sourcegit-scm · heartacker · May 9, 2026
diff --git a/src/Models/CommitGraph.cs b/src/Models/CommitGraph.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 
 using Avalonia;
@@ -62,7 +62,7 @@ public class Dot
         public List<Link> Links { get; } = [];
         public List<Dot> Dots { get; } = [];
 
-        public static CommitGraph Parse(List<Commit> commits, bool firstParentOnlyEnabled)
+        public static CommitGraph Parse(List<Commit> commits, bool firstParentOnlyEnabled, bool alwaysShowCurrentHeadOnLeft)
         {
             const double unitWidth = 12;
             const double halfWidth = 6;
@@ -75,49 +75,114 @@ public static CommitGraph Parse(List<Commit> commits, bool firstParentOnlyEnable
             var offsetY = -halfHeight;
             var colorPicker = new ColorPicker();
 
+            // 1. Pre-scan for the Grand Lineage (Trunk)
+            var headPathSHAs = new HashSet<string>();
+            string topTrunkSHA = null;
+            if (alwaysShowCurrentHeadOnLeft)
+            {
+                var head = commits.Find(x => x.IsCurrentHead);
+                if (head != null)
+                {
+                    headPathSHAs.Add(head.SHA);
+
+                    // Trace DOWN (Ancestors) via first parent
+                    string currentDown = head.SHA;
+                    for (int i = commits.IndexOf(head); i < commits.Count; i++)
+                    {
+                        if (commits[i].SHA == currentDown)
+                        {
+                            headPathSHAs.Add(currentDown);
+                            if (commits[i].Parents.Count > 0)
+                                currentDown = commits[i].Parents[0];
+                        }
+                    }
+
+                    // Trace UP (Descendants) via strict single line
+                    string currentUp = head.SHA;
+                    for (int i = commits.IndexOf(head) - 1; i >= 0; i--)
+                    {
+                        if (commits[i].Parents.Count > 0 && commits[i].Parents[0] == currentUp)
+                        {
+                            headPathSHAs.Add(commits[i].SHA);
+                            currentUp = commits[i].SHA;
+                        }
+                    }
+
+                    // Find the top-most trunk commit to anchor the Phantom Path
+                    foreach (var c in commits)
+                    {
+                        if (headPathSHAs.Contains(c.SHA))
+                        {
+                            topTrunkSHA = c.SHA;
+                            break;
+                        }
+                    }
+                }
+            }
+
+            // 2. Inject Phantom Path for Trunk at Y=0.
+            // This forces the Trunk to occupy Slot 0 (X=10) permanently, simulating an uncommitted node.
+            if (topTrunkSHA != null)
+            {
+                var phantom = new PathHelper(topTrunkSHA, false, colorPicker.Next(), new Point(10.0, offsetY));
+                phantom.IsTrunk = true;
+                unsolved.Add(phantom);
+                temp.Paths.Add(phantom.Path);
+            }
+
             foreach (var commit in commits)
             {
                 PathHelper major = null;
                 var isMerged = commit.IsMerged;
+                bool isCommitTrunk = alwaysShowCurrentHeadOnLeft && headPathSHAs.Contains(commit.SHA);
 
                 // Update current y offset
                 offsetY += unitHeight;
 
                 // Find first curves that links to this commit and marks others that links to this commit ended.
-                var offsetX = 4 - halfWidth;
-                var maxOffsetOld = unsolved.Count > 0 ? unsolved[^1].LastX : offsetX + unitWidth;
+                var maxOffsetOld = 0.0;
+                for (int i = 0; i < unsolved.Count; i++)
+                {
+                    if (unsolved[i].LastX > maxOffsetOld)
+                        maxOffsetOld = unsolved[i].LastX;
+                }
+
+                var currentOffsetX = 4 - halfWidth;
                 foreach (var l in unsolved)
                 {
+                    currentOffsetX += unitWidth;
+
                     if (l.Next.Equals(commit.SHA, StringComparison.Ordinal))
                     {
-                        if (major == null)
+                        // Only Trunk paths can claim major status for Trunk commits.
+                        bool canBeMajor = !isCommitTrunk || l.IsTrunk;
+
+                        if (major == null && canBeMajor)
                         {
-                            offsetX += unitWidth;
                             major = l;
 
