Basic introduction to android and android development

Transcript

1. Introduction to Android and Android app development BENJAMIN MASEBINU
2. Benjamin Masebinu ❖ Android engineer – PlanetNest ❖ Lead Engineer – Techatrek ❖ Lead organizer – GDG FUTA Social Media ❖ @benhaxe ❖ github.com/benhaxe Other Skills: ❖ Mobile UI/UX ❖ Firebase ❖ Nodejs
3. What we will learn today  What is android  Why develop for android  Android platform overview  Android app overview  Android app lifecycle  Android app fundamentals and building blocks(Activities/Fragments, Intent, Services, Broadcast Receiver, Content Provider/Content Resolver, )  Design  What we need to get started with android development
4. What is Android Android is the world’s most popular and dominant mobile operating system. It is based on Linux kernel 3.4/3.10 (depending on device) and is open-source (with proprietary bits). It runs on a wide variety of hardware, including smartphones, smart watches, cars, televisions, digital cameras and more. It was founded by Andy Rubin and three others in October 2003 and got acquired by Google in August 2005.
5. Why develop for android
6. Android is gigantic  Over 1B users  Over 1.5M activations per day  Over 200M smartphones running Android sold annually  Over 1.43M apps available  Over 76% smartphone operating system market share
7. Android is freedom  Thousands of third party libraries available  Free SDK, IDE and emulator  No restrictions; access anything*  Faster access to new form factors and hardware  Distribute your app anywhere (Playstore, Amazon Appstore, …)
8. Android platform overview
10. Android app overview
11. ► Java: Java class files containing app logic ► Res: Different resource files ► Anim: Animation resource files ► Drawable: Images ► Drawable-Xdpi: Images depending on screen density ► Layout: App layout files ► Menu: Layout menu files ► Values: Value files (strings, colors, arrays, etc) ► Values-vX: Value files depending on API level ► Values-Xdp: Value files depending on screen density ► XML: XML files (duh) ► AndroidManifest.xml: App metadata file ► build.gradle: Build related settings
12. Android app lifecycle
14. Please can we do something more interesting. Am so bored right now.
15. Android app fundamentals and building blocks
16. Activities  A presentation layer, window/interface of an application which a user can interact with  Every app has at least one activity, and an application can have several activities.  Activities can be ❖ Full-screen ❖ Floating ❖ Embedded inside another activity
17. How to start an activity Destination Activity Current Activity
18. Fragments  A piece of user interface that is meant to be reused  Adds modularity to your app and makes dynamic UI design easy  it has its own layout, behavior and lifecycle callbacks, but it killed/stop if the activity is too
19. How to start a fragment
20. Intents  An intent is an abstract description of an operation to be performed. Think of it as an “intention” to do something  Intents can be used to start activities, services or send a broadcast  Intents are of two types – Explicit (when you know what exactly you want to do), and Implicit (when you’re not sure what you want to do)
21. Use Cases  Implicit Intents ❖ One use case of Implicit intent is: take for example you want to open a link in a browser, and you have more than one browser, implicit intent helps you choose what browser you will like to open the defined link.  Explicit Intents ❖ The most used case of explicit intent is moving from activity to the other, and it can also be used to transfer data from one activity to the other.
22. Implicit Intents
23. Explicit Intents Destination Activity Current Activity
24. Services  A service is a long running operation in the background  There are two types of services in Android – Bounded (which runs as long as components which bind to it run) and Unbounded (which runs indefinitely) but a service can also be both  Services run on the main thread of the application by default  Faceless components that run in the background E.g. Music Player, Network download.
25. Broadcast Receiver  A broadcast is a system or app event that can be “broadcasted” so other apps/services can listen for it  Broadcasts are handled by a BroadcastReceiver, which is a component that allows you to listen for broadcasts  A BroadcastReceiver can be implemented in AndroidManifest.xml, or dynamically by calling registerReceiver(), or both  An app’s/services’s BroadcastReceiver is never called if the app/service hasn’t been explicitly started by the user. Battery level SMS Received Photo Captured System sends a broadcast App/Services
26. Content Providers / Resolvers  A content provider allows you to store data in your app in a structured way, similar to a relational database like SQL, for the purpose of providing it to other apps. Example usage: Contacts app, SMS app, etc  A content resolver allows you to get data from a content provider or manipulate its data (modify, delete, update, etc)  You cannot request to read data from a content provider at runtime, it has to be declared in AndroidManifest.xml App Database Update Delete Query
27. Designs
28. Layouts  A layout defines the visual structure for a user interface, such as the UI for an activity or app widget  Layouts can be defined both in XML or programmatically using View and ViewGroup objects  Some types of Layouts in Android: LinearLayout RelativeLayout FrameLayout & Constraint layout
29. Layouts
30. Views
31. Some other Code Sample
32. Interacting with the view through java codes
33. Interacting with the view through Kotlin codes
34. Layout file
35. What do I need to build an android app ?
36. Skills Java Programming language / Kotlin & XML
38. Tools Android SDK & SDK TOOLS
39. Environment Android Studio
40. Resources  https://developer.android.com  http://udacity.com
41. Thank You