Language switcher for the Data Capture Gallery

datacapturegallery/src/main/java/com/google/android/fhir/datacapture/gallery/MainActivity.kt

@@ -16,15 +16,71 @@
 
 package com.google.android.fhir.datacapture.gallery
 
+import android.content.Context
+import android.content.SharedPreferences
+import android.content.res.Configuration
 import android.os.Bundle
+import android.view.Menu
+import android.view.MenuItem
 import androidx.appcompat.app.AppCompatActivity
 import com.google.android.fhir.datacapture.gallery.databinding.ActivityMainBinding
+import com.google.android.fhir.datacapture.gallery.utils.LocaleUtils
 
 class MainActivity : AppCompatActivity() {
   private lateinit var binding: ActivityMainBinding
+  private lateinit var languageList: List<LocaleUtils.Language>
+  private lateinit var sharedPreferences: SharedPreferences
+
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     binding = ActivityMainBinding.inflate(layoutInflater)
     setContentView(binding.root)
+
+    languageList = LocaleUtils.getLanguageList(this)
+  }
+
+  override fun onCreateOptionsMenu(menu: Menu): Boolean {
+    menuInflater.inflate(R.menu.top_bar_menu, menu)
+
+    menu.findItem(R.id.action_submit).isVisible = false
+    menu.findItem(R.id.action_language).isVisible = true
+    return true
+  }
+
+  private fun refreshToSelectedLanguage(language: LocaleUtils.Language) {
+
+    LocaleUtils.saveSelectedLanguage(language, sharedPreferences)
+
+    this.recreate()
+  }
+
+  override fun attachBaseContext(baseContext: Context) {
+    sharedPreferences =
+      baseContext.getSharedPreferences(
+        BuildConfig.APPLICATION_ID.plus(this.javaClass.canonicalName),
+        Context.MODE_PRIVATE
+      )
+
+    var newContextResourceConfiguration: Configuration?
+
+    LocaleUtils.getSelectedLanguage(sharedPreferences).also {
+      newContextResourceConfiguration =
+        LocaleUtils.updateContextResourceConfiguration(baseContext, it)
+    }
+
+    super.attachBaseContext(baseContext)
+    applyOverrideConfiguration(newContextResourceConfiguration)
+  }
+
+  override fun onOptionsItemSelected(item: MenuItem): Boolean {
+    return when (item.itemId) {
+      R.id.action_language -> {
+        LocaleUtils.renderSelectLanguageDialog(this, languageList) { _, i ->
+          refreshToSelectedLanguage(languageList[i])
+        }
+        true
+      }
+      else -> super.onOptionsItemSelected(item)
+    }
   }
 }

datacapturegallery/src/main/java/com/google/android/fhir/datacapture/gallery/QuestionnaireContainerFragment.kt

@@ -78,7 +78,8 @@ class QuestionnaireContainerFragment : Fragment() {
   }
 
   override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
-    inflater.inflate(R.menu.top_bar_menu, menu)
+    menu.findItem(R.id.action_submit).isVisible = true
+    menu.findItem(R.id.action_language).isVisible = false
   }
 
   override fun onOptionsItemSelected(item: MenuItem): Boolean {

datacapturegallery/src/main/java/com/google/android/fhir/datacapture/gallery/utils/LocaleUtils.kt

@@ -0,0 +1,110 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.fhir.datacapture.gallery.utils
+
+import android.app.Activity
+import android.content.Context
+import android.content.DialogInterface
+import android.content.SharedPreferences
+import android.content.res.Configuration
+import android.content.res.Resources
+import android.os.Build
+import android.os.LocaleList
+import android.widget.ArrayAdapter
+import androidx.annotation.RequiresApi
+import androidx.appcompat.app.AlertDialog
+import com.google.android.fhir.datacapture.gallery.R
+import java.util.Locale
+
+object LocaleUtils {
+
+  private const val SHARED_PREF_KEY_LANG = "shared_pref_key_lang"
+
+  fun updateContextResourceConfiguration(context: Context, language: String?): Configuration? {
+    val resources: Resources = context.resources
+    val configuration = Configuration(resources.configuration)
+    try {
+      val locale = Locale.forLanguageTag(language)
+      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+        updateResourcesLocaleConfiguration(context, locale)
+      } else {
+        updateResourcesLocaleConfigurationLegacy(context, locale)
+      }
+    } catch (e: Exception) {
+      e.printStackTrace()
+    }
+    return configuration
+  }
+
+  @RequiresApi(Build.VERSION_CODES.N)
+  private fun updateResourcesLocaleConfiguration(context: Context, locale: Locale) {
+    context.resources.configuration.also {
+      val localeList = LocaleList(locale)
+      it.setLocales(localeList)
+      LocaleList.setDefault(it.locales)
+
+      context.createConfigurationContext(it)
+    }
+  }
+
+  @Suppress("DEPRECATION")
+  private fun updateResourcesLocaleConfigurationLegacy(context: Context, locale: Locale) {
+    context.resources.configuration.also {
+      it.locale = locale
+      context.resources.updateConfiguration(it, context.resources.displayMetrics)
+    }
+  }
+
+  fun getLanguageList(activity: Activity): List<Language> {
+    return activity.resources.getStringArray(R.array.languages).toList().map {
+      Language(it, Locale.forLanguageTag(it).displayName)
+    }
+  }
+
+  fun renderSelectLanguageDialog(
+    context: Activity,
+    languageList: List<Language>,
+    listener: DialogInterface.OnClickListener
+  ) {
+    val adapter: ArrayAdapter<Language> =
+      ArrayAdapter(context, android.R.layout.simple_list_item_1, languageList)
+
+    AlertDialog.Builder(context)
+      .apply {
+        setTitle(context.getString(R.string.select_language))
+        setIcon(R.drawable.outline_language_24)
+        setAdapter(adapter, listener)
+      }
+      .create()
+      .show()
+  }
+
+  fun saveSelectedLanguage(language: Language, sharedPreferences: SharedPreferences) {
+
+    with(sharedPreferences.edit()) {
+      putString(SHARED_PREF_KEY_LANG, language.tag)
+      commit()
+    }
+  }
+
+  fun getSelectedLanguage(sharedPreferences: SharedPreferences): String? =
+    sharedPreferences.getString(SHARED_PREF_KEY_LANG, null)
+
+  data class Language(val tag: String, val displayName: String) {
+    override fun toString() = displayName
+  }
+}

