Improve startup time

src/main/java/org/jabref/gui/JabRefFrame.java

@@ -565,7 +565,7 @@ public void showLibraryTab(LibraryTab libraryTab) {
     }
 
     public void init() {
-        sidePaneManager = new SidePaneManager(prefs, this, dialogService, stateManager);
+        sidePaneManager = new SidePaneManager(prefs, this, taskExecutor, dialogService, stateManager);
         sidePane = sidePaneManager.getPane();
 
         tabbedPane = new TabPane();

src/main/java/org/jabref/gui/SidePaneManager.java

@@ -10,6 +10,7 @@
 import org.jabref.gui.groups.GroupSidePane;
 import org.jabref.gui.importer.fetcher.WebSearchPane;
 import org.jabref.gui.openoffice.OpenOfficeSidePanel;
+import org.jabref.gui.util.TaskExecutor;
 import org.jabref.logic.openoffice.OpenOfficePreferences;
 import org.jabref.preferences.PreferencesService;
 
@@ -23,13 +24,13 @@ public class SidePaneManager {
     private final List<SidePaneComponent> visibleComponents = new LinkedList<>();
     private final PreferencesService preferencesService;
 
-    public SidePaneManager(PreferencesService preferencesService, JabRefFrame frame, DialogService dialogService, StateManager stateManager) {
+    public SidePaneManager(PreferencesService preferencesService, JabRefFrame frame, TaskExecutor taskExecutor, DialogService dialogService, StateManager stateManager) {
         this.preferencesService = preferencesService;
         this.sidePane = new SidePane();
 
         OpenOfficePreferences openOfficePreferences = preferencesService.getOpenOfficePreferences();
         Stream.of(
-                new GroupSidePane(this, preferencesService, dialogService),
+                new GroupSidePane(this, taskExecutor, stateManager, preferencesService, dialogService),
                 new WebSearchPane(this, preferencesService, dialogService, stateManager),
                 new OpenOfficeSidePanel(this, preferencesService, frame))
               .forEach(pane -> components.put(pane.getType(), pane));

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

@@ -11,26 +11,30 @@
 import org.jabref.gui.SidePaneComponent;
 import org.jabref.gui.SidePaneManager;
 import org.jabref.gui.SidePaneType;
+import org.jabref.gui.StateManager;
 import org.jabref.gui.actions.Action;
 import org.jabref.gui.actions.StandardActions;
 import org.jabref.gui.icon.IconTheme;
+import org.jabref.gui.util.TaskExecutor;
 import org.jabref.logic.l10n.Localization;
 import org.jabref.preferences.PreferencesService;
 
-import com.airhacks.afterburner.views.ViewLoader;
-
 /**
  * The groups side pane.
  */
 public class GroupSidePane extends SidePaneComponent {
 
     private final PreferencesService preferences;
     private final DialogService dialogService;
+    private final TaskExecutor taskExecutor;
+    private final StateManager stateManager;
     private final Button intersectionUnionToggle = IconTheme.JabRefIcons.GROUP_INTERSECTION.asButton();
 
-    public GroupSidePane(SidePaneManager manager, PreferencesService preferences, DialogService dialogService) {
+    public GroupSidePane(SidePaneManager manager, TaskExecutor taskExecutor, StateManager stateManager, PreferencesService preferences, DialogService dialogService) {
         super(manager, IconTheme.JabRefIcons.TOGGLE_GROUPS, Localization.lang("Groups"));
         this.preferences = preferences;
+        this.taskExecutor = taskExecutor;
+        this.stateManager = stateManager;
         this.dialogService = dialogService;
     }
 
@@ -83,9 +87,7 @@ private void setGraphicsAndTooltipForButton(GroupViewMode mode) {
 
     @Override
     protected Node createContentPane() {
-        return ViewLoader.view(GroupTreeView.class)
-                         .load()
-                         .getView();
+        return new GroupTreeView(taskExecutor, stateManager, preferences, dialogService);
     }
 
     @Override

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

@@ -6,15 +6,13 @@
 import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
-import javax.inject.Inject;
-
 import javafx.application.Platform;
 import javafx.beans.property.ObjectProperty;
 import javafx.css.PseudoClass;
-import javafx.fxml.FXML;
 import javafx.scene.control.Button;
 import javafx.scene.control.ContextMenu;
 import javafx.scene.control.Control;
@@ -23,6 +21,7 @@
 import javafx.scene.control.SelectionMode;
 import javafx.scene.control.SeparatorMenuItem;
 import javafx.scene.control.TextField;
+import javafx.scene.control.Tooltip;
 import javafx.scene.control.TreeItem;
 import javafx.scene.control.TreeTableColumn;
 import javafx.scene.control.TreeTableRow;
@@ -32,6 +31,9 @@
 import javafx.scene.input.MouseButton;
 import javafx.scene.input.MouseEvent;
 import javafx.scene.input.TransferMode;
+import javafx.scene.layout.BorderPane;
+import javafx.scene.layout.HBox;
+import javafx.scene.layout.Priority;
 import javafx.scene.layout.StackPane;
 import javafx.scene.text.Text;
 
