Closes mozilla-mobile#1346: Add ReaderView feature component

Author: csadilek

.buildconfig.yml

@@ -52,6 +52,10 @@ projects:
     path: components/feature/intent
     description: 'Combining various feature components for intent processing.'
     publish: true
+  feature-readerview:
+    path: components/feature/readerview
+    description: 'Feature implementation providing a Reader View WebExtension.'
+    publish: true
   feature-search:
     path: components/feature/search
     description: 'Feature implementation connecting an engine implementation with the search module.'

README.md

@@ -118,6 +118,8 @@ _Combined components to implement feature-specific use cases._
 
 * 🔴 [**Progressive Web Apps (PWA)**](components/feature/pwa/README.md) - A component that provides functionality for supporting Progressive Web Apps (PWA).
 
+* 🔴 [**Reader View**](components/feature/readerview/README.md) - A component that provides Reader View functionality.
+
 * ⚪ [**QR**](components/feature/qr/README.md) - A component that provides functionality for scanning QR codes.
 
 * 🔴 [**Search**](components/feature/search/README.md) - A component that connects an (concept) engine implementation with the browser search module.

components/feature/readerview/README.md

@@ -0,0 +1,49 @@
+# [Android Components](../../../README.md) > Feature > Reader View
+
+ A component wrapping/providing a Reader View WebExtension.
+
+## Usage
+
+### Setting up the dependency
+
+Use Gradle to download the library from [maven.mozilla.org](https://maven.mozilla.org/) ([Setup repository](../../../README.md#maven-repository)):
+
+```Groovy
+implementation "org.mozilla.components:feature-readerview:{latest-version}"
+```
+
+### Integration
+
+Initializing the feature:
+
+```kotlin
+val readerViewFeature = ReaderViewFeature(
+    context,
+    engine,
+    sessionManager,
+    onReaderViewAvailableChange = {
+    	// e.g. readerViewToolbarActionVisible = it
+    }
+)
+
+```
+
+Showing and hiding Reader View:
+
+```kotlin
+readerViewFeature.showReaderView()
+readerViewFeature.hideReaderView()
+```
+
+Showing and hiding the Reader View appearance UI (to adjust font size, font type and color scheme). Note that changes to the appearance settings are automatically persisted as user preferences.
+
+```kotlin
+readerViewFeature.showAppearanceControls()
+readerViewFeature.hideAppearanceControls()
+```
+
+## License
+
+    This Source Code Form is subject to the terms of the Mozilla Public
+    License, v. 2.0. If a copy of the MPL was not distributed with this
+    file, You can obtain one at http://mozilla.org/MPL/2.0/

components/feature/readerview/build.gradle

@@ -0,0 +1,46 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+apply plugin: 'com.android.library'
+apply plugin: 'kotlin-android'
+
+android {
+    compileSdkVersion config.compileSdkVersion
+
+    defaultConfig {
+        minSdkVersion config.minSdkVersion
+        targetSdkVersion config.targetSdkVersion
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+}
+
+dependencies {
+    implementation project(':browser-menu')
+    implementation project(':browser-session')
+    implementation project(':concept-engine')
+    implementation project(':support-base')
+    implementation project(':support-ktx')
+    implementation project(':support-utils')
+    implementation project(':ui-icons')
+
+    implementation Dependencies.kotlin_stdlib
+    implementation Dependencies.kotlin_coroutines
+
+    api Dependencies.support_customtabs
+
+    testImplementation project(':support-test')
+    testImplementation Dependencies.androidx_test_core
+    testImplementation Dependencies.testing_junit
+    testImplementation Dependencies.testing_robolectric
+    testImplementation Dependencies.testing_mockito
+}
+
+apply from: '../../../publish.gradle'
+ext.configurePublish(config.componentsGroupId, archivesBaseName, project.ext.description)

components/feature/readerview/proguard-rules.pro

@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

components/feature/readerview/src/main/AndroidManifest.xml

@@ -0,0 +1,5 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="mozilla.components.feature.readerview" />

components/feature/readerview/src/main/assets/extensions/readerview/manifest.json

@@ -0,0 +1,13 @@
+{
+  "manifest_version": 2,
+  "name": "Mozilla Android Components - ReaderView",
+  "version": "1.0",
+  "content_scripts": [
+    {
+      "matches": ["*://*/*"],
+      "js": ["readability/readability-0.2.0.js", "readability/readability-readerable-0.2.0.js", "moment/moment-2.24.0.js", "readerview.js"],
+      "css": ["readerview.css"],
+      "run_at": "document_end"
+    }
+  ]
+}