fix(api): allow to create input category node even if no matching files found (#2806)

jadx-gui/src/main/java/jadx/gui/plugins/context/ITreeInputCategory.java

@@ -4,6 +4,7 @@ import java.nio.file.Path;
 import java.util.List;
 
 import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nullable;
 
 import jadx.gui.treemodel.JNode;
 
@@ -19,7 +20,11 @@ public interface ITreeInputCategory {
 	boolean filesFilter(Path file);
 
 	/**
-	 * Build node for filtered files
+	 * Build node for filtered files.
+	 * Can be called with empty list (empty category might be useful)
+	 *
+	 * @return category node or null if not needed
 	 */
+	@Nullable
 	JNode buildInputNode(List<Path> files);
 }

jadx-gui/src/main/java/jadx/gui/utils/plugins/TreeInputsHelper.java

@@ -46,7 +46,6 @@ public class TreeInputsHelper {
 
 	public List<JNode> getCustomNodes() {
 		return categoryData.stream()
-				.filter(CategoryData::notEmpty)
 				.map(CategoryData::buildInputNode)
 				.filter(Objects::nonNull)
 				.collect(Collectors.toList());
@@ -84,9 +83,5 @@ public class TreeInputsHelper {
 				return null;
 			}
 		}
-
-		public boolean notEmpty() {
-			return !collectedFiles.isEmpty();
-		}
 	}
 }