Widget above widget (searchBox)

[AndrzejB]

I want make search ability in my editor. If I press control+F appears widget with string to search.
Now I have QVBoxLayout with searchBar and editor and searchBar can be visible or non visible:

    plainEdit = new PlainTextEdit(this);
    sideBar = new CodeEditorSidebar(this);
    searchBar = new SearchBar(this);
    auto *vLayout = new QVBoxLayout;
    auto *hLayout = new QHBoxLayout;
    vLayout->setContentsMargins(0,0,0,0);
    vLayout->setSpacing(0);
    hLayout->setContentsMargins(0,0,0,0);
    hLayout->setSpacing(0);
    hLayout->addWidget(sideBar);
    hLayout->addWidget(plainEdit);
    searchBar->hide();
    vLayout->addWidget(searchBar);
    vLayout->addLayout(hLayout);
    setLayout(vLayout);

It has small disadvantage: if sideBar appears, editor moves down (2D down), because now are visible two elements: sideBar and editor. I prefer : sidebar appears above (3D above) editor and partially obscures editor. I have tried QStackedLayout but editor was invisible.
How do it?

[JonB]

@AndrzejB
I believe you are asking here how to place one widget on top of another widget, right? Then I would Google for qt widget on top of widget. https://stackoverflow.com/questions/28147360/qt-widget-displayed-over-other-widgets is one such hit, though I don't know if there are better ones. I think you don't want to place the two widgets on a layout because that will adjust them to not overlap.

Someone else may have a better answer.