pvQLayoutHbox(p,ID_MAIN_WIDGET,-1);                   // horizontally layout all widgets

pvQLayoutVbox(p,layout1,ID_MAIN_WIDGET);              // create a vertical box layout 
                                                      // parent is main widget

pvQLayoutHbox(p,layout2,layout1);                     // create a horizontal box layout
                                                      // parent is layout1

pvAddWidgetOrLayout(p,ID_MAIN_WIDGET,layout1,-1,-1);  // put layout1 into the main layout
pvAddWidgetOrLayout(p,layout1,upperWidget,-1,-1);     // add the upperWidget
pvAddWidgetOrLayout(p,layout1,layout2,-1,-1);         // add layout2 below the upperWidget
pvAddWidgetOrLayout(p,layout2,leftWidget,-1,-1);      // add the reamining widgets from left to right
pvAddWidgetOrLayout(p,layout2,centerWidget,-1,-1);
pvAddWidgetOrLayout(p,layout2,rightWidget,-1,-1);