Restrict hidding of qsplitterhandle in qsplitter

[NoumanYosuf]

Hello all,

PROBLEM STATMENT :
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..

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
{
public:
    explicit MySplitterHandle(Qt::Orientation o, QSplitter *parent);
    void mouseReleaseEvent(QMouseEvent *) override;
signal:
void clicked();
};

class MySplitter : public QSplitter
{
public:
    explicit MySplitter(QWidget* parent = nullptr);
protected:
     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.

ISSUE:
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.

[NoumanYosuf]

Something like this :

QList<int> savedSize;
MySplitterHandle *splitterHandle=qobject_cast<MySplitterHandle*>(splitter.handle(1));
    connect(splitterHandle,SIGNAL(Clicked()),this,SLOT(handleClickedSot()));

void handleClickedSot() //slot
{
    QTimer::singleShot(50,this, &Widget2::showHideWidget);
}

void Widget2::showHideWidget()
{
    m_ShowHideFlag=!m_ShowHideFlag;
    if(m_ShowHideFlag)
    {
        savedSize=splitter.sizes();
        QList<int> newSize(savedSize);
        newSize[0]=0; //hide first widget
        splitter.setSizes(newSize);
    }
    else
    {
        splitter.setSizes(savedSize);
    }
}

[SGaist]

Hi,

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

[NoumanYosuf]

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.

[NoumanYosuf]

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.

[SGaist]

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 ?

[NoumanYosuf]

@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.

[NoumanYosuf]

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.

[NoumanYosuf]

Something like this :

QList<int> savedSize;
MySplitterHandle *splitterHandle=qobject_cast<MySplitterHandle*>(splitter.handle(1));
    connect(splitterHandle,SIGNAL(Clicked()),this,SLOT(handleClickedSot()));

void handleClickedSot() //slot
{
    QTimer::singleShot(50,this, &Widget2::showHideWidget);
}

void Widget2::showHideWidget()
{
    m_ShowHideFlag=!m_ShowHideFlag;
    if(m_ShowHideFlag)
    {
        savedSize=splitter.sizes();
        QList<int> newSize(savedSize);
        newSize[0]=0; //hide first widget
        splitter.setSizes(newSize);
    }
    else
    {
        splitter.setSizes(savedSize);
    }
}