feat.数字时钟，白板功能修复

LanMountainDesktop.Tests/WhiteboardWidgetLayoutSyncTests.cs

@@ -0,0 +1,155 @@
+using Avalonia;
+using Avalonia.Media;
+using LanMountainDesktop.Views.Components;
+using Xunit;
+
+namespace LanMountainDesktop.Tests;
+
+public sealed class WhiteboardWidgetLayoutSyncTests
+{
+    [Fact]
+    public void ResolveViewportSize_PrefersViewportRootSize()
+    {
+        var resolution = WhiteboardWidget.ResolveViewportSize(
+            viewportRootSize: new Size(320, 240),
+            canvasBorderSize: new Size(200, 160),
+            widgetSize: new Size(100, 80),
+            currentCellSize: 48,
+            baseWidthCells: 2);
+
+        Assert.Equal(new Size(320, 240), resolution.Size);
+        Assert.Equal("ViewportRoot", resolution.Source);
+        Assert.False(resolution.IsFallback);
+    }
+
+    [Fact]
+    public void ResolveViewportSize_FallsBackToCanvasBorderBeforeCellSize()
+    {
+        var resolution = WhiteboardWidget.ResolveViewportSize(
+            viewportRootSize: new Size(0, 0),
+            canvasBorderSize: new Size(260, 180),
+            widgetSize: new Size(100, 80),
+            currentCellSize: 48,
+            baseWidthCells: 2);
+
+        Assert.Equal(new Size(260, 180), resolution.Size);
+        Assert.Equal("CanvasBorder", resolution.Source);
+        Assert.False(resolution.IsFallback);
+    }
+
+    [Fact]
+    public void ResolveViewportSize_UsesCellSizeFallbackOnlyWhenLayoutIsUnavailable()
+    {
+        var resolution = WhiteboardWidget.ResolveViewportSize(
+            viewportRootSize: new Size(0, 0),
+            canvasBorderSize: new Size(1, 1),
+            widgetSize: new Size(0, 0),
+            currentCellSize: 48,
+            baseWidthCells: 2);
+
+        Assert.Equal(new Size(96, 96), resolution.Size);
+        Assert.Equal("Fallback", resolution.Source);
+        Assert.True(resolution.IsFallback);
+    }
+
+    [Fact]
+    public void ToOpaqueInkColor_ForcesColorPickerAlphaToVisibleInk()
+    {
+        var color = Color.FromArgb(0, 20, 40, 60);
+
+        var inkColor = WhiteboardWidget.ToOpaqueInkColor(color);
+
+        Assert.Equal((byte)255, inkColor.Alpha);
+        Assert.Equal((byte)20, inkColor.Red);
+        Assert.Equal((byte)40, inkColor.Green);
+        Assert.Equal((byte)60, inkColor.Blue);
+    }
+
+    [Fact]
+    public void WhiteboardWidget_DefinesDeferredViewportLayoutSynchronization()
+    {
+        var source = ReadRepositoryFile("LanMountainDesktop", "Views", "Components", "WhiteboardWidget.axaml.cs");
+        var synchronizeSource = ExtractMethodSource(source, "SynchronizeViewportLayout");
+
+        Assert.Contains("ViewportRoot.SizeChanged += OnViewportRootSizeChanged", source);
+        Assert.Contains("QueueViewportLayoutSync(\"attached-loaded\")", source);
+        Assert.Contains("DispatcherPriority.Loaded", source);
+        Assert.Contains("ResolveViewportSize(", source);
+        Assert.DoesNotContain("QueueNoteSave(", synchronizeSource);
+    }
+
+    [Fact]
+    public void WhiteboardWidget_RestoresInkInputAfterColorPopupCloses()
+    {
+        var source = ReadRepositoryFile("LanMountainDesktop", "Views", "Components", "WhiteboardWidget.axaml.cs");
+        var restoreSource = ExtractMethodSource(source, "RestoreInkInputAfterToolPopup");
+
+        Assert.Contains("ColorPickerPopup.Closed += OnColorPickerPopupClosed", source);
+        Assert.Contains("ColorPickerPopup.Closed -= OnColorPickerPopupClosed", source);
+        Assert.Contains("ToOpaqueInkColor(e.NewColor)", source);
+        Assert.Contains("SetToolMode(WhiteboardToolMode.Pen)", restoreSource);
+        Assert.Contains("SynchronizeViewportLayout(reason)", restoreSource);
+        Assert.Contains("InkCanvas.Focus", restoreSource);
+    }
+
+    [Fact]
+    public void WhiteboardWidget_ColorPickerDoesNotPersistTransparentInk()
+    {
+        var source = ReadRepositoryFile("LanMountainDesktop", "Views", "Components", "WhiteboardWidget.axaml.cs");
+        var colorChangedSource = ExtractMethodSource(source, "OnColorPickerColorChanged");
+
+        Assert.DoesNotContain("color.A", colorChangedSource);
+        Assert.DoesNotContain("e.NewColor.A", colorChangedSource);
+        Assert.Contains("byte.MaxValue", source);
+    }
+
+    private static string ReadRepositoryFile(params string[] segments)
+    {
+        var directory = new DirectoryInfo(AppContext.BaseDirectory);
+        while (directory is not null)
+        {
+            var candidate = Path.Combine(new[] { directory.FullName }.Concat(segments).ToArray());
+            if (File.Exists(candidate))
+            {
+                return File.ReadAllText(candidate);
+            }
+
+            if (File.Exists(Path.Combine(directory.FullName, "LanMountainDesktop.slnx")))
+            {
+                break;
+            }
+
+            directory = directory.Parent;
+        }
+
+        throw new FileNotFoundException($"Could not locate repository file '{Path.Combine(segments)}'.");
+    }
+
+    private static string ExtractMethodSource(string source, string methodName)
+    {
+        var methodIndex = source.IndexOf($"private void {methodName}(", StringComparison.Ordinal);
+        Assert.True(methodIndex >= 0, $"Could not locate method '{methodName}'.");
+
+        var braceIndex = source.IndexOf('{', methodIndex);
+        Assert.True(braceIndex >= 0, $"Could not locate method body for '{methodName}'.");
+
+        var depth = 0;
+        for (var i = braceIndex; i < source.Length; i++)
+        {
+            if (source[i] == '{')
+            {
+                depth++;
+            }
+            else if (source[i] == '}')
+            {
+                depth--;
+                if (depth == 0)
+                {
+                    return source.Substring(methodIndex, i - methodIndex + 1);
+                }
+            }
+        }
+
+        throw new InvalidOperationException($"Could not extract method '{methodName}'.");
+    }
+}