Added strikethrough

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

@@ -15,6 +15,7 @@ import android.text.style.ForegroundColorSpan;
 import android.text.style.ImageSpan;
 import android.text.style.QuoteSpan;
 import android.text.style.RelativeSizeSpan;
+import android.text.style.StrikethroughSpan;
 import android.text.style.StyleSpan;
 import android.text.style.TypefaceSpan;
 import android.text.style.URLSpan;
@@ -122,6 +123,8 @@ public class StyleHelper {
                                         return setFont(item);
                                     case R.id.group_style_blockquote:
                                         return setBlockquote(item);
+                                    case R.id.group_style_strikethrough:
+                                        return setStrikethrough(item);
                                     case R.id.group_style_clear:
                                         return clear(item);
                                     default:
@@ -321,6 +324,22 @@ public class StyleHelper {
                             return true;
                         }
 
+                        private boolean setStrikethrough(MenuItem item) {
+                            boolean has = false;
+                            for (StrikethroughSpan span : t.getSpans(s, e, StrikethroughSpan.class)) {
+                                has = true;
+                                t.removeSpan(span);
+                            }
+
+                            if (!has)
+                                t.setSpan(new StrikethroughSpan(), s, e, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+
+                            etBody.setText(t);
+                            etBody.setSelection(s, e);
+
+                            return true;
+                        }
+
                         private boolean clear(MenuItem item) {
                             for (Object span : t.getSpans(s, e, Object.class))
                                 if (!(span instanceof ImageSpan))

app/src/main/res/menu/popup_style.xml

@@ -64,8 +64,16 @@
     </group>
 
     <group
-        android:id="@+id/group_style_clear"
+        android:id="@+id/group_style_strikethrough"
         android:orderInCategory="6">
+        <item
+            android:id="@+id/menu_style_strikethrough"
+            android:title="@string/title_style_strikethrough" />
+    </group>
+
+    <group
+        android:id="@+id/group_style_clear"
+        android:orderInCategory="7">
         <item
             android:id="@+id/menu_style_clear"
             android:title="@string/title_style_clear" />

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

@@ -939,6 +939,7 @@
     <string name="title_style_font">Font</string>
     <string name="title_style_font_default">Default</string>
     <string name="title_style_blockquote">Block quote</string>
+    <string name="title_style_strikethrough">Strikethrough</string>
     <string name="title_style_clear">Clear formatting</string>
     <string name="title_style_link">Insert link</string>