feat: show full commit messages on subject hover

src/Views/CommitSubjectPresenter.cs

@@ -3,17 +3,36 @@
 using System.Collections.Specialized;
 using System.Globalization;
 using System.Text.RegularExpressions;
+using System.Threading.Tasks;
 
 using Avalonia;
 using Avalonia.Collections;
 using Avalonia.Controls;
 using Avalonia.Input;
+using Avalonia.Interactivity;
 using Avalonia.Media;
+using Avalonia.VisualTree;
 
 namespace SourceGit.Views
 {
     public partial class CommitSubjectPresenter : Control
     {
+        public static readonly StyledProperty<string> FullMessageProperty =
+            AvaloniaProperty.Register<CommitSubjectPresenter, string>(nameof(FullMessage));
+
+        public string FullMessage
+        {
+            get => GetValue(FullMessageProperty);
+            set => SetValue(FullMessageProperty, value);
+        }
+
+        public CommitSubjectPresenter()
+        {
+            ToolTip.SetShowDelay(this, 1000);
+            ToolTip.SetBetweenShowDelay(this, -1);
+            ToolTip.AddToolTipOpeningHandler(this, OnToolTipOpening);
+        }
+
         public static readonly StyledProperty<FontFamily> FontFamilyProperty =
             AvaloniaProperty.Register<CommitSubjectPresenter, FontFamily>(nameof(FontFamily));
 
@@ -175,6 +194,11 @@ protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs chang
                 _needRebuildInlines = true;
                 GenerateInlineElements();
                 InvalidateVisual();
+                UpdateMessageToolTip();
+            }
+            else if (change.Property == FullMessageProperty)
+            {
+                UpdateMessageToolTip();
             }
             else if (change.Property == IssueTrackersProperty)
             {
@@ -239,6 +263,73 @@ protected override void OnPointerExited(PointerEventArgs e)
             ClearHoveredIssueLink();
         }
 
+        protected override void OnDataContextChanged(EventArgs e)
+        {
+            base.OnDataContextChanged(e);
+
+            ToolTip.SetIsOpen(this, false);
+            ToolTip.SetIsOpen(_messageToolTipTarget ?? this, false);
+            _fullMessageTask = null;
+            ClearHoveredIssueLink();
+            UpdateMessageToolTip();
+        }
+
+        protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
+        {
+            base.OnAttachedToVisualTree(e);
+
+            // The presenter can be narrower than its cell (for example, with refs after the subject).
+            // Keep the message tooltip on the whole cell, and issue-link tooltips on the presenter.
+            _messageToolTipTarget = this.FindAncestorOfType<DataGridCell>();
+            if (_messageToolTipTarget != null)
+            {
+                ToolTip.SetIsOpen(this, false);
+                ToolTip.SetTip(this, null);
+                ToolTip.SetShowDelay(_messageToolTipTarget, 1000);
+                ToolTip.SetBetweenShowDelay(_messageToolTipTarget, -1);
+                ToolTip.AddToolTipOpeningHandler(_messageToolTipTarget, OnToolTipOpening);
+            }
+
+            UpdateMessageToolTip();
+        }
+
+        protected override void OnDetachedFromVisualTree(VisualTreeAttachmentEventArgs e)
+        {
+            ToolTip.SetIsOpen(this, false);
+            ClearHoveredIssueLink();
+            if (_messageToolTipTarget != null)
+            {
+                ToolTip.SetIsOpen(_messageToolTipTarget, false);
+                ToolTip.RemoveToolTipOpeningHandler(_messageToolTipTarget, OnToolTipOpening);
+                ToolTip.SetTip(_messageToolTipTarget, null);
+                _messageToolTipTarget = null;
+            }
+
+            base.OnDetachedFromVisualTree(e);
+        }
+
+        private async void OnToolTipOpening(object sender, CancelRoutedEventArgs e)
+        {
+            if (e.Cancel || _lastHover != null || !string.IsNullOrEmpty(FullMessage))
+                return;
+
+            if (DataContext is not Models.Commit commit ||
+                this.FindAncestorOfType<Histories>()?.DataContext is not ViewModels.Histories histories)
+                return;
+
+            var task = _fullMessageTask ??= histories.GetCommitFullMessageAsync(commit);
+            var message = await task;
+            if (_fullMessageTask == task && !string.IsNullOrEmpty(message))
+                _messageToolTip.Text = message;
+        }
+
+        private void UpdateMessageToolTip()
+        {
+            _messageToolTip.Text = string.IsNullOrEmpty(FullMessage) ? Subject : FullMessage;
+            if (_messageToolTipTarget != null || _lastHover == null)
+                ToolTip.SetTip(_messageToolTipTarget ?? this, string.IsNullOrEmpty(Subject) ? null : _messageToolTip);
+        }
+
         private void OnIssueTrackersChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
             _needRebuildInlines = true;
@@ -401,10 +492,14 @@ private void ClearHoveredIssueLink()
         {
             if (_lastHover != null)
             {
+                ToolTip.SetIsOpen(this, false);
                 ToolTip.SetTip(this, null);
                 SetCurrentValue(CursorProperty, Cursor.Parse("Arrow"));
                 _lastHover = null;
             }
+
+            if (!ReferenceEquals(ToolTip.GetTip(_messageToolTipTarget ?? this), _messageToolTip))
+                UpdateMessageToolTip();
         }
 
