Added Support for System Wide Dark Theme (#3460)

* Added Support for System Wide Dark Theme

* changed methods to private

* Moved Strings to strings.xml

* Used Dagger to reduce code repetition

* Changes made as per review suggestions

* Minor Changes

* Fixes as per suggestions

* Minor Fixes as per suggestion

* made the variables static

* removed irrelevant code

app/src/main/java/fr/free/nrw/commons/auth/LoginActivity.java

@@ -55,6 +55,7 @@ import fr.free.nrw.commons.explore.categories.ExploreActivity;
 import fr.free.nrw.commons.kvstore.JsonKvStore;
 import fr.free.nrw.commons.theme.NavigationBaseActivity;
 import fr.free.nrw.commons.utils.ConfigUtils;
+import fr.free.nrw.commons.utils.SystemThemeUtils;
 import fr.free.nrw.commons.utils.ViewUtil;
 import io.reactivex.disposables.CompositeDisposable;
 import retrofit2.Call;
@@ -83,6 +84,9 @@ public class LoginActivity extends AccountAuthenticatorActivity {
     @Inject
     LoginClient loginClient;
 
+    @Inject
+    SystemThemeUtils systemThemeUtils;
+
     @BindView(R.id.login_button)
     Button loginButton;
 
@@ -121,7 +125,7 @@ public class LoginActivity extends AccountAuthenticatorActivity {
                 .getCommonsApplicationComponent()
                 .inject(this);
 
-        boolean isDarkTheme = applicationKvStore.getBoolean("theme", false);
+        boolean isDarkTheme = systemThemeUtils.isDeviceInNightMode();
         setTheme(isDarkTheme ? R.style.DarkAppTheme : R.style.LightAppTheme);
         getDelegate().installViewFactory();
         getDelegate().onCreate(savedInstanceState);

app/src/main/java/fr/free/nrw/commons/nearby/fragments/NearbyParentFragment.java

@@ -9,7 +9,6 @@ import android.content.IntentFilter;
 import android.content.res.Configuration;
 import android.graphics.Bitmap;
 import android.os.Bundle;
-import android.text.TextUtils;
 import android.util.Log;
 import android.view.Gravity;
 import android.view.LayoutInflater;
@@ -93,6 +92,7 @@ import fr.free.nrw.commons.utils.LocationUtils;
 import fr.free.nrw.commons.utils.NearbyFABUtils;
 import fr.free.nrw.commons.utils.NetworkUtils;
 import fr.free.nrw.commons.utils.PermissionUtils;
+import fr.free.nrw.commons.utils.SystemThemeUtils;
 import fr.free.nrw.commons.utils.UiUtils;
 import fr.free.nrw.commons.utils.ViewUtil;
 import fr.free.nrw.commons.wikidata.WikidataEditListener;
@@ -156,6 +156,9 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
     @Inject ContributionController controller;
     @Inject WikidataEditListener wikidataEditListener;
 
+    @Inject
+    SystemThemeUtils systemThemeUtils;
+
     private NearbyFilterSearchRecyclerViewAdapter nearbyFilterSearchRecyclerViewAdapter;
 
     private BottomSheetBehavior bottomSheetListBehavior;
@@ -210,7 +213,7 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
     @Override
     public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
-        isDarkTheme = applicationKvStore.getBoolean("theme", false);
+        isDarkTheme = systemThemeUtils.isDeviceInNightMode();
         cameraMoveListener= () -> presenter.onCameraMove(mapBox.getCameraPosition().target);
         addCheckBoxCallback();
         presenter.attachView(this);

app/src/main/java/fr/free/nrw/commons/settings/Prefs.java

@@ -9,6 +9,7 @@ public class Prefs {
     public static final String IS_CONTRIBUTION_COUNT_CHANGED = "ccontributionCountChanged";
     public static final String MANAGED_EXIF_TAGS = "managed_exif_tags";
     public static final String KEY_LANGUAGE_VALUE = "languageDescription";
+    public static final String KEY_THEME_VALUE = "appThemePref";
 
     public static class Licenses {
         public static final String CC_BY_SA_3 = "CC BY-SA 3.0";

app/src/main/java/fr/free/nrw/commons/settings/SettingsFragment.java

@@ -12,18 +12,15 @@ import android.preference.SwitchPreference;
 import android.text.Editable;
 import android.text.TextWatcher;
 
