Fix for unnecessary horizontal scroll bar in group panel (#8756)

* Fix scrollbar shows up needlessly in group panel

* Update CHANGELOG.md

* Change solution to fix unneccesary scrollbar in group panel

* Remove first solution from GroupTree.css

CHANGELOG.md

@@ -20,6 +20,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 
 ### Fixed
 
+- We fixed the unnecessary horizontal scroll bar in group panel [#8467](https://github.com/JabRef/jabref/issues/8467)
 - We fixed an issue where the notification bar message, icon and actions appeared to be invisible. [#8761](https://github.com/JabRef/jabref/issues/8761)
 
 ### Removed

src/main/java/org/jabref/gui/groups/GroupTreeView.java

@@ -112,22 +112,28 @@ private void createNodes() {
 
         mainColumn = new TreeTableColumn<>();
         mainColumn.setId("mainColumn");
+        mainColumn.setResizable(true);
         numberColumn = new TreeTableColumn<>();
         numberColumn.getStyleClass().add("numberColumn");
-        numberColumn.setMinWidth(50d);
-        numberColumn.setMaxWidth(70d);
-        numberColumn.setPrefWidth(60d);
+        numberColumn.setMinWidth(40d);
+        numberColumn.setMaxWidth(40d);
+        numberColumn.setPrefWidth(40d);
+        numberColumn.setResizable(false);
         expansionNodeColumn = new TreeTableColumn<>();
         expansionNodeColumn.getStyleClass().add("expansionNodeColumn");
-        expansionNodeColumn.setMaxWidth(25d);
-        expansionNodeColumn.setMinWidth(25d);
+        expansionNodeColumn.setMaxWidth(20d);
+        expansionNodeColumn.setMinWidth(20d);
+        expansionNodeColumn.setPrefWidth(20d);
+        expansionNodeColumn.setResizable(false);
 
         groupTree = new TreeTableView<>();
         groupTree.setId("groupTree");
         groupTree.setColumnResizePolicy(TreeTableView.CONSTRAINED_RESIZE_POLICY);
         groupTree.getColumns().addAll(List.of(mainColumn, numberColumn, expansionNodeColumn));
         this.setCenter(groupTree);
 
+        mainColumn.prefWidthProperty().bind(groupTree.widthProperty().subtract(60d).subtract(15));
+
         addNewGroup = new Button(Localization.lang("Add group"));
         addNewGroup.setId("addNewGroup");
         addNewGroup.setMaxWidth(Double.MAX_VALUE);