Initial clickable errors in enhanced scrollbar.

HotSettings/ErrorMarginNavigator/ErrorInteractionMargin.cs

@@ -0,0 +1,149 @@
+namespace HotSettings.ErrorMarginNavigator
+{
+    using System.Collections.Generic;
+    using System.Diagnostics;
+    using System.Linq;
+    using System.Windows;
+    using System.Windows.Controls;
+    using System.Windows.Input;
+    using Microsoft.VisualStudio.Text;
+    using Microsoft.VisualStudio.Text.Editor;
+    using Microsoft.VisualStudio.Text.Tagging;
+
+    internal sealed class ErrorInteractionMargin : FrameworkElement, IWpfTextViewMargin
+    {
+        private readonly IWpfTextViewHost wpfTextViewHost;
+        private readonly IWpfTextViewMargin marginContainer;
+        private readonly ErrorInteractionMarginProvider factory;
+        private readonly ToolTip tooltip = new ToolTip();
+
+        private IWpfTextViewMargin errorMargin;
+        private bool isDisposed;
+        private ITagAggregator<IErrorTag> errorTagAggregator;
+
+        public ErrorInteractionMargin(IWpfTextViewHost wpfTextViewHost, IWpfTextViewMargin marginContainer, ErrorInteractionMarginProvider factory)
+        {
+            this.wpfTextViewHost = wpfTextViewHost;
+            this.marginContainer = marginContainer;
+            this.factory = factory;
+
+            marginContainer.VisualElement.MouseLeave += this.OnMouseLeave;
+            marginContainer.VisualElement.MouseMove += this.OnMouseMove;
+            marginContainer.VisualElement.PreviewMouseLeftButtonDown += this.OnLeftButtonDown;
+
+            this.tooltip.PlacementTarget = marginContainer.VisualElement;
+
+            // This margin only exists to hook UI input, so, hide it. Tried to avoid
+            // creating an actual FrameworkElement, but VS complains if you try to create
+            // a margin without one.
+            this.Visibility = Visibility.Collapsed;
+        }
+
+        public FrameworkElement VisualElement => this;
+
+        public double MarginSize => this.ActualWidth;
+
+        // No need to respond to options, we use the DeferCreation attribute on our provider
+        // to ensure that we are only created when the error margin is enabled.
+        public bool Enabled => true;
+
+        public void Dispose()
+        {
+            if (!this.isDisposed)
+            {
+
+                if (this.errorMargin != null)
+                {
+                    this.errorTagAggregator.Dispose();
+                }
+
+                this.marginContainer.VisualElement.MouseLeave -= this.OnMouseLeave;
+                this.marginContainer.VisualElement.MouseMove -= this.OnMouseMove;
+                this.marginContainer.VisualElement.PreviewMouseLeftButtonDown -= this.OnLeftButtonDown;
+
+                this.isDisposed = true;
+            }
+        }
+
+        public ITextViewMargin GetTextViewMargin(string marginName)
+            => string.Equals(nameof(ErrorInteractionMarginProvider), marginName) ? this : null;
+
+        private void OnMouseLeave(object sender, MouseEventArgs e) => this.Reset();
+
+        private void OnMouseMove(object sender, MouseEventArgs e)
+        {
+            if (this.TryGetErrorTagsAtLineUnderCursor(e, out var lineTags))
+            {
+                this.marginContainer.VisualElement.Cursor = Cursors.Hand;
+                this.tooltip.Content = string.Join("\r\n",
+                    lineTags.Select(tag => tag.Tag.ToolTipContent?.ToString()).Where(tag => tag != null));
+                this.tooltip.PlacementRectangle = new Rect(
+                    e.GetPosition(this.marginContainer.VisualElement),
+                    new Size(0, 0));
+                this.tooltip.IsOpen = true;
+            }
+            else
+            {
+                this.Reset();
+            }
+        }
+
+        private void OnLeftButtonDown(object sender, MouseButtonEventArgs e)
+        {
+            if (this.TryGetErrorTagsAtLineUnderCursor(e, out var lineTags))
+            {
+                // Left-most error span start or the start of the line.
+                var leftMostErrorStart = lineTags.Select(tag => tag.Span.Start.GetPoint(this.wpfTextViewHost.TextView.TextBuffer, PositionAffinity.Predecessor))
+                    .Where(start => (start != null))
+                    .OrderBy(start => start)
+                    .First().Value;
+
+                this.wpfTextViewHost.TextView.Caret.MoveTo(leftMostErrorStart);
+            }
+        }
+
+        private void Reset()
+        {
+            this.marginContainer.VisualElement.Cursor = Cursors.Arrow;
+            this.tooltip.IsOpen = false;
+        }
+
+        private bool TryGetErrorTagsAtLineUnderCursor(MouseEventArgs e, out IEnumerable<IMappingTagSpan<IErrorTag>> tags)
+        {
+            if (this.TryEnsureInitialized())
+            {
+                var mousePosition = e.GetPosition(this.errorMargin.VisualElement);
+                if ((mousePosition.X >= 0)
+                    && (mousePosition.X <= this.errorMargin.MarginSize)
+                    && this.marginContainer.VisualElement is IVerticalScrollBar scrollBar)
+                {
+                    var hoveredBufferPosition = scrollBar.GetBufferPositionOfYCoordinate(mousePosition.Y);
+                    var hoveredSnapshotLineExtent = hoveredBufferPosition.GetContainingLine().Extent;
+                    tags = this.errorTagAggregator.GetTags(hoveredSnapshotLineExtent);
+
+                    return tags.Any();
+                }
+            }
+
+            tags = Enumerable.Empty<IMappingTagSpan<IErrorTag>>();
+            return false;
+        }
+
+        private bool TryEnsureInitialized()
+        {
+            if (this.errorMargin == null)
+            {
+                this.errorMargin = this.wpfTextViewHost.GetTextViewMargin(PredefinedMarginNames.OverviewError);
+                if (this.errorMargin == null)
+                {
+                    Debug.Fail("Failed to find error margin");
+                    return false;
+                }
+
+                this.errorTagAggregator = this.factory.TagAggregatorFactoryService.CreateTagAggregator<IErrorTag>(this.wpfTextViewHost.TextView.TextBuffer);
+            }
+
+            return true;
+        }
+    }
+}

