Enable drag'n'drop from maintable to external application

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)
+- We added support for drag'n'drop on an entry in the maintable to an external application to get the entry preview dropped. [#11846](https://github.com/JabRef/jabref/pull/11846)
 - 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()) {

src/main/java/org/jabref/gui/preview/ClipboardContentGenerator.java

@@ -0,0 +1,136 @@
+package org.jabref.gui.preview;
+
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.ArrayList;
+import java.util.List;
+
+import javafx.scene.input.ClipboardContent;
+
+import org.jabref.logic.citationstyle.CitationStyleGenerator;
+import org.jabref.logic.citationstyle.CitationStyleOutputFormat;
+import org.jabref.logic.citationstyle.CitationStylePreviewLayout;
+import org.jabref.logic.journals.JournalAbbreviationRepository;
+import org.jabref.logic.layout.Layout;
+import org.jabref.logic.layout.LayoutFormatterPreferences;
+import org.jabref.logic.layout.LayoutHelper;
+import org.jabref.logic.layout.TextBasedPreviewLayout;
+import org.jabref.logic.os.OS;
+import org.jabref.logic.preview.PreviewLayout;
+import org.jabref.model.database.BibDatabaseContext;
+import org.jabref.model.entry.BibEntry;
+import org.jabref.model.entry.BibEntryTypesManager;
+
+import com.airhacks.afterburner.injection.Injector;
+import com.google.common.annotations.VisibleForTesting;
+
+public class ClipboardContentGenerator {
+
+    private PreviewPreferences previewPreferences;
+    private final LayoutFormatterPreferences layoutFormatterPreferences;
+    private final JournalAbbreviationRepository abbreviationRepository;
+
+    public ClipboardContentGenerator(PreviewPreferences previewPreferences,
+                                     LayoutFormatterPreferences layoutFormatterPreferences,
+                                     JournalAbbreviationRepository abbreviationRepository) {
+        this.previewPreferences = previewPreferences;
+        this.layoutFormatterPreferences = layoutFormatterPreferences;
+        this.abbreviationRepository = abbreviationRepository;
+    }
+
+    public ClipboardContent generate(List<BibEntry> selectedEntries, CitationStyleOutputFormat outputFormat, BibDatabaseContext bibDatabaseContext) throws IOException {
+        List<String> citations = generateCitations(selectedEntries, outputFormat, bibDatabaseContext);
+        PreviewLayout previewLayout = previewPreferences.getSelectedPreviewLayout();
+
+        // if it is not a citation style take care of the preview
+        if (!(previewLayout instanceof CitationStylePreviewLayout)) {
+            return processPreview(citations);
+        } else {
+            // if it's generated by a citation style take care of each output format
+            ClipboardContent content;
+            return switch (outputFormat) {
+                case HTML -> processHtml(citations);
+                case TEXT -> processText(citations);
+            };
+        }
+    }
+
+    private List<String> generateCitations(List<BibEntry> selectedEntries, CitationStyleOutputFormat outputFormat, BibDatabaseContext bibDatabaseContext) throws IOException {
+        // This worker stored the style as filename. The CSLAdapter and the CitationStyleCache store the source of the
+        // style. Therefore, we extract the style source from the file.
+        String styleSource = null;
+        PreviewLayout previewLayout = previewPreferences.getSelectedPreviewLayout();
+
+        if (previewLayout instanceof CitationStylePreviewLayout citationStyleLayout) {
+            styleSource = citationStyleLayout.getText();
+        }
+
+        if (styleSource != null) {
+            return CitationStyleGenerator.generateBibliographies(
+                    selectedEntries,
+                    styleSource,
+                    outputFormat,
+                    bibDatabaseContext,
+                    Injector.instantiateModelOrService(BibEntryTypesManager.class));
+        } else {
+            return generateTextBasedPreviewLayoutCitations(selectedEntries, bibDatabaseContext);
+        }
+    }
+
+    /**
+     * Generates a plain text string out of the preview (based on {@link org.jabref.logic.layout.TextBasedPreviewLayout} or {@link org.jabref.logic.bst.BstPreviewLayout})
+     * and copies it additionally to the html to the clipboard (WYSIWYG Editors use the HTML, plain text editors the text)
+     */
+    @VisibleForTesting
+    static ClipboardContent processPreview(List<String> citations) {
+        ClipboardContent content = new ClipboardContent();
+        content.putHtml(String.join(CitationStyleOutputFormat.HTML.getLineSeparator(), citations));
+        content.putString(String.join(CitationStyleOutputFormat.HTML.getLineSeparator(), citations));
+        return content;
+    }
+
+    /**
+     * Joins every citation with a newline and returns it.
+     */
+    @VisibleForTesting
+    static ClipboardContent processText(List<String> citations) {
+        ClipboardContent content = new ClipboardContent();
+        content.putString(String.join(CitationStyleOutputFormat.TEXT.getLineSeparator(), citations));
+        return content;
+    }
+
+    /**
+     * Inserts each citation into a HTML body and copies it to the clipboard.
+     * The given preview is based on {@link org.jabref.logic.citationstyle.CitationStylePreviewLayout}.
+     */
+    @VisibleForTesting
+    static ClipboardContent processHtml(List<String> citations) {
+        String result = "<!DOCTYPE html>" + OS.NEWLINE +
+                "<html>" + OS.NEWLINE +
+                "   <head>" + OS.NEWLINE +
+                "      <meta charset=\"utf-8\">" + OS.NEWLINE +
+                "   </head>" + OS.NEWLINE +
+                "   <body>" + OS.NEWLINE + OS.NEWLINE;
+
+        result += String.join(CitationStyleOutputFormat.HTML.getLineSeparator(), citations);
+        result += OS.NEWLINE +
+                "   </body>" + OS.NEWLINE +
+                "</html>" + OS.NEWLINE;
+
+        ClipboardContent content = new ClipboardContent();
+        content.putString(result);
+        content.putHtml(result);
+        return content;
+    }
+
+    private List<String> generateTextBasedPreviewLayoutCitations(List<BibEntry> selectedEntries, BibDatabaseContext bibDatabaseContext) throws IOException {
+        TextBasedPreviewLayout customPreviewLayout = previewPreferences.getCustomPreviewLayout();
+        StringReader customLayoutReader = new StringReader(customPreviewLayout.getText().replace("__NEWLINE__", "\n"));
+        Layout layout = new LayoutHelper(customLayoutReader, layoutFormatterPreferences, abbreviationRepository).getLayoutFromText();
+        List<String> citations = new ArrayList<>(selectedEntries.size());
+        for (BibEntry entry : selectedEntries) {
+            citations.add(layout.doLayout(entry, bibDatabaseContext.getDatabase()));
+        }
+        return citations;
+    }
+}