-import com.google.gson.reflect.TypeToken;
 import com.karumi.dexter.Dexter;
 import com.karumi.dexter.listener.PermissionGrantedResponse;
 import com.karumi.dexter.listener.single.BasePermissionListener;
 
-import java.lang.reflect.Type;
-import java.util.Collections;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
-import java.util.Set;
 
 import javax.inject.Inject;
 import javax.inject.Named;
@@ -37,14 +34,19 @@ import fr.free.nrw.commons.upload.Language;
 import fr.free.nrw.commons.utils.PermissionUtils;
 import fr.free.nrw.commons.utils.ViewUtil;
 
+import static fr.free.nrw.commons.utils.SystemThemeUtils.THEME_MODE_DEFAULT;
+
 public class SettingsFragment extends PreferenceFragment {
 
     @Inject
     @Named("default_preferences")
     JsonKvStore defaultKvStore;
+
     @Inject
     CommonsLogSender commonsLogSender;
-    private ListPreference listPreference;
+
+    private ListPreference themeListPreference;
+    private ListPreference langListPreference;
 
     @Override
     public void onCreate(Bundle savedInstanceState) {
@@ -57,11 +59,8 @@ public class SettingsFragment extends PreferenceFragment {
         // Load the preferences from an XML resource
         addPreferencesFromResource(R.xml.preferences);
 
-        SwitchPreference themePreference = (SwitchPreference) findPreference("theme");
-        themePreference.setOnPreferenceChangeListener((preference, newValue) -> {
-            getActivity().recreate();
-            return true;
-        });
+        themeListPreference = (ListPreference) findPreference(Prefs.KEY_THEME_VALUE);
+        prepareTheme();
 
         //Check if the Author Name switch is enabled and appropriately handle the author name usage
         SwitchPreference useAuthorName = (SwitchPreference) findPreference("useAuthorName");
@@ -117,7 +116,7 @@ public class SettingsFragment extends PreferenceFragment {
             }
         });
 
-        listPreference = (ListPreference) findPreference("descriptionDefaultLanguagePref");
+        langListPreference = (ListPreference) findPreference("descriptionDefaultLanguagePref");
         prepareLanguages();
         Preference betaTesterPreference = findPreference("becomeBetaTester");
         betaTesterPreference.setOnPreferenceClickListener(preference -> {
@@ -144,10 +143,32 @@ public class SettingsFragment extends PreferenceFragment {
         }
     }
 
+    /**
+     * Uses previously saved theme if there is any, if not then uses default.
+     */
+    private void prepareTheme() {
+
+        themeListPreference.setSummary(getThemeSummary(getCurrentTheme()));
+
+        themeListPreference.setOnPreferenceChangeListener((preference, newValue) -> {
+            getActivity().recreate();
+            return true;
+        });
+    }
+
+    private CharSequence getThemeSummary(String value) {
+        int prefIndex = themeListPreference.findIndexOfValue(value);
+        return themeListPreference.getEntries()[prefIndex];
+    }
+
+    private String getCurrentTheme() {
+        return defaultKvStore.getString(Prefs.KEY_THEME_VALUE, THEME_MODE_DEFAULT);
+    }
+
     /**
      * Prepares language summary and language codes list and adds them to list preference as pairs.
      * Uses previously saved language if there is any, if not uses phone local as initial language.
-     * Adds preference changed listener and saves value choosen by user to shared preferences
+     * Adds preference changed listener and saves value chosen by user to shared preferences
      * to remember later
      */
     private void prepareLanguages() {
@@ -167,26 +188,26 @@ public class SettingsFragment extends PreferenceFragment {
         CharSequence[] languageNames = languageNamesList.toArray(new CharSequence[0]);
         CharSequence[] languageCodes = languageCodesList.toArray(new CharSequence[0]);
         // Add all languages and languages codes to lists preference as pair
-        listPreference.setEntries(languageNames);
-        listPreference.setEntryValues(languageCodes);
+        langListPreference.setEntries(languageNames);
+        langListPreference.setEntryValues(languageCodes);
 
