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Read more about the article Getting Image location in the Phimpme Android’s Camera

Getting Image location in the Phimpme Android’s Camera

The Phimpme Android app along with a decent gallery and accounts section comes with a nice camera section stuffed with all the features which a user requires for the day to day usage. It comes with an Auto mode for the best experience and also with a manual mode for the users who like to have some tweaks in the camera according to their own liking. Along with all these, it also has an option to get the accurate coordinates where the image was clicked. When we enable the location from the settings, it extracts the latitude and longitude of the image when it is being clicked and displays the visible region of the map at the top of the image info section as depicted in the screenshot below.

In this tutorial, I will be discussing how we have implemented the location functionality to fetch the location of the image in the Phimpme app.

Step 1

For getting the location from the device, the first step we need is to add the permission in the androidmanifest.xml file to access the GPS and the location services. This can be done using the following lines of code below.

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

After this, we need to download install the google play services SDK to access the Google location API. Follow the official google developer’s guide on how to install the Google play services into the project from the resources section below.

Step 2

To get the last known location of the device at the time of clicking the picture we need to make use of the FusedLocationProviderClient class and need to create an object of this class and to initialise it in the onCreate method of the camera activity. This can be done using the following lines of code below:

private FusedLocationProviderClient mFusedLocationClient;
mFusedLocationClient = LocationServices.getFusedLocationProviderClient(this);

After we have created and initialised the object mFusedLocationClient, we need to call the getLastLocation method on it as soon as the user clicks on the take picture button in the camera. In this, we can also set onSuccessListener method which will return the Location object when it successfully extracts the present or the last known location of the device. This can be done using the following lines of code below:

mFusedLocationClient.getLastLocation()
       .addOnSuccessListener(this, new OnSuccessListener<Location>() {
           @Override
           public void onSuccess(Location location) {
               if (location != null) {
            //Get the latitude and longitude here
                  }

After this, we can successfully extract the latitude and the longitude of the device in the onSuccess method of the code snippet provided below and can store it in the shared preference to get the map view of the coordinates from a different activity of the application later on when the user tries to get the info of the images.

Step 3

After getting the latitude and longitude, we need to get the image view of the visible region of the map. We can make use of the Glide library to fetch the visible map area from the url which contains our location values and to set it to the image view.

The url of the visible map can be generated using the following lines of code.

String.format(Locale.US, getUrl(value), location.getLatitude(), location.getLongitude());

This is how we have added the functionality to fetch the coordinates of the device at the time of clicking the image and to display the map in the Phimpme Android application. To get the full source code, please refer to the Phimpme Android GitHub repository.

Resources

  1. Google Developer’s : Location services guide – https://developer.android.com/training/location/retrieve-current.html
  2. Google Developer’s : Google play services SDK guide – https://developer.android.com/studio/intro/update.html#channels
  3. GitHub : Open camera Source Code –  https://github.com/almalence/OpenCamera
  4. GitHub : Phimpme Android – https://github.com/fossasia/phimpme-android/
  5. GitHub : Glide library – https://github.com/bumptech/glide

 

Continue ReadingGetting Image location in the Phimpme Android’s Camera
Read more about the article Encoding and Decoding Images as Data in UserDefaults in SUSI iOS

Encoding and Decoding Images as Data in UserDefaults in SUSI iOS

In this blog post, I will be explaining how to encode and decode images and save them in UserDefaults so that the image persists even if it is removed from the Photos app. It happens a number of times that images are removed from the gallery by the users which results in the app loosing the image. So, to avoid this, we save the image by encoding it in a data object and save it inside UserDefaults. In SUSI iOS app we simply select an image from the image picker, encode it and save it in UserDefaults. To set the image, we simply fetch the image data from the UserDefaults and decode it to an image.

There are two ways we can do the encoding and decoding process:

  • Using Data object
  • Using Base64 string

For the scope of this tutorial, we will use the Data object.

Implementation Steps

  1. To use the image picker, we need to add permissions to `Info.plist` file.
<key>NSLocationWhenInUseUsageDescription</key>
<string>Susi is requesting to get your current location</string>
<key>NSPhotoLibraryUsageDescription</key>
<string>Susi needs to request your gallery access to select wallpaper</string>
  1. Select image from gallery

First, we present an alert which gives an option to select the image from the gallery.

// Show wallpaper options to set wallpaper or clear wallpaper
func showWallpaperOptions() {
  let imageDialog = UIAlertController(title: ControllerConstants.wallpaperOptionsTitle, message: nil, preferredStyle: UIAlertControllerStyle.alert)
  imageDialog.addAction(UIAlertAction(title: ControllerConstants.wallpaperOptionsPickAction, style: .default, handler: { (_: UIAlertAction!) in
  imageDialog.dismiss(animated: true, completion: nil)
  self.showImagePicker()
  }))
  imageDialog.addAction(UIAlertAction(title: ControllerConstants.wallpaperOptionsNoWallpaperAction, style: .default, handler: { (_: UIAlertAction!) in
    imageDialog.dismiss(animated: true, completion: nil)
    self.removeWallpaperFromUserDefaults()
  }))
  imageDialog.addAction(UIAlertAction(title: ControllerConstants.dialogCancelAction, style: .cancel, handler: { (_: UIAlertAction!) in
    imageDialog.dismiss(animated: true, completion: nil)
  }))
  self.present(imageDialog, animated: true, completion: nil)
}

Here, we create and UIAlertController with three options to select, one which presents the image picker controller, the second one removes the background wallpaper and the third dismisses the alert.

  1. Set the image as background view
// Callback when image is selected from gallery
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
  dismiss(animated: true, completion: nil)
  let chosenImage = info[UIImagePickerControllerOriginalImage] as? UIImage
  if let image = chosenImage {
    setBackgroundImage(image: image)
  }
}

We use the `didFinishPickingMediaWithInfo` delegate method to set the image as background. First we get the image using the the `info` dictionary using the `UIImagePickerControllerOriginalImage` key.

  1. Save the image in UserDefaults (encoding)
// Save image selected by user to user defaults
func saveWallpaperInUserDefaults(image: UIImage!) {
  let imageData = UIImageJPEGRepresentation(image!, 1.0)
  let defaults = UserDefaults.standard
  defaults.set(imageData, forKey: userDefaultsWallpaperKey)
}

We first convert the image to a data object using the `UIImageJPEGRepresentation` method followed by saving the data object in UserDefaults with the key `wallpaper`.

  1. Decode the data object back to UIImage 

Now whenever we need to decode the image, we simply get the data object from the UserDefaults and use it to display the image.

// Check if user defaults have an image data saved else return nil/Any
func getWallpaperFromUserDefaults() -> Any? {
  let defaults = UserDefaults.standard
  return defaults.object(forKey: userDefaultsWallpaperKey)
}

Below is the output when an image is selected and displayed as a background.

Resources:

Continue ReadingEncoding and Decoding Images as Data in UserDefaults in SUSI iOS