Qt QSpinBox加速步长

Question

I have a QSpinBox in Qt. The widget comes with one increaseValue and one decreaseValue arrow. Clicking the arrow increases the value as determined by singleStep , while pressing and holding the arrow increases the value by singleStep every X milliseconds (depending on system settings).

What is the best way to implement an experience where pressing and holding will increase / decrease the value faster as times goes on. I am thinking of either

• Start with singleStep increments for the first 2 seconds, then increment by 2 * singleStep , then 4 * singleStep , until released

• Increment by singleStep every X milliseconds, then after the first 2 seconds of holding the arrow pressed, increment by singleStep every X / 2 milliseconds, etc

Whichever is easier.

Answer 1

As a first suggestion you should try the built-in functionality of the QSpinBox .

#include <QSpinBox>
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    auto w=new QSpinBox;
    w->setAccelerated(true);
    w->show();

    return a.exec();
}