Used late initialization for context menus (#3340)

* Used late initialization for context menus in the entry editor with Supplier
Updated checkstyle in gradle to 8.3 to be able to use {@link ..} in doc comments that refer to classes that would otherwise be "unused".

* Annotation formatting and entry into changelog.

CHANGELOG.md

@@ -24,6 +24,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 - We changed the default paths for the OpenOffice/LibreOffice binaries to the default path for LibreOffice
 - We no longer create a new entry editor when selecting a new entry to increase performance. [#3187](https://github.com/JabRef/jabref/pull/3187)
 - We increased performance and decreased the memory footprint of the entry editor drastically. [#3331](https://github.com/JabRef/jabref/pull/3331)
+- Late initialization of the context menus in the entry editor. This improves performance and memory footprint further [#3340](https://github.com/JabRef/jabref/pull/3340)
 
 
 ### Fixed

build.gradle

@@ -355,7 +355,7 @@ task media(type: com.install4j.gradle.Install4jTask, dependsOn: "releaseJar") {
 checkstyle {
     // do not use other packages for checkstyle, excluding gen(erated) sources
     checkstyleMain.source = "src/main/java"
-    toolVersion = '8.0'
+    toolVersion = '8.3'
 }
 
 checkstyleMain.shouldRunAfter test

src/main/java/org/jabref/gui/fieldeditors/EditorTextArea.java

@@ -3,6 +3,7 @@
 import java.net.URL;
 import java.util.List;
 import java.util.ResourceBundle;
+import java.util.function.Supplier;
 
 import javafx.fxml.Initializable;
 import javafx.scene.control.ContextMenu;
@@ -49,14 +50,16 @@ public EditorTextArea(String text) {
     }
 
     /**
-     * Adds the given list of menu items to the context menu.
+     * Adds the given list of menu items to the context menu. The usage of {@link Supplier} prevents that the menus need
+     * to be instantiated at this point. They are populated when the user needs them which prevents many unnecessary
+     * allocations when the main table is just scrolled with the entry editor open.
      */
-    public void addToContextMenu(List<MenuItem> items) {
+    public void addToContextMenu(Supplier<List<MenuItem>> items) {
         TextAreaSkin customContextSkin = new TextAreaSkin(this) {
             @Override
             public void populateContextMenu(ContextMenu contextMenu) {
                 super.populateContextMenu(contextMenu);
-                contextMenu.getItems().addAll(0, items);
+                contextMenu.getItems().addAll(0, items.get());
             }
         };
         setSkin(customContextSkin);

src/main/java/org/jabref/gui/fieldeditors/IdentifierEditor.java

@@ -1,14 +1,11 @@
 package org.jabref.gui.fieldeditors;
 
-import java.util.ArrayList;
-import java.util.List;
 import java.util.Optional;
 
 import javafx.event.ActionEvent;
 import javafx.fxml.FXML;
 import javafx.scene.Parent;
 import javafx.scene.control.Button;
-import javafx.scene.control.MenuItem;
 import javafx.scene.control.Tooltip;
 import javafx.scene.layout.HBox;
 
@@ -43,12 +40,11 @@ public IdentifierEditor(String fieldName, TaskExecutor taskExecutor, DialogServi
         lookupIdentifierButton.setTooltip(
                 new Tooltip(Localization.lang("Look up %0", FieldName.getDisplayName(fieldName))));
 
-        List<MenuItem> menuItems = new ArrayList<>();
         if (fieldName.equalsIgnoreCase(FieldName.DOI)) {
-            menuItems.addAll(EditorMenus.getDOIMenu(textArea));
+            textArea.addToContextMenu(EditorMenus.getDOIMenu(textArea));
+        } else {
+            textArea.addToContextMenu(EditorMenus.getDefaultMenu(textArea));
         }
-        menuItems.addAll(EditorMenus.getDefaultMenu(textArea));
-        textArea.addToContextMenu(menuItems);
 
         new EditorValidator(preferences).configureValidation(viewModel.getFieldValidator().getValidationStatus(), textArea);
     }
@@ -82,5 +78,4 @@ private void lookupIdentifier(ActionEvent event) {
     private void openExternalLink(ActionEvent event) {
         viewModel.openExternalLink();
     }
-
 }

src/main/java/org/jabref/gui/fieldeditors/contextmenu/EditorMenus.java

@@ -2,6 +2,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.function.Supplier;
 
 import javax.swing.AbstractAction;
 import javax.swing.Action;
@@ -14,42 +15,73 @@
 import javafx.scene.control.Tooltip;
 
 import org.jabref.gui.actions.CopyDoiUrlAction;
+import org.jabref.gui.fieldeditors.EditorTextArea;
 import org.jabref.logic.formatter.bibtexfields.NormalizeNamesFormatter;
 import org.jabref.logic.l10n.Localization;
 
