For #162 - remove dependency to play-services-oss-licenses library

app/build.gradle

@@ -330,7 +330,6 @@ dependencies {
     implementation Deps.androidx_coordinatorlayout
 
     implementation Deps.sentry
-    implementation Deps.osslicenses_library
 
     implementation Deps.leanplum_core
     implementation Deps.leanplum_fcm

app/src/main/AndroidManifest.xml

@@ -228,13 +228,8 @@
         <activity android:name=".settings.account.AuthIntentReceiverActivity"
             android:exported="false" />
 
-        <activity android:name="com.google.android.gms.oss.licenses.OssLicensesMenuActivity"
-            android:exported="false"
-            android:theme="@style/Theme.AppCompat.DayNight.DarkActionBar"/>
-
-        <activity android:name="com.google.android.gms.oss.licenses.OssLicensesActivity"
-            android:exported="false"
-            android:theme="@style/Theme.AppCompat.DayNight.DarkActionBar"/>
+        <activity android:name=".settings.about.AboutLibrariesActivity"
+            android:exported="false" />
 
         <service android:name=".media.MediaService"
             android:exported="false" />

app/src/main/java/org/mozilla/fenix/settings/about/AboutFragment.kt

@@ -13,7 +13,6 @@ import android.view.ViewGroup
 import androidx.core.content.pm.PackageInfoCompat
 import androidx.fragment.app.Fragment
 import androidx.recyclerview.widget.DividerItemDecoration
-import com.google.android.gms.oss.licenses.OssLicensesMenuActivity
 import kotlinx.android.synthetic.main.fragment_about.*
 import org.mozilla.fenix.BrowserDirection
 import org.mozilla.fenix.BuildConfig
@@ -168,13 +167,8 @@ class AboutFragment : Fragment(), AboutPageListener {
     }
 
     private fun openLibrariesPage() {
-        startActivity(Intent(context, OssLicensesMenuActivity::class.java))
-        OssLicensesMenuActivity.setActivityTitle(
-            getString(
-                R.string.open_source_licenses_title,
-                appName
-            )
-        )
+        val intent = Intent(requireContext(), AboutLibrariesActivity::class.java)
+        startActivity(intent)
     }
 
     override fun onAboutItemClicked(item: AboutItem) {

app/src/main/java/org/mozilla/fenix/settings/about/AboutLibrariesActivity.kt

@@ -0,0 +1,120 @@
+/* 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/. */
+
+package org.mozilla.fenix.settings.about
+
+import android.graphics.Typeface
+import android.os.Bundle
+import android.text.util.Linkify
+import android.widget.ArrayAdapter
+import android.widget.ListView
+import android.widget.TextView
+import androidx.appcompat.app.AlertDialog
+import androidx.appcompat.app.AppCompatActivity
+import org.mozilla.fenix.R
+import java.nio.charset.Charset
+import java.util.Locale
+
+/**
+ * Displays the licenses of all the libraries used by Fenix.
+ *
+ * This is a re-implementation of play-services-oss-licenses library.
+ * We can't use the official implementation in the OSS flavor of Fenix
+ * because it is proprietary and closed-source.
+ *
+ * There are popular FLOSS alternatives to Google's plugin and library
+ * such as AboutLibraries (https://github.com/mikepenz/AboutLibraries)
+ * but we considered the risk of introducing such third-party dependency
+ * to Fenix too high. Therefore, we use Google's gradle plugin to
+ * extract the dependencies and their licenses, and this activity
+ * to show the extracted licenses to the end-user.
+ */
+class AboutLibrariesActivity : AppCompatActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        val appName = getString(R.string.app_name)
+        title = getString(R.string.open_source_licenses_title, appName)
+        setContentView(R.layout.about_libraries_activity)
+
+        setSupportActionBar(findViewById(R.id.toolbar))
+        supportActionBar?.setDisplayHomeAsUpEnabled(true)
+        supportActionBar?.setDisplayShowHomeEnabled(true)
+
+        setupLibrariesListView()
+    }
+
+    override fun onSupportNavigateUp(): Boolean {
+        onBackPressed()
+        return true
+    }
+
+    private fun setupLibrariesListView() {
+        val libraries = parseLibraries()
+        val listView = findViewById<ListView>(R.id.about_libraries_listview)
+        listView.adapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, libraries)
+        listView.setOnItemClickListener { _, _, position, _ ->
+            showLicenseDialog(libraries[position])
+        }
+    }
+
+    private fun parseLibraries(): List<LibraryItem> {
+        /*
+            The gradle plugin "oss-licenses-plugin" creates two "raw" resources:
+
+               - third_party_licenses which is the binary concatenation of all the licenses text for
+                 all the libraries. License texts can either be an URL to a license file or just the
+                 raw text of the license.
+
+               - third_party_licenses_metadata which contains one dependency per line formatted in
+                 the following way: "[start_offset]:[length] [name]"
+
+                 [start_offset]     : first byte in third_party_licenses that contains the license
+                                      text for this library.
+                 [length]           : length of the license text for this library in
+                                      third_party_licenses.
+                 [name]             : either the name of the library, or its artifact name.
+
+            See https://github.com/google/play-services-plugins/tree/master/oss-licenses-plugin
+        */
+        val licensesData = resources
+            .openRawResource(R.raw.third_party_licenses)
+            .readBytes()
+        val licensesMetadataReader = resources
+            .openRawResource(R.raw.third_party_license_metadata)
+            .bufferedReader()
+
+        return licensesMetadataReader.use { reader -> reader.readLines() }.map { line ->
+            val (section, name) = line.split(" ", limit = 2)
+            val (startOffset, length) = section.split(":", limit = 2).map(String::toInt)
+            val licenseData = licensesData.sliceArray(startOffset until startOffset + length)
+            val licenseText = licenseData.toString(Charset.forName("UTF-8"))
+            LibraryItem(name, licenseText)
+        }.sortedBy { item -> item.name.toLowerCase(Locale.ROOT) }
+    }
+
+    private fun showLicenseDialog(libraryItem: LibraryItem) {
+        val dialog = AlertDialog.Builder(this)
+            .setTitle(libraryItem.name)
+            .setMessage(libraryItem.license)
+            .create()
+        dialog.show()
+
+        val textView = dialog.findViewById<TextView>(android.R.id.message)!!
+        Linkify.addLinks(textView, Linkify.ALL)
+        textView.linksClickable = true
+        textView.textSize = LICENSE_TEXT_SIZE
+        textView.typeface = Typeface.MONOSPACE
+    }
+
+    companion object {
+        private const val LICENSE_TEXT_SIZE = 10F
+    }
+}
+
+private class LibraryItem(val name: String, val license: String) {
+    override fun toString(): String {
+        return name
+    }
+}