         // Gets current language code from shared preferences
         String languageCode = getCurrentLanguageCode();
         if (languageCode.equals("")){
             // If current language code is empty, means none selected by user yet so use phone local
-            listPreference.setSummary(Locale.getDefault().getDisplayLanguage());
-            listPreference.setValue(Locale.getDefault().getLanguage());
+            langListPreference.setSummary(Locale.getDefault().getDisplayLanguage());
+            langListPreference.setValue(Locale.getDefault().getLanguage());
         } else {
             // If any language is selected by user previously, use it
-            int prefIndex = listPreference.findIndexOfValue(languageCode);
-            listPreference.setSummary(listPreference.getEntries()[prefIndex]);
-            listPreference.setValue(languageCode);
+            int prefIndex = langListPreference.findIndexOfValue(languageCode);
+            langListPreference.setSummary(langListPreference.getEntries()[prefIndex]);
+            langListPreference.setValue(languageCode);
         }
 
-        listPreference.setOnPreferenceChangeListener((preference, newValue) -> {
+        langListPreference.setOnPreferenceChangeListener((preference, newValue) -> {
             String userSelectedValue = (String) newValue;
-            int prefIndex = listPreference.findIndexOfValue(userSelectedValue);
-            listPreference.setSummary(listPreference.getEntries()[prefIndex]);
+            int prefIndex = langListPreference.findIndexOfValue(userSelectedValue);
+            langListPreference.setSummary(langListPreference.getEntries()[prefIndex]);
             saveLanguageValue(userSelectedValue);
             return true;
         });

app/src/main/java/fr/free/nrw/commons/theme/BaseActivity.java

@@ -8,6 +8,7 @@ import javax.inject.Named;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.di.CommonsDaggerAppCompatActivity;
 import fr.free.nrw.commons.kvstore.JsonKvStore;
+import fr.free.nrw.commons.utils.SystemThemeUtils;
 import io.reactivex.disposables.CompositeDisposable;
 
 public abstract class BaseActivity extends CommonsDaggerAppCompatActivity {
@@ -15,20 +16,23 @@ public abstract class BaseActivity extends CommonsDaggerAppCompatActivity {
     @Named("default_preferences")
     public JsonKvStore defaultKvStore;
 
+    @Inject
+    SystemThemeUtils systemThemeUtils;
+
     protected CompositeDisposable compositeDisposable = new CompositeDisposable();
     protected boolean wasPreviouslyDarkTheme;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        wasPreviouslyDarkTheme = defaultKvStore.getBoolean("theme", false);
+        wasPreviouslyDarkTheme = systemThemeUtils.isDeviceInNightMode();
         setTheme(wasPreviouslyDarkTheme ? R.style.DarkAppTheme : R.style.LightAppTheme);
     }
 
     @Override
     protected void onResume() {
         // Restart activity if theme is changed
-        if (wasPreviouslyDarkTheme != defaultKvStore.getBoolean("theme", false)) {
+        if (wasPreviouslyDarkTheme != systemThemeUtils.isDeviceInNightMode()) {
             recreate();
         }
 

