From ba387764ca1590625d349e74eb8a8a64d1849b67 Mon Sep 17 00:00:00 2001 From: Tulir Asokan Date: Wed, 14 Nov 2018 00:00:35 +0200 Subject: Fix things --- vendor/maunium.net/go/tview/application.go | 376 ++++++++++++++++++++--------- 1 file changed, 260 insertions(+), 116 deletions(-) (limited to 'vendor/maunium.net/go/tview/application.go') diff --git a/vendor/maunium.net/go/tview/application.go b/vendor/maunium.net/go/tview/application.go index 7e6da3a..ae4d7f8 100644 --- a/vendor/maunium.net/go/tview/application.go +++ b/vendor/maunium.net/go/tview/application.go @@ -1,24 +1,36 @@ package tview import ( - "fmt" - "os" "sync" "maunium.net/go/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. + running bool + // The primitive which currently has the keyboard focus. focus Primitive @@ -48,13 +60,23 @@ type Application struct { // was drawn. afterDraw func(screen tcell.Screen) - // If this value is true, the application has entered suspended mode. - suspended bool + // 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{} } // NewApplication creates and returns a new application. func NewApplication() *Application { - return &Application{} + return &Application{ + events: make(chan tcell.Event, queueSize), + updates: make(chan func(), queueSize), + suspendToken: make(chan struct{}, 1), + } } // SetInputCapture sets a function which captures all key events before they are @@ -97,140 +119,222 @@ func (a *Application) GetScreen() tcell.Screen { return a.screen } +// SetScreen allows you to provide your own tcell.Screen object. For most +// applications, this is not needed and you should be familiar with +// tcell.Screen when using this function. Run() will call Init() and Fini() on +// the provided screen object. +// +// This function is typically called before calling Run(). Calling it while an +// application is running will switch the application to the new screen. Fini() +// will be called on the old screen and Init() on the new screen (errors +// returned by Init() will lead to a panic). +// +// Note that calling Suspend() will invoke Fini() on your screen object and it +// will not be restored when suspended mode ends. Instead, a new default screen +// object will be created. +func (a *Application) SetScreen(screen tcell.Screen) *Application { + a.Lock() + defer a.Unlock() + if a.running { + a.screen.Fini() + } + a.screen = screen + if a.running { + if err := a.screen.Init(); err != nil { + panic(err) + } + } + return a +} + // Run starts the application and thus the event loop. This function returns // when Stop() was called. func (a *Application) Run() error { var err error a.Lock() - // Make a screen. - a.screen, err = tcell.NewScreen() - if err != nil { - a.Unlock() - return err + // Make a screen if there is none yet. + if a.screen == nil { + a.screen, err = tcell.NewScreen() + if err != nil { + a.Unlock() + return err + } } if err = a.screen.Init(); err != nil { a.Unlock() return err } a.screen.EnableMouse() + a.running = true + + // We catch panics to clean up because they mess up the terminal. + defer func() { + if p := recover(); p != nil { + if a.screen != nil { + a.screen.Fini() + } + a.running = false + panic(p) + } + }() // Draw the screen for the first time. a.Unlock() - a.Draw() + 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 + } - // Start event loop. - for { - a.Lock() - screen := a.screen - if a.suspended { - a.suspended = false // Clear previous suspended flag. - } - a.Unlock() - if screen == nil { - 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 + } } + }() - // Wait for next event. - event := a.screen.PollEvent() - if event == nil { - a.Lock() - if a.suspended { - // This screen was renewed due to suspended mode. - a.suspended = false - a.Unlock() - continue // Resume. + // Start event loop. +EventLoop: + for { + select { + case event := <-a.events: + if event == nil { + break EventLoop } - a.Unlock() - // The screen was finalized. Exit the loop. - break - } + 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. + } + } - 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. + // 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() + // 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.EventMouse: - a.RLock() - p := a.focus - a.RUnlock() - - // Intercept keys. - if a.mouseCapture != nil { - event = a.mouseCapture(event) - if event == nil { - break // Don't forward event. + + case *tcell.EventMouse: + a.RLock() + p := a.focus + a.RUnlock() + + // Intercept keys. + if a.mouseCapture != nil { + event = a.mouseCapture(event) + if event == nil { + break // Don't forward event. + } } - } - // Pass other key events to the currently focused primitive. - if p != nil { - if handler := p.MouseHandler(); handler != nil { - handler(event, func(p Primitive) { - a.SetFocus(p) - }) - //a.Draw() + // Pass other key events to the currently focused primitive. + if p != nil { + if handler := p.MouseHandler(); handler != nil { + handler(event, func(p Primitive) { + a.SetFocus(p) + }) + //a.Draw() + } } - } - case *tcell.EventPaste: - a.RLock() - p := a.focus - a.RUnlock() - - if a.pasteCapture != nil { - event = a.pasteCapture(event) - if event == nil { - break + case *tcell.EventPaste: + a.RLock() + p := a.focus + a.RUnlock() + + if a.pasteCapture != nil { + event = a.pasteCapture(event) + if event == nil { + break + } } - } - if p != nil { - if handler := p.PasteHandler(); handler != nil { - handler(event) - a.Draw() + if p != nil { + if handler := p.PasteHandler(); handler != nil { + handler(event) + a.Draw() + } } + case *tcell.EventResize: + a.RLock() + screen := a.screen + a.RUnlock() + screen.Clear() + a.draw() } - case *tcell.EventResize: - a.Lock() - screen := a.screen - a.Unlock() - screen.Clear() - a.Draw() + + // If we have updates, now is the time to execute them. + case updater := <-a.updates: + updater() } } + a.running = false + close(a.suspendToken) + wg.Wait() + return nil } // Stop stops the application, causing Run() to return. func (a *Application) Stop() { - a.RLock() - defer a.RUnlock() - if a.screen == nil { + a.Lock() + defer a.Unlock() + screen := a.screen + if screen == nil { return } - a.screen.Fini() a.screen = nil + screen.Fini() + // a.running is still true, the main loop will clean up. } // Suspend temporarily suspends the application by exiting terminal UI mode and @@ -243,29 +347,24 @@ func (a *Application) Stop() { func (a *Application) Suspend(f func()) bool { a.Lock() - if a.suspended || a.screen == nil { - // Application is already suspended. + screen := a.screen + if screen == nil { + // Screen has not yet been initialized. a.Unlock() return false } - // Enter suspended mode. - a.suspended = true + // 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() - 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() - // Make a new screen and redraw. + // Initialize our new screen and draw the contents. a.Lock() var err error a.screen, err = tcell.NewScreen() @@ -278,23 +377,36 @@ func (a *Application) Suspend(f func()) bool { panic(err) } a.screen.EnableMouse() + a.running = true a.Unlock() - a.Draw() + a.draw() + a.suspendToken <- struct{}{} + // One key event will get lost, see https://github.com/gdamore/tcell/issues/194 // Continue application loop. return true } -// Draw refreshes the screen. It calls the Draw() function of the application's -// root primitive and then syncs the screen buffer. +// 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. func (a *Application) Draw() *Application { - a.RLock() + 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() + screen := a.screen root := a.root fullscreen := a.rootFullscreen before := a.beforeDraw after := a.afterDraw - a.RUnlock() // Maybe we're not ready yet or not anymore. if screen == nil || root == nil { @@ -427,3 +539,35 @@ 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 +} -- cgit v1.2.3