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

[Yash001]

Hello,
I am using QTabBar in my application. I would use the QTabBar::usesScrollButtons for many tab. I am getting usesScrollButtons in windows OS.

take screenshot from Windows OS.

But Whenever I tried same code in MAC system. At that time I am getting like below pic.

I tried setUsesScrollButtons(true) but i did not get any change in Mac System.

am I missing any step for MAC system?

MinimumWidthTabBar .h file

class MinimumWidthTabBar : public QTabBar {
public:
	MinimumWidthTabBar(QWidget *parent = 0);

	QSize minimumSizeHint() const Q_DECL_OVERRIDE;
};

MinimumWidthTabBar.cpp file

#include "MinimumWidthTabBar.h"

MinimumWidthTabBar::MinimumWidthTabBar(QWidget *parent) : 
	QTabBar(parent)
{
}
QSize MinimumWidthTabBar::minimumSizeHint() const {
	return sizeHint();
}

use MinimumWidthTabBar in function

static QWidget *w = 0;
	
	if (w) {
		return w;
	}

	// create New Object and give a name "new-data-window-owner"
	w = OBJ_NAME(WDG(), "new-data-window-owner");
	
	// create vertical layout
	auto *lay = NO_SPACING(NO_MARGIN(new QVBoxLayout(w)));
	
	// create pointer for Pushbutton "+" and Tile button
	QPushButton *addNewButton = nullptr;
	QPushButton *tileButton = nullptr;
	
	QTabBar *tabBar = nullptr;

	
	auto stackedLayWdg = OBJ_NAME(WDG(), "new-data-window-placeholder");
	

	auto stackedLayWdgLay = NO_SPACING(NO_MARGIN(new QHBoxLayout(stackedLayWdg)));
	auto mdiArea = new QMdiArea;
	
	mdiArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded);
	mdiArea->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
	
	m_ui.newDataTab.mdiArea = mdiArea;
	stackedLayWdgLay->addWidget(mdiArea);
	
	//create new frame for data window 
	QFrame *tabFrame = OBJ_NAME(new QFrame, "builder-tab-frame");
	auto *tabFrameLay = NO_SPACING(NO_MARGIN(new QHBoxLayout(tabFrame)));
	

	// create tab into tab bar
	tabFrameLay->addWidget(tabBar = OBJ_NAME(new MinimumWidthTabBar, "new-data-window-tab"));
	tabFrameLay->addWidget(addNewButton = OBJ_NAME(PBT("+"), "builder-tab-add-new"));
	tabFrameLay->addStretch(1);
	tabFrameLay->addWidget(tileButton = OBJ_NAME(PBT("View All Graphs"), "builder-tab-mdi"));

	m_ui.newDataTab.tabBar = tabBar;
	
	lay->addWidget(tabFrame);
	lay->addWidget(stackedLayWdg);
	

	tabBar->setExpanding(false);
	tabBar->setMovable(true);


auto UpdateTabAndCustomFrame = [=](const QUuid id, ExperimentType type, QWidget* customFrame, const QString tabName, const int tabIndex, bool isExperimentRun) {

		tabBar->insertTab(tabIndex, tabName);
		tabBar->setCurrentIndex(tabIndex);
		
	};

m_connections << QObject::connect(addNewButton, &QPushButton::clicked, [=]() {
		MainWindow::CsvFileData csvData;
		if (!m_mainWindow->ReadCsvFile(m_mainWindow, csvData)) {
			return;
		}
		
		// when we Pressed "+" button at that time tab will be shown into tabHeaderLay
		if (tabBar->isHidden()) {
			tabBar->show();
		}

		// print the name into tab bar
		QString tabName = csvData.fileName;
		
		// craete Uniq ID for for Window
		const QUuid id = QUuid::createUuid();

		auto dataTabWidget = CreateNewDataTabWidget(id,
			ET_SAVED,
			tabName,
			csvData.xAxisList,
			csvData.yAxisList,
			csvData.filePath,
			&csvData.container);

		UpdateTabAndCustomFrame(id, ET_SAVED, dataTabWidget, tabName, tabBar->count(), false);

	
	});

[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();
}