Fix color scheme for completion panel (#115)

Author: cyanzhong

MarkEditMac/Modules/Sources/TextCompletion/TextCompletionContext.swift

@@ -24,6 +24,15 @@ public final class TextCompletionContext {
     }
   }
 
+  public var appearance: NSAppearance? {
+    get {
+      panel.appearance
+    }
+    set {
+      panel.appearance = newValue
+    }
+  }
+
   public var fromIndex: Int = 0
   public var toIndex: Int = 0
   public var selectedText: String { panel.selectedCompletion() }

MarkEditMac/Sources/Editor/Controllers/EditorViewController+Completion.swift

@@ -73,6 +73,7 @@ extension EditorViewController {
 extension EditorViewController {
   func updateCompletionPanel(isVisible: Bool) {
     let changed = completionContext.isPanelVisible != isVisible
+    completionContext.appearance = view.window?.appearance
     completionContext.isPanelVisible = isVisible
 
     if changed {