Add text formatting key commands

Tusker/Screens/Compose/MainComposeTextView.swift

@@ -59,7 +59,7 @@ struct MainComposeWrappedTextView: UIViewRepresentable {
     @State var visibilityButton: UIBarButtonItem?
     
     func makeUIView(context: Context) -> UITextView {
-        let textView = UITextView()
+        let textView = WrappedTextView()
         textView.delegate = context.coordinator
         textView.isEditable = true
         textView.backgroundColor = .clear
@@ -171,6 +171,35 @@ struct MainComposeWrappedTextView: UIViewRepresentable {
         return Coordinator(text: $text, uiState: uiState, didChange: textDidChange)
     }
     
+    class WrappedTextView: UITextView {
+        private let formattingActions = [#selector(toggleBoldface(_:)), #selector(toggleItalics(_:))]
+        
+        override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
+            if formattingActions.contains(action) {
+                return Preferences.shared.statusContentType != .plain
+            }
+            
+            return super.canPerformAction(action, withSender: sender)
+        }
+        
+        override func toggleBoldface(_ sender: Any?) {
+            (delegate as! Coordinator).applyFormat(.bold)
+        }
+        
+        override func toggleItalics(_ sender: Any?) {
+            (delegate as! Coordinator).applyFormat(.italics)
+        }
+        
+        override func validate(_ command: UICommand) {
+            super.validate(command)
+            
+            if formattingActions.contains(command.action),
+               Preferences.shared.statusContentType != .plain {
+                command.attributes.remove(.disabled)
+            }
+        }
+    }
+    
     class Coordinator: NSObject, UITextViewDelegate, ComposeAutocompleteHandler, ComposeTextViewCaretScrolling {
         weak var textView: UITextView?
         var text: Binding<String>
@@ -192,9 +221,16 @@ struct MainComposeWrappedTextView: UIViewRepresentable {
         }
         
         @objc func formatButtonPressed(_ sender: UIBarButtonItem) {
-            guard let textView = textView, textView.isFirstResponder else { return }
             let format = StatusFormat.allCases[sender.tag]
-            guard let insertionResult = format.insertionResult else { return }
+            applyFormat(format)
+        }
+        
+        func applyFormat(_ format: StatusFormat) {
+            guard let textView = textView,
+                  textView.isFirstResponder,
+                  let insertionResult = format.insertionResult else {
+                return
+            }
             
             let currentSelectedRange = textView.selectedRange
             if currentSelectedRange.length == 0 {