Merge pull request #683 from noborus/notify-eof

Add EOF notification feature

Author: noborus

main.go

@@ -513,6 +513,10 @@ func init() {
 	rootCmd.PersistentFlags().BoolP("hide-other-section", "", false, "hide other section")
 	_ = viper.BindPFlag("general.HideOtherSection", rootCmd.PersistentFlags().Lookup("hide-other-section"))
 
+	rootCmd.PersistentFlags().IntP("notify-eof", "", 0, "notify at the end of the file")
+	_ = viper.BindPFlag("NotifyEOF", rootCmd.PersistentFlags().Lookup("notify-eof"))
+	rootCmd.PersistentFlags().Lookup("notify-eof").NoOptDefVal = "1"
+
 	// Config
 	rootCmd.PersistentFlags().BoolP("quit-if-one-screen", "F", false, "quit if the output fits on one screen")
 	_ = viper.BindPFlag("QuitSmall", rootCmd.PersistentFlags().Lookup("quit-if-one-screen"))

oviewer/draw.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"strings"
+	"time"
 
 	"github.com/gdamore/tcell/v2"
 )
@@ -389,3 +390,29 @@ func (root *Root) reverseRange(y int, start int, end int, sel bool) {
 		}
 	}
 }
+
+// notifyEOFReached notifies that EOF has been reached.
+func (root *Root) notifyEOFReached(m *Document) {
+	root.setMessagef("EOF reached %s", m.FileName)
+	root.notify(root.Config.NotifyEOF)
+}
+
+// notify notifies by beeping and flashing the screen the specified number of times.
+func (root *Root) notify(count int) {
+	for i := 0; i < count; i++ {
+		root.Screen.Beep()
+		root.flash()
+	}
+}
+
+// flash flashes the screen.
+func (root *Root) flash() {
+	root.Screen.Fill(' ', tcell.StyleDefault.Background(tcell.ColorWhite))
+	root.Screen.Sync()
+	time.Sleep(50 * time.Millisecond)
+	root.Screen.Fill(' ', tcell.StyleDefault.Background(tcell.ColorBlack))
+	root.Screen.Sync()
+	time.Sleep(50 * time.Millisecond)
+	root.draw(context.Background())
+	time.Sleep(100 * time.Millisecond)
+}

oviewer/event.go

@@ -98,6 +98,8 @@ func (root *Root) event(ctx context.Context, ev tcell.Event) bool {
 		root.saveBuffer(ev.value)
 	case *eventSectionNum:
 		root.setSectionNum(ev.value)
+	case *eventReachEOF:
+		root.notifyEOFReached(ev.m)
 
 	// tcell events
 	case *tcell.EventResize:
@@ -361,3 +363,36 @@ func (root *Root) postEvent(ev tcell.Event) {
 		root.releaseEventBuffer()
 	}
 }
+
+// eventReachEOF represents an EOF event.
+type eventReachEOF struct {
+	m *Document
+	tcell.EventTime
+}
+
+// sendReachEOF fires the eventReachEOF event.
+func (root *Root) sendReachEOF(m *Document) {
+	ev := &eventReachEOF{}
+	ev.m = m
+	ev.SetEventNow()
+	root.postEvent(ev)
+}
+
+// monitorEOF monitors the EOF of the document.
+func (root *Root) monitorEOF() {
+	if root.Config.NotifyEOF == 0 {
+		return
+	}
+	log.Println("monitorEOF")
+	for _, m := range root.DocList {
+		go func() {
+			if !m.BufEOF() {
+				m.cond.L.Lock()
+				m.cond.Wait()
+				m.cond.L.Unlock()
+			}
+			root.sendReachEOF(m)
+			log.Println("EOF reached", m.FileName)
+		}()
+	}
+}

oviewer/oviewer.go

@@ -274,6 +274,8 @@ type Config struct {
 	RegexpSearch bool
 	// Incsearch is incremental search if true.
 	Incsearch bool
+	// NotifyEOF specifies the number of times to notify EOF.
+	NotifyEOF int
 
 	// ShrinkChar is the character to display when the column is shrunk.
 	ShrinkChar string
@@ -641,6 +643,8 @@ func (root *Root) Run() error {
 	sigSuspend := registerSIGTSTP()
 	quitChan := make(chan struct{})
 
+	root.monitorEOF()
+
 	go func() {
 		// Undo screen when goroutine panic.
 		defer func() {