switch event := event.(type) {
-			case *tcell.EventKey:
-				a.RLock()
-				p := a.focus
-				inputCapture := a.inputCapture
-				a.RUnlock()
-
-				// Intercept keys.
-				if inputCapture != nil {
-					event = inputCapture(event)
-					if event == nil {
-						continue // Don't forward event.
-					}
-				}
-
-				// Ctrl-C closes the application.
-				if event.Key() == tcell.KeyCtrlC {
-					a.Stop()
-				}
-
-				// Pass other key events to the currently focused primitive.
-				if p != nil {
-					if handler := p.InputHandler(); handler != nil {
-						handler(event, func(p Primitive) {
-							a.SetFocus(p)
-						})
-						a.draw()
-					}
-				}
-			case *tcell.EventResize:
-				a.RLock()
-				screen := a.screen
-				a.RUnlock()
-				screen.Clear()
-				a.draw()
+			// Ctrl-C closes the application.
+			if event.Key() == tcell.KeyCtrlC {
+				a.Stop()
 			}
 
-		// If we have updates, now is the time to execute them.
-		case updater := <-a.updates:
-			updater()
+			// Pass other key events to the currently focused primitive.
+			if p != nil {
+				if handler := p.InputHandler(); handler != nil {
+					handler(event, func(p Primitive) {
+						a.SetFocus(p)
+					})
+					a.Draw()
+				}
+			}
+		case *tcell.EventResize:
+			a.RLock()
+			screen := a.screen
+			a.RUnlock()
+			screen.Clear()
+			a.Draw()
 		}
 	}
 
-	a.running = false
-	close(a.suspendToken)
-	wg.Wait()
-
 	return nil
 }
 
@@ -259,13 +200,12 @@ EventLoop:
 func (a *Application) Stop() {
 	a.Lock()
 	defer a.Unlock()
-	screen := a.screen
-	if screen == nil {
+	if a.screen == nil {
 		return
 	}
+	a.screen.Fini()
 	a.screen = nil
-	screen.Fini()
-	// a.running is still true, the main loop will clean up.
+	a.running = false
 }
 
 // Suspend temporarily suspends the application by exiting terminal UI mode and
@@ -276,26 +216,32 @@ func (a *Application) Stop() {
 // was called. If false is returned, the application was already suspended,
 // terminal UI mode was not exited, and "f" was not called.
 func (a *Application) Suspend(f func()) bool {
-	a.Lock()
+	a.RLock()
 
-	screen := a.screen
-	if screen == nil {
+	if a.screen == nil {
 		// Screen has not yet been initialized.
-		a.Unlock()
+		a.RUnlock()
 		return false
 	}
 
-	// Enter suspended mode. Make a new screen here already so our event loop can
-	// continue.
-	a.screen = nil
-	a.running = false
-	screen.Fini()
-	a.Unlock()
+	// Enter suspended mode.
+	a.suspendMutex.Lock()
+	defer a.suspendMutex.Unlock()
+	a.RUnlock()
+	a.Stop()
+
+	// Deal with panics during suspended mode. Exit the program.
+	defer func() {
+		if p := recover(); p != nil {
+			fmt.Println(p)
+			os.Exit(1)
+		}
+	}()
 
 	// Wait for "f" to return.
 	f()
 
-	// Initialize our new screen and draw the contents.
+	// Make a new screen and redraw.
 	a.Lock()
 	var err error
 	a.screen, err = tcell.NewScreen()
@@ -309,26 +255,15 @@ func (a *Application) Suspend(f func()) bool {
 	}
 	a.running = true
 	a.Unlock()
-	a.draw()
-	a.suspendToken <- struct{}{}
-	// One key event will get lost, see https://github.com/gdamore/tcell/issues/194
+	a.Draw()
 
 	// Continue application loop.
 	return true
 }
 
-// Draw refreshes the screen (during the next update cycle). It calls the Draw()
-// function of the application's root primitive and then syncs the screen
-// buffer.
+// Draw refreshes the screen. It calls the Draw() function of the application's
+// root primitive and then syncs the screen buffer.
 func (a *Application) Draw() *Application {
-	a.QueueUpdate(func() {
-		a.draw()
-	})
-	return a
-}
-
-// draw actually does what Draw() promises to do.
-func (a *Application) draw() *Application {
 	a.Lock()
 	defer a.Unlock()
 
@@ -469,35 +404,3 @@ func (a *Application) GetFocus() Primitive {
 	defer a.RUnlock()
 	return a.focus
 }
-
-// QueueUpdate is used to synchronize access to primitives from non-main
-// goroutines. The provided function will be executed as part of the event loop
-// and thus will not cause race conditions with other such update functions or
-// the Draw() function.
-//
-// Note that Draw() is not implicitly called after the execution of f as that
-// may not be desirable. You can call Draw() from f if the screen should be
-// refreshed after each update. Alternatively, use QueueUpdateDraw() to follow
-// up with an immediate refresh of the screen.
-func (a *Application) QueueUpdate(f func()) *Application {
-	a.updates <- f
-	return a
-}
-
-// QueueUpdateDraw works like QueueUpdate() except it refreshes the screen
-// immediately after executing f.
-func (a *Application) QueueUpdateDraw(f func()) *Application {
-	a.QueueUpdate(func() {
-		f()
-		a.draw()
-	})
-	return a
-}
-
-// QueueEvent sends an event to the Application event loop.
-//
-// It is not recommended for event to be nil.
-func (a *Application) QueueEvent(event tcell.Event) *Application {
-	a.events <- event
-	return a
-}