Next/back buttons

[viniltc]

Hi all,

I'm trying to implement the following:

Clicking Next/ Back button should navigate through 1, 2, 3, 4 buttons above and change its color. Let's say if I have slots for each of number buttons to change its property.

How do I implement using signals and slots ?

Thanks in advance

[jsulm]

@viniltc said in Next/back buttons:

How do I implement using signals and slots ?

Like any other? What exactly is the problem? You do not need a slot for each of these 1/2/3/4 buttons, just one which is connected to Next button.
In the slot connected to Next button check which of the 1/2/3/4 buttons was selected before and then take the next one.

[Pl45m4]

@viniltc

// #######################################################
// ############### MainWindow Constructor ################

int m_currentBtn = 0;
QPushButton * btn1 = new QPushButton(this, "1");
QPushButton * btn2 = new QPushButton(this, "2");
QPushButton * btn3 = new QPushButton(this, "3");
QPushButton * btn4 = new QPushButton(this, "4");
QPushButton * btnNxt = new QPushButton(this, "Next");
QPushButton * btnPrev = new QPushButton(this, "Back");
QButtonGroup * btnGrp = new QButtonGroup(this);
btnGrp->addButton(btn1, 1);
btnGrp->addButton(btn2, 2);
btnGrp->addButton(btn3, 3);
btnGrp->addButton(btn4, 4);

btn1->setStylesheet("Style"); // initial style (start with btn1)
m_currentBtn = 1;

connect(btnNxt, &QPushButton::clicked, this, &MainWindow::nextBtn);
connect(btnPrev, &QPushButton::clicked, this, &MainWindow::prevBtn);
connect(this, &MainWindow::buttonChanged, this, &MainWindow::paintBtn);

// #################################################


void MainWindow::nextBtn()
{
    m_currentBtn++;
    if(m_currentBtn > btnGrp->buttons().size())
    {
        m_currentBtn = 1
    }
    emit buttonChanged(m_currentBtn);
}

void MainWindow::prevBtn()
{
    m_currentBtn--;
     if(m_currentBtn < 1)
     {
         m_currentBtn = btnGrp->buttons().size();
     }
    
  emit buttonChanged(m_currentBtn);
}

void MainWindow::paintBtn(int id)
{
   for(int i = 1; i < btnGrp->buttons().size() + 1; i++)
   {
        if(i == id)
        {
            btnGrp->button(id)->setStylesheet("Style");
        }
        else
        {
           btnGrp->button(id)->setStylesheet(""); // reset all btns to default
        }
   }
   
}

[mr ZX]

@Pl45m4 said in Next/back buttons:

QPushButton * btn1 = new QPushButton(this, "1");
QPushButton * btn2 = new QPushButton(this, "2");
QPushButton * btn3 = new QPushButton(this, "3");
QPushButton * btn4 = new QPushButton(this, "4");
QPushButton * btnNxt = new QPushButton(this, "Next");
QPushButton * btnPrev = new QPushButton(this, "Back");
QButtonGroup * btnGrp = new QButtonGroup(this);

hi bro
i see many error in your code .
u can use -> just in pointer no in variable for example btnGrp->buttons()->size() is mistake u should writebtnGrp->buttons().size() ;
secondly you have 4 button but wen btn1 selected and click in back you emit 5 , but btn5 is not exist ["m_currentBtn = btnGrp->buttons()->size() + 1;"] remove +1;
and verry error ...
for using Signal and slot you can write like :

    connect(btnNxt, SIGNAL(clicked(bool)), this, SLOT(nextBtn()));
    connect(btnPrev, SIGNAL(clicked(bool)), this, SLOT(prevBtn()));
    connect(this, SIGNAL(buttonChanged(int)), this, SLOT(paintBtn(int)));

in your class in Header (MainWindow.h ) you can write :

private slots:
    void nextBtn();
    void prevBtn();
    void paintBtn(int id);
signals:
    void buttonChanged(int);

now when user click on next or prev (emit buttonChanged) run paintBtn(int id) .

good luck

[Pl45m4]

@mr-ZX

I never had the intention to provide compilable code incl. headers etc... I wrote this to point OP ( @viniltc ) into the right direction.

@mr-ZX said in Next/back buttons:

writebtnGrp->buttons().size()

But yes, you are right in this case :)

@mr-ZX said in Next/back buttons:

secondly you have 4 button but wen btn1 selected and click in back you emit 5 , but btn5 is not exist ["m_currentBtn = btnGrp->buttons()->size() + 1;"] remove +1;

I messed it up, because I copied it from the if-statement above...

@mr-ZX said in Next/back buttons:

and verry error ...
for using Signal and slot you can write like

My signals and slots are correct... I used the newer, Qt5 syntax.

@mr-ZX said in Next/back buttons:

in your class in Header (MainWindow.h ) you can write :
private slots:
void nextBtn();
void prevBtn();
void paintBtn(int id);
signals:
void buttonChanged(int);

As I said before, I never had the intention to write complete and fully compilable program code with de- and constructors, headers and so on...

[viniltc]

@Pl45m4 Many thanks for the code to point me in the right direction :)
@jsulm @mr-ZX Thanks a lot for your feedback :)