HotSettings/ErrorMarginNavigator/ErrorInteractionMarginProvider.cs

@@ -0,0 +1,32 @@
+namespace HotSettings.ErrorMarginNavigator
+{
+    using System;
+    using System.ComponentModel.Composition;
+    using Microsoft.VisualStudio.Text.Editor;
+    using Microsoft.VisualStudio.Text.Tagging;
+    using Microsoft.VisualStudio.Utilities;
+
+    [Export(typeof(IWpfTextViewMarginProvider))]
+    [Name(nameof(ErrorInteractionMarginProvider))]
+    [Order(After = PredefinedMarginNames.OverviewError)]
+    [ContentType("any")]
+    [MarginContainer(PredefinedMarginNames.VerticalScrollBar)]
+    [TextViewRole(PredefinedTextViewRoles.Interactive)]
+    [DeferCreation(OptionName = DefaultTextViewHostOptions.ShowErrorsOptionName)]
+    internal sealed class ErrorInteractionMarginProvider : IWpfTextViewMarginProvider
+    {
+        internal readonly IBufferTagAggregatorFactoryService TagAggregatorFactoryService;
+
+        [ImportingConstructor]
+        public ErrorInteractionMarginProvider(IBufferTagAggregatorFactoryService tagAggregatorFactoryService)
+        {
+            this.TagAggregatorFactoryService = tagAggregatorFactoryService
+                ?? throw new ArgumentNullException(nameof(tagAggregatorFactoryService));
+        }
+
+        public IWpfTextViewMargin CreateMargin(IWpfTextViewHost wpfTextViewHost, IWpfTextViewMargin marginContainer)
+        {
+            return new ErrorInteractionMargin(wpfTextViewHost, marginContainer, this);
+        }
+    }
+}

HotSettings/HotSettings.csproj

@@ -61,6 +61,8 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="Common\ServicesUtil.cs" />
+    <Compile Include="ErrorMarginNavigator\ErrorInteractionMargin.cs" />
+    <Compile Include="ErrorMarginNavigator\ErrorInteractionMarginProvider.cs" />
     <Compile Include="ErrorStatus\ErrorStatusTextViewCreationListener.cs" />
     <Compile Include="ErrorStatus\ErrorStatusTracker.cs" />
     <Compile Include="HotSettingsCommandFilter.cs" />