@@ -57,29 +59,85 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class GroupTreeView {
+public class GroupTreeView extends BorderPane {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(GroupTreeView.class);
 
-    @FXML private TreeTableView<GroupNodeViewModel> groupTree;
-    @FXML private TreeTableColumn<GroupNodeViewModel, GroupNodeViewModel> mainColumn;
-    @FXML private TreeTableColumn<GroupNodeViewModel, GroupNodeViewModel> numberColumn;
-    @FXML private TreeTableColumn<GroupNodeViewModel, GroupNodeViewModel> expansionNodeColumn;
-    @FXML private CustomTextField searchField;
-    @FXML private Button addNewGroup;
+    private TreeTableView<GroupNodeViewModel> groupTree;
+    private TreeTableColumn<GroupNodeViewModel, GroupNodeViewModel> mainColumn;
+    private TreeTableColumn<GroupNodeViewModel, GroupNodeViewModel> numberColumn;
+    private TreeTableColumn<GroupNodeViewModel, GroupNodeViewModel> expansionNodeColumn;
+    private CustomTextField searchField;
+    private Button addNewGroup;
 
-    @Inject private StateManager stateManager;
-    @Inject private DialogService dialogService;
-    @Inject private TaskExecutor taskExecutor;
-    @Inject private PreferencesService preferencesService;
+    private final StateManager stateManager;
+    private final DialogService dialogService;
+    private final TaskExecutor taskExecutor;
+    private final PreferencesService preferencesService;
 
     private GroupTreeViewModel viewModel;
     private CustomLocalDragboard localDragboard;
 
     private DragExpansionHandler dragExpansionHandler;
 
-    @FXML
-    public void initialize() {
+    /**
+     * The groups panel
+     *
+     * Note: This panel is deliberately not created in FXML, since parsing of this took about 500 msecs. In an attempt
+     * to speed up the startup time of JabRef, this has been rewritten to plain java.
+     */
+    public GroupTreeView(TaskExecutor taskExecutor, StateManager stateManager, PreferencesService preferencesService, DialogService dialogService) {
+        this.taskExecutor = taskExecutor;
+        this.stateManager = stateManager;
+        this.preferencesService = preferencesService;
+        this.dialogService = dialogService;
+
+        createNodes();
+        this.getStylesheets().add(Objects.requireNonNull(GroupTreeView.class.getResource("GroupTree.css")).toExternalForm());
+        initialize();
+    }
+
+    private void createNodes() {
+        searchField = new CustomTextField();
+
+        searchField.setPromptText(Localization.lang("Filter groups"));
+        searchField.setId("searchField");
+        HBox.setHgrow(searchField, Priority.ALWAYS);
+        HBox groupFilterBar = new HBox(searchField);
+        groupFilterBar.setId("groupFilterBar");
+        this.setTop(groupFilterBar);
+
+        mainColumn = new TreeTableColumn<>();
+        mainColumn.setId("mainColumn");
+        numberColumn = new TreeTableColumn<>();
+        numberColumn.getStyleClass().add("numberColumn");
+        numberColumn.setMinWidth(50d);
+        numberColumn.setMaxWidth(70d);
+        numberColumn.setPrefWidth(60d);
+        expansionNodeColumn = new TreeTableColumn<>();
+        expansionNodeColumn.getStyleClass().add("expansionNodeColumn");
+        expansionNodeColumn.setMaxWidth(25d);
+        expansionNodeColumn.setMinWidth(25d);
+
+        groupTree = new TreeTableView<>();
+        groupTree.setId("groupTree");
+        groupTree.setColumnResizePolicy(TreeTableView.CONSTRAINED_RESIZE_POLICY);
+        groupTree.getColumns().addAll(List.of(mainColumn, numberColumn, expansionNodeColumn));
+        this.setCenter(groupTree);
+
+        addNewGroup = new Button(Localization.lang("Add group"));
+        addNewGroup.setId("addNewGroup");
+        addNewGroup.setMaxWidth(Double.MAX_VALUE);
+        HBox.setHgrow(addNewGroup, Priority.ALWAYS);
+        addNewGroup.setTooltip(new Tooltip(Localization.lang("New group")));
+        addNewGroup.setOnAction(event -> addNewGroup());
+
+        HBox groupBar = new HBox(addNewGroup);
+        groupBar.setId("groupBar");
+        this.setBottom(groupBar);
+    }
+
+    private void initialize() {
         this.localDragboard = stateManager.getLocalDragboard();
         viewModel = new GroupTreeViewModel(stateManager, dialogService, preferencesService, taskExecutor, localDragboard);
 
@@ -396,13 +454,12 @@ private ContextMenu createContextMenuForGroup(GroupNodeViewModel group) {
         return menu;
     }
 
-    @FXML
     private void addNewGroup() {
         viewModel.addNewGroupToRoot();
     }
 
     /**
-     * Workaround taken from https://bitbucket.org/controlsfx/controlsfx/issues/330/making-textfieldssetupclearbuttonfield
+     * Workaround taken from https://github.com/controlsfx/controlsfx/issues/330
      */
     private void setupClearButtonField(CustomTextField customTextField) {
         try {