                             if (commit.Parents.Count > 0)
                             {
                                 major.Next = commit.Parents[0];
-                                major.Goto(offsetX, offsetY, halfHeight);
+                                major.Goto(currentOffsetX, offsetY, halfHeight);
                             }
                             else
                             {
-                                major.End(offsetX, offsetY, halfHeight);
+                                major.End(currentOffsetX, offsetY, halfHeight);
                                 ended.Add(l);
                             }
                         }
                         else
                         {
-                            l.End(major.LastX, offsetY, halfHeight);
+                            l.End(major?.LastX ?? currentOffsetX, offsetY, halfHeight);
                             ended.Add(l);
                         }
 
                         isMerged = isMerged || l.IsMerged;
                     }
                     else
                     {
-                        offsetX += unitWidth;
-                        l.Pass(offsetX, offsetY, halfHeight);
+                        l.Pass(currentOffsetX, offsetY, halfHeight);
                     }
                 }
 
@@ -133,11 +198,10 @@ public static CommitGraph Parse(List<Commit> commits, bool firstParentOnlyEnable
                 // Otherwise, create new curve for new merged commit
                 if (major == null)
                 {
-                    offsetX += unitWidth;
-
                     if (commit.Parents.Count > 0)
                     {
-                        major = new PathHelper(commit.Parents[0], isMerged, colorPicker.Next(), new Point(offsetX, offsetY));
+                        currentOffsetX += unitWidth;
+                        major = new PathHelper(commit.Parents[0], isMerged, colorPicker.Next(), new Point(currentOffsetX, offsetY));
                         unsolved.Add(major);
                         temp.Paths.Add(major.Path);
                     }
@@ -149,7 +213,7 @@ public static CommitGraph Parse(List<Commit> commits, bool firstParentOnlyEnable
                 }
 
                 // Calculate link position of this commit.
-                var position = new Point(major?.LastX ?? offsetX, offsetY);
+                var position = new Point(major?.LastX ?? Math.Max(currentOffsetX, 10.0), offsetY);
                 var dotColor = major?.Path.Color ?? 0;
                 var anchor = new Dot() { Center = position, Color = dotColor, IsMerged = isMerged };
                 if (commit.IsCurrentHead)
@@ -187,10 +251,10 @@ public static CommitGraph Parse(List<Commit> commits, bool firstParentOnlyEnable
                         }
                         else
                         {
-                            offsetX += unitWidth;
+                            currentOffsetX += unitWidth;
 
                             // Create new curve for parent commit that not includes before
-                            var l = new PathHelper(parentHash, isMerged, colorPicker.Next(), position, new Point(offsetX, position.Y + halfHeight));
+                            var l = new PathHelper(parentHash, isMerged, colorPicker.Next(), position, new Point(currentOffsetX, position.Y + halfHeight));
                             unsolved.Add(l);
                             temp.Paths.Add(l.Path);
                         }
@@ -200,7 +264,7 @@ public static CommitGraph Parse(List<Commit> commits, bool firstParentOnlyEnable
                 // Margins & merge state (used by Views.Histories).
                 commit.IsMerged = isMerged;
                 commit.Color = dotColor;
-                commit.LeftMargin = Math.Max(offsetX, maxOffsetOld) + halfWidth + 2;
+                commit.LeftMargin = Math.Max(currentOffsetX, maxOffsetOld) + halfWidth + 2;
             }
 
             // Deal with curves haven't ended yet.
@@ -246,6 +310,7 @@ private class PathHelper
             public Path Path { get; private set; }
             public string Next { get; set; }
             public double LastX { get; private set; }
+            public bool IsTrunk { get; set; } = false;
 
             public bool IsMerged => Path.IsMerged;
 
