Shortcut server search

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

@@ -886,6 +886,23 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
 
         private static final String FROM = "from:";
 
+        boolean onServer() {
+            if (query == null)
+                return false;
+
+            for (String w : query.trim().split("\\s+"))
+                if (w.length() > 1 && w.startsWith("+"))
+                    return true;
+                else if (w.length() > 1 && w.startsWith("-"))
+                    return true;
+                else if (w.length() > 1 && w.startsWith("?"))
+                    return true;
+                else if (w.length() > FROM.length() && w.startsWith(FROM))
+                    return true;
+
+            return false;
+        }
+
         SearchTerm getTerms(boolean utf8, Flags flags, String[] keywords) {
             List<SearchTerm> or = new ArrayList<>();
             List<SearchTerm> and = new ArrayList<>();

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

@@ -10015,6 +10015,15 @@ public class FragmentMessages extends FragmentBase
     static void search(
             final Context context, final LifecycleOwner owner, final FragmentManager manager,
             long account, long folder, boolean server, BoundaryCallbackMessages.SearchCriteria criteria) {
+        if (criteria.onServer()) {
+            if (account > 0 && folder > 0)
+                server = true;
+            else {
+                ToastEx.makeText(context, R.string.title_complex_search, Toast.LENGTH_LONG).show();
+                return;
+            }
+        }
+
         if (owner.getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED))
             manager.popBackStack("search", FragmentManager.POP_BACK_STACK_INCLUSIVE);
 

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

@@ -1331,6 +1331,7 @@
     <string name="title_no_folder">Folder does not exist</string>
     <string name="title_no_format">The originally received message will be included</string>
     <string name="title_no_search">Search on server is not available for this account</string>
+    <string name="title_complex_search">Select a folder for a complex search</string>
     <string name="title_too_large">Message too large to completely reformat</string>
     <string name="title_truncated">Message too large to display completely</string>
     <string name="title_insufficient_memory">Message too large for the available memory (%1$d)</string>