Closes #4075: Add Feature Flag class (#4077)

app/build.gradle

@@ -259,14 +259,6 @@ android.applicationVariants.all { variant ->
         buildConfigField 'String', 'LEANPLUM_TOKEN', 'null'
         println("X_X")
     }
-
-// -------------------------------------------------------------------------------------------------
-// Feature build flags
-// -------------------------------------------------------------------------------------------------
-    // NB: flipping SEND_TAB_ENABLED flag back and worth is currently not well supported and may need hand-holding.
-    // Consult with the android-components peers before changing.
-    buildConfigField 'Boolean', 'SEND_TAB_ENABLED', (buildType == "nightly" || buildType == "nightlyLegacy" || isDebug).toString()
-    buildConfigField 'Boolean', 'PULL_TO_REFRESH_ENABLED', (false).toString()
 }
 
 androidExtensions {

app/src/main/java/org/mozilla/fenix/FeatureFlags.kt

@@ -0,0 +1,32 @@
+package org.mozilla.fenix
+
+/**
+ * A single source for setting feature flags that are mostly based on build type.
+ */
+object FeatureFlags {
+    // A convenience flag for production builds.
+    private val production by lazy { BuildConfig.BUILD_TYPE == "production" }
+    // A convenience flag for beta builds.
+    private val beta by lazy { BuildConfig.BUILD_TYPE == "beta" }
+    // A convenience flag for the nightly build and (legacy) nightly channel in Google Play.
+    private val nightly by lazy { BuildConfig.BUILD_TYPE == "nightly" || BuildConfig.BUILD_TYPE == "nightlyLegacy" }
+    // A convenience flag for debug builds.
+    private val debug by lazy { BuildConfig.BUILD_TYPE == "debug" }
+
+    /**
+     * Send Tab is a feature to lets you send a url/tab from a desktop to device and vice versa.
+     *
+     * NB: flipping this flag back and worth is currently not well supported and may need
+     * hand-holding. Consult with the android-components peers before changing.
+     *
+     * This flag is temporarily also used for the push service that is requires it to.
+     * See: https://github.com/mozilla-mobile/fenix/issues/4063
+     */
+    val sendTabEnabled = nightly || debug
+
+    /**
+     * Pull-to-refresh allows you to pull the web content down far enough to have the page to
+     * reload.
+     */
+    const val pullToRefreshEnabled = false
+}

app/src/main/java/org/mozilla/fenix/browser/BrowserFragment.kt

@@ -57,7 +57,7 @@ import mozilla.components.support.base.feature.BackHandler
 import mozilla.components.support.base.feature.ViewBoundFeatureWrapper
 import mozilla.components.support.ktx.android.view.exitImmersiveModeIfNeeded
 import org.mozilla.fenix.BrowsingModeManager
-import org.mozilla.fenix.BuildConfig
+import org.mozilla.fenix.FeatureFlags
 import org.mozilla.fenix.FenixViewModelProvider
 import org.mozilla.fenix.HomeActivity
 import org.mozilla.fenix.IntentReceiverActivity
@@ -343,7 +343,7 @@ class BrowserFragment : Fragment(), BackHandler {
             view = view
         )
 
-        if (BuildConfig.PULL_TO_REFRESH_ENABLED) {
+        if (FeatureFlags.pullToRefreshEnabled) {
             val primaryTextColor = ThemeManager.resolveAttribute(R.attr.primaryText, requireContext())
             view.swipeRefresh.setColorSchemeColors(primaryTextColor)
             swipeRefreshFeature.set(

app/src/main/java/org/mozilla/fenix/components/BackgroundServices.kt

@@ -33,8 +33,8 @@ import mozilla.components.feature.push.PushType
 import mozilla.components.service.fxa.manager.FxaAccountManager
 import mozilla.components.service.fxa.sync.GlobalSyncableStoreProvider
 import mozilla.components.support.base.log.logger.Logger
-import org.mozilla.fenix.BuildConfig
 import org.mozilla.fenix.Experiments
+import org.mozilla.fenix.FeatureFlags
 import org.mozilla.fenix.R
 import org.mozilla.fenix.isInExperiment
 import org.mozilla.fenix.test.Mockable
@@ -63,7 +63,7 @@ class BackgroundServices(
         // NB: flipping this flag back and worth is currently not well supported and may need hand-holding.
         // Consult with the android-components peers before changing.
         // See https://github.com/mozilla/application-services/issues/1308
-        capabilities = if (BuildConfig.SEND_TAB_ENABLED) {
+        capabilities = if (FeatureFlags.sendTabEnabled) {
             setOf(DeviceCapability.SEND_TAB)
         } else {
             emptySet()
@@ -120,7 +120,7 @@ class BackgroundServices(
         GlobalSyncableStoreProvider.configureStore("bookmarks" to bookmarkStorage)
 
         // Sets the PushFeature as the singleton instance for push messages to go to.
-        if (BuildConfig.SEND_TAB_ENABLED && pushConfig != null) {
+        if (FeatureFlags.sendTabEnabled && pushConfig != null) {
             PushProcessor.install(push)
         }
     }
@@ -175,7 +175,7 @@ class BackgroundServices(
         it.registerForDeviceEvents(deviceEventObserver, ProcessLifecycleOwner.get(), true)
 
         // This should be removed in the future. See comment on `accountObserver`.
-        if (BuildConfig.SEND_TAB_ENABLED && pushConfig != null) {
+        if (FeatureFlags.sendTabEnabled && pushConfig != null) {
             it.register(accountObserver)
         }
         CoroutineScope(Dispatchers.Main).launch { it.initAsync().await() }

app/src/main/java/org/mozilla/fenix/share/ShareUIView.kt

@@ -12,7 +12,7 @@ import io.reactivex.Observable
 import io.reactivex.Observer
 import io.reactivex.functions.Consumer
 import kotlinx.android.synthetic.main.component_share.*
-import org.mozilla.fenix.BuildConfig
+import org.mozilla.fenix.FeatureFlags
 import org.mozilla.fenix.R
 import org.mozilla.fenix.ext.components
 import org.mozilla.fenix.mvi.UIView
@@ -41,7 +41,7 @@ class ShareUIView(
         intent_handler_recyclerview.adapter = adapter
 
         // And authorized
-        if (BuildConfig.SEND_TAB_ENABLED &&
+        if (FeatureFlags.sendTabEnabled &&
             !view.context.components.backgroundServices.accountManager.accountNeedsReauth()
         ) {
             account_devices_recyclerview.adapter = AccountDevicesShareAdapter(view.context, actionEmitter)