Change the colors of tabs without using StyleSheets

[JoeCFD]

https://forum.qt.io/topic/33307/solved-qtabwidget-change-tab-s-background-color/4

[leinad]

This is using stylesheets. Stylesheets is no good for what I'm doing.

[JoeCFD]

Then create customized tab bar(setTabBar()) and tab area(addTab()). Color them separately. Their geometries might have to be handled manually as well. Could be messy. Take a detailed look at the source code of QTabWidget if it is the case. Post your problem here if you have any issues.

[leinad]

I think I have a work around by sub-classing paintEvent but now I'm running into this issue where I'm trying to use a signal/slot to tell me when a user clicks on a tab. I keep getting "QObject::connect: No such slot QTabWidget::processTab(int)" Can anyone explain to me why subclassing does not allow me to use signal/slot? Is there a work around?

MyTabWidget.h:
#ifndef MYTABWIDGET_H
#define MYTABWIDGET_H

#include <QApplication>
#include <QTabWidget>
#include <QPalette>
#include <QTabBar>
#include <QLabel>
#include <QDebug>
#include "tabbar.h"

class MyTabWidget : public QTabWidget
{

TabBar *mTabBar;

public:
MyTabWidget(QWidget *parent=0);
~MyTabWidget();

private slots:
void processTab(int tabIndex);

};

#endif // MYTABWIDGET_H

MytabWidget.cpp

#include "mytabwidget.h"

MyTabWidget::~MyTabWidget()
{

}

MyTabWidget::MyTabWidget(QWidget *parent) : QTabWidget(parent)
{
QString text = NULL;

mTabBar = new TabBar;
setTabBar(mTabBar);

// connect(mTabBar, SIGNAL(tabBarClicked(int)), this, SLOT(processTab(int))); //get the error described above when running
connect(mTabBar, SIGNAL(currentChanged(int)), this, SLOT(processTab(int))); //get the error described above when running

for(int i=0; i < 5; i++)
{
    if(i == 4)
        text = QString("Alert    ");
    else
        text = QString("Tab %1    ").arg(i);
    addTab(new QLabel(text, this), text);
//    mTabBar->setTabTextColor(i,  QColor(0, 200, 0));
}

}

void MyTabWidget::processTab(int tabIndex)
{
qDebug() << tabIndex;
}

[JonB]

@leinad
Using new style signals/slots might give a better error. Did you include the slots word in the header? You do not have Q_OBJECT word in your class, and you define a slot. Shouldn't you include it? And do a full rebuild.

[leinad]

Yes, in the header I have a private slots with the slot name. As far a Q_OBJECT, I tried placing it but I keep getting an error.

#include <QApplication>
#include <QTabWidget>
#include <QPalette>
#include <QTabBar>
#include <QLabel>
#include <QDebug>
#include <QObject>
#include "tabbar.h"

class MyTabWidget : public QTabWidget , Q_OBJECT 
{
    Q_OBJECT    <---------------------
    TabBar *mTabBar;

public:
    MyTabWidget(QWidget *parent=0);
    ~MyTabWidget();



private slots:
  void processTab(int tabIndex);
};

When I add Q_OBJECT as public I get non-member function cannot have 'const' qualifier. How can I add Q_OBJECT when I declare the following?

class MyTabWidget : public QTabWidget , Q_OBJECT   <--------------
{
    Q_OBJECT    <---------------------

[jsulm]

@leinad said in Change the colors of tabs without using StyleSheets:

class MyTabWidget : public QTabWidget , Q_OBJECT

What is this?!
Q_OBJECT is a macro which goes inside the class definition, like you already did:

class MyTabWidget : public QTabWidget
{
    Q_OBJECT

[leinad]

Sorry I had a typo I meant to show this is how I define QObject in MyTabWidget.

class MyTabWidget : public QTabWidget, public QObject
{
Q_OBJECT

The error I get "direct base 'QObject' is inaccessible dur to ambiguity:

[jsulm]

@leinad said in Change the colors of tabs without using StyleSheets:

class MyTabWidget : public QTabWidget, public QObject

QTabWidget is already a QObject, should be

class MyTabWidget : public QTabWidget

[leinad]

@leinad said in Change the colors of tabs without using StyleSheets:

direct base 'QObject' is inaccessible dur to ambiguity

Yes, that was the original code but I still got no such slot. I got around it by using eventFilters which basically does the same thing. Thanks.