app/src/main/res/layout/about_libraries_activity.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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/. -->
+
+<RelativeLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/about_libraries"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:fillViewport="true"
+    tools:context="org.mozilla.fenix.settings.about.AboutLibrariesActivity">
+    <androidx.appcompat.widget.Toolbar
+        android:id="@+id/toolbar"
+        android:layout_width="match_parent"
+        android:layout_height="?attr/actionBarSize"
+        android:background="?attr/colorPrimary"
+        android:elevation="4dp"
+        android:theme="@style/ThemeOverlay.AppCompat.ActionBar" />
+    <ListView
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:id="@+id/about_libraries_listview" />
+</RelativeLayout>

app/src/test/java/org/mozilla/fenix/settings/about/AboutLibrariesActivityTest.kt

@@ -0,0 +1,45 @@
+/* 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/. */
+
+package org.mozilla.fenix.settings.about
+
+import android.widget.ListView
+import android.widget.TextView
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mozilla.fenix.R
+import org.mozilla.fenix.helpers.FenixRobolectricTestRunner
+import org.robolectric.Robolectric
+import org.robolectric.Shadows.shadowOf
+import org.robolectric.shadows.ShadowAlertDialog
+
+@RunWith(FenixRobolectricTestRunner::class)
+class AboutLibrariesActivityTest {
+    @Test
+    fun `activity should display licenses`() {
+        val activity = Robolectric.buildActivity(AboutLibrariesActivity::class.java).create().get()
+        val listView = activity.findViewById<ListView>(R.id.about_libraries_listview)
+
+        assertTrue(0 < listView.count)
+    }
+
+    @Test
+    fun `item click should open license dialog`() {
+        val activity = Robolectric.buildActivity(AboutLibrariesActivity::class.java).create().get()
+
+        val listView = activity.findViewById<ListView>(R.id.about_libraries_listview)
+        val listViewShadow = shadowOf(listView)
+        listViewShadow.clickFirstItemContainingText("org.mozilla.geckoview:geckoview")
+
+        val alertDialogShadow = ShadowAlertDialog.getLatestDialog()
+        assertTrue(alertDialogShadow.isShowing)
+
+        val alertDialogText = alertDialogShadow
+            .findViewById<TextView>(android.R.id.message)
+            .text
+            .toString()
+        assertTrue(alertDialogText.contains("MPL"))
+    }
+}

buildSrc/src/main/java/Dependencies.kt

@@ -10,7 +10,6 @@ object Versions {
     const val leakcanary = "2.4"
     const val leanplum = "5.4.0"
     const val osslicenses_plugin = "0.9.5"
-    const val osslicenses_library = "17.0.0"
     const val detekt = "1.9.1"
 
     const val androidx_appcompat = "1.2.0-rc01"
@@ -59,7 +58,6 @@ object Deps {
 
     const val allopen = "org.jetbrains.kotlin:kotlin-allopen:${Versions.kotlin}"
     const val osslicenses_plugin = "com.google.android.gms:oss-licenses-plugin:${Versions.osslicenses_plugin}"
-    const val osslicenses_library = "com.google.android.gms:play-services-oss-licenses:${Versions.osslicenses_library}"
 
     const val mozilla_concept_engine = "org.mozilla.components:concept-engine:${Versions.mozilla_android_components}"
     const val mozilla_concept_menu = "org.mozilla.components:concept-menu:${Versions.mozilla_android_components}"