c++ - Comparing QWidgets -

how can compare qwidgets? lets have list , change sizes of widgets qpushbutton:

for example, there function or method this?

qlist<qlayoutitem *> itemlist;  if(itemlist->items->type() == qpushbutton) {   item.setgeometry(newrect); } 

there several ways this, actually. qobject::inherits() one:

for (int = 0; < itemlist.size(); ++i) {     if (itemlist[i]->inherits("qpushbutton")) {         itemlist[i]->setgeometry(newrect);     } } 

another way using qobject_cast, recommend. returns null pointer if object not inherit (directly or not) class cast to:

for (int = 0; < itemlist.size(); ++i) {     if (qobject_cast<qpushbutton*>(itemlist[i])) {         itemlist[i]->setgeometry(newrect);     } } 

note qobject_cast not need rtti support enabled in compiler.

and there's of course standard c++ dynamic_cast need rtti support enabled:

for (int = 0; < itemlist.size(); ++i) {     if (dynamic_cast<qpushbutton*>(itemlist[i])) {         itemlist[i]->setgeometry(newrect);     } } 

another method appear ok @ first glance, should not used in case, qmetaobject::classname(). not use this, because you'll false negatives qpushbutton subclasses.

the reason recommend qobject_cast because allows compiler check typename. important when changing name of class. compiler isn't able check when using string-based qobject::inherits() function, code continue compile without problems won't work @ runtime.