Improve text editing exp of MarkEdit.showTextBox (#979)

Author: cyanzhong

MarkEditMac/Modules/Sources/AppKitExtensions/Foundation/NSEvent+Extension.swift

@@ -35,6 +35,7 @@ public extension NSEvent.ModifierFlags {
 
 // https://gist.github.com/eegrok/949034
 public extension UInt16 {
+  static let kVK_ANSI_A: Self = 0x00
   static let kVK_ANSI_F: Self = 0x03
   static let kVK_ANSI_I: Self = 0x22
   static let kVK_Return: Self = 0x24

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

@@ -437,16 +437,42 @@ extension EditorViewController {
   }
 
   func showTextBox(title: String?, placeholder: String?, defaultValue: String?) -> String? {
+    class TextField: NSTextField {
+      override func performKeyEquivalent(with event: NSEvent) -> Bool {
+        // The default "selectAll" is not available here
+        if event.deviceIndependentFlags == .command, event.keyCode == .kVK_ANSI_A {
+          currentEditor()?.selectAll(nil)
+          return true
+        }
+
+        return super.performKeyEquivalent(with: event)
+      }
+    }
+
     let alert = NSAlert()
     alert.messageText = title ?? ""
     alert.addButton(withTitle: Localized.General.done)
     alert.addButton(withTitle: Localized.General.cancel)
 
-    let textField = NSTextField(frame: CGRect(x: 0, y: 0, width: 256, height: 22))
+    let textField = TextField(frame: CGRect(x: 0, y: 0, width: 256, height: 22))
     textField.placeholderString = placeholder
     textField.stringValue = defaultValue ?? ""
     alert.accessoryView = textField
 
+    textBoxInputObserver = NotificationCenter.default.addObserver(
+      forName: NSWindow.didBecomeKeyNotification,
+      object: nil,
+      queue: .main
+    ) { [weak self] in
+      if let window = $0.object as? NSWindow, window == textField.window {
+        window.makeFirstResponder(textField)
+        if let observer = self?.textBoxInputObserver {
+          self?.textBoxInputObserver = nil
+          NotificationCenter.default.removeObserver(observer)
+        }
+      }
+    }
+
     return alert.runModal() == .alertFirstButtonReturn ? textField.stringValue : nil
   }
 

MarkEditMac/Sources/Editor/Controllers/EditorViewController.swift

@@ -21,6 +21,7 @@ final class EditorViewController: NSViewController {
   var initialContent: String?
   var webBackgroundColor = AppPreferences.Window.cachedBackgroundColor?.nsColor
   var localEventMonitor: Any?
+  var textBoxInputObserver: Any?
   var writingToolsObservation: NSKeyValueObservation?
   var safeAreaObservation: NSKeyValueObservation?
   var userDefinedMenuItems = [EditorMenuItem]()