No source file named android

Organizing your Source Files

Android applications should always be neatly organized with a clear folder structure that makes your code easy to read. In addition, proper naming conventions for code and classes are important to ensure your code is clean and maintainable.

Be sure to check out the Ribot Code and Style Guidelines for a more extensive breakdown of suggested style and naming guidelines.

The following naming and casing conventions are important for your Java code:

Type	Example	Description	Link
Variable	incomeTaxRate	All variables should be camel case	Read More
Constant	DAYS_IN_WEEK	All constants should be all uppercase	Read More
Method	convertToEuroDollars	All methods should be camel case	Read More
Parameter	depositAmount	All parameter names should be camel case	Read More

See this naming guide for more details.

Android classes should be named with a particular convention that makes their purpose clear in the name. For example all activities should end with Activity as in MoviesActivity . The following are the most important naming conventions:

Name	Convention	Inherits
Activity	CreateTodoItemActivity	AppCompatActivity , Activity
List Adapter	TodoItemsAdapter	BaseAdapter , ArrayAdapter
Database Helper	TodoItemsDbHelper	SQLiteOpenHelper
Network Client	TodoItemsClient	N/A
Fragment	TodoItemDetailFragment	Fragment
Service	FetchTodoItemService	Service , IntentService

Use your best judgement for other types of files. The goal is for any Android-specific classes to be identifiable by the suffix.

There are several best practices for organizing your app’s package structure.

The way to do this is to group things together by their category. Each component goes to the corresponding package:

• com.example.myapp.activities — Contains all activities
• com.example.myapp.adapters — Contains all custom adapters
• com.example.myapp.models — Contains all our data models
• com.example.myapp.network — Contains all networking code
• com.example.myapp.fragments — Contains all fragments
• com.example.myapp.utils — Contains all helpers supporting code.
• com.example.myapp.interfaces — Contains all interfaces

Keeping these folders in each app means that code is logically organized and scanning the code is a pleasant experience. You can see a slight variation on this structure as suggested by Futurice on their best-practices repo.

Alternatively, we can package-by-feature rather than layers. This approach uses packages to reflect the feature set. Consider the following package structure as outlined in this post:

• com.example.myapp.service.* — Is a subpackage for all background related service packages/classes
• com.example.myapp.ui.* — Is a subpackage for all UI-related packages/classes
• com.example.myapp.ui.mainscreen — Contains classes related to some app’s Main Screen
• com.example.myapp.ui.detailsscreen — Contains classes related to some app’s Item Details Screen

This feature allows you to place DetailsActivity , DetailsFragment , DetailsListAdapter , DetailsItemModel in one package, which provides comfortable navigation when you’re working on «item details» feature.

DetailsListAdapter and DetailsItemModel classes and/or their properties can be made package-private, and thus not exposed outside of the package. Within the package you may access their properties directly without generating tons of boilerplate «setter» methods.

This can make object creation really simple and intuitive, while objects remain immutable outside the package.

Resources should be split up into the following key files and folders:

Name	Path	Description
XML Layouts	res/layout/	This is where we put our XML layout files.
XML Menus	res/menu/	This is where we put our AppBar menu actions.
Drawables	res/drawable	This is where we put images and XML drawables.
Colors	res/values/colors.xml	This is where we put color definitions.
Dimensions	res/values/dimens.xml	This is where we put dimension values.
Strings	res/values/strings.xml	This is where we put strings.
Styles	res/values/styles.xml	This is where we put style values.

See the full list of resources here and note the following:

• Don’t hardcode color hex values in the layout. Instead of hardcoding these values, be sure to move all colors into res/values/colors.xml and reference the colors in layouts with @color/royal_blue .
• Don’t hardcode margin / padding dimensions in the layout. Instead of hardcoding these values, be sure to move all dimension values into res/values/dimens.xml and reference these in layouts with @dimen/item_padding_left .
• To support multiple devices, we can then use the alternative resources system to provide different colors, strings, dimens, styles, etc based on the device type, screen size, API version and much more.

