Labels:text | screenshot | diagram | font | parallel | number | line | document | receipt OCR: keybd event mouse event System Input Queue Journal Playback Hook The system's asynchronous keystate array Filter Function is updated as keyboard messages are put into the virtualized input queue. Putting Messages into the Virtual The thread's synchronous keystate array Input Queue (via user actions or a is updated just before keyboard messages Journal Playback hook filter are sent to the keyboard hook filter function. function) Virtual Input Queue Getting Messages out of the LEGEND Virtual Input Queue (via Get Message or Peek Messagel Mouse Hook Hardware Hook Executed by system threads Filter Function Filter Function Executed by the thread that installed Journal Record Hook the hook Filter Function Executed by the thread that called Get Message or Peak Message Keyboard Hook Filter Function . The CBT hook filter function is called with the following CBT hook codes for hardware events: CBT Hook Filter Function HCBT_QS: Called if WM_QUEUESYNC is played back by a journal playback hook filter function. HCBT_CLICKSKIPPED: Called if a mouse message Get Message Hook " . is retrieved and a mouse hook is currently installed. HCBT_KEYSKIPPED: Called if a keyboard message Filter Function is retrieved and a keyboard hook is currently installed. * * The GetMessage hook filter function is called only if any installed keyboard, mouse, or hardware hooks do not return 1 to reject the event. Figure 6.1 Hardware input message filtering.
