Improved localization of help files

app/src/main/java/eu/faircode/email/FragmentDialogMarkdown.java

@@ -21,8 +21,11 @@ package eu.faircode.email;
 
 import android.app.Dialog;
 import android.content.Context;
+import android.os.Build;
 import android.os.Bundle;
+import android.os.LocaleList;
 import android.text.Spanned;
+import android.text.TextUtils;
 import android.text.method.LinkMovementMethod;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -33,6 +36,7 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
 import java.io.InputStream;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
@@ -72,28 +76,48 @@ public class FragmentDialogMarkdown extends FragmentDialogBase {
             @Override
             protected Spanned onExecute(Context context, Bundle args) throws Throwable {
                 String name = args.getString("name");
-                String[] c = name.split("\\.");
+                if (name == null || !name.contains("."))
+                    throw new IllegalArgumentException(name);
 
+                List<String> names = new ArrayList<>();
+                String[] c = name.split("\\.");
                 List<String> assets = Arrays.asList(getResources().getAssets().list(""));
 
-                String country = Locale.getDefault().getCountry();
-                String language = Locale.getDefault().getLanguage();
-
-                String localized = c[0] + "-" + language + "-r" + country + "." + c[1];
-                Log.i("Checking " + localized);
-                if (assets.contains(localized))
-                    name = localized;
+                List<Locale> locales = new ArrayList<>();
+                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
+                    locales.add(Locale.getDefault());
                 else {
-                    String prefix = c[0] + "-" + language;
+                    LocaleList ll = context.getResources().getConfiguration().getLocales();
+                    for (int i = 0; i < ll.size(); i++)
+                        locales.add(ll.get(i));
+                }
+
+                for (Locale locale : locales) {
+                    String language = locale.getLanguage();
+                    String country = locale.getCountry();
+                    if ("en".equals(language) && "US".equals(country))
+                        names.add(name);
+                    else {
+                        String localized = c[0] + "-" + language + "-r" + country + "." + c[1];
+                        if (assets.contains(localized))
+                            names.add(localized);
+                    }
+                }
+
+                for (Locale locale : locales) {
+                    String prefix = c[0] + "-" + locale.getLanguage();
                     for (String asset : assets)
-                        if (asset.startsWith(prefix)) {
-                            name = asset;
-                            break;
-                        }
+                        if (asset.startsWith(prefix))
+                            names.add(asset);
                 }
-                Log.i("Using " + name);
 
-                try (InputStream is = context.getAssets().open(name)) {
+                names.add(name);
+                String asset = names.get(0);
+
+                Log.i("Using " + asset +
+                        " of " + TextUtils.join(",", names) +
+                        " (" + TextUtils.join(",", locales) + ")");
+                try (InputStream is = context.getAssets().open(asset)) {
                     byte[] buffer = new byte[is.available()];
                     is.read(buffer);
                     Markwon markwon = Markwon.create(context);