         [GeneratedRegex(@"`.*?`")]
@@ -425,6 +520,9 @@ public Inline(double x, FormattedText text, Models.InlineElement elem)
         }
 
         private string _subject = string.Empty;
+        private readonly TextBlock _messageToolTip = new() { MaxWidth = 640, TextWrapping = TextWrapping.Wrap };
+        private Control _messageToolTipTarget = null;
+        private Task<string> _fullMessageTask = null;
         private AvaloniaList<Models.IssueTracker> _issueTrackers = null;
         private Models.InlineElementCollector _elements = new();
         private Models.InlineElement _lastHover = null;

src/Views/InteractiveRebase.axaml

@@ -170,6 +170,7 @@
                                               Foreground="{DynamicResource Brush.FG1}"
                                               LinkForeground="{DynamicResource Brush.Link}"
                                               Subject="{Binding Subject}"
+                                              FullMessage="{Binding FullMessage}"
                                               IssueTrackers="{Binding $parent[v:InteractiveRebase].((vm:InteractiveRebase)DataContext).IssueTrackers}"
                                               FontWeight="Normal"
                                               Opacity="{Binding Action, Mode=OneWay, Converter={x:Static c:InteractiveRebaseActionConverters.ToOpacity}}"

tests/CommitSubjectTooltipChecks/CommitSubjectTooltipChecks.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="../../src/SourceGit.csproj" />
+    <PackageReference Include="Avalonia.Headless" Version="11.3.22" />
+  </ItemGroup>
+</Project>

