How to change the QToolButton opacity when the cursor is on int?

[nanor]

@Pl45m4 Thank you so much for your complete reply. I set your code into my project, but I got some errors . Here is my updated code:

dialog.h:

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>
#include <QToolButton>
#include <QGraphicsOpacityEffect>

namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
    Q_OBJECT

public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();
    QToolButton *butt;
    QGraphicsOpacityEffect *effect;


private:
    Ui::Dialog *ui;

protected:
    void enterEvent(QEvent * event);
    bool eventFilter(QObject *obj, QEvent *event) override;



};

bool Dialog::eventFilter(QObject *obj, QEvent *event)
{
    if(obj == butt)
    {
        if(event->type() == QEvent::Enter)
        {
            // SET YOUR OPACITY
            effect->setOpacity(1);
            butt->setGraphicsEffect(effect);
        }
        else if(event->type() == QEvent::Leave)
        {
           // SET OPACITY BACK TO NORMAL
            effect->setOpacity(0.5);
            butt->setGraphicsEffect(effect);

        }
        return true;
    }
    else
    {
        return QDialog::eventFilter(obj, event);
    }
}

#endif // DIALOG_H

dialog.cpp:

    QImage image;
    image.load("F:/qt codes/opacity4/2-2");

    image = image.convertToFormat(QImage::Format_ARGB32);

    QPainter painter(&image);
    painter.setOpacity(0.5);

    QPixmap pixmap = QPixmap::fromImage(image);
    QIcon icon(pixmap);
    butt->setIcon(icon);
    butt->setIconSize(QSize(widthW/2,heightW/3.3));
    butt->setText("my book");
    butt->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
    butt->setCursor(Qt::PointingHandCursor);


    effect = new QGraphicsOpacityEffect(this);
    effect->setOpacity(0.5);
    butt->setGraphicsEffect(effect);

    //butt->setAttribute(Qt::WA_Hover, true);
    butt->setMouseTracking(true);
    butt->installEventFilter(this);

}

Dialog::~Dialog()
{
    delete ui;
}


void Dialog::enterEvent(QEvent * event)
{
    QToolButton::enterEvent(event);
    effect->setOpacity(1);
    butt->setGraphicsEffect(effect);

}

Have I written the part re-implementation (bool Dialog::eventFilter(QObject *obj, QEvent *event)) in the correct place?

The errors I get:

[Pl45m4]

@nanor said in How to change the QToolButton opacity when the cursor is on int?:

Have I written the part re-implementation (bool Dialog::eventFilter(QObject *obj, QEvent *event)) in the correct place?

This belongs in your dialog.cpp. If this does not help, also #include <QEvent> .

... and remove or comment your Dialog::EnterEvent. It will always fire, when you move your mouse over your dialog.

BTW: butt is a hilarious name for a button :D

[nanor]

@Pl45m4 I added #include<QEvent> to both dialog.h and dialog.cpp files and commented the part:

void Dialog::enterEvent(QEvent * event)
{

    QToolButton::enterEvent(event);
    effect->setOpacity(1);
    butt->setGraphicsEffect(effect);

}

but I got error.

Here is my updated code:

dialog.h:

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>
#include <QToolButton>
#include <QGraphicsOpacityEffect>
#include <QEvent>

namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
    Q_OBJECT

public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();
    QToolButton *butt;
    QGraphicsOpacityEffect *effect;


private:
    Ui::Dialog *ui;

protected:
    void enterEvent(QEvent * event);
    bool eventFilter(QObject *obj, QEvent *event) override;


};


bool Dialog::eventFilter(QObject *obj, QEvent *event)
    {
        if(obj == butt)
        {
            if(event->type() == QEvent::Enter)
            {
                // SET YOUR OPACITY
                effect->setOpacity(1);
                butt->setGraphicsEffect(effect);
            }
            else if(event->type() == QEvent::Leave)
            {
               // SET OPACITY BACK TO NORMAL
                effect->setOpacity(0.5);
                butt->setGraphicsEffect(effect);

            }
            return true;
        }
        else
        {
            return QDialog::eventFilter(obj, event);
        }
    }

#endif // DIALOG_H

dialog.cpp:

QImage image;
    image.load("F:/qt codes/opacity4/2-2");

    image = image.convertToFormat(QImage::Format_ARGB32);

    QPainter painter(&image);
    painter.setOpacity(0.5);

    QPixmap pixmap = QPixmap::fromImage(image);
    QIcon icon(pixmap);
    butt->setIcon(icon);
    butt->setIconSize(QSize(widthW/2,heightW/3.3));
    butt->setText("my book");
    butt->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
    butt->setCursor(Qt::PointingHandCursor);


    effect = new QGraphicsOpacityEffect(this);
    effect->setOpacity(0.5);
    butt->setGraphicsEffect(effect);

    //butt->setAttribute(Qt::WA_Hover, true);
    butt->setMouseTracking(true);
    butt->installEventFilter(this);






}

Dialog::~Dialog()
{
    delete ui;
}


/*void Dialog::enterEvent(QEvent * event)
{

    QToolButton::enterEvent(event);
    effect->setOpacity(1);
    butt->setGraphicsEffect(effect);

}*/

The error I got:

[Pl45m4]

@nanor

Not in both. Only in your header is enough. Your cpp already includes your header file.

