nachiketavadera/flashlight

An android application that makes using LED as a torch easier.

Flashlight

Summary

The base of this project is LED provided along with the Camera in a typical Android smart phone. After seeing that Play Store has a number of apps that ask for unnecessary permissions, I decided to create an app that toggles the LED without asking for any type of permission. This app also implements a service that detects when the device is shook (used to toggle the flashlight).

As of June 24th of 2018, Flashlight is licensed under Apache License version 2.0.

Downloads

Latest apk: Flashlight.apk

Source Code (zip): Flashlight.zip

Source Code (tar.gz): Flashlight.tar.gz

Contributors

• Code Optimization : RamusisTrenksmas
• Logo and Images : Dee-y

Code

The majority of the code is written in Java and is simple. For detecting shake motion: Declare global variables:

    SensorManager sensorManager = null;
    public static final float SHAKE_THRESHOLD = 10.25f; // How hard should user shake to invoke the service
    public static final int MIN_TIME_BETWEEN_SHAKES = 1000;
    private long lastShakeTime = 0;
    private boolean isFlashlightOn = false;

Initialize sensorManager:

    sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
    if (sensorManager != null) {
        Sensor accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        sensorManager.registerListener((SensorEventListener) this, accelerometer, SensorManager.SENSOR_DELAY_NORMAL);
    }

Make class implement SensorEventListener interface and override it's onSensorChanged method:

      @Override
    public void onSensorChanged(SensorEvent event) {
        if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
            long curTime = System.currentTimeMillis();
            if ((curTime - lastShakeTime) > MIN_TIME_BETWEEN_SHAKES) {

                float x = event.values[0];
                float y = event.values[1];
                float z = event.values[2];

                double acceleration = Math.sqrt(Math.pow(x, 2) +
                        Math.pow(y, 2) +
                        Math.pow(z, 2)) - SensorManager.GRAVITY_EARTH;

                if (acceleration > SHAKE_THRESHOLD) {
                    lastShakeTime = curTime;
                    if (!isFlashlightOn) {
                        torchToggle("on");
                        isFlashlightOn = true;
                    }
                    else {
                        torchToggle("off");
                        isFlashlightOn = false;
                    }
                }
            }
        }

Create a function torchToggle(String command):

    private void torchToggle(String command) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            CameraManager camManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
            String cameraId = null; // Usually back camera is at 0 position.
            try {
                if (camManager != null) {
                    cameraId = camManager.getCameraIdList()[0];
                }
                if (camManager != null) {
                    if (command.equals("on")) {
                        camManager.setTorchMode(cameraId, true);   // Turn ON
                        isFlashlightOn = true;
                    } else {
                        camManager.setTorchMode(cameraId, false);  // Turn OFF
                        isFlashlightOn = false;
                    }
                }
            } catch (CameraAccessException e) {
                e.getMessage();
            }
        }
    }

Contributing

Any help, including feedback, is highly appriciated. I have just started out with Android and I’m relatively new to app development.

1. Fork it!
2. Create your feature branch: git checkout -b new-branch
3. Commit your changes: git commit -am 'Make a valuable addition'
4. Push to the branch: git push origin new-feature
5. Submit a pull request :D

Next Step

Once staretd, an app can never be completely finished.

1. Revamp the project and make it better.

flashlight's Issues

Logo proposal

Hello, i am a graphic designer and i'd like to contribute a logo to your project, it's free of course.

Null Pointer Exception onSensorChanged

Describe the bug
Upon vibrating the phone app is crashing with the following exception!

Exception

FATAL EXCEPTION: main
Process: android.nachiketa.flashlight, PID: 13636
java.lang.NullPointerException
	at java.util.Objects.requireNonNull(Objects.java:203)
	at android.nachiketa.flashlight.Global.changeBackground(Global.java:34)
	at android.nachiketa.flashlight.Global.torchToggle(Global.java:55)
	at android.nachiketa.flashlight.FlashlightShakeToggle.onSensorChanged(FlashlightShakeToggle.java:67)
	at android.hardware.SystemSensorManager$SensorEventQueue.dispatchSensorEvent(SystemSensorManager.java:857)
	at android.os.MessageQueue.nativePollOnce(Native Method)
	at android.os.MessageQueue.next(MessageQueue.java:336)
	at android.os.Looper.loop(Looper.java:181)
	at android.app.ActivityThread.main(ActivityThread.java:7562)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)

Device details
Android version: 10
Device vendor: Xaomi
Device name: Redmi note 9s

add more gestures & details on power consumption

I haven't found a single word on how much extra energy that service would consume if left working in background.

As for 'more gestures' feature request, actually, this doesn't relate to the flashlight. I'd like to build a similar background service that would listen to 'triple wrist-twist' gestures clockwise and counter clock wise when the phone is locked to perform two different BLE requests, but I am not quite sure how to recognize such gestures (if possible at all)

add blinking light in order to look more feature

add this with UI in order to add blinking light . I am beginner so I don't know about mobile developement
public void toggle(View view)
{
Button button = (Button) view;
// mine coding for disco light
if(button.getText().equals("Switch On") )
{
int i=1000;
while (i>3)
{
if(i%80!=0)
{
//button.setText(R.string.switch_on_text);
torchToggle("off");
}
if(i%80==0)
{
// button.setText(R.string.switch_off_text);
torchToggle("on");
}
if (i==10000)
{
button.setText(R.string.switch_off_text);
torchToggle("off");
break;
}
i++;
}
}
// mine coding

}