Use Accessibility API's for copying selected text and use copy action as a fallback

VoiceInk/Services/SelectedTextService.swift

@@ -1,15 +1,83 @@
 import Foundation
 import AppKit
-class SelectedTextService {
-    // Private pasteboard type to avoid clipboard history pollution
-    private static let privatePasteboardType = NSPasteboard.PasteboardType("com.prakashjoshipax.VoiceInk.transient")
+import ApplicationServices
 
+class SelectedTextService {
     static func fetchSelectedText() -> String? {
+        guard ensureAccessibilityPermission() else {
+            return nil
+        }
+
+        let strategies: [() -> String?] = [
+            getSelectedTextViaAccessibility,
+            getSelectedTextViaKeyboardCopy
+        ]
+
+        for fetch in strategies {
+            if let text = fetch(), !text.isEmpty {
+                return text
+            }
+        }
+
+        return nil
+    }
+
+    private static func getSelectedTextViaAccessibility() -> String? {
+        let systemWideElement = AXUIElementCreateSystemWide()
+
+        var focusedElement: AnyObject?
+        let focusedResult = AXUIElementCopyAttributeValue(
+            systemWideElement,
+            kAXFocusedUIElementAttribute as CFString,
+            &focusedElement
+        )
+
+        guard focusedResult == .success, let focusedElement else {
+            return nil
+        }
+
+        let element = focusedElement as! AXUIElement
+
+        if let selectedText = stringAttribute(kAXSelectedTextAttribute as CFString, of: element) {
+            return selectedText
+        }
+
+        guard
+            let selectedRange = rangeAttribute(kAXSelectedTextRangeAttribute as CFString, of: element),
+            let value = stringAttribute(kAXValueAttribute as CFString, of: element),
+            let textRange = Range(selectedRange, in: value)
+        else {
+            return nil
+        }
+
+        let substring = String(value[textRange])
+        return substring.isEmpty ? nil : substring
+    }
+
+    private static func getSelectedTextViaKeyboardCopy() -> String? {
+        return readSelectedTextUsingCopyAction {
+            let source = CGEventSource(stateID: .hidSystemState)
+            let cmdDown = CGEvent(keyboardEventSource: source, virtualKey: 0x37, keyDown: true)
+            cmdDown?.flags = .maskCommand
+            let cDown = CGEvent(keyboardEventSource: source, virtualKey: 0x08, keyDown: true)
+            cDown?.flags = .maskCommand
+            let cUp = CGEvent(keyboardEventSource: source, virtualKey: 0x08, keyDown: false)
+            cUp?.flags = .maskCommand
+            let cmdUp = CGEvent(keyboardEventSource: source, virtualKey: 0x37, keyDown: false)
+
+            cmdDown?.post(tap: .cghidEventTap)
+            cDown?.post(tap: .cghidEventTap)
+            cUp?.post(tap: .cghidEventTap)
+            cmdUp?.post(tap: .cghidEventTap)
+
+            return true
+        }
+    }
+
+    private static func readSelectedTextUsingCopyAction(_ copyAction: () -> Bool) -> String? {
 
         let pasteboard = NSPasteboard.general
         let originalClipboardText = pasteboard.string(forType: .string)
-
-        // Save original clipboard content (all UTIs with their data)
         let originalPasteboardItems = pasteboard.pasteboardItems?.map { item in
             item.types.reduce(into: [NSPasteboard.PasteboardType: Data]()) { acc, type in
                 if let data = item.data(forType: type) {
@@ -18,34 +86,35 @@ class SelectedTextService {
             }
         }
 
+        defer {
+            restorePasteboard(
+                pasteboard,
+                items: originalPasteboardItems,
+                string: originalClipboardText
+            )
+        }
+
         // Clear clipboard to prepare for selection detection
         pasteboard.clearContents()
-        
-        // Simulate Cmd+C to copy any selected text
-        let source = CGEventSource(stateID: .hidSystemState)
-        let cmdDown = CGEvent(keyboardEventSource: source, virtualKey: 0x37, keyDown: true)
-        cmdDown?.flags = .maskCommand
-        let cDown = CGEvent(keyboardEventSource: source, virtualKey: 0x08, keyDown: true)
-        cDown?.flags = .maskCommand
-        let cUp = CGEvent(keyboardEventSource: source, virtualKey: 0x08, keyDown: false)
-        cUp?.flags = .maskCommand
-        let cmdUp = CGEvent(keyboardEventSource: source, virtualKey: 0x37, keyDown: false)
 
-        cmdDown?.post(tap: .cghidEventTap)
-        cDown?.post(tap: .cghidEventTap)
-        cUp?.post(tap: .cghidEventTap)
-        cmdUp?.post(tap: .cghidEventTap)
-        
+        guard copyAction() else { return nil }
+
         // Wait for copy operation to complete
         Thread.sleep(forTimeInterval: 0.1)
 
         // Read the copied text
-        let selectedText = pasteboard.string(forType: .string)
+        return pasteboard.string(forType: .string)
+    }
 
-        // Restore original clipboard content
+    private static func restorePasteboard(
+        _ pasteboard: NSPasteboard,
+        items: [[NSPasteboard.PasteboardType: Data]]?,
+        string: String?
+    ) {
         pasteboard.clearContents()
-        if let originalItems = originalPasteboardItems, !originalItems.isEmpty {
-            let restoredItems: [NSPasteboardItem] = originalItems.compactMap { dataMap in
+
+        if let items, !items.isEmpty {
+            let restoredItems: [NSPasteboardItem] = items.compactMap { dataMap in
                 guard !dataMap.isEmpty else { return nil }
                 let item = NSPasteboardItem()
                 for (type, data) in dataMap {
@@ -53,15 +122,65 @@ class SelectedTextService {
                 }
                 return item
             }
+
             if !restoredItems.isEmpty {
                 pasteboard.writeObjects(restoredItems)
-            } else if let originalClipboardText {
-                _ = pasteboard.setString(originalClipboardText, forType: .string)
+                return
             }
-        } else if let originalClipboardText {
-            _ = pasteboard.setString(originalClipboardText, forType: .string)
         }
 
-        return selectedText
+        if let string {
+            _ = pasteboard.setString(string, forType: .string)
+        }
+    }
+
+    private static func stringAttribute(_ attribute: CFString, of element: AXUIElement) -> String? {
+        var value: AnyObject?
+        let result = AXUIElementCopyAttributeValue(element, attribute, &value)
+
+        guard result == .success, let value else {
+            return nil
+        }
+
+        if let text = value as? String {
+            return text
+        }
+
+        if let attributed = value as? NSAttributedString {
+            return attributed.string
+        }
+
+        return nil
+    }
+
+    private static func rangeAttribute(_ attribute: CFString, of element: AXUIElement) -> NSRange? {
+        var value: AnyObject?
+        let result = AXUIElementCopyAttributeValue(element, attribute, &value)
+
+        guard result == .success, let value else {
+            return nil
+        }
+
+        guard CFGetTypeID(value) == AXValueGetTypeID() else {
+            return nil
+        }
+
+        let rangeValue = value as! AXValue
+        guard AXValueGetType(rangeValue) == .cfRange else {
+            return nil
+        }
+
+        var range = CFRange()
+        let success = AXValueGetValue(rangeValue, .cfRange, &range)
+
+        guard success else {
+            return nil
+        }
+
+        return NSRange(location: range.location, length: range.length)
+    }
+
+    private static func ensureAccessibilityPermission() -> Bool {
+        AXIsProcessTrustedWithOptions(nil)
     }
 }