+/**
+ * Provides context menus for the text fields of the entry editor. Note that we use {@link Supplier} to prevent an early
+ * instantiation of the menus. Therefore, they are attached to each text field but instantiation happens on the first
+ * right-click of the user in that field. The late instantiation is done by {@link
+ * EditorTextArea#addToContextMenu(java.util.function.Supplier)}.
+ */
 public class EditorMenus {
 
-    public static List<MenuItem> getDefaultMenu(TextArea textArea) {
-        List<MenuItem> menuItems = new ArrayList<>(5);
-        menuItems.add(new CaseChangeMenu(textArea.textProperty()));
-        menuItems.add(new ConversionMenu(textArea.textProperty()));
-        menuItems.add(new SeparatorMenuItem());
-        menuItems.add(new ProtectedTermsMenu(textArea));
-        menuItems.add(new SeparatorMenuItem());
-        return menuItems;
+    /**
+     * The default menu that contains functions for changing the case of text and doing several conversions.
+     *
+     * @param textArea text-area that this menu will be connected to
+     * @return default context menu available for most text fields
+     */
+    public static Supplier<List<MenuItem>> getDefaultMenu(TextArea textArea) {
+        return () -> {
+            List<MenuItem> menuItems = new ArrayList<>(5);
+            menuItems.add(new CaseChangeMenu(textArea.textProperty()));
+            menuItems.add(new ConversionMenu(textArea.textProperty()));
+            menuItems.add(new SeparatorMenuItem());
+            menuItems.add(new ProtectedTermsMenu(textArea));
+            menuItems.add(new SeparatorMenuItem());
+            return menuItems;
+        };
     }
 
-    public static List<MenuItem> getNameMenu(TextArea textArea) {
-        CustomMenuItem normalizeNames = new CustomMenuItem(new Label(Localization.lang("Normalize to BibTeX name format")));
-        normalizeNames.setOnAction(event -> textArea.setText(new NormalizeNamesFormatter().format(textArea.getText())));
-        Tooltip toolTip = new Tooltip(Localization.lang("If possible, normalize this list of names to conform to standard BibTeX name formatting"));
-        Tooltip.install(normalizeNames.getContent(),toolTip);
+    /**
+     * The default context menu with a specific menu for normalizing person names regarding to BibTex rules.
+     *
+     * @param textArea text-area that this menu will be connected to
+     * @return menu containing items of the default menu and an item for normalizing person names
+     */
+    public static Supplier<List<MenuItem>> getNameMenu(TextArea textArea) {
+        return () -> {
+            CustomMenuItem normalizeNames = new CustomMenuItem(new Label(Localization.lang("Normalize to BibTeX name format")));
+            normalizeNames.setOnAction(event -> textArea.setText(new NormalizeNamesFormatter().format(textArea.getText())));
+            Tooltip toolTip = new Tooltip(Localization.lang("If possible, normalize this list of names to conform to standard BibTeX name formatting"));
+            Tooltip.install(normalizeNames.getContent(), toolTip);
 
-        List<MenuItem> menuItems = new ArrayList<>(6);
-        menuItems.add(normalizeNames);
-        menuItems.addAll(getDefaultMenu(textArea));
-
-        return menuItems;
+            List<MenuItem> menuItems = new ArrayList<>(6);
+            menuItems.add(normalizeNames);
+            menuItems.addAll(getDefaultMenu(textArea).get());
+            return menuItems;
+        };
     }
 
-    public static List<MenuItem> getDOIMenu(TextArea textArea) {
-        AbstractAction copyDoiUrlAction = new CopyDoiUrlAction(textArea);
-        MenuItem copyDoiUrlMenuItem = new MenuItem((String) copyDoiUrlAction.getValue(Action.NAME));
-        copyDoiUrlMenuItem.setOnAction(event -> copyDoiUrlAction.actionPerformed(null));
+    /**
+     * The default context menu with a specific menu copying a DOI URL.
+     *
+     * @param textArea text-area that this menu will be connected to
+     * @return menu containing items of the default menu and an item for copying a DOI URL
+     */
+    public static Supplier<List<MenuItem>> getDOIMenu(TextArea textArea) {
+        return () -> {
+            AbstractAction copyDoiUrlAction = new CopyDoiUrlAction(textArea);
+            MenuItem copyDoiUrlMenuItem = new MenuItem((String) copyDoiUrlAction.getValue(Action.NAME));
+            copyDoiUrlMenuItem.setOnAction(event -> copyDoiUrlAction.actionPerformed(null));
 
-        List<MenuItem> menuItems = new ArrayList<>();
-        menuItems.add(copyDoiUrlMenuItem);
-        menuItems.add(new SeparatorMenuItem());
-        return menuItems;
+            List<MenuItem> menuItems = new ArrayList<>();
+            menuItems.add(copyDoiUrlMenuItem);
+            menuItems.add(new SeparatorMenuItem());
+            menuItems.addAll(getDefaultMenu(textArea).get());
+            return menuItems;
+        };
     }
 }