How to get usesScrollButtons buttons to scroll tabs when it has many tabs For MAC?

[SGaist]

Hi,

What version of Qt are you using ?
On what version of macOS ?

Can you provide a minimal compilable example that shows that behaviour ?

[AndyS]

I think that this is because the style does not support it, so if you are using the macOS style you won't get the buttons. Try running your application with -style fusion and then it should show up.

[Yash001]

@SGaist Thank you for taking interest in my question.

I am using Qt 5.11.0 and MacOS version is 10.13.5.

Here I put separate function using QTabBar.

QWidget* TestClass::getwidget(){
    static QWidget *w = 0;
    
    if (w) {
        return w;
    }
    
    w = new QWidget();
    
    auto *lay = (new QVBoxLayout(w));
    lay->setContentsMargins(0,0,0,0);
    lay->setSpacing(0);
    
    QPushButton *addNewButton = nullptr;
    QPushButton *tileButton = nullptr;
    
    QTabBar *tabBar = nullptr;
    
    
    QFrame *tabFrame = new QFrame();
    auto *tabFrameLay = new QHBoxLayout(tabFrame);
    tabFrameLay->setContentsMargins(0,0,0,0);
    tabFrameLay->setSpacing(0);
    
    tabFrameLay->addWidget(tabBar = new QTabBar);
    tabFrameLay->addWidget(addNewButton = new QPushButton("+"));
    tabFrameLay->addStretch(1);
    tabFrameLay->addWidget(tileButton = new QPushButton("View All Graphs"));
    lay->addWidget(tabFrame);
    
    tabBar->setExpanding(false);
    tabBar->setMovable(true);
    //tabBar->setUsesScrollButtons(true);
    
    static int tabIndex = 0;
    QObject::connect(addNewButton, &QPushButton::clicked, [=]() {
        tabBar->insertTab(tabIndex, "---------------TabName----123456789");
        tabBar->setCurrentIndex(tabIndex);
        tabIndex++;
    });
    
    return w;
}

Pic from windows

pic from MAC

[Yash001]

@AndyS Thank you for direction. I am sorry, May be it is silly question. But I don't about -style fusion. What is -style fusion? How can I use it?

[AndyS]

@Yash001 I suggest you have a look at http://doc.qt.io/qt-5/qstyle.html as this will give more details. But the quick version is to just start your application with the "-style fusion" arguments.

[Yash001]

@AndyS Thank you I will go in more detail.

[Yash001]

Hi @AndyS,

I am still stuck in same issue, as per your guideline, and from reading documents.

The style of the entire application can be set using the QApplication::setStyle() function. It can also be specified by the user of the application, using the -style command-line option:

I create my own style for QToolButton with help GUI.css file, and I applied to application with help of ApplyStyle() function.

I am calling ApplyStyle() function is from constructor.

ApplyStyle() function definition.

void MainWindow::ApplyStyle() {

    QFile f("./GUI.css");

    if(!f.open(QIODevice::ReadOnly))
        return;

   QString newStyleSheet = f.readAll();
	
    qobject_cast<QApplication *>(QApplication::instance())->setStyleSheet(newStyleSheet);

    f.close();
}

GUI.css file.

QTabBar QToolButton { /* the scroll buttons are tool buttons */
    background:light yellow;
}

QTabBar QToolButton::right-arrow { /* the arrow mark in the tool buttons */
border:5px solid red;
}

QTabBar QToolButton::left-arrow {
border:5px solid green;
}

Still Mac System does not recognized the usesScrollButtons.

I checked ```tabbar->usesScrollButtons();``, and It is return false on Mac.

[SGaist]

That's because the macOS style doesn't implement them. As stated in the QTabBar documentation: By default the value is style dependant.. It's not a bug it's a platform guideline. Just check with Safari, open lots of tabs. You won't see any scroll button.

[Yash001]

@SGaist got it.

[Yash001]

Thank You @SGaist and @AndyS. I am able to get QToolButton of QTabBar by applying Fusion style.

I applied Fusion Style By:

#include "mainwindow.h"

#include <QTimer>
#include <QtGlobal>


#include <QFile>


#include <QLocale>
#include <QSplashScreen>
#include <QGuiApplication>
#include <qstylefactory.h>


int main(int argc, char *argv[]) {
    QLocale::setDefault(QLocale::system());

    QApplication a(argc, argv);
    a.setStyle(QStyleFactory::create("Fusion"));
    
    MainWindow w;
    w.showMaximized();
    return a.exec();
}