And you didn't move the implemention from your header to your code file.

Only this

bool eventFilter(QObject *obj, QEvent *event) override;

should stay in your header.

What to put where, is general OOP / C++ knowledge ;-)

[nanor]

@Pl45m4 I'm really sorry , if I understood correctly, I have to remove the line void enterEvent(QEvent * event); from my header file?

[Pl45m4]

@nanor said in How to change the QToolButton opacity when the cursor is on int?:

remove the line void enterEvent(QEvent * event);

Or comment it to test if my code works for you. You dont need a QDialog::EnterEvent. AND move the eventFilter implementation to your cpp. The errors should be gone now.

[nanor]

@Pl45m4 I commented the line void enterEvent(QEvent * event); in the header file and added bool eventFilter(QObject *obj, QEvent *event) override; to the cpp file, after ui->setupUi(this);
in the constructor, but I get this errer:

[Pl45m4]

@nanor

AHHHHHH.

No :)

This (bool eventFilter(QObject *obj, QEvent *event) override;) is not the implementation.

HEADER (Dialog.h)

protected:
   bool eventFilter(QObject *obj, QEvent *event) override;

DIALOG.CPP

bool Dialog::eventFilter(QObject *obj, QEvent *event)
{
    if(obj == YOUR_BUTTON)
    {
        if(event->type() == QEvent::Enter)
        {
            // SET YOUR OPACITY
        }
        else if(event->type() == QEvent::Leave)
        {
           // SET OPACITY BACK TO NORMAL
        }
        return true;
    }
    else
    {
        return QDialog::eventFilter(obj, event);
    }

[nanor]

@Pl45m4 Really sorry :( I set that part to my cpp file :

QImage image;
    image.load("F:/qt codes/opacity4/2-2");

    image = image.convertToFormat(QImage::Format_ARGB32);

    QPainter painter(&image);
    painter.setOpacity(0.5);

    QPixmap pixmap = QPixmap::fromImage(image);
    QIcon icon(pixmap);
    butt->setIcon(icon);
    butt->setIconSize(QSize(widthW/2,heightW/3.3));
    butt->setText("my book");
    butt->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
    butt->setCursor(Qt::PointingHandCursor);


    effect = new QGraphicsOpacityEffect(this);
    effect->setOpacity(0.5);
    butt->setGraphicsEffect(effect);

    //butt->setAttribute(Qt::WA_Hover, true);
    butt->setMouseTracking(true);
    butt->installEventFilter(this);



}

Dialog::~Dialog()
{
    delete ui;
}


bool Dialog::eventFilter(QObject *obj, QEvent *event)
    {
        if(obj == butt)
        {
            if(event->type() == QEvent::Enter)
            {
                // SET YOUR OPACITY
                effect->setOpacity(1);
                butt->setGraphicsEffect(effect);
            }
            else if(event->type() == QEvent::Leave)
            {
               // SET OPACITY BACK TO NORMAL
                effect->setOpacity(0.5);
                butt->setGraphicsEffect(effect);

            }
            return true;
        }
        else
        {
            return QDialog::eventFilter(obj, event);
        }
    }



/*void Dialog::enterEvent(QEvent * event)
{

    QToolButton::enterEvent(event);
    effect->setOpacity(1);
    butt->setGraphicsEffect(effect);

}*/

But got this error:

[Pl45m4]

@nanor

I assume you still have the Dialog::eventFilter implementation in your header file?!
(Because it says, that you are re-defining it in your cpp).

If not, try a "Clean" followed by "Build" or "Rebuild" and "Run QMake".

