From dcec92659053a4de8837f20d3fa94ee69f617bbf Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 31 Aug 2022 21:24:13 +0530
Subject: [PATCH] Do not allow adding timers before loop is run

---
 tools/tui/loop/api.go | 12 +++++++++---
 tools/tui/loop/run.go |  1 +
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/tools/tui/loop/api.go b/tools/tui/loop/api.go
index 576412c8c..e0fb996cc 100644
--- a/tools/tui/loop/api.go
+++ b/tools/tui/loop/api.go
@@ -72,7 +72,7 @@ type Loop struct {
 }
 
 func New() (*Loop, error) {
-	l := Loop{controlling_term: nil, timers: make([]*timer, 0)}
+	l := Loop{controlling_term: nil}
 	l.terminal_options.alternate_screen = true
 	l.escape_code_parser.HandleCSI = l.handle_csi
 	l.escape_code_parser.HandleOSC = l.handle_osc
@@ -84,16 +84,22 @@ func New() (*Loop, error) {
 	return &l, nil
 }
 
-func (self *Loop) AddTimer(interval time.Duration, repeats bool, callback TimerCallback) IdType {
+func (self *Loop) AddTimer(interval time.Duration, repeats bool, callback TimerCallback) (IdType, error) {
+	if self.timers == nil {
+		return 0, fmt.Errorf("Cannot add timers before starting the run loop, add them in OnInitialize instead")
+	}
 	self.timer_id_counter++
 	t := timer{interval: interval, repeats: repeats, callback: callback, id: self.timer_id_counter}
 	t.update_deadline(time.Now())
 	self.timers = append(self.timers, &t)
 	self.sort_timers()
-	return t.id
+	return t.id, nil
 }
 
 func (self *Loop) RemoveTimer(id IdType) bool {
+	if self.timers == nil {
+		return false
+	}
 	for i := 0; i < len(self.timers); i++ {
 		if self.timers[i].id == id {
 			self.timers = append(self.timers[:i], self.timers[i+1:]...)
diff --git a/tools/tui/loop/run.go b/tools/tui/loop/run.go
index 4ab769d1a..dd4f28f95 100644
--- a/tools/tui/loop/run.go
+++ b/tools/tui/loop/run.go
@@ -203,6 +203,7 @@ func (self *Loop) run() (err error) {
 	self.death_signal = SIGNULL
 	self.escape_code_parser.Reset()
 	self.exit_code = 0
+	self.timers = make([]*timer, 0, 1)
 	no_timeout_channel := make(<-chan time.Time)
 	finalizer := ""