CST 2301 Chapter 13.docx

CST 2301 Chapter 13

1. **Introduction to Android Sensors:**

- Android categorizes sensors into three types: motion, environment, and position sensors.

- Motion sensors measure device motion, environmental sensors measure environmental conditions, and position sensors measure physical device position.

- Examples of sensors include the accelerometer, proximity sensor, gyroscope, magnetic sensor, light sensor, and compass.

2. **Accelerometer Sensor:**

- Measures the acceleration force applied to a device on the (x, y, and z) axes.

- Data from the accelerometer can be used to detect movement, tilts, and vibrations.

- Common uses of the accelerometer include determining device orientation (portrait or landscape), device direction (up or down), and linear motion detection.

- The accelerometer operates within the device's coordinate system, with the x-axis pointing horizontally, the y-axis vertically, and the z-axis outward from the screen.

3. **Using the Accelerometer:**

- Utilizes Android APIs such as SensorManager, Sensors, SensorEvent, and SensorEventListener to read accelerometer data.

- Implementation involves six steps:

- Implementing the SensorEventListener interface.

- Getting Sensor Service and Sensor Manager objects.

- Displaying accelerometer readings.

- Calculating acceleration force.

- Registering listener for sensor events.

- Unregistering listener when not in use.

4. **Accelerometer App:**

- Demonstrates capturing changes in the x, y, and z axes.

- Changes background color in response to device movement.

- Provides code snippets for implementation, including displaying accelerometer data and calculating acceleration force.

1. **Retrieving Sensor Information:**

- Use `SensorManager` to get the list of sensors available on an Android device.

- Example code snippet:

```java

SensorManager mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);

List<Sensor> sensorList = mSensorManager.getSensorList(Sensor.TYPE_ALL);

```

2. **Location-Based Services:**

- Android provides classes like `LocationManager`, `LocationProvider`, and `Geocoder` for creating location-based apps.

- Key considerations for location-based apps:

- Respect user privacy by updating location only when necessary, informing the user about location tracking, etc.

- Two ways to get the user's location:

- Using `android.location.LocationListener` interface (part of Android Network Location API).

- Using `com.google.android.gms.location.LocationListener` API (Google Play Services API).

- Steps for developing location-based service apps:

1. **Permission:** Include permissions in `AndroidManifest.xml` for accessing location (`ACCESS_FINE_LOCATION` or `ACCESS_COARSE_LOCATION`).

2. **Obtaining Location Manager:** Use `LocationManager` to obtain location data.

3. **Obtaining Location Providers:** Android uses GPS_PROVIDER, NETWORK_PROVIDER, and PASSIVE_PROVIDER to get location.

4. **Geocoder:** Used for forward and reverse geocoding.

5. **Register LocationListener:** Receive notifications from `LocationManager` when the user's location changes.

6. **Location Manager Setup:** Set up `LocationManager` and specify location provider.

7. **Check and Request Permission:** Ask the user for permission to track their location.

8. **Refresh Current Location:** Use `LocationListener` to receive location change notifications.

9. **Use Geocoding:** Convert latitude and longitude to readable addresses using `Geocoder`.

Here are the key points from the provided text:

1. **Revising Weather App:**

- Using Android location API to retrieve user location for a weather app.

- Changes made to `DisplayAddress` class to initialize static variables for current city.

- Highlighted change in `WeatherForecastActivity` class where current city is added to the top of the spinner list.

2. **Do It Yourself:**

- Experiment with changing the value of `maxAddress` in the `geocoder.getFromLocation(latitude, longitude, 1)` line of code to observe address granularity.

3. **Use Google Maps in Your App:**

- Exploring how to include Google Maps in Android apps.

- Creating a new project using Android Studio and selecting the Google Maps template.

The provided text contains detailed instructions and explanations regarding the integration of Google Maps into an Android app. Here's a summary of the key points:

1. **Obtaining API Key:**

- Create a new project in Android Studio and select the Google Maps template.

- Navigate to the `google_maps_api.xml` file located in the values folder of the project.

- Replace the placeholder text "YOUR_KEY_HERE" with the obtained Google Maps API key.

- Update the `AndroidManifest.xml` file to include a meta-data element with the API key.

- Ensure that the necessary dependencies for Google Maps are added to the Gradle module of the app.

2. **Google Maps Integration:**

- Use fragments to add Google Maps to an activity. The `SupportMapFragment` class is commonly used for this purpose.

- Implement the `OnMapReadyCallback` interface to handle the map initialization.

- Call the `getMapAsync()` method to register a callback for when the map is ready.

- Configure initial map settings programmatically or via XML layout attributes.

- Use the `GoogleMap` class to interact with the map, such as adding markers, setting UI settings, etc.

3. **Covid App Integration:**

- Use location data to provide Covid information relevant to the user's area.

- Retrieve latitude and longitude from the user's location using the `Location` object.

- Match the user's location with data from a Covid XML file to provide updated Covid status information.

- Update the Covid app to include functionality that easily provides Covid data based on the user's location.