tests/CommitSubjectTooltipChecks/Program.cs

@@ -0,0 +1,97 @@
+using Avalonia;
+using Avalonia.Collections;
+using Avalonia.Controls;
+using Avalonia.Controls.Templates;
+using Avalonia.Headless;
+using Avalonia.Media;
+using Avalonia.Threading;
+using SourceGit.Views;
+
+AppBuilder.Configure<Application>()
+    .UseSkia()
+    .UseHeadless(new AvaloniaHeadlessPlatformOptions { UseHeadlessDrawing = false })
+    .SetupWithoutStarting();
+Application.Current.Styles.Add(new Avalonia.Themes.Fluent.FluentTheme());
+
+var subject = new CommitSubjectPresenter
+{
+    Subject = "Fix #123",
+    FullMessage = "Fix #123\n\nThe complete commit message body.",
+    FontFamily = FontFamily.Default,
+    CodeFontFamily = FontFamily.Default,
+    FontSize = 14,
+    Width = 120,
+    Height = 26,
+    HorizontalAlignment = Avalonia.Layout.HorizontalAlignment.Left,
+    IssueTrackers = new AvaloniaList<SourceGit.Models.IssueTracker>
+    {
+        new() { RegexString = @"#(\d+)", URLTemplate = "https://example.com/issues/$1" }
+    }
+};
+var cell = new DataGridCell
+{
+    Content = subject,
+    Template = new FuncControlTemplate<DataGridCell>((_, _) => new Border
+    {
+        Background = Brushes.Transparent,
+        Child = new Avalonia.Controls.Presenters.ContentPresenter { Name = "PART_ContentPresenter", Content = subject }
+    })
+};
+var row = new Grid { ColumnDefinitions = new ColumnDefinitions("600,100"), Height = 30 };
+row.Children.Add(cell);
+var neighbor = new Border { Background = Brushes.Transparent };
+Grid.SetColumn(neighbor, 1);
+row.Children.Add(neighbor);
+var window = new Window { Width = 700, Height = 100, Content = row };
+window.Show();
+Pump(100);
+AvaloniaHeadlessPlatform.ForceRenderTimerTick();
+var y = row.Bounds.Y + 15;
+window.MouseMove(new Point(650, y));
+Pump(50);
+window.MouseMove(new Point(580, y));
+Pump(300);
+Check(!ToolTip.GetIsOpen(cell), "short hover over blank cell space does not open tooltip");
+Pump(900);
+Check(ToolTip.GetIsOpen(cell), "blank space at the far end of SUBJECT opens tooltip");
+Check(ToolTip.GetTip(cell) is TextBlock { Text: var message } && message == subject.FullMessage,
+    "cell tooltip contains the full multiline commit message");
+
+window.MouseMove(new Point(32, y));
+Pump(1200);
+Check(ToolTip.GetIsOpen(subject), "issue-link URL tooltip opens over the link");
+Check(ToolTip.GetTip(subject) is string link && link == "https://example.com/issues/123",
+    "issue links retain their URL tooltip");
+window.MouseMove(new Point(580, y));
+Pump(1200);
+Check(ToolTip.GetTip(subject) == null && ToolTip.GetIsOpen(cell),
+    "moving from an issue link back to blank space restores the message tooltip");
+
+window.MouseMove(new Point(650, y));
+Pump(100);
+Check(!ToolTip.GetIsOpen(cell), "moving into another column closes the message tooltip");
+window.MouseMove(new Point(580, y));
+Pump(1200);
+subject.DataContext = new object();
+subject.Subject = "Another commit";
+subject.FullMessage = "Another commit\n\nAnother body";
+Check(!ToolTip.GetIsOpen(cell), "recycling a row closes the cell tooltip");
+Check(((TextBlock)ToolTip.GetTip(cell)).Text == subject.FullMessage, "recycled row replaces previous message");
+
+row.Children.Remove(cell);
+Check(ToolTip.GetTip(cell) == null, "detaching the presenter clears the cell tooltip");
+window.Close();
+
+static void Check(bool value, string description)
+{
+    if (!value)
+        throw new InvalidOperationException(description);
+    Console.WriteLine($"PASS: {description}");
+}
+
+static void Pump(int milliseconds)
+{
+    var frame = new DispatcherFrame();
+    DispatcherTimer.RunOnce(() => frame.Continue = false, TimeSpan.FromMilliseconds(milliseconds));
+    Dispatcher.UIThread.PushFrame(frame);
+}

tests/CommitSubjectTooltipChecks/README.md

@@ -0,0 +1,5 @@
+# Commit subject tooltip checks
+
+Run `dotnet run --project tests/CommitSubjectTooltipChecks/CommitSubjectTooltipChecks.csproj`.
+
+These headless UI checks use a deliberately narrow subject presenter inside a wider SUBJECT cell, matching layouts with badges after the subject. They verify delayed full-message tooltips over blank cell space, issue-link URL tooltips, dismissal when entering another column, and cleanup when a row is recycled or detached.