Android Architecture

Architecture

Typical Android apps look like this And this Looking at this I am building an app with the architecture of The was discussion on god class which I had not heard before

• Contains a high number of components
• Components are coupled
• Lengthy class

Avoid a all costs or don't cos I like getting rid of them

Design Patterns

Just a reminder of the design patterns but with maybe a more Android flare.

MVC

MVP

MVVM

Summary

Clean Architecture

Activity Lifecycle

Here is a simplified version of the lifecycle By implementing the addObserver and don't forget the removeObserver the functions in the component (object instance) are envoked.

Application Tidy Up

Introduction

Here is an overview of the app prior to looking at it. All of the code is in on Main Activity

Step 1

• Created TrackerActivity which extends AppCompatActivity and will be now good for other activities
• Move Tracker to its own class and implement the Lifecycle Observer interface
• When using lifecycle observer we need to remote it on destory

    @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
    public void trackOnDestroy() {
        Log.d(TAG, "trackOnDestroy called");
        ((AppCompatActivity) con).getLifecycle().removeObserver(this);
        // mQueue.add(generateTrackingStringRequest("destroy"));
    }

Step 2

• Moved CoinModel, Divider and MyCryptoAdapter to their own files in recview package
• Add LocationManager, implemented lifecycle observer
• Added create and destruction of FusedLocationProviderClient in lifecyle
• Added disconnect of GoogleAPiClient and removal of lifecycle observer

    @OnLifecycleEvent(Lifecycle.Event.ON_START)
    public void init() {
        Log.d(TAG, "init() called");
        mFusedLocationClient = LocationServices.getFusedLocationProviderClient(mCon);
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
    public void clean() {
        Log.d(TAG, "clean() called");
        if(mGoogleApiClient !=null) {
            mGoogleApiClient.disconnect();
        }
        final LifecycleOwner lcOwner = (LifecycleOwner)mCon;
        lcOwner.getLifecycle().removeObserver(this);
        mCon = null;
    }

Step 3

• Created a LocationActivity to contain all of the logic for the runtime permission to use Location
• Add LocationManger to LocationActivity
• Change MainActivity to be derived from LocationActivity

Current State 01