datacapturegallery/src/main/res/drawable/outline_language_24.xml

@@ -0,0 +1,13 @@
+<vector
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal"
+>
+  <path
+        android:fillColor="@android:color/white"
+        android:pathData="M11.99,2C6.47,2 2,6.48 2,12s4.47,10 9.99,10C17.52,22 22,17.52 22,12S17.52,2 11.99,2zM18.92,8h-2.95c-0.32,-1.25 -0.78,-2.45 -1.38,-3.56 1.84,0.63 3.37,1.91 4.33,3.56zM12,4.04c0.83,1.2 1.48,2.53 1.91,3.96h-3.82c0.43,-1.43 1.08,-2.76 1.91,-3.96zM4.26,14C4.1,13.36 4,12.69 4,12s0.1,-1.36 0.26,-2h3.38c-0.08,0.66 -0.14,1.32 -0.14,2s0.06,1.34 0.14,2L4.26,14zM5.08,16h2.95c0.32,1.25 0.78,2.45 1.38,3.56 -1.84,-0.63 -3.37,-1.9 -4.33,-3.56zM8.03,8L5.08,8c0.96,-1.66 2.49,-2.93 4.33,-3.56C8.81,5.55 8.35,6.75 8.03,8zM12,19.96c-0.83,-1.2 -1.48,-2.53 -1.91,-3.96h3.82c-0.43,1.43 -1.08,2.76 -1.91,3.96zM14.34,14L9.66,14c-0.09,-0.66 -0.16,-1.32 -0.16,-2s0.07,-1.35 0.16,-2h4.68c0.09,0.65 0.16,1.32 0.16,2s-0.07,1.34 -0.16,2zM14.59,19.56c0.6,-1.11 1.06,-2.31 1.38,-3.56h2.95c-0.96,1.65 -2.49,2.93 -4.33,3.56zM16.36,14c0.08,-0.66 0.14,-1.32 0.14,-2s-0.06,-1.34 -0.14,-2h3.38c0.16,0.64 0.26,1.31 0.26,2s-0.1,1.36 -0.26,2h-3.38z"
+    />
+</vector>

datacapturegallery/src/main/res/menu/top_bar_menu.xml

@@ -22,6 +22,13 @@
     android:layout_height="match_parent"
     tools:context=".MainActivity"
 >
+    <item
+        android:id="@+id/action_language"
+        android:orderInCategory="300"
+        android:title="@string/select_language"
+        android:icon="@drawable/outline_language_24"
+        app:showAsAction="always"
+    />
 
     <item
         android:id="@+id/action_submit"

datacapturegallery/src/main/res/values-vi/strings.xml

@@ -0,0 +1,20 @@
+<!--
+ Copyright 2020 Google LLC
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+-->
+<resources>
+    <string name="app_name">Thư viện thu thập dữ liệu</string>
+    <string name="submit_button_text">Gửi</string>
+    <string name="select_language">Chọn ngôn ngữ</string>
+</resources>

datacapturegallery/src/main/res/values/languages.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<resources>
+    <string-array name="languages">
+        <item>en</item>
+        <item>vi-VN</item>
+    </string-array>
+</resources>

datacapturegallery/src/main/res/values/strings.xml

@@ -16,4 +16,5 @@
 <resources>
     <string name="app_name">Data Capture Gallery</string>
     <string name="submit_button_text">Submit</string>
+    <string name="select_language">Select Language</string>
 </resources>