Only update auto completion suggestions upon major changes

CHANGELOG.md

@@ -18,6 +18,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 ### Fixed
 
 - We fixed an issue where the fetcher for the Astrophysics Data System (ADS) added some non-bibtex data to the entry returned from the search [#3035](https://github.com/JabRef/jabref/issues/3035)
+- We improved the auto completion so that minor changes are not added as suggestions. [#2998](https://github.com/JabRef/jabref/issues/2998)
 - We readded the undo mechanism for changes in the entry editor [#2973](https://github.com/JabRef/jabref/issues/2973)
 - We fixed an issue where assigning an entry via drag and drop to a group caused JabRef to stop/freeze completely [#3036](https://github.com/JabRef/jabref/issues/3036)
 - We fixed the shortcut <kbd>Ctrl</kbd>+<kbd>F</kbd> for the search field.

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

@@ -127,6 +127,7 @@
 import org.jabref.model.database.DatabaseLocation;
 import org.jabref.model.database.KeyCollisionException;
 import org.jabref.model.database.event.BibDatabaseContextChangedEvent;
+import org.jabref.model.database.event.CoarseChangeFilter;
 import org.jabref.model.database.event.EntryAddedEvent;
 import org.jabref.model.database.event.EntryRemovedEvent;
 import org.jabref.model.entry.BibEntry;
@@ -1396,7 +1397,8 @@ private void setupAutoCompletion() {
             suggestionProviders = new SuggestionProviders(autoCompletePreferences, Globals.journalAbbreviationLoader);
             suggestionProviders.indexDatabase(getDatabase());
             // Ensure that the suggestion providers are in sync with entries
-            this.getDatabase().registerListener(new AutoCompleteUpdater(suggestionProviders));
+            CoarseChangeFilter changeFilter = new CoarseChangeFilter(bibDatabaseContext);
+            changeFilter.registerListener(new AutoCompleteUpdater(suggestionProviders));
         } else {
             // Create empty suggestion providers if auto completion is deactivated
             suggestionProviders = new SuggestionProviders();

src/main/java/org/jabref/logic/autosaveandbackup/BackupManager.java

@@ -22,7 +22,7 @@
 import org.jabref.logic.util.io.FileUtil;
 import org.jabref.model.database.BibDatabaseContext;
 import org.jabref.model.database.event.BibDatabaseContextChangedEvent;
-import org.jabref.model.entry.event.FieldChangedEvent;
+import org.jabref.model.database.event.CoarseChangeFilter;
 import org.jabref.preferences.JabRefPreferences;
 
 import com.google.common.eventbus.Subscribe;
@@ -43,8 +43,6 @@ public class BackupManager {
 
     private static Set<BackupManager> runningInstances = new HashSet<>();
 
-    private String lastFieldChanged;
-
     private final BibDatabaseContext bibDatabaseContext;
     private final JabRefPreferences preferences;
     private final ExecutorService executor;
@@ -56,9 +54,8 @@ private BackupManager(BibDatabaseContext bibDatabaseContext) {
         BlockingQueue<Runnable> workerQueue = new ArrayBlockingQueue<>(1);
         this.executor = new ThreadPoolExecutor(1, 1, 0, TimeUnit.SECONDS, workerQueue);
 
-        // Listen for change events
-        bibDatabaseContext.getDatabase().registerListener(this);
-        bibDatabaseContext.getMetaData().registerListener(this);
+        CoarseChangeFilter changeFilter = new CoarseChangeFilter(bibDatabaseContext);
+        changeFilter.registerListener(this);
     }
 
     static Path getBackupPath(Path originalPath) {
@@ -131,18 +128,7 @@ private void performBackup(Path backupPath) {
 
     @Subscribe
     public synchronized void listen(@SuppressWarnings("unused") BibDatabaseContextChangedEvent event) {
-        if (!(event instanceof FieldChangedEvent)) {
-            startBackupTask();
-        } else {
-            // only do a backup if the field changes are more than one character or a new field is edited
-            FieldChangedEvent fieldChange = (FieldChangedEvent) event;
-            boolean isEditOnNewField = lastFieldChanged == null || !lastFieldChanged.equals(fieldChange.getFieldName());
-
-            if (fieldChange.getDelta() > 1 || isEditOnNewField) {
-                lastFieldChanged = fieldChange.getFieldName();
-                startBackupTask();
-            }
-        }
+        startBackupTask();
     }
 
     private void startBackupTask() {

src/main/java/org/jabref/model/database/event/CoarseChangeFilter.java

@@ -0,0 +1,42 @@
+package org.jabref.model.database.event;
+
+import org.jabref.model.database.BibDatabaseContext;
+import org.jabref.model.entry.event.FieldChangedEvent;
+
+import com.google.common.eventbus.EventBus;
+import com.google.common.eventbus.Subscribe;
+
+/**
+ * Filters change events and only relays major changes.
+ */
+public class CoarseChangeFilter {
+
+    private final EventBus eventBus = new EventBus();
+    private String lastFieldChanged;
+
+    public CoarseChangeFilter(BibDatabaseContext bibDatabaseContext) {
+        // Listen for change events
+        bibDatabaseContext.getDatabase().registerListener(this);
+        bibDatabaseContext.getMetaData().registerListener(this);
+    }
+
+    @Subscribe
+    public synchronized void listen(@SuppressWarnings("unused") BibDatabaseContextChangedEvent event) {
+        if (!(event instanceof FieldChangedEvent)) {
+            eventBus.post(event);
+        } else {
+            // Only relay event if the field changes are more than one character or a new field is edited
+            FieldChangedEvent fieldChange = (FieldChangedEvent) event;
+            boolean isEditOnNewField = lastFieldChanged == null || !lastFieldChanged.equals(fieldChange.getFieldName());
+
+            if (fieldChange.getDelta() > 1 || isEditOnNewField) {
+                lastFieldChanged = fieldChange.getFieldName();
+                eventBus.post(event);
+            }
+        }
+    }
+
+    public void registerListener(Object listener) {
+        eventBus.register(listener);
+    }
+}