From b60a903b9868d15641436facf92aae819887c665 Mon Sep 17 00:00:00 2001
From: eNV25 <61089994+eNV25@users.noreply.github.com>
Date: Sat, 12 Jun 2021 02:43:12 +0000
Subject: [PATCH] Add Screen.ChannelEvents v2 (#465)

---
 console_win.go | 20 ++++++++++++++++++++
 event_test.go  | 39 +++++++++++++++++++++++++++++++++++++++
 screen.go      | 11 +++++++++++
 simulation.go  | 22 +++++++++++++++++++++-
 tscreen.go     | 22 +++++++++++++++++++++-
 5 files changed, 112 insertions(+), 2 deletions(-)

diff --git a/console_win.go b/console_win.go
index 7c57160..a901a12 100644
--- a/console_win.go
+++ b/console_win.go
@@ -343,6 +343,26 @@ func (s *cScreen) PostEvent(ev Event) error {
 	}
 }
 
+func (s *cScreen) ChannelEvents(ch chan<- Event, quit <-chan struct{}) {
+	defer close(ch)
+	for {
+		select {
+		case <-quit:
+			return
+		case <-s.stopQ:
+			return
+		case ev := <-s.evch:
+			select {
+			case <-quit:
+				return
+			case <-s.stopQ:
+				return
+			case ch <- ev:
+			}
+		}
+	}
+}
+
 func (s *cScreen) PollEvent() Event {
 	select {
 	case <-s.stopQ:
diff --git a/event_test.go b/event_test.go
index f8ede20..7908d26 100644
--- a/event_test.go
+++ b/event_test.go
@@ -68,3 +68,42 @@ func TestMouseEvents(t *testing.T) {
 		t.Errorf("Modifiers should be control")
 	}
 }
+
+func TestChannelMouseEvents(t *testing.T) {
+
+	s := mkTestScreen(t, "")
+	defer s.Fini()
+
+	s.EnableMouse()
+	s.InjectMouse(4, 9, Button1, ModCtrl)
+	evch := make(chan Event)
+	quit := make(chan struct{})
+	em := new(EventMouse)
+	go s.ChannelEvents(evch, quit)
+
+loop:
+	for {
+		select {
+		case ev := <-evch:
+			if evm, ok := ev.(*EventMouse); ok {
+				em = evm
+				close(quit)
+				break loop
+			}
+			continue
+		case <-time.After(time.Second):
+			close(quit)
+			break loop
+		}
+	}
+
+	if x, y := em.Position(); x != 4 || y != 9 {
+		t.Errorf("Mouse position wrong (%v, %v)", x, y)
+	}
+	if em.Buttons() != Button1 {
+		t.Errorf("Should be Button1")
+	}
+	if em.Modifiers() != ModCtrl {
+		t.Errorf("Modifiers should be control")
+	}
+}
diff --git a/screen.go b/screen.go
index 2d9a9ad..cbe505f 100644
--- a/screen.go
+++ b/screen.go
@@ -78,6 +78,17 @@ type Screen interface {
 	// response to a call to Clear or Flush.
 	Size() (int, int)
 
+	// ChannelEvents is an infinite loop that waits for an event and
+	// channels it into the user provided channel ch.  Closing the
+	// quit channel and calling the Fini method are cancellation
+	// signals.  When a cancellation signal is received the method
+	// returns after closing ch.
+	//
+	// This method should be used as a goroutine.
+	//
+	// NOTE: PollEvent should not be called while this method is running.
+	ChannelEvents(ch chan<- Event, quit <-chan struct{})
+
 	// PollEvent waits for events to arrive.  Main application loops
 	// must spin on this to prevent the application from stalling.
 	// Furthermore, this will return nil if the Screen is finalized.
diff --git a/simulation.go b/simulation.go
index 468aeeb..451460b 100644
--- a/simulation.go
+++ b/simulation.go
@@ -351,6 +351,26 @@ func (s *simscreen) Colors() int {
 	return 256
 }
 
+func (s *simscreen) ChannelEvents(ch chan<- Event, quit <-chan struct{}) {
+	defer close(ch)
+	for {
+		select {
+		case <-quit:
+			return
+		case <-s.quit:
+			return
+		case ev := <-s.evch:
+			select {
+			case <-quit:
+				return
+			case <-s.quit:
+				return
+			case ch <- ev:
+			}
+		}
+	}
+}
+
 func (s *simscreen) PollEvent() Event {
 	select {
 	case <-s.quit:
@@ -531,4 +551,4 @@ func (s *simscreen) Suspend() error {
 
 func (s *simscreen) Resume() error {
 	return nil
-}
\ No newline at end of file
+}
diff --git a/tscreen.go b/tscreen.go
index 49aacf1..ebd61a2 100644
--- a/tscreen.go
+++ b/tscreen.go
@@ -638,7 +638,7 @@ func (t *tScreen) drawCell(x, y int) int {
 			t.TPuts(ti.TGoto(x-1, y))
 			t.TPuts(ti.InsertChar)
 			t.cy = y
-			t.cx = x-1
+			t.cx = x - 1
 			t.cells.SetDirty(x-1, y, true)
 			_ = t.drawCell(x-1, y)
 			t.TPuts(t.ti.TGoto(0, 0))
@@ -941,6 +941,26 @@ func (t *tScreen) nColors() int {
 	return t.ti.Colors
 }
 
+func (t *tScreen) ChannelEvents(ch chan<- Event, quit <-chan struct{}) {
+	defer close(ch)
+	for {
+		select {
+		case <-quit:
+			return
+		case <-t.quit:
+			return
+		case ev := <-t.evch:
+			select {
+			case <-quit:
+				return
+			case <-t.quit:
+				return
+			case ch <- ev:
+			}
+		}
+	}
+}
+
 func (t *tScreen) PollEvent() Event {
 	select {
 	case <-t.quit: