Refactor TimeCode frame-based formatting into ITimeFormatter strategy

src/libse/Common/FixDurationLimits.cs

@@ -29,7 +29,7 @@ private void FixShortDisplayTimes(Subtitle subtitle)
             for (int i = 0; i < subtitle.Paragraphs.Count; i++)
             {
                 var p = subtitle.Paragraphs[i];
-                var displayTime = p.DurationTotalMilliseconds;
+                var displayTime = p.Duration.TotalMilliseconds;
                 if (displayTime < _minDurationMs)
                 {
                     var next = subtitle.GetParagraphOrDefault(i + 1);
@@ -65,7 +65,7 @@ private void FixLongDisplayTimes(Subtitle subtitle)
             for (int i = 0; i < subtitle.Paragraphs.Count; i++)
             {
                 var p = subtitle.Paragraphs[i];
-                var displayTime = p.DurationTotalMilliseconds;
+                var displayTime = p.Duration.TotalMilliseconds;
                 if (displayTime > _maxDurationMs)
                 {
                     p.EndTime.TotalMilliseconds = p.StartTime.TotalMilliseconds + _maxDurationMs;

src/libse/Common/Paragraph.cs

@@ -3,7 +3,7 @@
 
 namespace Nikse.SubtitleEdit.Core.Common
 {
-    public class Paragraph 
+    public class Paragraph
     {
         public int Number { get; set; }
 
@@ -13,9 +13,7 @@ public class Paragraph
 
         public TimeCode EndTime { get; set; }
 
-        public TimeCode Duration => new TimeCode(EndTime.TotalMilliseconds - StartTime.TotalMilliseconds);
-        public double DurationTotalMilliseconds => EndTime.TotalMilliseconds - StartTime.TotalMilliseconds;
-        public double DurationTotalSeconds => (EndTime.TotalMilliseconds - StartTime.TotalMilliseconds) / TimeCode.BaseUnit;
+        public TimeSpan Duration => TimeSpan.FromMilliseconds(EndTime.TotalMilliseconds - StartTime.TotalMilliseconds);
 
         public bool Forced { get; set; }
 
@@ -121,28 +119,28 @@ public double WordsPerMinute
                     return 0;
                 }
 
-                return 60.0 / DurationTotalSeconds * Text.CountWords();
+                return 60.0 / Duration.TotalSeconds * Text.CountWords();
             }
         }
 
         public double GetCharactersPerSecond()
         {
-            if (DurationTotalMilliseconds < 1)
+            if (Duration.TotalMilliseconds < 1)
             {
                 return 999;
             }
 
-            return (double)Text.CountCharacters(true) / DurationTotalSeconds;
+            return (double)Text.CountCharacters(true) / Duration.TotalSeconds;
         }
 
         public double GetCharactersPerSecond(ICalcLength calc)
         {
-            if (DurationTotalMilliseconds < 1)
+            if (Duration.TotalMilliseconds < 1)
             {
                 return 999;
             }
 
-            return (double)calc.CountCharacters(Text, true) / DurationTotalSeconds;
+            return (double)calc.CountCharacters(Text, true) / Duration.TotalSeconds;
         }
     }
 }

src/libse/Common/Subtitle.cs

@@ -622,7 +622,7 @@ public void RecalculateDisplayTime(double maxCharactersPerSecond, int index, dou
 
             p.EndTime.TotalMilliseconds = wantedEndMs <= bestEndMs ? wantedEndMs : bestEndMs;
 
-            if (p.DurationTotalMilliseconds <= 0)
+            if (p.Duration.TotalMilliseconds <= 0)
             {
                 p.EndTime.TotalMilliseconds = p.StartTime.TotalMilliseconds + 1;
             }
@@ -658,7 +658,7 @@ public void SetFixedDuration(List<int> selectedIndexes, double fixedDurationMill
 
                     p.EndTime.TotalMilliseconds = wantedEndMs <= bestEndMs ? wantedEndMs : bestEndMs;
 
-                    if (p.DurationTotalMilliseconds <= 0)
+                    if (p.Duration.TotalMilliseconds <= 0)
                     {
                         p.EndTime.TotalMilliseconds = p.StartTime.TotalMilliseconds + 1;
                     }
@@ -857,7 +857,7 @@ public void Sort(SubtitleSortCriteria sortCriteria)
                     Paragraphs = Paragraphs.OrderBy(p => p.EndTime.TotalMilliseconds).ThenBy(p => p.Number).ToList();
                     break;
                 case SubtitleSortCriteria.Duration:
-                    Paragraphs = Paragraphs.OrderBy(p => p.DurationTotalMilliseconds).ThenBy(p => p.Number).ToList();
+                    Paragraphs = Paragraphs.OrderBy(p => p.Duration.TotalMilliseconds).ThenBy(p => p.Number).ToList();
                     break;
                 case SubtitleSortCriteria.Gap:
                     var lookupDictionary = new Dictionary<string, double>();

src/libse/Common/TextEffect/KaraokeEffect.cs

@@ -17,7 +17,7 @@ public IEnumerable<Paragraph> Transform(Paragraph paragraph, SKColor color, doub
             var fontInsertIndex = CalculateColorInsertIndex(text);
             text = text.Insert(fontInsertIndex, GetColor(color));
             var result = _splitStrategy.Transform(text);
-            var duration = paragraph.DurationTotalMilliseconds - delay;
+            var duration = paragraph.Duration.TotalMilliseconds - delay;
             var durationPerSentence = duration / result.Length;
             var baseStartTime = paragraph.StartTime.TotalMilliseconds;
 

src/libse/Common/TextSplit.cs

@@ -323,12 +323,12 @@ public static Subtitle TryForWholeSentences(Subtitle inputSubtitle, string langu
 
         public static double CalcDurationToMove(Paragraph oldCurrent, Paragraph current, Paragraph next)
         {
-            if (current.DurationTotalMilliseconds < 0 || next.DurationTotalMilliseconds < 0)
+            if (current.Duration.TotalMilliseconds < 0 || next.Duration.TotalMilliseconds < 0)
             {
                 return 0;
             }
 
-            var totalDuration = current.DurationTotalMilliseconds + next.DurationTotalMilliseconds;
+            var totalDuration = current.Duration.TotalMilliseconds + next.Duration.TotalMilliseconds;
             var totalChars = current.Text.Length + next.Text.Length;
             var durChar = totalDuration / totalChars;
 

src/libse/Common/TimeCode.cs

@@ -1,4 +1,5 @@
-using Nikse.SubtitleEdit.Core.SubtitleFormats;
+using Nikse.SubtitleEdit.Core.Common.TimeFormatters;
+using Nikse.SubtitleEdit.Core.SubtitleFormats;
 using System;
 using System.Globalization;
 
@@ -160,163 +161,15 @@ public TimeSpan TimeSpan
 
         public override string ToString() => ToString(false);
 
-        public string ToString(bool localize)
-        {
-            var ts = TimeSpan;
-            var decimalSeparator = localize ? CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator : ",";
-            var s = $"{ts.Hours + ts.Days * 24:00}:{ts.Minutes:00}:{ts.Seconds:00}{decimalSeparator}{ts.Milliseconds:000}";
-
-            return PrefixSign(s);
-        }
-
-        public string ToShortString(bool localize = false)
-        {
-            var ts = TimeSpan;
-            var decimalSeparator = localize ? CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator : ",";
-            string s;
-            if (ts.Minutes == 0 && ts.Hours == 0 && ts.Days == 0)
-            {
-                s = $"{ts.Seconds:0}{decimalSeparator}{ts.Milliseconds:000}";
-
-                if (s == $"0{decimalSeparator}000")
-                {
-                    return s; // no sign
-                }
-            }
-            else if (ts.Hours == 0 && ts.Days == 0)
-            {
-                s = $"{ts.Minutes:0}:{ts.Seconds:00}{decimalSeparator}{ts.Milliseconds:000}";
-
-                if (s == $"0:00{decimalSeparator}000")
-                {
-                    return s; // no sign
-                }
-            }
-            else
-            {
-                s = $"{ts.Hours + ts.Days * 24:0}:{ts.Minutes:00}:{ts.Seconds:00}{decimalSeparator}{ts.Milliseconds:000}";
-
-                if (s == $"0:00:00{decimalSeparator}000")
-                {
-                    return s; // no sign
-                }
-            }
-
-            return PrefixSign(s);
-        }
-
-        public string ToShortStringHHMMSSFF()
-        {
-            var s = ToHHMMSSFF();
-            var pre = string.Empty;
-            if (s.StartsWith('-'))
-            {
-                pre = "-";
-                s = s.TrimStart('-');
-            }
-
-            var j = 0;
-            var len = s.Length;
-            while (j + 6 < len && s[j] == '0' && s[j + 1] == '0' && s[j + 2] == ':')
-            {
-                j += 3;
-            }
-            s = j > 0 ? s.Substring(j) : s;
-            return pre + s;
-        }
-
-        public string ToHHMMSSFF()
-        {
-            string s;
-            var ts = TimeSpan;
-            var frames = Math.Round(ts.Milliseconds / (BaseUnit / Configuration.Settings.General.CurrentFrameRate));
-            if (frames >= Configuration.Settings.General.CurrentFrameRate - 0.001)
-            {
-                var newTs = new TimeSpan(ts.Ticks);
-                newTs = newTs.Add(new TimeSpan(0, 0, 1));
-                s = $"{newTs.Days * 24 + newTs.Hours:00}:{newTs.Minutes:00}:{newTs.Seconds:00}:{0:00}";
-            }
-            else
-            {
-                s = $"{ts.Days * 24 + ts.Hours:00}:{ts.Minutes:00}:{ts.Seconds:00}:{SubtitleFormat.MillisecondsToFramesMaxFrameRate(ts.Milliseconds):00}";
-            }
-
-            return PrefixSign(s);
-        }
-
-        public string ToHHMMSS()
-        {
-            string s;
-            var ts = TimeSpan;
-            var frames = Math.Round(ts.Milliseconds / (BaseUnit / Configuration.Settings.General.CurrentFrameRate));
-            if (frames >= Configuration.Settings.General.CurrentFrameRate - 0.001)
-            {
-                var newTs = new TimeSpan(ts.Ticks);
-                newTs = newTs.Add(new TimeSpan(0, 0, 1));
-                s = $"{newTs.Days * 24 + newTs.Hours:00}:{newTs.Minutes:00}:{newTs.Seconds:00}";
-            }
-            else
-            {
-                s = $"{ts.Days * 24 + ts.Hours:00}:{ts.Minutes:00}:{ts.Seconds:00}";
-            }
-            return PrefixSign(s);
-        }
-
-        public string ToHHMMSSFFDropFrame()
-        {
-            string s;
-            var ts = TimeSpan;
-            var frames = Math.Round(ts.Milliseconds / (BaseUnit / Configuration.Settings.General.CurrentFrameRate));
-            if (frames >= Configuration.Settings.General.CurrentFrameRate - 0.001)
-            {
-                var newTs = new TimeSpan(ts.Ticks);
-                newTs = newTs.Add(new TimeSpan(0, 0, 1));
-                s = $"{newTs.Days * 24 + newTs.Hours:00}:{newTs.Minutes:00}:{newTs.Seconds:00};{0:00}";
-            }
-            else
-            {
-                s = $"{ts.Days * 24 + ts.Hours:00}:{ts.Minutes:00}:{ts.Seconds:00};{SubtitleFormat.MillisecondsToFramesMaxFrameRate(ts.Milliseconds):00}";
-            }
-            return PrefixSign(s);
-        }
+        public string ToString(bool localize) => TimeSpan.ToString(localize);
 
-        public string ToSSFF()
-        {
-            string s;
-            var ts = TimeSpan;
-            var frames = Math.Round(ts.Milliseconds / (BaseUnit / Configuration.Settings.General.CurrentFrameRate));
-            if (frames >= Configuration.Settings.General.CurrentFrameRate - 0.001)
-            {
-                s = $"{ts.Seconds + 1:00}:{0:00}";
-            }
-            else
-            {
-                s = $"{ts.Seconds:00}:{SubtitleFormat.MillisecondsToFramesMaxFrameRate(ts.Milliseconds):00}";
-            }
+        public string ToShortString(bool localize = false) => TimeSpan.ToShortString(localize);
 
-            return PrefixSign(s);
-        }
+        public string ToString(ITimeFormatter formatter) => formatter.Format(TimeSpan);
 
-        public string ToHHMMSSPeriodFF()
-        {
-            string s;
-            var ts = TimeSpan;
-            var frames = Math.Round(ts.Milliseconds / (BaseUnit / Configuration.Settings.General.CurrentFrameRate));
-            if (frames >= Configuration.Settings.General.CurrentFrameRate - 0.001)
-            {
-                var newTs = new TimeSpan(ts.Ticks);
-                newTs = newTs.Add(new TimeSpan(0, 0, 1));
-                s = $"{newTs.Days * 24 + newTs.Hours:00}:{newTs.Minutes:00}:{newTs.Seconds:00}.{0:00}";
-            }
-            else
-            {
-                s = $"{ts.Days * 24 + ts.Hours:00}:{ts.Minutes:00}:{ts.Seconds:00}.{SubtitleFormat.MillisecondsToFramesMaxFrameRate(ts.Milliseconds):00}";
-            }
-
-            return PrefixSign(s);
-        }
+        internal static string PrefixSign(string time, double totalMilliseconds) => totalMilliseconds >= 0 ? time : $"-{time.RemoveChar('-')}";
 
-        private string PrefixSign(string time) => TotalMilliseconds >= 0 ? time : $"-{time.RemoveChar('-')}";
+        private string PrefixSign(string time) => PrefixSign(time, TotalMilliseconds);
 
         public string ToDisplayString()
         {
@@ -327,7 +180,7 @@ public string ToDisplayString()
 
             if (Configuration.Settings?.General.UseTimeFormatHHMMSSFF == true)
             {
-                return ToHHMMSSFF();
+                return ToString(TimeFormatter.HhMmSsFf);
             }
 
             return ToString(true);
@@ -342,7 +195,7 @@ public string ToShortDisplayString()
 
             if (Configuration.Settings?.General.UseTimeFormatHHMMSSFF == true)
             {
-                return ToShortStringHHMMSSFF();
+                return ToString(TimeFormatter.ShortHhMmSsFf);
             }
 
             return ToShortString(true);

src/libse/Common/TimeFormatters/FrameBasedTimeFormatter.cs

@@ -0,0 +1,30 @@
+using Nikse.SubtitleEdit.Core.SubtitleFormats;
+using System;
+
+namespace Nikse.SubtitleEdit.Core.Common.TimeFormatters
+{
+    /// <summary>
+    /// Base for formatters that convert milliseconds to frames using the current frame rate,
+    /// carrying over to the next second when the frame count rounds up to the frame rate.
+    /// </summary>
+    public abstract class FrameBasedTimeFormatter : ITimeFormatter
+    {
+        public string Format(TimeSpan timeSpan)
+        {
+            var frames = Math.Round(timeSpan.Milliseconds / (TimeCode.BaseUnit / Configuration.Settings.General.CurrentFrameRate));
+            string s;
+            if (frames >= Configuration.Settings.General.CurrentFrameRate - 0.001)
+            {
+                s = FormatTime(timeSpan.Add(new TimeSpan(0, 0, 1)), 0);
+            }
+            else
+            {
+                s = FormatTime(timeSpan, SubtitleFormat.MillisecondsToFramesMaxFrameRate(timeSpan.Milliseconds));
+            }
+
+            return TimeCode.PrefixSign(s, timeSpan.TotalMilliseconds);
+        }
+
+        protected abstract string FormatTime(TimeSpan ts, int frames);
+    }
+}

src/libse/Common/TimeFormatters/HhMmSsFfDropFrameTimeFormatter.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace Nikse.SubtitleEdit.Core.Common.TimeFormatters
+{
+    /// <summary>
+    /// Formats as "HH:MM:SS;FF" (drop frame, semicolon before frames).
+    /// </summary>
+    public class HhMmSsFfDropFrameTimeFormatter : FrameBasedTimeFormatter
+    {
+        protected override string FormatTime(TimeSpan ts, int frames)
+        {
+            return $"{ts.Days * 24 + ts.Hours:00}:{ts.Minutes:00}:{ts.Seconds:00};{frames:00}";
+        }
+    }
+}

src/libse/Common/TimeFormatters/HhMmSsFfTimeFormatter.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace Nikse.SubtitleEdit.Core.Common.TimeFormatters
+{
+    /// <summary>
+    /// Formats as "HH:MM:SS:FF".
+    /// </summary>
+    public class HhMmSsFfTimeFormatter : FrameBasedTimeFormatter
+    {
+        protected override string FormatTime(TimeSpan ts, int frames)
+        {
+            return $"{ts.Days * 24 + ts.Hours:00}:{ts.Minutes:00}:{ts.Seconds:00}:{frames:00}";
+        }
+    }
+}

src/libse/Common/TimeFormatters/HhMmSsPeriodFfTimeFormatter.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace Nikse.SubtitleEdit.Core.Common.TimeFormatters
+{
+    /// <summary>
+    /// Formats as "HH:MM:SS.FF" (period before frames).
+    /// </summary>
+    public class HhMmSsPeriodFfTimeFormatter : FrameBasedTimeFormatter
+    {
+        protected override string FormatTime(TimeSpan ts, int frames)
+        {
+            return $"{ts.Days * 24 + ts.Hours:00}:{ts.Minutes:00}:{ts.Seconds:00}.{frames:00}";
+        }
+    }
+}