1. user
   1. action
      1. CLICK MOUSE
      2. TYPES CHARACTER
      3. SURFACES WINDOW
2. OS platform
   1. detection
      1. actions
         1. user
   2. generation
      1. GUI events
         1. MOUSE CLICKS
         2. KEYSTROKES
         3. PAINT EVENT
   3. determination
      1. receiver
         1. application
         2. window
   4. placement
      1. in
      2. queues
         1. application
         2. event
3. LOOP
   1. structure
      1. applications
         1. any
         2. windowed
         3. GUI
   2. purpose
      1. reading
         1. what
            1. events
            2. GUI
         2. from
            1. application's queue
      2. dispatching
         1. what
            1. OS
            2. events
   3. location
      1. thread
         1. main
            1. application
         2. UI
4. code
   1. all
   2. triggered
      1. thread
         1. from
         2. UI
   3. handlers
      1. access
         1. freely
         2. widgets