Catalog Android Sample App

(CASA or "Home" in Spanish)

A framework to bootstrap the creation of catalog samples apps by removing all the boilerplate and dynamically including all available samples into a single activity.

🚧 Work in-progress: this is an experiment project and it is under heavy development, APIs might change frequently.

How to use it

Three main steps:

1. Setup project structure
2. Create catalog-app
3. Create sample modules

Note: you can also check the app-catalog folder for an example.

Setup project structure

Create a project with the following structure (names can be changed):

• app
• samples/
  • first
  • second

Note: the framework supports nested folders too (e.g samples/folder/first, samples/folder/second..)

For example, the settings.gradle might look like this:

include ':app'
include ':samples:sampleOne'
include ':samples:sampleTwo'
// ...other samples

Create catalog-app

This will be the application module that wires all the samples under a single app. It requires three steps:

1. Set up build.gradle
2. Create the catalog activity and app classes
3. Setup AndroidManifest.xml
4. [Optional] provide sourcecode, documentation and bug report URLs

In the app module's build.gradle include the framework dependencies, Hilt and KAPT plugins:

plugins {
    id 'com.android.application'
    id 'org.jetbrains.kotlin.android'
    id 'kotlin-kapt'
    id 'dagger.hilt.android.plugin'
}

android {
    // your app's configuration
}

dependencies {
    implementation "com.google.android.catalog.framework:casa-ui:$version"

    implementation "com.google.dagger:hilt-android:2.44.2"
    kapt "com.google.dagger:hilt-android-compiler:2.44.2"

    // include all module samples.
}

Then, create a new Activity that extends CatalogActivity and add the Hilt wiring for the Application and Activity entry points:

@HiltAndroidApp
class MainApp : Application()

@AndroidEntryPoint
class MainActivity : CatalogActivity()

Finally, don't forget to declare them in the AndroidManifest.xml:

<application android:name=".MainApp" android:allowBackup="true">

    <activity android:name=".MainActivity" android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

</application>

The framework provides quick access to the sourcecode, documentation, bug report or owner of a sample in the default UI toolbar.

To enable it, provide the base URLs and use the @Sample annotation parameters

<resources>
  <string name="app_name">app-catalog</string>
  <string name="source_base_url">https://github.com/google/casa-android/tree/main/app-catalog/samples/%1$s</string>
  <string name="documentation_base_url">https://github.com/google/casa-android</string>
  <string name="bug_report_url">https://github.com/google/casa-android/issues/new?assignees=&amp;labels=&amp;template=bug_report.md&amp;title=%1$s</string>
  <!-- owner as github username -->
  <string name="owner_base_url">https://github.com/%1$s</string>
  <!-- owner as email -->
  <string name="owner_base_url">mailto://%1$s</string>
</resources>

Note: the resources can take one optional string argument by adding %1$s.

Create sample modules

Place any new samples under the samples folder and for each new module add the framework dependencies and plugins in their build.gradle files:

plugins {
    id 'com.android.library'
    id 'kotlin-android'
    id 'kotlin-kapt'
    id "com.google.devtools.ksp"
    id 'dagger.hilt.android.plugin'
}

android {
    // your configuration
}

// See https://kotlinlang.org/docs/ksp-quickstart.html#make-ide-aware-of-generated-code
kotlin {
  sourceSets {
    main.kotlin.srcDirs += 'build/generated/ksp/main/kotlin'
    test.kotlin.srcDirs += 'build/generated/ksp/test/kotlin'
  }
}

dependencies {
    implementation "com.google.android.catalog.framework:casa-base:$version"
    ksp "com.google.android.catalog.framework:casa-processor:$version"

    implementation "com.google.dagger:hilt-android:2.44.2"
    kapt "com.google.dagger:hilt-android-compiler:2.44.2"

    // other dependencies like compose
}

Then create as many entry points as desired by annotating any composable function, activity or fragment with the @Sample annotation:

@Sample(
  name = "Compose sample",
  description = "Shows how to add a compose target in the catalog",
  documentation = "https://github.com/google/casa-android#create-sample-modules"
)
@Composable
fun ComposeSample() {
  Box(Modifier.fillMaxSize()) {
    Text(text = "Hi, I am a compose sample target!")
  }
}

Each entry point will be automatically included in the main app and displayed for you.

Launch a specific sample

To launch a specific sample from Android Studio you can pass the sample name or the sample path via the am start command using the -e parameter and the CatalogActivity.KEY_START key value.

-e start "Name of the sample as defined in the @Sample annotation

Contributions

Please contribute! We will gladly review any pull requests. Make sure to read the Contributing page first though.