canPaste method

bool canPaste (TextSelectionDelegate delegate)

Whether the current Clipboard content can be pasted into the text field managed by the given delegate.

Subclasses can use this to decide if they should expose the paste functionality to the user.

Implementation 

bool canPaste(TextSelectionDelegate delegate) {
  // TODO(goderbauer): return false when clipboard is empty, https://github.com/flutter/flutter/issues/11254
  return true;
}