ci_view: Fix screen freeze

fmuellner · prarit · commit 33de0c3cfd61 · 2020-12-23T08:52:46.000-05:00
After the tcell/v2 update, any key press during `lab ci view` results
in a lock up. It is unclear whether the changes in input handling on
the tcell side are intentional, but we can address the issue by making
the channel that notifies about input events asynchronous and ensure
that we don't overrun its queue.
diff --git a/cmd/ci_view.go b/cmd/ci_view.go
@@ -72,7 +72,7 @@ Feedback Encouraged!: https://github.com/zaquestion/lab/issues`,
 
 		boxes = make(map[string]*tview.TextView)
 		jobsCh := make(chan []*gitlab.Job)
-		inputCh := make(chan struct{})
+		inputCh := make(chan struct{}, 1)
 
 		screen, err := tcell.NewScreen()
 		if err != nil {
@@ -98,17 +98,22 @@ Feedback Encouraged!: https://github.com/zaquestion/lab/issues`,
 }
 
 func inputCapture(a *tview.Application, root *tview.Pages, navi navigator, inputCh chan struct{}) func(event *tcell.EventKey) *tcell.EventKey {
+	queueInputUpdate := func() {
+		if len(inputCh) == 0 {
+			inputCh <- struct{}{}
+		}
+	}
 	return func(event *tcell.EventKey) *tcell.EventKey {
 		if event.Rune() == 'q' || event.Key() == tcell.KeyEscape {
 			switch {
 			case modalVisible:
 				modalVisible = !modalVisible
 				root.HidePage("yesno")
-				inputCh <- struct{}{}
+				queueInputUpdate()
 			case logsVisible:
 				logsVisible = !logsVisible
 				root.HidePage("logs-" + curJob.Name)
-				inputCh <- struct{}{}
+				queueInputUpdate()
 				a.ForceDraw()
 			default:
 				a.Stop()
@@ -119,7 +124,7 @@ func inputCapture(a *tview.Application, root *tview.Pages, navi navigator, input
 			curJob = navi.Navigate(jobs, event)
 			root.SendToFront("jobs-" + curJob.Name)
 			// update jobs view on input changes
-			inputCh <- struct{}{}
+			queueInputUpdate()
 		}
 		switch event.Rune() {
 		case 'c':
@@ -130,7 +135,7 @@ func inputCapture(a *tview.Application, root *tview.Pages, navi navigator, input
 			}
 			curJob = job
 			root.RemovePage("logs-" + curJob.Name)
-			inputCh <- struct{}{}
+			queueInputUpdate()
 			a.ForceDraw()
 		case 'p', 'r':
 			if modalVisible {
@@ -161,15 +166,15 @@ func inputCapture(a *tview.Application, root *tview.Pages, navi navigator, input
 					}
 				})
 			root.AddAndSwitchToPage("yesno", modal, false)
-			inputCh <- struct{}{}
+			queueInputUpdate()
 			a.ForceDraw()
 			return nil
 		case 't':
 			logsVisible = !logsVisible
 			if !logsVisible {
 				root.HidePage("logs-" + curJob.Name)
 			}
-			inputCh <- struct{}{}
+			queueInputUpdate()
 			a.ForceDraw()
 			return nil
 		case 'T':
@@ -198,10 +203,10 @@ func inputCapture(a *tview.Application, root *tview.Pages, navi navigator, input
 					}
 				}
 			})
-			inputCh <- struct{}{}
+			queueInputUpdate()
 			return nil
 		}
-		inputCh <- struct{}{}
+		queueInputUpdate()
 		return event
 	}
 }
