AMP requires WebView

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

@@ -2821,7 +2821,9 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                                     !EntityMessage.SMIME_SIGNENCRYPT.equals(message.encrypt));
 
                     // Show AMP
-                    ibAmp.setVisibility(args.getBoolean("has_amp") ? View.VISIBLE : View.GONE);
+                    boolean has_amp = args.getBoolean("has_amp");
+                    ibAmp.setVisibility(has_amp && Helper.hasWebView(context)
+                            ? View.VISIBLE : View.GONE);
 
                     // Show encrypt actions
                     ibVerify.setVisibility(verifyable ? View.VISIBLE : View.GONE);

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

@@ -157,6 +157,7 @@ import java.util.concurrent.atomic.AtomicLong;
 import java.util.regex.Pattern;
 
 public class Helper {
+    private static Boolean hasWebView = null;
     private static Boolean hasPlayStore = null;
     private static Boolean hasValidFingerprint = null;
 
@@ -410,6 +411,12 @@ public class Helper {
     }
 
     static boolean hasWebView(Context context) {
+        if (hasWebView == null)
+            hasWebView = _hasWebView(context);
+        return hasWebView;
+    }
+
+    private static boolean _hasWebView(Context context) {
         try {
             PackageManager pm = context.getPackageManager();
             if (pm.hasSystemFeature(PackageManager.FEATURE_WEBVIEW)) {