Be sure to start properly organizing your resources early on in the development of an application. Be sure to check out the Ribot Code and Style Guidelines for a more extensive breakdown of suggested style and naming guidelines.

Often there are questions about organizing not just the source files but also better organizing the application resources. In a modern app, there are often hundreds of different layout files, drawables, styles, etc and by default these are all grouped together in a flat list within a single subdirectory (i.e res/layout ). For now, keep the layout resource files in the same directory.

Refer to stackoverflow post for a discussion of explored options. The main problem is that if you try to use the nested resource layout approach, the current logic for the Android Studio’s Gradle plug-in will not update the resource files after they have changed for nested resource sets. The current implementation attempts to check the resource directories using startsWith(), so a directory structure that is nested (i.e. src/main/res/layout/layouts and src/main/res/layout/layouts_category2) will choose src/main/res/layout/layouts consistently and never actually update the changes. A result, you will you have to rebuild/clean the project each time whenever making layout file changes.

It is up to you to decide which of the aforementioned approaches suits your project best.

However, in general Java programming, packaging apps by feature is considered preferable and makes a lot of sense.

Источник

Open Source Your Android Code — The Complete Guide

ADA | Adam Deconstructs Android

Aug 29, 2017 · 8 min read

9/17/17 Update: JitPack.io appears to be a fast and easy alternative to open source Android code vs. the method below by integrating directly with GitHub. I have not tested JitPack so please share your feedback in the comments if you’ve implemented it.

You’ve spent hours building cool shit. What’s the next step? By open sourcing your work you’ll (hopefully) provide valuable code to the Android community, receive constructive feedback, and collaborate on building something better than what you originally had.

The current state of open sourcing for Android is unintuitive, involving integrating multiple services, waiting for manual approvals, and before this post, spending hours Googling obscure steps. That’s why I created a beginning-to-end guide to expedite the process.

The more open sourced code, the better.

Implementation

I will walk through each step of how I open sourced a CustomRippleView library for Android.

Place code inside an Android Archive Library (AAR) — Step 1 of 6

Besides open sourcing, AARs are useful when building multiple apps or versions with the same components.

About

• Structurally the same as an Android app module
• Includes source code, resource files, manifest (unlike JAR)
• Compiles into Android Archive (AAR) rather than into APK
• Post to some maven repository where devs can pull it as a dependency through Gradle (can also convert an app to a module)
• Code Overlap — The app module will take precedence over a library if a resource ID is defined in both, library defined first will take precedence between libraries.

Implementation

If you’re creating a standalone library outside an existing app you’ll want to both create a new project to host the library module as well as test the library module in an existing app.

1. Build the open sourced library module in an existing project so that you can test the code as you go.

a) Create library module

Click the plus or File > New > Module > Android Library > provide unique Library Module Name ( customrippleview)

b) Ensure local library module shows in project and compile local library in the app module.

build.gradle ( app module)

Add tools:replace=”android:name” to the app module’s Manifest file.

2. Create a new Android project to host the open source code by itself so that it can be uploaded to bintray

Create the default app module with app following the name ( customrippleviewapp) to differentiate the app module name from the open source library module we’ll create in the next step.

• Application name: CustomRippleViewApp
• Company domain: com.ebay.customrippleviewapp ( needs to be a domain you own in order to get approved for open sourcing)
• Package name: com.ebay.customrippleviewapp

3. Add your library module (refer to step 1A above)

4. Place the open source code inside new library module created

5. Remove original app module

Right-click on app module > Open Module Settings > remove original app module.

6. Choose resources to make public (Optional)

All resources default to public: By declaring at least one resource public it makes the rest private

res > values > public.xml

Publish library publicly on GitHub with licensing and Docs — Step 2 of 6

Apache License 2.0 is one of the most popular, similar to the MIT License, but provides grant of patent rights from contributors to users. Apache 2.0 is commonly found in Android, Apache, and Swift.

Make sure library module ( customrippleview/) and build.gradle are not in the ignore list list and edit .gitignore to only contain library module files added.

Bintray and Sonatype Setup — Step 3 of 6

You only need to go through this painful steps once to setup your bintray account. Praise the lord! As this isn’t difficult, but the most annoying step.

