You are going to send me to the .... excuse me for not explaining better.

This is the psedo-code I have :
Qt Code: 
  1. A_panel() // constructor type 1
  2. { call generic_constructor}
  3. A_panel() // constructor type 2
  4. { call generic_constructor}
  5.  
  6. generic_constructor() {
  7.    set some variables;
  8.    i_am_ready=false;
  9.    launch a timer of 1 milisecond interval to check if the parent_widget is already visible.it calls timer_slot_function
  10. }
  11. the timer_slot_function () {
  12. if (my_parent_visible)   place_things() ;
  13. }
  14.  
  15. place_things() {
  16. I measure the size and other things of widget parent to set the size and position of this custom_widget
  17. i_am_ready=true; // finally I set 'i_am_ready' to true.
  18. }
  19.  
  20. resize_event() {
  21. qDebug()<<"Resize_event";
  22. if (i_am_ready) place_things } 
  23. }
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Due to some reasons I dont want to execute 'place_things' on undesirable resize_events . I control this using 'i_am_ready' variable.

I have this code a_panel is the custom widget)
Qt Code: 
  1. A_panel * a_panel = new A_panel(a_widget, parent, sizable );    
  2.  
  3.     a_panel->resize(parent->width()*float(tam_100_or_0)/100, parent->height()*float(tam_100_or_0)/100);
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And I discover I have a resize_event (showed by the qdebug) before all the last code is executed.
( that is: genericcontructor-timer-placethings).

Ok, this is due to the timer... i know.

I have just found that the problem is the timer i use...
Sorry again .