Enable Gravatars and warn about privacy risks

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

@@ -170,7 +170,7 @@ public class ContactInfo {
 
         if (info.bitmap == null) {
             boolean gravatars = prefs.getBoolean("gravatars", false);
-            if (gravatars && BuildConfig.DEBUG) {
+            if (gravatars) {
                 boolean lookup;
                 synchronized (emailGravatar) {
                     Gravatar g = emailGravatar.get(address.getAddress());

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

@@ -41,6 +41,7 @@ import android.widget.ImageView;
 import android.widget.RadioGroup;
 import android.widget.SeekBar;
 import android.widget.Spinner;
+import android.widget.TextView;
 import android.widget.Toast;
 
 import androidx.annotation.NonNull;
@@ -62,6 +63,7 @@ public class FragmentOptionsDisplay extends FragmentBase implements SharedPrefer
     private SwitchCompat swHighlightUnread;
     private SwitchCompat swColorStripe;
     private SwitchCompat swAvatars;
+    private TextView tvGravatarsHint;
     private SwitchCompat swGravatars;
     private SwitchCompat swGeneratedIcons;
     private SwitchCompat swIdenticons;
@@ -128,6 +130,7 @@ public class FragmentOptionsDisplay extends FragmentBase implements SharedPrefer
         swColorStripe = view.findViewById(R.id.swColorStripe);
         swAvatars = view.findViewById(R.id.swAvatars);
         swGravatars = view.findViewById(R.id.swGravatars);
+        tvGravatarsHint = view.findViewById(R.id.tvGravatarsHint);
         swGeneratedIcons = view.findViewById(R.id.swGeneratedIcons);
         swIdenticons = view.findViewById(R.id.swIdenticons);
         swCircular = view.findViewById(R.id.swCircular);
@@ -261,6 +264,14 @@ public class FragmentOptionsDisplay extends FragmentBase implements SharedPrefer
             }
         });
 
+        tvGravatarsHint.getPaint().setUnderlineText(true);
+        tvGravatarsHint.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                Helper.view(getContext(), Uri.parse(Helper.GRAVATAR_PRIVACY_URI), true);
+            }
+        });
+
         swGeneratedIcons.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
@@ -599,7 +610,6 @@ public class FragmentOptionsDisplay extends FragmentBase implements SharedPrefer
         swColorStripe.setChecked(prefs.getBoolean("color_stripe", true));
         swAvatars.setChecked(prefs.getBoolean("avatars", true));
         swGravatars.setChecked(prefs.getBoolean("gravatars", false));
-        swGravatars.setVisibility(BuildConfig.DEBUG ? View.VISIBLE : View.GONE);
         swGeneratedIcons.setChecked(prefs.getBoolean("generated_icons", true));
         swIdenticons.setChecked(prefs.getBoolean("identicons", false));
         swIdenticons.setEnabled(swGeneratedIcons.isChecked());

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

@@ -139,6 +139,7 @@ public class Helper {
     static final String SUPPORT_URI = "https://contact.faircode.eu/?product=fairemailsupport";
     static final String TEST_URI = "https://play.google.com/apps/testing/" + BuildConfig.APPLICATION_ID;
     static final String CROWDIN_URI = "https://crowdin.com/project/open-source-email";
+    static final String GRAVATAR_PRIVACY_URI = "https://meta.stackexchange.com/questions/44717/is-gravatar-a-privacy-risk";
 
     static ExecutorService getBackgroundExecutor(int threads, String name) {
         ThreadFactory factory = new ThreadFactory() {

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

@@ -202,6 +202,18 @@
             app:layout_constraintTop_toBottomOf="@id/swAvatars"
             app:switchPadding="12dp" />
 
+        <TextView
+            android:id="@+id/tvGravatarsHint"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_marginEnd="48dp"
+            android:text="@string/title_advanced_gravatars_hint"
+            android:textAppearance="@style/TextAppearance.AppCompat.Small"
+            android:textColor="?android:attr/textColorLink"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/swGravatars" />
+
         <androidx.appcompat.widget.SwitchCompat
             android:id="@+id/swGeneratedIcons"
             android:layout_width="0dp"
@@ -211,7 +223,7 @@
             android:text="@string/title_advanced_generated_icons"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/swGravatars"
+            app:layout_constraintTop_toBottomOf="@id/tvGravatarsHint"
             app:switchPadding="12dp" />
 
         <androidx.appcompat.widget.SwitchCompat

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

@@ -428,6 +428,7 @@
     <string name="title_advanced_layout_hint">Switching to a more compact layout and changing the message text size can be done in the top action bar menu in the message view</string>
     <string name="title_advanced_date_hint">Messages are only grouped by date if they are sorted by time</string>
     <string name="title_advanced_threading_hint">Group messages related to each other</string>
+    <string name="title_advanced_gravatars_hint">There might be a privacy risk</string>
     <string name="title_advanced_name_email_hint">When disabled only names will be shown when available</string>
     <string name="title_advanced_preview_hint">Only available when message text has been downloaded</string>
     <string name="title_advanced_inline_hint">Inline images are images included in the message</string>