如何在Mac上以编程方式禁用我的Qt应用程序的滚动条惯性

Question

在Qt项目中，如何禁用应用程序的OSX滚动条惯性？这是为了我可以提供对惯性等的自定义控制。

Answer 1

这样做：

project.pro

QT       += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = project
TEMPLATE = app
macx {
    LIBS += -framework Foundation
    OBJECTIVE_SOURCES += helper.m
}
SOURCES += main.cpp

helper.m

#include <Foundation/NSUserDefaults.h>
#include <Foundation/NSDictionary.h>
#include <Foundation/NSString.h>
void disableMomentumScroll(void)
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSDictionary *appDefaults = [NSDictionary dictionaryWithObject:@"NO" forKey:@"AppleMomentumScrollSupported"];
    [defaults registerDefaults:appDefaults];
}

main.cpp

#include <QApplication>
#include <QGraphicsScene>
#include <QGraphicsView>
#ifndef Q_OS_MAC
void disableMomentumScroll() {}
#else
extern "C" { void disableMomentumScroll(); }
#endif
float rnd(float range) { return (qrand() / static_cast<float>(RAND_MAX)) * range; }
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    disableMomentumScroll();
    QGraphicsScene s;
    for (int n = 0; n < 30; n++) {
        s.addRect(rnd(500), rnd(3000), rnd(200), rnd(1000), QPen(Qt::red), QBrush(Qt::gray));
    }
    QGraphicsView w(&s);
    w.show();
    return a.exec();
}