嵌入式系统 屏保设置

2019-07-12 20:44发布

简单总结下在嵌入式arm板中设置屏保的方法: 在Qt中有二个QWSScreenSaver类 这个类的定义如下 定义路径qwindowsystem_qws.h class Q_GUI_EXPORT QWSScreenSaver 086 { 087 public: 088     virtual~QWSScreenSaver(); 089     virtualvoidrestore()=0; 090     virtualboolsave(intlevel)=0; 091 }; 是类class QWSServerPrivate 的成员,在成类中与屏保设置相关的类成员还有 QTime screensavertime; 097     QTimer* screensavertimer; 098     int* screensaverintervals; 099     intscreensavereventblocklevel; 100     boolscreensaverblockevents; 101     boolscreensaverblockevent(intindex, int *screensaverinterval,bool isDown ); 102     QWSScreenSaver* saver; void screenSave(intlevel); 在设置屏保的时候,Qt程序要作为服务端来运行,QWSScreenSaver中的虚函数virtualvoidrestore()和virtualboolsave(intlevel)都是用来重载, 设置在屏保状态的处理在后面的函数中重载,设置恢复屏保的处理在前面的虚函数中执行,为了节省功耗,我在屏保状态下关掉屏幕的背光,在恢复状态下开启背光。 我用这个方法做个简单的测试,能实现屏保时间设置的动态更。说下我这个测试的调试过程 定义了个SCreenSaver类,继承自QWSScreenSaver 类的定义和实现代码如下 #ifndef SCREENSAVER_H
#define SCREENSAVER_H
#include
#include
class ScreenSaver : public QWSScreenSaver
{
public:
     ScreenSaver();
    virtual void restore();     virtual bool save(int level); private:
   int freq;
   int dutycycle;
public slots:
    void ScreenSaver_parameter_changed(int);
   
}; #endif // SCREENSAVER_H
实现文件如下 #include "screensaver.h"
#include
#include
#include   
#include   
#include   
#include   
#include   
#include   
#define IOCTL_FREQUENCY 0
#define IOCTL_DUTYCYCLE 1
static int fd; ScreenSaver::ScreenSaver()
    :QWSScreenSaver()
{
//    window=new QMainWindow();
    qDebug()<<"Inlize";     QSettings *readini = new QSettings("/home/config.ini", QSettings::IniFormat, 0); //初始化读取当前背光值,并存储
    readini->beginGroup("backlight");
     dutycycle=readini->value("backlight_duty").toInt();
     qDebug("dutycycle=%d",dutycycle);
    readini->endGroup();
    delete readini;      freq= 6500; } void ScreenSaver::restore()
{
    qDebug("enter screen restore");
     //open pwm
    if((fd=open("/dev/pwm9",O_RDWR)) < 0)
    {
        printf("open device gptimer8 error ");
       exit(1);// close();
    }     printf("The frequecy is %d Hz ",freq);
    printf("The duty cycle is %d percent ",dutycycle);     ioctl(fd,IOCTL_FREQUENCY,freq);
    ioctl(fd,IOCTL_DUTYCYCLE,dutycycle);
     ::close(fd);
}
bool ScreenSaver::save(int level)
{
   //close pwm  反逻辑     if((fd=open("/dev/pwm9",O_RDWR)) < 0)
    {
        printf("open device gptimer8 error ");
       exit(1);// close();
    }     printf("The frequecy is %d Hz ",freq);
    printf("The duty cycle is 90 ");     ioctl(fd,IOCTL_FREQUENCY,freq);
    ioctl(fd,IOCTL_DUTYCYCLE,100);
     ::close(fd);     qDebug()<<"window show";
            return true;   }
void ScreenSaver::ScreenSaver_parameter_changed(int interval)
{
    QWSServer::setScreenSaverInterval(interval*1000);
    // ignore the key/mouse event that turns on the screen }
屏保设置还需要做一些其他的设置。 我创建一个另外两个类,Input和mainwindow,在mainwindow的构造函数中对屏保进行了设置  saver = new ScreenSaver;
    QWSServer::setScreenSaver((QWSScreenSaver *)saver);
    QWSServer::setScreenSaverInterval(10000);//读配置文件得出初始值
    QWSServer::screenSaverActivate(true);
//    int blocklevel = 1;  //   QWSServer::setScreenSaverBlockLevel( blocklevel );