Improve completion panel (#110)

* More chances to cancel completions

* Fix typo

* Fix the sudden flip of the completion panel

Author: cyanzhong

MarkEditMac/Modules/Sources/TextCompletion/Internal/TextCompletionPanel.swift

@@ -35,6 +35,12 @@ final class TextCompletionPanel: NSPanel, TextCompletionPanelProtocol {
     self.backgroundColor = .clear
   }
 
+  override var canBecomeKey: Bool {
+    // We don't need the completion panel to be the key window,
+    // keyboard events are handled in the editor and redirected.
+    false
+  }
+
   override func layoutIfNeeded() {
     super.layoutIfNeeded()
 

MarkEditMac/Modules/Sources/TextCompletion/TextCompletionContext.swift

@@ -19,6 +19,7 @@ public final class TextCompletionContext {
     didSet {
       if !isPanelVisible {
         panel.orderOut(nil)
+        wasFlipped = false
       }
     }
   }
@@ -41,7 +42,7 @@ public final class TextCompletionContext {
       parentWindow.addChildWindow(panel, ordered: .above)
     }
 
-    // Don't make the list absurdly wrong
+    // Don't make the list absurdly long
     panel.updateCompletions(Array(completions.prefix(50)))
     panel.selectTop()
 
@@ -60,9 +61,10 @@ public final class TextCompletionContext {
       origin.x = parentWindow.frame.size.width - panelPadding - panelSize.width
     }
 
-    // Too close to the bottom
-    if origin.y - panelPadding < 0 {
+    // Too close to the bottom, or was already upside down during one typing session
+    if (origin.y - panelPadding < 0) || wasFlipped {
       origin.y = parentWindow.frame.height - caretRect.minY - safeArea + caretPadding
+      wasFlipped = true
     }
 
     let screenOrigin = parentWindow.convertPoint(toScreen: origin)
@@ -93,6 +95,11 @@ public final class TextCompletionContext {
     commitCompletion: commitCompletion
   )
 
+  // The flag to track whether the panel was flipped during a session,
+  // as the word gets longer, we will likely see fewer suggestions,
+  // we don't want the panel to suddenly flip in this case.
+  private var wasFlipped = false
+
   private let localizable: TextCompletionLocalizable
   private let commitCompletion: () -> Void
 }

MarkEditMac/Sources/Editor/Models/EditorDocument.swift

@@ -104,6 +104,10 @@ extension EditorDocument {
       await saveAsynchronously {
         super.save(sender)
       }
+
+      if sender != nil {
+        hostViewController?.cancelCompletion()
+      }
     }
   }
 

MarkEditMac/Sources/Main/Application/AppDelegate.swift

@@ -79,6 +79,11 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
 
 private extension AppDelegate {
   @objc private func windowDidResignKey(_ notification: Notification) {
+    // Cancel completion when an editor is no longer the key window
+    if let editor = (notification.object as? NSWindow)?.contentViewController as? EditorViewController {
+      editor.cancelCompletion()
+    }
+
     // To reduce the glitches between switching windows,
     // close openPanel once we don't have any key windows.
     if NSApp.windows.allSatisfy({ !$0.isKeyWindow }) {