feat: add clipboard watcher to monitor and update IO placeholder

aider/copypaste.py

@@ -0,0 +1,63 @@
+import threading
+import time
+import pyperclip
+
+class ClipboardWatcher:
+    """Watches clipboard for changes and updates IO placeholder"""
+
+    def __init__(self, io, verbose=False):
+        self.io = io
+        self.verbose = verbose
+        self.stop_event = None
+        self.watcher_thread = None
+        self.last_clipboard = None
+
+    def start(self):
+        """Start watching clipboard for changes"""
+        self.stop_event = threading.Event()
+        self.last_clipboard = pyperclip.paste()
+
+        def watch_clipboard():
+            while not self.stop_event.is_set():
+                try:
+                    current = pyperclip.paste()
+                    if current != self.last_clipboard:
+                        self.last_clipboard = current
+                        self.io.placeholder = current
+                        self.io.interrupt_input()
+                    time.sleep(0.5)
+                except Exception as e:
+                    if self.verbose:
+                        from aider.dump import dump
+                        dump(f"Clipboard watcher error: {e}")
+                    continue
+
+        self.watcher_thread = threading.Thread(target=watch_clipboard, daemon=True)
+        self.watcher_thread.start()
+
+    def stop(self):
+        """Stop watching clipboard for changes"""
+        if self.stop_event:
+            self.stop_event.set()
+        if self.watcher_thread:
+            self.watcher_thread.join()
+            self.watcher_thread = None
+            self.stop_event = None
+
+def main():
+    """Example usage of the clipboard watcher"""
+    from aider.io import InputOutput
+
+    io = InputOutput()
+    watcher = ClipboardWatcher(io, verbose=True)
+    
+    try:
+        watcher.start()
+        while True:
+            time.sleep(1)
+    except KeyboardInterrupt:
+        print("\nStopped watching clipboard")
+        watcher.stop()
+
+if __name__ == "__main__":
+    main()