Add external drag'n'drop feature

CHANGELOG.md

@@ -29,6 +29,7 @@ Note that this project **does not** adhere to [Semantic Versioning](https://semv
 - We improved [cleanup](https://docs.jabref.org/finding-sorting-and-cleaning-entries/cleanupentries) of `arXiv` IDs in distributed in the fields `note`, `version`, `institution`, and `eid` fields. [#11306](https://github.com/JabRef/jabref/issues/11306)
 - We added a switch not to store the linked file URL, because it caused troubles at other apps. [#11735](https://github.com/JabRef/jabref/pull/11735)
 - When starting a new SLR, the selected catalogs now persist within and across JabRef sessions. [koppor#614](https://github.com/koppor/jabref/issues/614)
+- One can drag'n'drop an entry from the maintable to an external application to get the entry preview dropped.
 - We added a different background color to the search bar to indicate when the search syntax is wrong. [#11658](https://github.com/JabRef/jabref/pull/11658)
 - We added a setting which always adds the literal "Cited on pages" text before each JStyle citation. [#11691](https://github.com/JabRef/jabref/pull/11732)
 

src/main/java/org/jabref/gui/maintable/MainTable.java

@@ -1,6 +1,7 @@
 package org.jabref.gui.maintable;
 
 import java.io.File;
+import java.io.IOException;
 import java.nio.file.Path;
 import java.util.List;
 import java.util.Objects;
@@ -39,12 +40,14 @@
 import org.jabref.gui.maintable.columns.LibraryColumn;
 import org.jabref.gui.maintable.columns.MainTableColumn;
 import org.jabref.gui.preferences.GuiPreferences;
+import org.jabref.gui.preview.ClipboardContentGenerator;
 import org.jabref.gui.search.MatchCategory;
 import org.jabref.gui.util.ControlHelper;
 import org.jabref.gui.util.CustomLocalDragboard;
 import org.jabref.gui.util.UiTaskExecutor;
 import org.jabref.gui.util.ViewModelTableRowFactory;
 import org.jabref.logic.FilePreferences;
+import org.jabref.logic.citationstyle.CitationStyleOutputFormat;
 import org.jabref.logic.journals.JournalAbbreviationRepository;
 import org.jabref.logic.util.TaskExecutor;
 import org.jabref.model.database.BibDatabaseContext;
@@ -75,6 +78,8 @@ public class MainTable extends TableView<BibEntryTableViewModel> {
     private final UndoManager undoManager;
     private final FilePreferences filePreferences;
     private final ImportHandler importHandler;
+    private final ClipboardContentGenerator clipboardContentGenerator;
+
     private long lastKeyPressTime;
     private String columnSearchTerm;
 
@@ -100,6 +105,7 @@ public MainTable(MainTableDataModel model,
         this.undoManager = libraryTab.getUndoManager();
         this.filePreferences = preferences.getFilePreferences();
         this.importHandler = importHandler;
+        this.clipboardContentGenerator = new ClipboardContentGenerator(preferences.getPreviewPreferences(), preferences.getLayoutFormatterPreferences(), Injector.instantiateModelOrService(JournalAbbreviationRepository.class));
 
         MainTablePreferences mainTablePreferences = preferences.getMainTablePreferences();
 
@@ -392,12 +398,18 @@ private void handleOnDragDetected(TableRow<BibEntryTableViewModel> row, BibEntry
 
         List<BibEntry> entries = getSelectionModel().getSelectedItems().stream().map(BibEntryTableViewModel::getEntry).collect(Collectors.toList());
 
-        // The following is necessary to initiate the drag and drop in JavaFX,
-        // although we don't need the contents, it does not work without
+        ClipboardContent content;
+        try {
+            content = clipboardContentGenerator.generate(entries, CitationStyleOutputFormat.HTML, database);
+        } catch (IOException e) {
+            LOGGER.warn("Could not generate clipboard content. Falling back to empty clipboard", e);
+            content = new ClipboardContent();
+        }
+        // Required to be able to drop the entries inside JabRef
+        content.put(DragAndDropDataFormats.ENTRIES, "");
+
         // Drag'n'drop to other tabs use COPY TransferMode, drop to group sidepane use MOVE
-        ClipboardContent content = new ClipboardContent();
         Dragboard dragboard = startDragAndDrop(TransferMode.COPY_OR_MOVE);
-        content.put(DragAndDropDataFormats.ENTRIES, "");
         dragboard.setContent(content);
 
         if (!entries.isEmpty()) {