Restrict hidding of qsplitterhandle in qsplitter

  • Hello all,

    I wanted to give clickable feature to QSplitterHandle of QSplitter. as I wanted to perform show or hide some of the widgets in QSplitter.
    Something like the button between pdf and bookmark in pdf readers, which is drag-able ( to incress/decrees widget size ratio) and clickable too( to show/hide bookmarks) in the below screenshot.0_1554476234460_0c82bc8a-4b35-43b3-8c30-e53652b229d6-image.png.

    I have extended the QSplitterHandle to add a signal which is emited when handle is clicked (mouseReleaseEvent()). and also extended qsplitter to use above QSplitterHandle in the createHandle() of qsplitter.
    Below is the sample code of the same:

    class MySplitterHandle : public QSplitterHandle
        explicit MySplitterHandle(Qt::Orientation o, QSplitter *parent);
        void mouseReleaseEvent(QMouseEvent *) override;
    void clicked();
    class MySplitter : public QSplitter
        explicit MySplitter(QWidget* parent = nullptr);
         QSplitterHandle *createHandle()
         return new MySplitterHandle(this->orientation(),this);

    I added 2 widgets to MySplitter and made MySplitterHandle widget as 15.and I have connected the emit signal of the QSplitterHandle to a slot which hide/show (toggle) the first widget.
    Now my GUI is something like first widget, then 15 pxl QSplitterHandle and then second widget.

    when I try to hide the first widget, QSplitterHandle also get hidden along with first widget. And I am not able to get it back.
    How can I restrict QSplitterHandle to hide when hiding the first widget.

    I have tried my best to give all details so that you all can understand the issue well and guide me. Any initiative is appreciated.

  • Lifetime Qt Champion


    Do you mean like if you would have use QSplitter::setCollapsible on that widget ?

  • Yes I tried using setCollapsible false also but this also did not helped.
    In that case also when I try to hide the first widget, qsplitterhandle next to it also gets hidden. That's strange to me.

  • This may be out of context of this issue but I found something stranger.
    I was playing around with qsplitter and setOpaqueResize as false with a intention that resized event should not get called for added widgets in qsplitter. When I click on the handle ( without moving the handle), mouse click event is emitted and splitterMoved() signal is also emitted (even though handle is not moved).

    But on the contrary, when I set setOpaqueResize as true , on click of the handle without moving it, only mouse click event is triggered.

    This is very surprising to me. I am using qt5.12.

  • Lifetime Qt Champion

    It's indeed a bit surprising but there might be some filtering done on the mouse with regard to that.

    As for my question, I think I miswrote it. From your description, it seems that you are re-implementing collapsible widgets but I may have misunderstood you. Is that the case ?

  • @SGaist
    I am not trying to re-implement collapsible widgets.My intention is to use the custum qsplitterhandle hence I have overridden the 'QSplitterHandle *createHandle()' of qsplitter baseclass.

  • I used setSizes() to hide my first widget in my onSplitterHandleClicked slot. And in that slot I am also saving the splitter sizes to restore back widgets sizes when the handle is clicked again. This works fine now.

  • Something like this :

    QList<int> savedSize;
    MySplitterHandle *splitterHandle=qobject_cast<MySplitterHandle*>(splitter.handle(1));
    void handleClickedSot() //slot
        QTimer::singleShot(50,this, &Widget2::showHideWidget);
    void Widget2::showHideWidget()
            QList<int> newSize(savedSize);
            newSize[0]=0; //hide first widget

Log in to reply

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.