[nanor]

@Pl45m4 Oh sorry. I have thought you mean the protected part of the header file.
My header file now is:

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>
#include <QToolButton>
#include <QGraphicsOpacityEffect>
#include <QEvent>

namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
    Q_OBJECT

public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();
    QToolButton *butt;
    QGraphicsOpacityEffect *effect;


private:
    Ui::Dialog *ui;

protected:
    bool eventFilter(QObject *obj, QEvent *event) override;


};



#endif // DIALOG_H

and my cpp file is:

#include "dialog.h"
#include "ui_dialog.h"
#include <QDesktopWidget>
#include <QIcon>
#include <QPixmap>
#include <QToolButton>
#include <QImage>
#include <QPainter>
#include <QGraphicsOpacityEffect>
#include <QDebug>


Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);




    QDesktopWidget wid;
    int screenWidth = wid.screen()->width();
    int screenHeight = wid.screen()->height();

    this->setFixedSize(screenWidth/2.5,screenHeight/1.5);

    int widthW = this->frameGeometry().width();
    int heightW = this->frameGeometry().height();
    //qDebug() << widthW;
    //qDebug() << heightW;
    this->setGeometry((screenWidth/2)-(widthW/2),(screenHeight/2)-(heightW/2),widthW,heightW);

    butt= new QToolButton(this);
    butt->setFixedSize(widthW/2.5,heightW/2.5);
    int width_button_EM = butt->frameGeometry().width();
    int height_buttin_EM = butt->frameGeometry().height();
    butt->setGeometry(widthW*50/100,heightW*20/100,width_button_EM,height_buttin_EM);



    butt->setObjectName("butt-name");
    butt->setStyleSheet(

    "QToolButton#butt-name {"
        "border:5px solid #303030;"
        "border-width: 3px;"
        " }"
    " QToolButton#butt-name {"
        "  border-radius: 0px;"
        " }"

    "QToolButton#butt-name {"
        "padding-left:5px; padding-right:5px; padding-bottom:5px;  padding-top:5px;"
       "}"
        );




    QImage image;
    image.load("F:/qt codes/opacity4/2-2");

    image = image.convertToFormat(QImage::Format_ARGB32);

    QPainter painter(&image);
    painter.setOpacity(0.5);

    QPixmap pixmap = QPixmap::fromImage(image);
    QIcon icon(pixmap);
    butt->setIcon(icon);
    butt->setIconSize(QSize(widthW/2,heightW/3.3));
    butt->setText("my book");
    butt->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
    butt->setCursor(Qt::PointingHandCursor);


    effect = new QGraphicsOpacityEffect(this);
   // effect->setOpacity(0.5);
    //butt->setGraphicsEffect(effect);

    //butt->setAttribute(Qt::WA_Hover, true);
    butt->setMouseTracking(true);
    butt->installEventFilter(this);



}

Dialog::~Dialog()
{
    delete ui;
}


bool Dialog::eventFilter(QObject *obj, QEvent *event)
    {
        if(obj == butt)
        {
            if(event->type() == QEvent::Enter)
            {
                // SET YOUR OPACITY
                effect->setOpacity(1);
                butt->setGraphicsEffect(effect);
            }
            else if(event->type() == QEvent::Leave)
            {
               // SET OPACITY BACK TO NORMAL
                effect->setOpacity(0.5);
                butt->setGraphicsEffect(effect);

            }
            return true;
        }
        else
        {
            return QDialog::eventFilter(obj, event);
        }
    }

But the output is only an empty dialog window without button and button icon.

[Pl45m4]

@nanor

How is your button set to your dialog and where?

QDesktopWidget is deprecated and shouldn't be used anymore. All in all, you picked the wrong approach. Better apply some QLayout (horizontal or vertical) to your QDialog and then add your button.

[nanor]

@Pl45m4 Actually I have used QDesktopWidget, because I want to set the geometry based on my screen width and height.

When I comment the part:

bool Dialog::eventFilter(QObject *obj, QEvent *event)
    {
        if(obj == butt)
        {
            if(event->type() == QEvent::Enter)
            {

                effect->setOpacity(1);
                butt->setGraphicsEffect(effect);
            }
            else if(event->type() == QEvent::Leave)
            {

                effect->setOpacity(0.5);
                butt->setGraphicsEffect(effect);

            }
            return true;
        }
        else
        {
            return QDialog::eventFilter(obj, event);
        }
    }

from my cpp file , and the part:

protected:
    bool eventFilter(QObject *obj, QEvent *event) override;

from my header file, I got the following output:

And when I don't comment those parts, I got an empty dialog window.

[Pl45m4]

@nanor said in How to change the QToolButton opacity when the cursor is on int?:

I want to set the geometry based on my screen width and height

QScreen is the alternative / replacement.
https://doc.qt.io/qt-5/qscreen.html

Your button is floating around / just drawn on your widget (dialog).