app/src/main/java/fr/free/nrw/commons/utils/SystemThemeUtils.java

@@ -0,0 +1,49 @@
+package fr.free.nrw.commons.utils;
+
+import android.content.Context;
+import android.content.res.Configuration;
+
+import javax.inject.Inject;
+import javax.inject.Named;
+
+import fr.free.nrw.commons.kvstore.JsonKvStore;
+import fr.free.nrw.commons.settings.Prefs;
+
+public class SystemThemeUtils {
+
+    private Context context;
+    private JsonKvStore applicationKvStore;
+
+    public static final String THEME_MODE_DEFAULT = "0";
+    public static final String THEME_MODE_DARK = "1";
+    public static final String THEME_MODE_LIGHT = "2";
+
+    @Inject
+    public SystemThemeUtils(Context context, @Named("default_preferences") JsonKvStore applicationKvStore) {
+        this.context = context;
+        this.applicationKvStore = applicationKvStore;
+    }
+
+    // Return true is system wide dark theme is enabled else false
+    public boolean getSystemDefaultThemeBool(String theme) {
+        if (theme.equals(THEME_MODE_DARK)) {
+            return true;
+        } else if (theme.equals(THEME_MODE_DEFAULT)) {
+            return getSystemDefaultThemeBool(getSystemDefaultTheme());
+        }
+        return false;
+    }
+
+    // Returns the default system wide theme
+    public String getSystemDefaultTheme() {
+        return (context.getResources().getConfiguration().uiMode &
+                Configuration.UI_MODE_NIGHT_MASK) == Configuration.UI_MODE_NIGHT_YES ? THEME_MODE_DARK : THEME_MODE_LIGHT;
+    }
+
+    // Returns true if the device is in night mode or false otherwise
+    public boolean isDeviceInNightMode() {
+        return getSystemDefaultThemeBool(
+                applicationKvStore.getString(Prefs.KEY_THEME_VALUE, getSystemDefaultTheme()));
+    }
+
+}

app/src/main/res/values/arrays.xml

@@ -35,4 +35,15 @@
         <item>@string/exif_tag_software</item>
     </array>
 
+    <array name="pref_theme_entries">
+        <item>@string/theme_default_name</item>
+        <item>@string/theme_dark_name</item>
+        <item>@string/theme_light_name</item>
+    </array>
+
+    <string-array name="pref_theme_entries_values">
+        <item>0</item>
+        <item>1</item>
+        <item>2</item>
+    </string-array>
 </resources>

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

@@ -113,8 +113,7 @@
   <string name="use_previous">Use previous title and description</string>
   <string name="allow_gps">Automatically get current location</string>
   <string name="allow_gps_summary">Retrieves current location if image is not geotagged, and geotags image with it. Warning: This will reveal your current location.</string>
-  <string name="preference_theme">Night mode</string>
-  <string name="preference_theme_summary">Use dark theme</string>
+  <string name="preference_theme">Theme</string>
   <string name="license_name_cc_by_sa_four"> Attribution-ShareAlike 4.0</string>
   <string name="license_name_cc_by_four"> Attribution 4.0</string>
   <string name="license_name_cc_by_sa"> Attribution-ShareAlike 3.0</string>
@@ -599,4 +598,7 @@ Upload your first media by tapping on the add button.</string>
   <string name="wallpaper_set_unsuccessfully">Something went wrong. Could not set the wallpaper</string>
   <string name="setting_wallpaper_dialog_title">Set as Wallpaper</string>
   <string name="setting_wallpaper_dialog_message">Setting Wallpaper. Please wait…</string>
+  <string name="theme_default_name">Default</string>
+  <string name="theme_dark_name">Dark</string>
+  <string name="theme_light_name">Light</string>
 </resources>

app/src/main/res/xml/preferences.xml

@@ -5,11 +5,13 @@
     <fr.free.nrw.commons.ui.LongTitlePreferences.LongTitlePreferenceCategory
         android:title="@string/preference_category_appearance">
 
-        <fr.free.nrw.commons.ui.LongTitlePreferences.LongTitleSwitchPreference
+        <fr.free.nrw.commons.ui.LongTitlePreferences.LongTitleListPreference
+            android:key="appThemePref"
             android:title= "@string/preference_theme"
-            android:defaultValue="false"
-            android:summary="@string/preference_theme_summary"
-            android:key="theme" />
+            android:entries="@array/pref_theme_entries"
+            android:entryValues="@array/pref_theme_entries_values"
+            android:defaultValue="0"
+            android:summary="@string/theme_default_name" />
 
     </fr.free.nrw.commons.ui.LongTitlePreferences.LongTitlePreferenceCategory>