Question

I’m trying to use the systemLock() to lock the device when the getSpeed() returns a value greater than 20 m/s.

public void locationUpdated(LocationProvider provider, Location location)
        {
            if(location.isValid())
            {
                float speed = location.getSpeed();

                 // Information to be displayed on the device
                StringBuffer sb = new StringBuffer();
                sb.append("\n");
                sb.append("Speed : ");
                sb.append(speed);
                sb.append(" m/s");

                if(speed < 20){
                    appMan = ApplicationManager.getApplicationManager();
                    appMan.lockSystem(true);
                }else{

                }
                MyApp.this.updateLocationScreen(sb.toString());
            }

        }

I have a RichTextField and I can use the .settext() successfully in the if/else statement to change the RichTextField’s text so I must be using the lockSystem() wrong.

Edit

if(speed > 20 || Double.isNaN(speed)){
                    requestForeground();
                    appMan = ApplicationManager.getApplicationManager();
                    appMan.lockSystem(true);
                }else{

                }

Answer 1

From the docs on Location

public float getSpeed()
Returns:
the current ground speed in m/s for
the terminal or Float.NaN if the speed is not known

In Java, any comparison against Float.NaN will return false, so your lock screen code block won’t execute if your device is returning NaN as the speed. You might want to add Double.isNaN(speed) to your condition.