From d503d5dbf6bfb3ed311ebc222e77d6874f7787ff Mon Sep 17 00:00:00 2001
From: Christian Rocha <christian@rocha.is>
Date: Tue, 5 May 2020 14:26:06 -0400
Subject: [PATCH] Every sends the time at which the timer ticked

---
 examples/fullscreen/main.go |  8 +++++--
 examples/simple/main.go     |  8 ++++---
 examples/views/main.go      | 48 +++++++++++++++++++++++--------------
 subscriptions.go            | 12 ++++++----
 4 files changed, 49 insertions(+), 27 deletions(-)

diff --git a/examples/fullscreen/main.go b/examples/fullscreen/main.go
index 1c2cab3..7fe2938 100644
--- a/examples/fullscreen/main.go
+++ b/examples/fullscreen/main.go
@@ -12,7 +12,11 @@ import (
 
 type model int
 
-type tickMsg struct{}
+type tickMsg time.Time
+
+func newTickMsg(t time.Time) tea.Msg {
+	return tickMsg(t)
+}
 
 func main() {
 	tea.AltScreen()
@@ -55,7 +59,7 @@ func update(message tea.Msg, mdl tea.Model) (tea.Model, tea.Cmd) {
 
 func subscriptions(_ tea.Model) tea.Subs {
 	return tea.Subs{
-		"tick": tea.Every(time.Second, tickMsg{}),
+		"tick": tea.Every(time.Second, newTickMsg),
 	}
 }
 
diff --git a/examples/simple/main.go b/examples/simple/main.go
index 93eabc9..60bf791 100644
--- a/examples/simple/main.go
+++ b/examples/simple/main.go
@@ -17,7 +17,7 @@ type Model int
 
 // Messages are events that we respond to in our Update function. This
 // particular one indicates that the timer has ticked.
-type TickMsg struct{}
+type tickMsg time.Time
 
 func main() {
 	// Initialize our program
@@ -41,7 +41,7 @@ func update(msg tea.Msg, model tea.Model) (tea.Model, tea.Cmd) {
 	switch msg.(type) {
 	case tea.KeyMsg:
 		return m, tea.Quit
-	case TickMsg:
+	case tickMsg:
 		m -= 1
 		if m <= 0 {
 			return m, tea.Quit
@@ -61,6 +61,8 @@ func view(model tea.Model) string {
 // second, sends a tick, and then restarts.
 func subscriptions(_ tea.Model) tea.Subs {
 	return tea.Subs{
-		"tick": tea.Every(time.Second, TickMsg{}),
+		"tick": tea.Every(time.Second, func(t time.Time) tea.Msg {
+			return tickMsg(t)
+		}),
 	}
 }
diff --git a/examples/views/main.go b/examples/views/main.go
index 387dbd7..1021bdf 100644
--- a/examples/views/main.go
+++ b/examples/views/main.go
@@ -12,20 +12,6 @@ import (
 	"github.com/fogleman/ease"
 )
 
-// Model contains the data for our application.
-type Model struct {
-	Choice   int
-	Chosen   bool
-	Ticks    int
-	Frames   int
-	Progress float64
-	Loaded   bool
-}
-
-type tickMsg struct{}
-
-type frameMsg struct{}
-
 func main() {
 	p := tea.NewProgram(
 		initialize,
@@ -38,6 +24,32 @@ func main() {
 	}
 }
 
+// MSG
+
+type tickMsg time.Time
+
+func newTickMsg(t time.Time) tea.Msg {
+	return tickMsg(t)
+}
+
+type frameMsg time.Time
+
+func newFrameMsg(t time.Time) tea.Msg {
+	return frameMsg(t)
+}
+
+// MODEL
+
+// Model contains the data for our application.
+type Model struct {
+	Choice   int
+	Chosen   bool
+	Ticks    int
+	Frames   int
+	Progress float64
+	Loaded   bool
+}
+
 // INIT
 
 func initialize() (tea.Model, tea.Cmd) {
@@ -50,15 +62,15 @@ func subscriptions(model tea.Model) tea.Subs {
 	m, _ := model.(Model)
 	if !m.Chosen || m.Loaded {
 		return tea.Subs{
-			"tick": tea.Every(time.Second, tickMsg{}),
+			"tick": tea.Every(time.Second, newTickMsg),
 		}
 	}
 	return tea.Subs{
-		"frame": tea.Every(time.Second/60, frameMsg{}),
+		"frame": tea.Every(time.Second/60, newFrameMsg),
 	}
 }
 
-// UPDATES
+// UPDATE
 
 func update(msg tea.Msg, model tea.Model) (tea.Model, tea.Cmd) {
 	m, _ := model.(Model)
@@ -145,7 +157,7 @@ func updateChosen(msg tea.Msg, m Model) (tea.Model, tea.Cmd) {
 	return m, nil
 }
 
-// VIEWS
+// VIEW
 
 func view(model tea.Model) string {
 	m, _ := model.(Model)
diff --git a/subscriptions.go b/subscriptions.go
index a6e128d..b428d0a 100644
--- a/subscriptions.go
+++ b/subscriptions.go
@@ -4,18 +4,22 @@ import (
 	"time"
 )
 
+// NewEverMsg is used by Every to create a new message. It contains the time
+// at which the timer finished.
+type NewEveryMsg func(time.Time) Msg
+
 // Every is a subscription that ticks with the system clock at the given
-// duration
+// duration.
 //
 // TODO: make it cancelable
-func Every(duration time.Duration, msg Msg) Sub {
+func Every(duration time.Duration, newMsg NewEveryMsg) Sub {
 	return func() Msg {
 		n := time.Now()
 		d := n.Truncate(duration).Add(duration).Sub(n)
 		t := time.NewTimer(d)
 		select {
-		case <-t.C:
-			return msg
+		case now := <-t.C:
+			return newMsg(now)
 		}
 	}
 }