1. What's Happening Today Working with Images
What does this mean for the UI?
What does this mean for resources?
What about shaking things up?
What happens when you slip the schedule? …
...

2. Android Sensors
Sensors come in several flavors
We'll only use accelerometer in examples
Use is similar to other Android features
Register Sensor in AndroidManifest.XML
<uses-feature android:name="android.hardware.sensor.accelerometer" android:required="true" />

3. Registering/Using Sensor
Typical of Observable Design Pattern
AKA Publish Subscribe
Observer is registered with Observable, which typically could have several observers
See code for getting SensorManager and the sensor/accelerometer
RecyclerViewActivity

4. Create SensorEventListener
This is the Observer in design pattern
Standard Android, we use ShakeDetector and implement the Interface
Notice nested Interface in ShakeDetector
Register a listener with this detector, what is doing the listening? Activity indirectly

5. Activity Life Cycle
Code in onResume and onPause to handle the SensorManager and ShakeDetector
What might happen in onPause if not unregistered?
What does "listening" do? What's important in App management?
Sensor can continue to collect data, but not be able to do anything with data

6. Android aside in ShakeDetector
Notice float values in SensorManager
What about value returned Math.sqrt?
Is there an issue between float and double?
Documentation for Android says …
What are the key take-aways on that page?

7. Code to handle shakes …
Anonymous inner class to implement the OnShakeListener interface
Expedient (?) way to call a method in the Activity, note the local method
Take advantage of RecylerView Adapter
Attention to all components in Adapter, e.g., The ViewHolder
What happens in method updateList ?

8. Handling ClickEvents Another example of Observer pattern
How does this happen with CardView?
Examine RecyclerView.ViewHolder …
Is this bound to position? How to test?
What if we wanted to do more with click, not simply create a Toast
How do we notify another Activity?

9. What is an Intent? Start one activity from another Start a service
Launch when something happens
Start a service
Camera, phone, music player
Broadcast message (app or service)
Apps can respond

10. Intent basics Create Intent, provide Activity class
Launch with method startActivity
Store "extras" in intent to pass information from one activity to another
Can also start activity and "wait" for result
See these examples later