QWidget resize to layout, после SetFixedSize

void Basic_scroll_area::animate(QWidget* need_show){
    if(!animation_locker.tryLock()){
        return;
    }
 
    QWidget* need_hide = NULL;
    for(int i = 0; i < inners_widgets.size(); i++){
        if(!inners_widgets.at(i)->isHidden()){
            need_hide = inners_widgets.at(i);
        }
    }
    if(need_hide == need_show){
        animation_locker.unlock();
        return;
    }
    need_show->setMaximumWidth(0);
    need_show->show();
 
    animation_pair.need_show = need_show;
    animation_pair.need_hide = need_hide;
    animation_timer.start(30);
}
 
void Basic_scroll_area::resizeEvent(QResizeEvent *event){
    QGroupBox::resizeEvent(event);
    if(!animation_locker.tryLock()){
        return;
    }
    for(int i = 0; i < inners_widgets.size(); i++){
        if(!inners_widgets.at(i)->isHidden()){
            this->layout()->update();
            inners_widgets.at(i)->setMaximumWidth(this->size().width());
            inners_widgets.at(i)->update();
        }
    }
    animation_locker.unlock();
}
 
void Basic_scroll_area::animation_process(){
    int offset = animation_pair.need_hide->size().width() * 0.12 + 12;
    int one = animation_pair.need_hide->width() - offset;
    int two = animation_pair.need_show->width() + offset;
 
    if(one < 0){
        one = 0;
    }
 
    if(two < 0){
        two = 0;
    }
 
    animation_pair.need_hide->setMaximumWidth(one);
    animation_pair.need_show->setMaximumWidth(two);
    if(animation_pair.need_hide->size().width() != 0){
        animation_timer.start(30);
    } else {
        animation_pair.need_hide->hide();
        animation_pair.need_show->setMaximumWidth(this->size().width());
        animation_timer.stop();
        animation_pair.need_hide = NULL;
        animation_pair.need_show = NULL;
        animation_locker.unlock();
    }
}

    if(two < 0){
        two = 0;
    }
this->layout()->update();
inners_widgets.at(i)->update();