Work with QTabWidget

fomikadze

Hi! I'm developing the simple application and use QTabWidget in it. I want to make the dynamic adding/closing of the tabs. With setTabsClosable() - I've add the close buttons on the tabs, but the don't react on clicks. How can I add signal and slot to that buttons?

lgeyer

QTabWidget emits the tabCloseRequested() signal, which can be connected to to actually remove the tab using removeTab(). Be aware that the page widget itself is not deleted automatically.

fomikadze

Thanks
And is there any ways to get the number of the tab, on which close button was presse, or I need to figure it by my own?

lgeyer

"QTabWidget::tabCloseRequested()":http://qt-project.org/doc/qt-4.8/qtabwidget.html#tabCloseRequested

fomikadze

I've added the tabCloseRequested() signal to the removeTab() slot, but I don't understand how it works. Because when I write
@connect(tabWidget, SIGNAL(tabCloseRequested(index)), this, SLOT(removeTab(index)));@
where "index" is the index of the page, it gives me the mistake "no such SIGNAL tabCloseRequested(index)", but when I live as
@connect(tabWidget, SIGNAL(tabCloseRequested(int)), this, SLOT(removeTab(int)));@
it woks. But now when I press on close button, it closes all tabs that follows the tab I'm closing.
How does it work?

lgeyer

A signal, as well as a slot, is always identified by its signature, <code>tabCloseRequested(int)</code>. You cannot pass actual values, <code>tabCloseRequested(index)</code>.

Although beeing ordinary methods, slots have to be marked as such, <code>public slots:</code>, which is not true for QTabWidget::removeTab() and you cannot connect to.

The initial post might have been a bit misleading. You can connect to the tabCloseRequested() signal, but not to removeTab(), due to not beeing a slot.

The common use case is to add a (private) slot to the embracing class, which is responsible for closing the tab and deleting the page widget.
@
class MainWindow : public QMainWindow
{
Q_OBJECT

public:
MainWindow() : QMainWindow()
{
tabWidget_ = new QTabWidget;
tabWidget_->addTab(new QLabel("TabA"), "TabA");
tabWidget_->addTab(new QLabel("TabB"), "TabB");
tabWidget_->addTab(new QLabel("TabC"), "TabC");
tabWidget_->setTabsClosable(true);

    connect(tabWidget_, SIGNAL(tabCloseRequested(int)), this, SLOT(closeTab_(int)));

    setCentralWidget(tabWidget_);
}

private slots:
void closeTab_(int index)
{
// Remove the tab using removeTab(). Be aware that the
// page widget itself is not deleted!
tabWidget_->removeTab(index);

    // OR (do NOT do both)

    // Delete the page widget, which automatically removes
    // the tab as well.
    delete tabWidget_->widget(index);
}

private:
QTabWidget *tabWidget_;
};
@

fomikadze

I did that, but when I delete one tab, following tabs are deleted too!
I don't understand why such thing appears. I have almost the same code as you, but the promblome is still there. Maybe I miss some thing?

fomikadze

I've found the problem! ;)
@tabWidget_->removeTab(index);@ - here we remove the tab from the tabWidget_, and indexes of tabs are updated. Now we have anothe tab on the plase of the removed one.
So, when I was trying to delete the page widget itself, in fact I was deleting the next tab. That on that moment was on the place of the removed tab.

Thanks for help!!!

lgeyer

Well, that's what I meant with <code>do NOT do both</code> ;-)

You're welcome.

deepak.jangra

Hi all,

I am using tab widget in my application and I need to update the tab text color in order to show notification to the user. But I dint any way to do this. My requirement is to show alert to the user for the tab which is not currently selected. I have try many things to implement this behaviour but get failed every time. I have also use the qtabbar stylesheet but even that not provide any way to update the random tab style as there are only limited stated provided by the QTabbar stylesheet.
I also find a method setTabTextColor in QTabbar class but dont find any way to use it. Please suggest me the way to implement the desired behaviour as I have spent much time on this.

Thanks in advance
Deepak Jangra

lgeyer

QTabWidget::tabBar() (and thus QTabBar::setTabTextColor()) is protected, so you'll need to subclass QTabWidget in order to make it publicly available.
@
class TabWidget : public QTabWidget
{
public:
TabWidget(QWidget *parent = 0) : QTabWidget(parent) {}

void setTabTextColor(int index, const QColor &color)
{
    tabBar()->setTabTextColor(index, color);
}

};

...

TabWidget *tabWidget = new TabWidget;
tabWidget->setTabTextColor(0, Qt::red);
@