Basics. How to use <a href> equivalent to display new content?

Andrey Volodin

no, it wont change pages with Combo Box http://imgur.com/kkudCQI
though of 9 comboboxes one now changes page

the_

What exactly did you try? This screenshot does not help much as it is the Designer View...

Andrey Volodin

shall I refrain from using of Qt Designer in favor of text editor?
https://pastebin.com/x9qLmd6z

Andrey Volodin

to where should I paste the fragment:
QComboBox *pageComboBox = new QComboBox;
pageComboBox->addItem(tr("Page 1"));
pageComboBox->addItem(tr("Page 2"));
pageComboBox->addItem(tr("Page 3"));
connect(pageComboBox, SIGNAL(activated(int)),
stackedWidget, SLOT(setCurrentIndex(int)));
?

jsulm

@Andrey-Volodin Depends on where you have this stacked widget. If it is in main window, then in mainwindow constructor. If you're using Designer then no need to use this code snippet: add the combo box in designer and connect signal and slot in Designer.

Andrey Volodin

thank you for your reply
it is getting working and now it works finally with the combobox

Andrey Volodin

QPushButton and setCurrentIndex(int) slot.

No, I can not use the above. The mainwindow constructor which seems to be a designer doesn't seem to have that option in a list for a pushbutton item.

jsulm

@Andrey-Volodin Well, setCurrentIndex(int) needs a parameter, so you cannot connect the push button directly. But you can add a slot in main window, connect it to the push button and in this slot call setCurrentIndex(int).

Andrey Volodin

https://github.com/AndreV84/pilot
it seems that there should be 4 objects defined:
button , the main window, stack widget , as in
http://doc.qt.io/qt-4.8/signalsandslots.html
how to add trigger? comparator? logical + or -?

jsulm

@Andrey-Volodin said in Basics. How to use <a href> equivalent to display new content?:

how to add trigger

What trigger do you mean?

Andrey Volodin

on button press a call is passed to a slot

how to make the slot to change stackWidget page on the button press

https://en.wikipedia.org/wiki/Event-driven_programming
https://en.wikipedia.org/wiki/Schmitt_trigger
it seems that the button and the stackwidget are always in separate sets, despite a new slot and a new signal created

jsulm

@Andrey-Volodin Not sure I understand the problem. Did you read http://doc.qt.io/qt-5.8/signalsandslots.html ?
You just define a slot in lets say MainWindow:

// Header
class MainWindow:
{
private slots:
    void onButtonPressed();
};

// cpp
MainWindow::MainWindow()
{
    connect(ui->pushButton, SIGNAL(clicked(bool)), this, SLOT(onButtonPressed()));
}

void MainWindow::onButtonPressed()
{
    int pageToShow = 1; // you need to find out what the next index is
    ui->stackedWidget->setCurrentIndex(pageToShow);
}

"it seems that the button and the stackwidget are always in separate sets, despite a new slot and a new signal created" - sorry, I don't understand. What do you mean by "sets"?

Andrey Volodin

https://en.wikipedia.org/wiki/Set_(mathematics)
I used to read: http://doc.qt.io/qt-4.8/signalsandslots.html , which seems to be a mirror of the link http://doc.qt.io/qt-5.8/signalsandslots.html .
I tried to perform the task in Designer, without sources editing manually. It doesnt appear to seem possible.

jsulm

@Andrey-Volodin
https://en.wikipedia.org/wiki/Set_(mathematics) - still don't understand what you mean with sets in this particular context.
In designer you can connect existing signals/slots. You can even define a new slot in Designer, but you have to implement it by yourself.
That means: add slot to main window in Designer, connect this slot to the clicked() signal of your push button in Designer, implement the slot in main window.

Andrey Volodin

@jsulm said in Basics. How to use <a href> equivalent to display new content?:

In designer you can connect existing signals/slots. You can even define a new slot in Designer, but you have to implement it by yourself.
That means: add slot to main window in Designer, connect this slot to the clicked() signal of your push button in Designer, implement the slot in main window.

The above is what I have done ;
How to connect the stackWidgets call with the above?
What do you mean saying "implement the slot in mine window" ?

jsulm

@Andrey-Volodin You mean setCurrentIndex()? I did it in the example above.
What I mean with implement: write the body of the slot since Designer does not know what you want to do in the slot. From my example above:

// You have to write this code even if you added the slot in Designer
void MainWindow::onButtonPressed()
{
    int pageToShow = 1; // you need to find out what the next index is
    ui->stackedWidget->setCurrentIndex(pageToShow);
}