From 4ff68b1e853dc6f3c6c26c53ee60e4f9e2344a95 Mon Sep 17 00:00:00 2001
From: Kai Takac <kai.takac@gmail.com>
Date: Wed, 11 Dec 2019 00:00:12 +0100
Subject: [PATCH] Fix #2868 - keep source groups selected after drag and drop

---
 CHANGELOG.md                                  |  1 +
 .../org/jabref/gui/groups/GroupTreeView.java  | 28 +++++++++++++++++--
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e62873f5eedf..2e296b6fad7a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -71,6 +71,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 - We fixed an issue where the side pane was not remembering its position. [#5615](https://github.com/JabRef/jabref/issues/5615)
 - We fixed an issue where JabRef could not interact with [Oracle XE](https://www.oracle.com/de/database/technologies/appdev/xe.html) in the [shared SQL database setup](https://docs.jabref.org/collaborative-work/sqldatabase).
 - We fixed an issue where the toolbar icons were hidden on smaller screens.
+- We fixed a bug where the selection of groups was lost after drag and drop.[#2868](https://github.com/JabRef/jabref/issues/2868)
 
 ### Removed
 
diff --git a/src/main/java/org/jabref/gui/groups/GroupTreeView.java b/src/main/java/org/jabref/gui/groups/GroupTreeView.java
index ddfbf0434e13..d6cf0f29f0bc 100644
--- a/src/main/java/org/jabref/gui/groups/GroupTreeView.java
+++ b/src/main/java/org/jabref/gui/groups/GroupTreeView.java
@@ -4,6 +4,7 @@
 import java.lang.reflect.Method;
 import java.time.Duration;
 import java.util.ArrayList;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Optional;
 import java.util.stream.Collectors;
@@ -232,14 +233,18 @@ public void initialize() {
 
                 if (dragboard.hasContent(DragAndDropDataFormats.GROUP)) {
                     List<String> pathToSources = (List<String>) dragboard.getContent(DragAndDropDataFormats.GROUP);
+                    List<GroupNodeViewModel> changedGroups = new LinkedList<>();
                     for (String pathToSource : pathToSources) {
                         Optional<GroupNodeViewModel> source = viewModel.rootGroupProperty().get()
                                 .getChildByPath(pathToSource);
                         if (source.isPresent()) {
                             source.get().draggedOn(row.getItem(), ControlHelper.getDroppingMouseLocation(row, event));
+                            changedGroups.add(source.get());
                             success = true;
                         }
                     }
+                    groupTree.getSelectionModel().clearSelection();
+                    changedGroups.forEach(value -> selectNode(value, true));
                 }
 
                 if (localDragboard.hasBibEntries()) {
@@ -268,8 +273,21 @@ private void updateSelection(List<TreeItem<GroupNodeViewModel>> newSelectedGroup
     }
 
     private void selectNode(GroupNodeViewModel value) {
+        selectNode(value, false);
+    }
+
+    private void selectNode(GroupNodeViewModel value, boolean expandParents) {
         getTreeItemByValue(value)
-                .ifPresent(treeItem -> groupTree.getSelectionModel().select(treeItem));
+                .ifPresent(treeItem -> {
+                    if (expandParents) {
+                        TreeItem<GroupNodeViewModel> parent = treeItem.getParent();
+                        while (parent != null) {
+                            parent.setExpanded(true);
+                            parent = parent.getParent();
+                        }
+                    }
+                    groupTree.getSelectionModel().select(treeItem);
+                });
     }
 
     private Optional<TreeItem<GroupNodeViewModel>> getTreeItemByValue(GroupNodeViewModel value) {
@@ -281,7 +299,13 @@ private Optional<TreeItem<GroupNodeViewModel>> getTreeItemByValue(TreeItem<Group
         if (root.getValue().equals(value)) {
             return Optional.of(root);
         }
-        return root.getChildren().stream().filter(child -> getTreeItemByValue(child, value).isPresent()).findFirst();
+
+        Optional<TreeItem<GroupNodeViewModel>> node = Optional.empty();
+        for (int i = 0; i < root.getChildren().size() && node.isEmpty(); i++) {
+            node = getTreeItemByValue(root.getChildren().get(i), value);
+        }
+
+        return node;
     }
 
     private ContextMenu createContextMenuForGroup(GroupNodeViewModel group) {