@@ -273,9 +338,6 @@ public PathHelper(string next, bool isMerged, int color, Point start, Point to)
             /// <summary>
             ///     A path that just passed this row.
             /// </summary>
-            /// <param name="x"></param>
-            /// <param name="y"></param>
-            /// <param name="halfHeight"></param>
             public void Pass(double x, double y, double halfHeight)
             {
                 if (x > LastX)
@@ -297,9 +359,6 @@ public void Pass(double x, double y, double halfHeight)
             /// <summary>
             ///     A path that has commit in this row but not ended
             /// </summary>
-            /// <param name="x"></param>
-            /// <param name="y"></param>
-            /// <param name="halfHeight"></param>
             public void Goto(double x, double y, double halfHeight)
             {
                 if (x > LastX)
@@ -324,9 +383,6 @@ public void Goto(double x, double y, double halfHeight)
             /// <summary>
             ///     A path that has commit in this row and end.
             /// </summary>
-            /// <param name="x"></param>
-            /// <param name="y"></param>
-            /// <param name="halfHeight"></param>
             public void End(double x, double y, double halfHeight)
             {
                 if (x > LastX)
@@ -385,4 +441,4 @@ private void Add(double x, double y)
             Colors.Teal,
         ];
     }
-}
+}
diff --git a/src/Resources/Locales/en_US.axaml b/src/Resources/Locales/en_US.axaml
@@ -653,6 +653,7 @@
   <x:String x:Key="Text.Preferences.DiffMerge.Path.Placeholder" xml:space="preserve">Input path for diff/merge tool</x:String>
   <x:String x:Key="Text.Preferences.DiffMerge.Type" xml:space="preserve">Tool</x:String>
   <x:String x:Key="Text.Preferences.General" xml:space="preserve">GENERAL</x:String>
+  <x:String x:Key="Text.Preferences.General.AlwaysShowCurrentHeadOnLeft" xml:space="preserve">Always show current HEAD on the left</x:String>
   <x:String x:Key="Text.Preferences.General.Check4UpdatesOnStartup" xml:space="preserve">Check for updates on startup</x:String>
   <x:String x:Key="Text.Preferences.General.DateFormat" xml:space="preserve">Date Format</x:String>
   <x:String x:Key="Text.Preferences.General.EnableCompactFolders" xml:space="preserve">Enable compact folders in changes tree</x:String>

diff --git a/src/Resources/Locales/zh_CN.axaml b/src/Resources/Locales/zh_CN.axaml
@@ -657,6 +657,7 @@
   <x:String x:Key="Text.Preferences.DiffMerge.Path.Placeholder" xml:space="preserve">填写工具可执行文件所在位置</x:String>
   <x:String x:Key="Text.Preferences.DiffMerge.Type" xml:space="preserve">工具</x:String>
   <x:String x:Key="Text.Preferences.General" xml:space="preserve">通用配置</x:String>
+  <x:String x:Key="Text.Preferences.General.AlwaysShowCurrentHeadOnLeft" xml:space="preserve">HEAD 路径永远显示在最左边</x:String>
   <x:String x:Key="Text.Preferences.General.Check4UpdatesOnStartup" xml:space="preserve">启动时检测软件更新</x:String>
   <x:String x:Key="Text.Preferences.General.DateFormat" xml:space="preserve">日期时间格式</x:String>
   <x:String x:Key="Text.Preferences.General.EnableCompactFolders" xml:space="preserve">在变更列表树中启用紧凑文件夹模式</x:String>

diff --git a/src/ViewModels/Preferences.cs b/src/ViewModels/Preferences.cs
@@ -211,6 +211,12 @@ public string IgnoreUpdateTag
             set => SetProperty(ref _ignoreUpdateTag, value);
         }
 
