#include "stdafx.h"
#include <windows.h>

BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam)
{
  // There are too many windows on the screen, actually.
  // We are interested in the visible ones only.
  if (IsWindowVisible(hwnd)) {
    static const char ReplaceFrom[] = "Oskom Client";
    static const char ReplaceTo[]   = "Ultima Online";
    const int ReplaceFromLen = sizeof(ReplaceFrom) - 1;
    const int ReplaceToLen = sizeof(ReplaceTo) - 1;
    
    // Get the original window's title and its length.
    int OriginalBufferLen = GetWindowTextLength(hwnd) + 1;
    char* OriginalTitle = new char[OriginalBufferLen];
    int OriginalTitleLen = GetWindowText(hwnd, OriginalTitle, OriginalBufferLen);
    
    // First, we check if the window's title contains no less characters
    // than the string we are looking for (that is ReplaceFrom string).
    // This check seems to be redundant, since we compare the strings later on, but
    // we have to check the return value of the function GetWindowText to be non-zero.
    // Then, we check if the window's title begins with the string ReplaceFrom.
    if (OriginalTitleLen >= ReplaceFromLen &&
        strncmp(OriginalTitle, ReplaceFrom, ReplaceFromLen) == 0) {
      // Composing a new title:
      // it will start with the string ReplaceTo instead of ReplaceFrom.
      int ChangedTitleLen = OriginalTitleLen - ReplaceFromLen + ReplaceToLen;
      char* ChangedTitle = new char[ChangedTitleLen + 1];
      strncpy(ChangedTitle, ReplaceTo, ReplaceToLen);
      strcpy(ChangedTitle + ReplaceToLen, OriginalTitle + ReplaceFromLen);
      
      // Set the new title.
      SetWindowText(hwnd, ChangedTitle);
      
      delete [] ChangedTitle;
    }
    
    delete [] OriginalTitle;
  }
  
  return TRUE;
}

int _tmain(int argc, _TCHAR* argv[])
{
  // Enumerate all top-level windows on the screen.
  // Function EnumWindowsProc will be called for every window.
  EnumWindows(&EnumWindowsProc, 0);
  
  return 0;
}