Filter Completions from Object Mappers (#334)

* Filter Completions from Object Mappers

* Review

* fix

---------

Co-authored-by: brachy84

Author: IntegerLimit

src/main/java/com/cleanroommc/groovyscript/server/Completions.java

@@ -10,14 +10,17 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.function.Function;
 
 public class Completions extends ArrayList<CompletionItem> {
 
     private final int limit;
+    private String filter;
 
     public Completions(int limit) {
         this.limit = limit;
+        this.filter = null;
     }
 
     public int getLimit() {
@@ -28,6 +31,18 @@ public boolean reachedLimit() {
         return size() >= this.limit;
     }
 
+    public void setFilter(String filter) {
+        this.filter = filter.toLowerCase(Locale.ENGLISH);
+    }
+
+    @Override
+    public boolean add(CompletionItem item) {
+        if (filter == null || item.getLabel().toLowerCase(Locale.ENGLISH).contains(filter)) {
+            return super.add(item);
+        }
+        return false;
+    }
+
     public <V> void addAll(Iterable<V> values, Function<V, @Nullable CompletionItem> toCompletionItem) {
         for (V v : values) {
             if (reachedLimit()) break;

src/main/java/net/prominic/groovyls/providers/CompletionProvider.java

@@ -197,6 +197,7 @@ private boolean populateItemsFromConstantExpression(ConstantExpression node, AST
                             break;
                         }
                     }
+                    items.setFilter(node.getText());
                     mapper.provideCompletion(index, params, items);
                 }
             }