3 ms·

What if the OS only sent key-up events to a window if it also received the corresponding key-down event?

• jackewiehose 6y ago
  Then we wouldn't have this conversation.
• dmurray 6y ago
  Then you'd lose useful functionality like dragging a file from your file manager to an application window to open it there.
  • efreak 6y ago
    That's your mouse button, not a keyboard key. Although modifier keys occasionally are used, what's important here is the state of those keys (ctrl for copy, shift/alt or whatever for shortcut); nothing happens when you release them.
    • dmurray 6y ago
      You can do it with arrow keys, too. I remember doing this all the time back on Windows 3.1 and I'm sure it's still used now especially by people with disabilities. Anyway, there's a way to fix this: send a reference to the key-down event when you send the key-up event. Then the receiving window can determine if it cares about it or not. If this is a security hole, send a reference to the window where the key-up event was sent instead.