It is always better to use layouts unless there is any reason to not, which I dont see in your case :)

dialog.cpp (after butt->setCursor(Qt::PointingHandCursor);)

QVBoxLayout *layout = new QVBoxLayout;
layout->addWidget(butt);
setLayout(layout);

[nanor]

@Pl45m4 I added the layout and now my cpp file is:

#include "dialog.h"
#include "ui_dialog.h"
#include <QDesktopWidget>
#include <QIcon>
#include <QPixmap>
#include <QToolButton>
#include <QImage>
#include <QPainter>
#include <QGraphicsOpacityEffect>
#include <QDebug>
#include <QVBoxLayout>

Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);




    /*QDesktopWidget wid;
    int screenWidth = wid.screen()->width();
    int screenHeight = wid.screen()->height();

    this->setFixedSize(screenWidth/2.5,screenHeight/1.5);

    int widthW = this->frameGeometry().width();
    int heightW = this->frameGeometry().height();
    qDebug() << widthW;
    qDebug() << heightW;
    this->setGeometry((screenWidth/2)-(widthW/2),(screenHeight/2)-(heightW/2),widthW,heightW);

    
    butt->setFixedSize(widthW/2.5,heightW/2.5);
    int width_button_EM = butt->frameGeometry().width();
    int height_buttin_EM = butt->frameGeometry().height();
    butt->setGeometry(widthW*50/100,heightW*20/100,width_button_EM,height_buttin_EM);*/


    butt= new QToolButton(this);
    butt->setObjectName("butt-name");
    butt->setStyleSheet(

    "QToolButton#butt-name {"
        "border:5px solid #303030;"
        "border-width: 3px;"
        " }"
    " QToolButton#butt-name {"
        "  border-radius: 0px;"
        " }"

    "QToolButton#butt-name {"
        "padding-left:5px; padding-right:5px; padding-bottom:5px;  padding-top:5px;"
       "}"
        );




    QImage image;
    image.load("F:/qt codes/opacity4/2-2");

    image = image.convertToFormat(QImage::Format_ARGB32);

    QPainter painter(&image);
    painter.setOpacity(0.5);

    QPixmap pixmap = QPixmap::fromImage(image);
    QIcon icon(pixmap);
    butt->setIcon(icon);
   // butt->setIconSize(QSize(widthW/2,heightW/3.3));
    butt->setIconSize(QSize(100,200));
    butt->setText("my book");
    butt->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
    butt->setCursor(Qt::PointingHandCursor);


    effect = new QGraphicsOpacityEffect(this);
    effect->setOpacity(0.5);
    butt->setGraphicsEffect(effect);

    //butt->setAttribute(Qt::WA_Hover, true);
    butt->setMouseTracking(true);
    butt->installEventFilter(this);

    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(butt);
    setLayout(layout);



}

Dialog::~Dialog()
{
    delete ui;
}


bool Dialog::eventFilter(QObject *obj, QEvent *event)
    {
        if(obj == butt)
        {
            if(event->type() == QEvent::Enter)
            {

                effect->setOpacity(1);
                butt->setGraphicsEffect(effect);
            }
            else if(event->type() == QEvent::Leave)
            {

                effect->setOpacity(0.5);
                butt->setGraphicsEffect(effect);

            }
            return true;
        }
        else
        {
            return QDialog::eventFilter(obj, event);
        }
    }

Again, when I don't comment the eventfilter parts, the output is an empty dialog window and when I comment those parts, I got:

The reason I use QDesktopWidget is that I want to have my program exe file and then use the program in different computers with different widths and heights, so I have to set geometry to my elements based on the screen geometry.

[nanor]

@Pl45m4 Hi. Finally I succeed! I changed the protected part of my header file to:

protected:
bool eventFilter(QObject *obj, QEvent *event){
         if(obj == butt)
          {
             if(event->type() == QEvent::Enter)
             {
                 effect->setOpacity(1);
                 butt->setGraphicsEffect(effect);
             }
             else if(event->type() == QEvent::Leave)
              {
                 effect->setOpacity(0.5);
                 butt->setGraphicsEffect(effect);
              }
     }

     }

and clear the bool part from the cpp file and my code worked fine.
Thank you so much for the code you provided yesterday. Really appreciate your help .
Best regards.

[Pl45m4]

@nanor

I dont see any difference, since the code is the same and you can put your defintions / implementation in your header, but normally you put them in your code (cpp) file. You find getters / setters defined in header file very often. So I dont know what was going on before :) It should work with the code in your cpp file as well.

@nanor said in How to change the QToolButton opacity when the cursor is on int?:

The reason I use QDesktopWidget is that I want to have my program exe file and then use the program in different computers with different widths and heights, so I have to set geometry to my elements based on the screen geometry.

There is nothing wrong with it. I also didn't say, you shouldn't do it, but there will be one day, they remove QDesktopWidget completely. It's already kept because of compatibilty reasons. With QScreen you can do the same and it will stay in Qt Framework for a longer time than QDesktopWidget.
But you really should consider using layouts (you can set a fixed geometry as well as min / max sizes).

[nanor]

@Pl45m4 I didn't know about QScreen and I thought that the only way to use my device screen geometry is using QDesktopWidget. I will change it to QScreen .
About layouts, also I didn't know that I can set size for them :)
Thank you for valuable points you mentioned. I will definitely use them in my project.