How to add a hover transition to QPushButton?

Question

I try to make a custom QPushButton with a stylesheet. I want to custom color of button when we mouse over it. It works, but I want to put a transition duration.

Answer 1

You can use Animation.

MyButton.h

#include 
#include 
#include 

class MyButton : public QPushButton
{
    Q_OBJECT
    Q_PROPERTY(QColor color READ GetColor WRITE SetColor)

public:
    explicit MyButton(QWidget *parent = 0);

    void SetColor(const QColor& color);
    const QColor& GetColor() const;

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

private:
    QColor m_currentColor;

    QPropertyAnimation m_colorAnimation;

    void StartHoverEnterAnimation();
    void StartHoverLeaveAnimation();
};

MyButton.cpp

#include "MyButton.h"

#include 
#include 

MyButton::MyButton(QWidget *parent) :
    QPushButton(parent),
    m_colorAnimation(this, "color")
{
    this->installEventFilter(this);
}

void MyButton::SetColor(const QColor& color)
{
    m_currentColor = color;
    QString css = "QPushButton { border-radius: 5px; ";
    css.append("border: 1.5px solid rgb(91,231,255); ");
    QString strColor = QString("rgb(%1, %2, %3)").arg(color.red()).arg(color.green()).arg(color.blue());
    css.append("background-color: " + strColor + "; }");
    setStyleSheet(css);
}

const QColor& MyButton::GetColor() const
{
    return m_currentColor;
}

bool MyButton::eventFilter(QObject *obj, QEvent *e)
{
    if (e->type() == QEvent::HoverEnter) {
        StartHoverEnterAnimation();
    }

    if (e->type() == QEvent::HoverLeave) {
        StartHoverLeaveAnimation();
    }

    return false;
}

void MyButton::StartHoverEnterAnimation()
{
    m_colorAnimation.stop();

    m_colorAnimation.setDuration(900); //set your transition
    m_colorAnimation.setStartValue(GetColor()); //starts from current color
    m_colorAnimation.setEndValue(QColor(100, 100, 100));//set your hover color

    m_colorAnimation.setEasingCurve(QEasingCurve::Linear);//animation style

    m_colorAnimation.start();
}

void MyButton::StartHoverLeaveAnimation()
{
    m_colorAnimation.stop();

    m_colorAnimation.setDuration(900); //set your transition
    m_colorAnimation.setStartValue(GetColor()); //starts from current color
    m_colorAnimation.setEndValue(QColor(255, 0, 0));//set your regular color

    m_colorAnimation.setEasingCurve(QEasingCurve::Linear);//animation style

    m_colorAnimation.start();
}

It will conflict with external qss setting. So set all qss in SetColor.