Fix #2852: Improve performance of group filtering.

CHANGELOG.md

@@ -13,6 +13,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 ### Changed
 - We continued to improve the new groups interface:
   - You can now again select multiple groups (and a few related settings were added to the preferences) [#2786](https://github.com/JabRef/jabref/issues/2786).
+  - We further improved performance of group operations, especially of the new filter feature [#2852](https://github.com/JabRef/jabref/issues/2852). 
 - The entry editor got a fresh coat of paint:
   - Homogenize the size of text fields.
   - The buttons were changed to icons.

build.gradle

@@ -114,6 +114,7 @@ dependencies {
     compile 'de.codecentric.centerdevice:javafxsvg:1.2.1'
     compile 'org.controlsfx:controlsfx:8.40.12'
     compile 'org.fxmisc.easybind:easybind:1.0.3'
+    compile 'net.corda:jfx:0.11.0'
     compile 'org.fxmisc.flowless:flowless:0.5.2'
     compile 'de.jensd:fontawesomefx-materialdesignfont:1.7.22-4'
 

external-libraries.txt

@@ -131,17 +131,22 @@ URL:     http://fxexperience.com/controlsfx/
 License: BSD-3-Clause
 
 Id:      org.fx.misc.easybin:easybind
-Projekt: EasyBind
+Project: EasyBind
 URL:     https://github.com/TomasMikula/EasyBind
 License: BSD-2-Clause
 
+Id:      net.corda:jfx
+Project: Corda
+URL:     https://github.com/corda/corda/tree/master/client/jfx
+License: Apache-2.0
+
 Id:      org.fxmisc.flowless:flowless
-Projekt: Flowless
+Project: Flowless
 URL:     https://github.com/TomasMikula/Flowless
 License: BSD-2-Clause
 
 Id:      de.jensd:fontawesomefx-materialdesignfont
-Projekt: FontAwesomeFX
+Project: FontAwesomeFX
 URL:     https://bitbucket.org/Jerady/fontawesomefx
 License: Apache-2.0
 

src/main/java/org/jabref/gui/errorconsole/ErrorConsoleViewModel.java

@@ -16,7 +16,6 @@
 import org.jabref.gui.AbstractViewModel;
 import org.jabref.gui.ClipBoardManager;
 import org.jabref.gui.DialogService;
-import org.jabref.gui.MappedList;
 import org.jabref.gui.desktop.JabRefDesktop;
 import org.jabref.logic.l10n.Localization;
 import org.jabref.logic.logging.LogMessages;
@@ -27,6 +26,7 @@
 import org.apache.commons.logging.LogFactory;
 import org.apache.http.client.utils.URIBuilder;
 import org.apache.logging.log4j.core.LogEvent;
+import org.fxmisc.easybind.EasyBind;
 
 public class ErrorConsoleViewModel extends AbstractViewModel {
     private static final Log LOGGER = LogFactory.getLog(ErrorConsoleViewModel.class);
@@ -42,7 +42,7 @@ public ErrorConsoleViewModel(DialogService dialogService, ClipBoardManager clipB
         this.dialogService = Objects.requireNonNull(dialogService);
         this.clipBoardManager = Objects.requireNonNull(clipBoardManager);
         this.buildInfo = Objects.requireNonNull(buildInfo);
-        ObservableList<LogEventViewModel> eventViewModels = new MappedList<>(LogMessages.getInstance().getMessages(), LogEventViewModel::new);
+        ObservableList<LogEventViewModel> eventViewModels = EasyBind.map(LogMessages.getInstance().getMessages(), LogEventViewModel::new);
         allMessagesData = new ReadOnlyListWrapper<>(eventViewModels);
     }
 

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

@@ -67,7 +67,7 @@ public GroupNodeViewModel(BibDatabaseContext databaseContext, StateManager state
                     .sorted((group1, group2) -> group1.getDisplayName().compareToIgnoreCase(group2.getDisplayName()))
                     .collect(Collectors.toCollection(FXCollections::observableArrayList));
         } else {
-            children = EasyBind.map(groupNode.getChildren(), this::toViewModel);
+            children = BindingsHelper.mapBacked(groupNode.getChildren(), this::toViewModel);
         }
         hasChildren = new SimpleBooleanProperty();
         hasChildren.bind(Bindings.isNotEmpty(children));

src/main/java/org/jabref/gui/util/BindingsHelper.java

@@ -18,6 +18,8 @@
 import javafx.css.PseudoClass;
 import javafx.scene.Node;
 
+import net.corda.client.jfx.utils.MappedList;
+
 
 /**
  * Helper methods for javafx binding.
@@ -57,6 +59,18 @@ public String getName() {
         pseudoClassState.bind(condition);
     }
 
+    /**
+     * Creates a new list in which each element is converted using the provided mapping.
+     * All changes to the underlying list are propagated to the converted list.
+     *
+     * In contrast to {@link org.fxmisc.easybind.EasyBind#map(ObservableList, Function)},
+     * the items are converted when the are inserted (and at the initialization) instead of when they are accessed.
+     * Thus the initial CPU overhead and memory consumption is higher but the access to list items is quicker.
+     */
+    public static <A, B> ObservableList<B> mapBacked(ObservableList<A> source, Function<A, B> mapper) {
+        return new MappedList<>(source, mapper::apply);
+    }
+
     /**
      * Binds propertA bidirectional to propertyB using the provided map functions to convert between them.
      */