It's not easy, but I try to explain:

The window is created as a library that is used as object in the main application.

Before the arrival of a message from the main aplicacatio, updated a number of areas of the window:

Qt Code: 
  1. switch (consoleId) {
  2.         case 1:
  3.         {
  4.             itsRoleWindow->writeTF_roleConsole01(strdup(static_cast<char*> (roleActiveName[consoleId - 1])));
  5.             break;
  6.         }
  7.         case 2:
  8.         {
  9.             itsRoleWindow->writeTF_roleConsole02(strdup(static_cast<char*> (roleActiveName[consoleId - 1])));
  10.             break;
  11.         }
  12.        [...]
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Let's see what happens in the window:

Qt Code: 
  1. void roleWindow::writeTF_roleConsole01(char* c)
  2. {
  3.   GetForm()->setText(c,1); 
  4. }
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The class that receives it does this:

Qt Code: 
  1. void impl_role::setText(char* c, int i)
  2. {
  3.   emit(signalSetText(c,i));
  4. }
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Qt Code: 
  1. connect( this, SIGNAL(signalSetText(char*, int)), this, SLOT(slotSetText(char*, int)) );
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Qt Code: 
  1. void impl_role::slotSetText(char* c, int i)
  2. {
  3.   switch(i) {
  4.    case 1: TF_roleConsole01->setText(c); break;
  5.    case 2: TF_roleConsole02->setText(c); break;
  6.    case 3: TF_roleConsole03->setText(c); break;
  7.    case 4: TF_roleConsole04->setText(c); break;
  8.    case 5: TF_roleConsole05->setText(c); break;
  9.    case 6: TF_roleConsole06->setText(c); break;
  10.    case 7: TF_roleConsole07->setText(c); break;
  11.    default: break;
  12.   };
  13.   delete (c);
  14. }
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with each TF_roleConsole0x really is ui-> TF_roleConsole0x;

Therefore, writes directly to each window Textfield.

I hope I explained more or less.