+        public bool AlwaysShowCurrentHeadOnLeftInGraph
+        {
+            get => _alwaysShowCurrentHeadOnLeftInGraph;
+            set => SetProperty(ref _alwaysShowCurrentHeadOnLeftInGraph, value);
+        }
+
         public bool ShowTagsInGraph
         {
             get => _showTagsInGraph;
@@ -833,6 +839,7 @@ private bool RemoveInvalidRepositoriesRecursive(List<RepositoryNode> collection)
         private string _ignoreUpdateTag = string.Empty;
 
         private bool _showTagsInGraph = true;
+        private bool _alwaysShowCurrentHeadOnLeftInGraph = false;
         private bool _useTwoColumnsLayoutInHistories = false;
         private bool _displayTimeAsPeriodInHistories = false;
         private bool _useSideBySideDiff = false;

diff --git a/src/ViewModels/Repository.cs b/src/ViewModels/Repository.cs
@@ -1212,7 +1212,7 @@ public void RefreshCommits()
                     .Append(_uiStates.BuildHistoryParams());
 
                 var commits = await new Commands.QueryCommits(FullPath, builder.ToString()).GetResultAsync().ConfigureAwait(false);
-                var graph = Models.CommitGraph.Parse(commits, _uiStates.HistoryShowFlags.HasFlag(Models.HistoryShowFlags.FirstParentOnly));
+                var graph = Models.CommitGraph.Parse(commits, _uiStates.HistoryShowFlags.HasFlag(Models.HistoryShowFlags.FirstParentOnly), Preferences.Instance.AlwaysShowCurrentHeadOnLeftInGraph);
 
                 Dispatcher.UIThread.Invoke(() =>
                 {

diff --git a/src/Views/Preferences.axaml b/src/Views/Preferences.axaml
@@ -47,7 +47,7 @@
           <TabItem.Header>
             <TextBlock Classes="tab_header" Text="{DynamicResource Text.Preferences.General}"/>
           </TabItem.Header>
-          <Grid Margin="8" RowDefinitions="32,32,32,32,32,32,32,32,32,32,32,32,Auto" ColumnDefinitions="Auto,*">
+          <Grid Margin="8" RowDefinitions="32,32,32,32,32,32,32,32,32,32,32,32,32,Auto" ColumnDefinitions="Auto,*">
             <TextBlock Grid.Row="0" Grid.Column="0"
                        Text="{DynamicResource Text.Preferences.General.Locale}"
                        HorizontalAlignment="Right"
@@ -167,16 +167,21 @@
                       IsChecked="{Binding ShowChildren, Mode=TwoWay}"/>
 
             <CheckBox Grid.Row="10" Grid.Column="1"
+                      Height="32"
+                      Content="{DynamicResource Text.Preferences.General.AlwaysShowCurrentHeadOnLeft}"
+                      IsChecked="{Binding AlwaysShowCurrentHeadOnLeftInGraph, Mode=TwoWay}"/>
+
+            <CheckBox Grid.Row="11" Grid.Column="1"
                       Height="32"
                       Content="{DynamicResource Text.Preferences.General.EnableCompactFolders}"
                       IsChecked="{Binding EnableCompactFoldersInChangesTree, Mode=TwoWay}"/>
 
-            <CheckBox Grid.Row="11" Grid.Column="1"
+            <CheckBox Grid.Row="12" Grid.Column="1"
                       Height="32"
                       Content="{DynamicResource Text.Preferences.General.UseGitHubStyleAvatar}"
                       IsChecked="{Binding UseGitHubStyleAvatar, Mode=TwoWay}"/>
 
-            <CheckBox Grid.Row="12" Grid.Column="1"
+            <CheckBox Grid.Row="13" Grid.Column="1"
                       Height="32"
                       Content="{DynamicResource Text.Preferences.General.Check4UpdatesOnStartup}"
                       IsVisible="{x:Static s:App.IsCheckForUpdateCommandVisible}"