init: pristine aerc 0.20.0 source

lib/ui/ui.go

@@ -0,0 +1,186 @@
+package ui
+
+import (
+	"os"
+	"os/signal"
+	"sync/atomic"
+	"syscall"
+
+	"git.sr.ht/~rjarry/aerc/config"
+	"git.sr.ht/~rjarry/aerc/lib/log"
+	"git.sr.ht/~rockorager/vaxis"
+)
+
+// Use unbuffered channels (always blocking unless somebody can read
+// immediately) We are merely using this as a proxy to the internal vaxis event
+// channel.
+var Events = make(chan vaxis.Event)
+
+var Quit = make(chan struct{})
+
+var Callbacks = make(chan func(), 50)
+
+// QueueFunc queues a function to be called in the main goroutine. This can be
+// used to prevent race conditions from delayed functions
+func QueueFunc(fn func()) {
+	Callbacks <- fn
+}
+
+// Use a buffered channel of size 1 to avoid blocking callers of Invalidate()
+var Redraw = make(chan bool, 1)
+
+// Invalidate marks the entire UI as invalid and request a redraw as soon as
+// possible. Invalidate can be called from any goroutine and will never block.
+func Invalidate() {
+	if atomic.SwapUint32(&state.dirty, 1) != 1 {
+		Redraw <- true
+	}
+}
+
+var state struct {
+	content DrawableInteractive
+	ctx     *Context
+	vx      *vaxis.Vaxis
+	popover *Popover
+	dirty   uint32 // == 1 if render has been queued in Redraw channel
+	// == 1 if suspend is pending
+	suspending uint32
+	refresh    uint32 // == 1 if a refresh has been queued
+}
+
+func Initialize(content DrawableInteractive) error {
+	opts := vaxis.Options{
+		DisableMouse: !config.Ui.MouseEnabled,
+		CSIuBitMask:  vaxis.CSIuDisambiguate,
+		WithTTY:      "/dev/tty",
+	}
+	vx, err := vaxis.New(opts)
+	if err != nil {
+		return err
+	}
+
+	vx.Window().Clear()
+	vx.HideCursor()
+
+	state.content = content
+	state.vx = vx
+	state.ctx = NewContext(state.vx, onPopover)
+	vx.SetTitle("aerc")
+
+	Invalidate()
+	if beeper, ok := content.(DrawableInteractiveBeeper); ok {
+		beeper.OnBeep(vx.Bell)
+	}
+	content.Focus(true)
+
+	go func() {
+		defer log.PanicHandler()
+		for event := range vx.Events() {
+			Events <- event
+		}
+	}()
+
+	return nil
+}
+
+func onPopover(p *Popover) {
+	state.popover = p
+}
+
+func Exit() {
+	close(Quit)
+}
+
+var SuspendQueue = make(chan bool, 1)
+
+func QueueSuspend() {
+	if atomic.SwapUint32(&state.suspending, 1) != 1 {
+		SuspendQueue <- true
+	}
+}
+
+// SuspendScreen should be called from the main thread.
+func SuspendScreen() {
+	_ = state.vx.Suspend()
+}
+
+func ResumeScreen() {
+	err := state.vx.Resume()
+	if err != nil {
+		log.Errorf("ui: cannot resume after suspend: %v", err)
+	}
+	Invalidate()
+}
+
+func Suspend() error {
+	var err error
+	if atomic.SwapUint32(&state.suspending, 0) != 0 {
+		err = state.vx.Suspend()
+		if err == nil {
+			sigcont := make(chan os.Signal, 1)
+			signal.Notify(sigcont, syscall.SIGCONT)
+			err = syscall.Kill(0, syscall.SIGTSTP)
+			if err == nil {
+				<-sigcont
+			}
+			signal.Reset(syscall.SIGCONT)
+			err = state.vx.Resume()
+			state.content.Draw(state.ctx)
+			state.vx.Render()
+		}
+	}
+	return err
+}
+
+func Close() {
+	state.vx.Close()
+}
+
+func QueueRefresh() {
+	if atomic.SwapUint32(&state.refresh, 1) != 1 {
+		Invalidate()
+	}
+}
+
+func Render() {
+	if atomic.SwapUint32(&state.dirty, 0) != 0 {
+		state.vx.Window().Clear()
+		// reset popover for the next Draw
+		state.popover = nil
+		state.vx.HideCursor()
+		state.content.Draw(state.ctx)
+		if state.popover != nil {
+			// if the Draw resulted in a popover, draw it
+			state.popover.Draw(state.ctx)
+		}
+		switch atomic.SwapUint32(&state.refresh, 0) {
+		case 0:
+			state.vx.Render()
+		case 1:
+			state.vx.Refresh()
+		}
+	}
+}
+
+func HandleEvent(event vaxis.Event) {
+	switch event := event.(type) {
+	case vaxis.Resize:
+		state.ctx = NewContext(state.vx, onPopover)
+		Invalidate()
+	case vaxis.Redraw:
+		Invalidate()
+	default:
+		// We never care about num or caps lock. Remove them so it
+		// doesn't interfere with key matching
+		if key, ok := event.(vaxis.Key); ok {
+			key.Modifiers &^= vaxis.ModCapsLock
+			key.Modifiers &^= vaxis.ModNumLock
+			event = key
+		}
+		// if we have a popover, and it can handle the event, it does so
+		if state.popover == nil || !state.popover.Event(event) {
+			// otherwise, we send the event to the main content
+			state.content.Event(event)
+		}
+	}
+}