c# - How to find out if the caret exists [in opera]? -

i'm trying solve following task: have opera browser , want find out, whether caret (text cursor) exist @ time. example, click on address bar, , want know caret blinking now. click on empty place on page , know there no caret exists.

in other words want define text element in focus now.

i know how solve task in many applications, of them uses standard windows controls such edit, can obtain focused window , check it's class winapi.

in other applications, controls rendering without native windows, can obtain automation ui.

but regret opera has 1 main window , doesn't provide access ui automation technology.

so, know how approach goal?)

edit:

thanks eric brown, solution of problem:

// consoleformsaa.cpp: определяет точку входа для консольного приложения. //  #include "stdafx.h" #include <oleacc.h> #include <iostream>  #pragma comment (lib, "oleacc.lib")  void processcaretpos(hwnd hwnd);  int _tmain(int argc, _tchar* argv[]) {      (;;)     {         // active toplevel window         hwnd hwnd = getforegroundwindow();          // current thread         dword currentthreadid = getcurrentthreadid();          dword targetthreadid, targetprocessid;          // target process , thread         targetthreadid = getwindowthreadprocessid(hwnd, &targetprocessid);           // attach current thread target thread messaging queue         bool attached = attachthreadinput(currentthreadid, targetthreadid, true);          // что это даст? Мы участвуем в обработке сообщений того потока         // и все сис. вызовы, которые мы сделаем, будут посланы от имени того потока.         if (attached)         {             try             {                 // focused window handle (focused child of toplevel window)                 hwnd targetwindow = getfocus();                  // procedure                  processcaretpos(targetwindow);             }             catch(...) {;}              attachthreadinput(currentthreadid, targetthreadid, false);         }          sleep(1000);     }     return 0; }  //  void processcaretpos(hwnd hwnd) {     iaccessible *pacccaret = null;      variant varcaret;     rect rccaret;     varcaret.vt = vt_i4;     varcaret.lval = childid_self;      if (succeeded(accessibleobjectfromwindow(hwnd, objid_caret, iid_iaccessible, (void **)&pacccaret)))     {         hresult hr = pacccaret->acclocation( &rccaret.left, &rccaret.top, &rccaret.right, &rccaret.bottom, varcaret);          if (!hr)         {             std::cout << "caret positon: " << rccaret.left << " " << rccaret.top << " " << rccaret.right << " " << rccaret.bottom << "\n";         }         else             std::cout << "there nothing carets" << "\n";           pacccaret->release();     } } 

you're out of luck. however, if opera uses system caret (which might not; ie doesn't, example), can try using msaa query system caret location:

iaccessible *pacccaret = null;  variant varcaret; rect rccaret; varcaret.vt = vt_i4; varcaret.lval = childid_self;  if (succeeded(accessibleobjectfromwindow(hwnd, objid_caret, iid_iaccessible, (void **)&pacccaret))) {      hr = pacccaret->acclocation( &rccaret.left, &rccaret.top, &rccaret.right, &rccaret.bottom, varcaret);       pacccaret->release(); }