cmd/demo-progress/demo.go

@@ -21,6 +21,7 @@ var (
 	flagNumTrackers        = flag.Int("num-trackers", 13, "Number of Trackers")
 	flagShowSpeed          = flag.Bool("show-speed", false, "Show the tracker speed?")
 	flagShowSpeedOverall   = flag.Bool("show-speed-overall", false, "Show the overall tracker speed?")
+	flagShowPinned         = flag.Bool("show-pinned", false, "Show a pinned message?")
 	flagRandomFail         = flag.Bool("rnd-fail", false, "Introduce random failures in tracking")
 	flagRandomLogs         = flag.Bool("rnd-logs", false, "Output random logs in the middle of tracking")
 
@@ -33,6 +34,7 @@ var (
 		text.FgCyan,
 		text.FgWhite,
 	}
+	timeStart = time.Now()
 )
 
 func getMessage(idx int64, units *progress.Units) string {
@@ -87,6 +89,10 @@ func trackSomething(pw progress.Writer, idx int64, updateMessage bool) {
 			} else if *flagRandomFail && rand.Float64() < 0.1 {
 				tracker.MarkAsErrored()
 			}
+			pw.SetPinnedMessages(
+				fmt.Sprintf(">> Current Time: %-32s", time.Now().Format(time.RFC3339)),
+				fmt.Sprintf(">>   Total Time: %-32s", time.Now().Sub(timeStart).Round(time.Millisecond)),
+			)
 		case <-updateTicker:
 			if updateMessage {
 				rndIdx := rand.Intn(len(messageColors))
@@ -123,6 +129,7 @@ func main() {
 	pw.Style().Visibility.Time = !*flagHideTime
 	pw.Style().Visibility.TrackerOverall = !*flagHideOverallTracker
 	pw.Style().Visibility.Value = !*flagHideValue
+	pw.Style().Visibility.Pinned = *flagShowPinned
 
 	// call Render() in async mode; yes we don't have any trackers at the moment
 	go pw.Render()

progress/progress.go

@@ -24,16 +24,19 @@ var (
 type Progress struct {
 	autoStop              bool
 	done                  chan bool
-	lengthTracker         int
 	lengthProgress        int
 	lengthProgressOverall int
-	outputWriter          io.Writer
+	lengthTracker         int
 	logsToRender          []string
 	logsToRenderMutex     sync.RWMutex
 	messageWidth          int
 	numTrackersExpected   int64
+	outputWriter          io.Writer
 	overallTracker        *Tracker
 	overallTrackerMutex   sync.RWMutex
+	pinnedMessages        []string
+	pinnedMessageMutex    sync.RWMutex
+	pinnedMessageNumLines int
 	renderInProgress      bool
 	renderInProgressMutex sync.RWMutex
 	sortBy                SortBy
@@ -183,6 +186,16 @@ func (p *Progress) SetOutputWriter(writer io.Writer) {
 	p.outputWriter = writer
 }
 
+// SetPinnedMessages sets message(s) pinned above all the trackers of the
+// progress bar. This method can be used to overwrite all the pinned messages.
+// Call this function without arguments to "clear" the pinned messages.
+func (p *Progress) SetPinnedMessages(messages ...string) {
+	p.pinnedMessageMutex.Lock()
+	defer p.pinnedMessageMutex.Unlock()
+
+	p.pinnedMessages = messages
+}
+
 // SetSortBy defines the sorting mechanism to use to sort the Active Trackers
 // before rendering the. Default: no-sorting == sort-by-insertion-order.
 func (p *Progress) SetSortBy(sortBy SortBy) {

progress/progress_test.go

@@ -119,6 +119,14 @@ func TestProgress_SetOutputWriter(t *testing.T) {
 	assert.Equal(t, os.Stdout, p.outputWriter)
 }
 
+func TestProgress_SetPinnedMessages(t *testing.T) {
+	p := Progress{}
+	assert.Nil(t, p.pinnedMessages)
+
+	p.SetPinnedMessages("pin1", "pin2")
+	assert.Equal(t, []string{"pin1", "pin2"}, p.pinnedMessages)
+}
+
 func TestProgress_SetSortBy(t *testing.T) {
 	p := Progress{}
 	assert.Zero(t, p.sortBy)

progress/render.go

@@ -158,9 +158,29 @@ func (p *Progress) moveCursorToTheTop(out *strings.Builder) {
 	if p.style.Visibility.TrackerOverall && p.overallTracker != nil && !p.overallTracker.IsDone() {
 		numLinesToMoveUp++
 	}
-	if numLinesToMoveUp > 0 {
-		out.WriteString(text.CursorUp.Sprintn(numLinesToMoveUp))
+	if p.style.Visibility.Pinned {
+		numLinesToMoveUp += p.pinnedMessageNumLines
 	}
+	for numLinesToMoveUp > 0 {
+		out.WriteString(text.CursorUp.Sprint())
+		out.WriteString(text.EraseLine.Sprint())
+		numLinesToMoveUp--
+	}
+}
+
+func (p *Progress) renderPinnedMessages(out *strings.Builder) {
+	p.pinnedMessageMutex.RLock()
+	defer p.pinnedMessageMutex.RUnlock()
+
+	numLines := len(p.pinnedMessages)
+	for _, msg := range p.pinnedMessages {
+		msg = strings.TrimSpace(msg)
+		out.WriteString(p.style.Colors.Pinned.Sprint(msg))
+		out.WriteRune('\n')
+
+		numLines += strings.Count(msg, "\n")
+	}
+	p.pinnedMessageNumLines = numLines
 }
 
 func (p *Progress) renderTracker(out *strings.Builder, t *Tracker, hint renderHint) {
@@ -180,7 +200,6 @@ func (p *Progress) renderTracker(out *strings.Builder, t *Tracker, hint renderHi
 		}
 	}
 
-	out.WriteString(text.EraseLine.Sprint())
 	if hint.isOverallTracker {
 		if !t.IsDone() {
 			hint := renderHint{hideValue: true, isOverallTracker: true}
@@ -309,6 +328,11 @@ func (p *Progress) renderTrackersDoneAndActive(out *strings.Builder) {
 	p.logsToRender = nil
 	p.logsToRenderMutex.Unlock()
 
+	// render pinned messages
+	if len(trackersActive) > 0 && p.style.Visibility.Pinned {
+		p.renderPinnedMessages(out)
+	}
+
 	// sort and render the active trackers
 	for _, tracker := range trackersActive {
 		p.renderTracker(out, tracker, renderHint{})