replace one widget with another on a layout with a button

[marlenet15]

I am trying to replace a qscrollarea with a qgroupbox which contains two qlabels that are images of charts. I have tried the following but nothing happens.

QGroupBox *videoChart = new QGroupBox;
QHBoxLayout *videoChartLayout = new QHBoxLayout;
videoChartLayout->addWidget(leftVideos2);
videoChartLayout->addWidget(rightVideos2);
if(startTest->clicked())
{
    videoChartLayout->removeWidget(instructionsScrollArea1);
    videoChartLayout->addWidget(charts,0,Qt::AlignHCenter);
}
else
{
    videoChartLayout->addWidget(instructionsScrollArea1);
}

videoChartLayout->setStretch(0,2);
videoChartLayout->setStretch(1,2);
videoChartLayout->setStretch(2,6);
videoChart->setLayout(videoChartLayout);

[mrjj]

Hi
Is that the actual code ?

videoChart = new QGroupBox;

but you add
addWidget(charts,0,Qt::AlignHCenter);

and what is startTest->clicked() ?

[marlenet15]

@mrjj when I press that button, i would like for the charts to replace the QScrollArea that is there right now. And that is not the whole whole code that it is the section I am trying to say when I click this button replace this with this

[mrjj]

@marlenet15

Hi. I understand what you want to happen, but code seems
strange. (to me)

the
if(startTest->clicked())

Confused me a bit if startTest is a button. ?

the "clicked" is a signal and should be connected to a slot that will
be called when the buttons is clicked.
calling it directly will not work.

Please place a QPushbutton on the form, then right click it and
select Go to Slot, then select released().
you will then go to a function.
Put you code here.

you can also connect stuff in code:
http://doc.qt.io/qt-5/signalsandslots.html

[marlenet15]

I have created everything from scratch so nothing is in the ui file. I have tried using SIGNAL and SLOTS but it didn't seem to recognize the widgets I wanted to replace

[mrjj]

@marlenet15
well in the sample you call the groupbox for videoChart
but in the addwidget you have "charts" ?
I would expect it to be videoChart ?

Well lets assume you replace function is called
ReplaceNow and lives in mainwindow
and your button is called startTest
then you should have to have a statement like

connect( startTest, SIGNAL(clicked()), this, SLOT(ReplaceNow()));

for the button to do anything when clicked.
Not sure if that is your issue ?

[marlenet15]

@mrjj chart is also a QGroupBox which I didn't include in the code. Sorry. Ok so how will it know what exact widgets to replace? That is my question. Would it be something like this?

void ReplaceNow()
{
 videoChartLayout->removeWidget(instructionsScrollArea1);
 videoChartLayout->addwidget(charts,0,Qt::AlignHCenter);
}

[mrjj]

@marlenet15
Ahh. ok.
yes then you would use the pointer to the widget.
Like instructionsScrollArea1 if that was the one you used to insert it with in first place?

[SGaist]

Hi,

Sounds rather like a job for QStackedLayout

[marlenet15]

@mrjj I did this but it says that the variables are not declared on the scope

void ReplaceNow()
{
 *videoChartLayout->removeWidget(*instructionsScrollArea1);
 *videoChartLayout->addwidget(charts,0,Qt::AlignHCenter);
}

[mrjj]

@marlenet15

instructionsScrollArea1 and ReplaceNow() should be
in same object or same file at least.

that what scope means.

so where is instructionsScrollArea1 declared and where
is void ReplaceNow() ?

Also
the * in
removeWidget(*instructionsScrollArea1);
is wrong.

If possible,post whole code here and its easier for us to help.