Add a Battery Saver warning to Services

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- added: Battery Saver warning message for Android
+
 ## 4.14.0
 
 - added: `ExpandableList` component, replacing the address hint dropdown in `AddressFormScene`

src/components/services/Services.tsx

@@ -1,6 +1,8 @@
 import { asDate, asJSON, asObject, uncleaner } from 'cleaners'
 import { EdgeAccount } from 'edge-core-js'
 import * as React from 'react'
+import { EmitterSubscription } from 'react-native'
+import { powerSavingModeChanged, powerSavingOn } from 'react-native-power-saving-mode'
 
 import { updateExchangeInfo } from '../../actions/ExchangeInfoActions'
 import { refreshConnectedWallets } from '../../actions/FioActions'
@@ -11,16 +13,18 @@ import { ENV } from '../../env'
 import { useAsyncEffect } from '../../hooks/useAsyncEffect'
 import { useHandler } from '../../hooks/useHandler'
 import { useRefresher } from '../../hooks/useRefresher'
+import { lstrings } from '../../locales/strings'
 import { defaultAccount } from '../../reducers/CoreReducer'
 import { FooterAccordionEventService } from '../../state/SceneFooterState'
 import { useDispatch, useSelector } from '../../types/reactRedux'
 import { NavigationBase } from '../../types/routerTypes'
 import { height, ratioHorizontal, ratioVertical, width } from '../../util/scaling'
 import { snooze } from '../../util/utils'
 import { FioCreateHandleModal } from '../modals/FioCreateHandleModal'
+import { AlertDropdown } from '../navigation/AlertDropdown'
 import { AccountCallbackManager } from './AccountCallbackManager'
 import { ActionQueueService } from './ActionQueueService'
-import { Airship } from './AirshipInstance'
+import { Airship, showDevError } from './AirshipInstance'
 import { AutoLogout } from './AutoLogout'
 import { ContactsLoader } from './ContactsLoader'
 import { EdgeContextCallbackManager } from './EdgeContextCallbackManager'
@@ -123,6 +127,60 @@ export function Services(props: Props) {
     'Services 2'
   )
 
+  // Subscribe to Android Power Saver state, and show a warning only if it
+  // changes from off to on:
+  useAsyncEffect(
+    async () => {
+      let previousState = false
+      let isWarningShowing = false
+
+      const showBatterySaverWarning = async () => {
+        if (isWarningShowing) return
+
+        isWarningShowing = true
+        await Airship.show(bridge => <AlertDropdown bridge={bridge} message={lstrings.warning_battery_saver} warning persistent />)
+        isWarningShowing = false
+      }
+
+      const checkPowerSavingMode = async () => {
+        // This method is only available for Android
+        if (powerSavingOn != null) {
+          try {
+            previousState = await powerSavingOn()
+            if (previousState) {
+              // Show warning if power-saving mode is on initially
+              await showBatterySaverWarning()
+            }
+          } catch (error) {
+            showDevError(`Error checking power-saving mode: ${String(error)}`)
+          }
+        }
+      }
+
+      const handlePowerSavingModeChanged = async (state: boolean) => {
+        if (state && !previousState) {
+          await showBatterySaverWarning()
+        }
+        previousState = state
+      }
+
+      await checkPowerSavingMode()
+
+      let subscription: EmitterSubscription | undefined
+      if (powerSavingModeChanged != null) {
+        subscription = powerSavingModeChanged(handlePowerSavingModeChanged)
+      }
+
+      return () => {
+        if (subscription != null) {
+          subscription.remove()
+        }
+      }
+    },
+    [],
+    'Services 3'
+  )
+
   // Methods to call periodically
   useRefresher(
     async () => {

src/locales/en_US.ts

@@ -128,6 +128,7 @@ const strings = {
     'The entered token %1$s exists as a built-in token %2$s with the same contract address. Please proceed with caution and verify the contract is legitimate as use of this token can result in loss of funds. If you have questions about this feature please contact %3$s.',
   warning_token_exists_1s: 'The entered token already exists as a built-in token %1$s',
   warning_uk_risk: `Don't invest unless you're prepared to lose all the money you invest. This is a high-risk investment and you should not expect to be protected if something goes wrong. Take 2 min to learn more.`,
+  warning_battery_saver: `Battery Saver mode detected. Balances and transactions may be inaccurate`,
 
   // Alert component:
   alert_dropdown_alert: 'Alert! ',

src/locales/strings/enUS.json

@@ -82,6 +82,7 @@
   "warning_token_contract_override_3s": "The entered token %1$s exists as a built-in token %2$s with the same contract address. Please proceed with caution and verify the contract is legitimate as use of this token can result in loss of funds. If you have questions about this feature please contact %3$s.",
   "warning_token_exists_1s": "The entered token already exists as a built-in token %1$s",
   "warning_uk_risk": "Don't invest unless you're prepared to lose all the money you invest. This is a high-risk investment and you should not expect to be protected if something goes wrong. Take 2 min to learn more.",
+  "warning_battery_saver": "Battery Saver mode detected. Balances and transactions may be inaccurate",
   "alert_dropdown_alert": "Alert! ",
   "alert_dropdown_warning": "Warning! ",
   "azteco_success": "You've redeemed an Azteco bitcoin card. Funds should arrive shortly.",