Added VirusTotal info button

FAQ.md

@@ -383,6 +383,7 @@ Fonts, sizes, colors, etc should be material design whenever possible.
 * [(178) Why are widgets not updating?](#user-content-faq178)
 * [(179) What are reply templates?](#user-content-faq179)
 * [(180) How do I use LanguageTool?](#user-content-faq180)
+* [(181) How do I use VirusTotal?](#user-content-faq181)
 
 [I have another question.](#user-content-get-support)
 
@@ -4845,7 +4846,7 @@ Templates can have the following options:
 <a name="faq180"></a>
 **(180) How do I use LanguageTool?**
 
-LanguageTool need to be enabled in the miscellaneous settings.
+LanguageTool integration needs to be enabled in the miscellaneous settings.
 
 After writing some text, you can long press on the save draft button to perform a grammar, style, and spell check via [LanguageTool](https://languagetool.org/).
 Texts with suggestions will be marked and if you tap on a marked suggestion,
@@ -4854,6 +4855,24 @@ else you can double tap or long press the marked text to show suggestions.
 
 <br />
 
+<a name="faq181"></a>
+**(181) How do I use VirusTotal?**
+
+VirusTotal integration needs to be enabled in the miscellaneous settings.
+This will show a *scan* icon button for each attachment.
+
+Without entering an API key, tapping on the scan button will calculate the SHA-256 hash of the attached file and open the corresponding file report on the VirusTotal website.
+If the file is not known by VirusTotal ("*Item not found*"), it is probably okay, unless it contains a new virus not being detected by virus scanners yet.
+
+With entering an API key, there will be a dialog showing the number of virus scanners detecting the file.
+Tapping on the info button will open the corresponding file report on the VirusTotal website.
+
+To get an API key, you'll need to register on the VirusTotal website.
+
+This feature was added in version 1.1941 and is available in non Play store versions only.
+
+<br />
+
 <h2><a name="get-support"></a>Get support</h2>
 
 &#x1F30E; [Google Translate](https://translate.google.com/translate?sl=en&u=https://github.com/M66B/FairEmail/blob/master/FAQ.md%23user-content-get-support)

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

@@ -124,6 +124,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
     private ImageButton ibDeepL;
     private SwitchCompat swVirusTotal;
     private TextView tvVirusTotalPrivacy;
+    private ImageButton ibVirusTotal;
     private EditText etVirusTotal;
     private SwitchCompat swUpdates;
     private ImageButton ibChannelUpdated;
@@ -314,6 +315,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         ibDeepL = view.findViewById(R.id.ibDeepL);
         swVirusTotal = view.findViewById(R.id.swVirusTotal);
         tvVirusTotalPrivacy = view.findViewById(R.id.tvVirusTotalPrivacy);
+        ibVirusTotal = view.findViewById(R.id.ibVirusTotal);
         etVirusTotal = view.findViewById(R.id.etVirusTotal);
         swUpdates = view.findViewById(R.id.swUpdates);
         ibChannelUpdated = view.findViewById(R.id.ibChannelUpdated);
@@ -659,6 +661,13 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             }
         });
 
+        ibVirusTotal.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                Helper.viewFAQ(v.getContext(), 181);
+            }
+        });
+
         etVirusTotal.addTextChangedListener(new TextWatcher() {
             @Override
             public void beforeTextChanged(CharSequence s, int start, int count, int after) {

app/src/main/res/layout/fragment_options_misc.xml

@@ -416,6 +416,17 @@
                     app:layout_constraintStart_toStartOf="parent"
                     app:layout_constraintTop_toBottomOf="@id/swVirusTotal" />
 
+                <ImageButton
+                    android:id="@+id/ibVirusTotal"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="12dp"
+                    android:contentDescription="@string/title_info"
+                    android:tooltipText="@string/title_info"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toBottomOf="@id/tvVirusTotalPrivacy"
+                    app:srcCompat="@drawable/twotone_info_24" />
+
                 <EditText
                     android:id="@+id/etVirusTotal"
                     android:layout_width="0dp"
@@ -426,7 +437,7 @@
                     android:textAppearance="@style/TextAppearance.AppCompat.Small"
                     app:layout_constraintEnd_toEndOf="parent"
                     app:layout_constraintStart_toStartOf="parent"
-                    app:layout_constraintTop_toBottomOf="@id/tvVirusTotalPrivacy" />
+                    app:layout_constraintTop_toBottomOf="@id/ibVirusTotal" />
 
                 <androidx.appcompat.widget.SwitchCompat
                     android:id="@+id/swUpdates"
@@ -587,7 +598,7 @@
                     android:id="@+id/grpVirusTotal"
                     android:layout_width="0dp"
                     android:layout_height="0dp"
-                    app:constraint_referenced_ids="swVirusTotal,tvVirusTotalPrivacy,etVirusTotal" />
+                    app:constraint_referenced_ids="swVirusTotal,tvVirusTotalPrivacy,ibVirusTotal,etVirusTotal" />
 
                 <androidx.constraintlayout.widget.Group
                     android:id="@+id/grpUpdates"