Bintray Implementation

2. Create new repository

a) Add New Repository → Type: Maven → Default Licenses: Apache 2.0

b) Use lowercase naming convention: customrippleview

3. Enable auto signing

Enter Repository → Edit → General Settings → select GPG sign uploaded files automatically

a) Generate keys (Only done once for bintray account)

In terminal for project:

Fill in Real name, Email address, and passphrase. If command does not work, run following command to install gpg and retry the command above.

View keys created

Upload the public key to keyservers. Call the following command and replace PUBLIC_KEY_ID with value after 2048 in the pub line.

Export both public and private key.

Enter your passphrase when prompted for private key.

Copy and paste public and private keys into bintray: Under profile Edit > GPG Signing. Make sure to copy and paste from beginning and end tags or else bintray will not accept the keys.

Sonatype Implementation

This step requires filling a Jira ticket. If you thought you could escape Jira in your free coding time, you’re mistaken. It’s not too bad, as both times I’ve submitted a ticket they’ve approved it within the same day.

3. Provide bintray your Sonatype OSS username

In your bintray profile Edit > Accounts > Sonatype OSS User: _____________

Prepare Project for Upload — Step 4 of 6

Prepare Library Module With Bintray

1. Add Jcenter and Maven dependency

Add to project’s build.gradle (not app or library build.gradle)

2. Define your bintray username, api key, and GPG Passphrase.

This info should be secure, which is why we’re adding it to local.properties which should not be tracked in GitHub as it is commonly ignored at the start of an Android project in the .gitignore file.

3. Add repository information and build scripts

Update library’s build.gradle with repository information and add scripts for building library files and uploading the built files to bintray.

4. If using Kotlin in your code, disable Javadocs in library’s build.gradle

Upload to jcenter— Step 5 of 6

Why is jcenter better than maven central?

• Delivers library through CDN → faster loading
• Largest Java Repository on earth
• “Friendly” UI (perhaps in comparison)

Implementation

1. Upload to bintray/jcenter (Once Sonatype Open Source Project Repository Hosting request is approved)

Expected Result: BUILD SUCCESSFUL

Expected Result: BUILD SUCCESSFUL

I kept getting the BUILD FAILED response when attempting to upload. After many hours cursing at my terminal I realized even with this message, the package was being uploaded, so check the bintray package UI.

2. Sync to Jcenter for easy one line implementation in Android

3 hrs — How is this not automated too?!

a) Under the uploaded package settings select Add to JCenter

b) Select Host my snapshot…, fill in group id for package, and Select Send

Once approved, you’ll receive an email.

In the meantime you can check by searching on bintray which will also show when your package is hosted.

3. Maintaining library

Linking to jcenter only needs to be done once. Moving forward, any package changes (updates, deletes), will be reflected in jcenter 2–3 min later.

• Updates: Change the libraryVersion in library module and re-upload using Step 5, part 1.
• Deleting: Remove each version from bintray before removing the entire package.

Use In Project — Step 6 of 6

Declare the library in gradle and call the desired files.

build.gradle ( app module)

• Group_Id — com.ebay.customrippleview(package name followed by group name)
• Artifact_Id: customrippleview
• Version: 1.0

Resources

• JitPack.io — JitPack is an Android specific open sourcing solution that appears to work seamlessly with GitHub repositories. For a premium, JitPack also provides private library hosting. I haven’t given it a try, but thanks to Rakshak and Vikarti for calling it out in the comments below!
• The Cheese Factory Blog — How to distribute your own Android library through jCenter and Maven Central from Android Studio. BIG thanks! There were details that changed since this was published in 2015, but it was a great place to start.
• Android Studio — Create an Android Library
• bintray
• sonatype
• sonatype — request to host new open source project ( only works when logged in to sonatype)
• bintray documentation — Including your Package in JCenter
• CustomRippleView GitHub sample and JCenter hosting

I’m Adam Hurwitz — hit the clapping hands icon and check out the rest of my writing if you enjoyed the above | Thanks!

Источник