src/main/java/org/jabref/gui/preview/CopyCitationAction.java

@@ -1,9 +1,6 @@
 package org.jabref.gui.preview;
 
 import java.io.IOException;
-import java.io.StringReader;
-import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
 import javafx.scene.input.ClipboardContent;
@@ -14,22 +11,13 @@
 import org.jabref.gui.actions.ActionHelper;
 import org.jabref.gui.actions.SimpleCommand;
 import org.jabref.gui.preferences.GuiPreferences;
-import org.jabref.logic.citationstyle.CitationStyleGenerator;
 import org.jabref.logic.citationstyle.CitationStyleOutputFormat;
-import org.jabref.logic.citationstyle.CitationStylePreviewLayout;
 import org.jabref.logic.journals.JournalAbbreviationRepository;
 import org.jabref.logic.l10n.Localization;
-import org.jabref.logic.layout.Layout;
-import org.jabref.logic.layout.LayoutHelper;
-import org.jabref.logic.layout.TextBasedPreviewLayout;
-import org.jabref.logic.os.OS;
-import org.jabref.logic.preview.PreviewLayout;
 import org.jabref.logic.util.BackgroundTask;
 import org.jabref.logic.util.TaskExecutor;
 import org.jabref.model.entry.BibEntry;
-import org.jabref.model.entry.BibEntryTypesManager;
 
-import com.airhacks.afterburner.injection.Injector;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -47,8 +35,7 @@ public class CopyCitationAction extends SimpleCommand {
     private final DialogService dialogService;
     private final ClipBoardManager clipBoardManager;
     private final TaskExecutor taskExecutor;
-    private final GuiPreferences preferences;
-    private final JournalAbbreviationRepository abbreviationRepository;
+    private final ClipboardContentGenerator clipboardContentGenerator;
 
     public CopyCitationAction(CitationStyleOutputFormat outputFormat,
                               DialogService dialogService,
@@ -63,8 +50,7 @@ public CopyCitationAction(CitationStyleOutputFormat outputFormat,
         this.selectedEntries = stateManager.getSelectedEntries();
         this.clipBoardManager = clipBoardManager;
         this.taskExecutor = taskExecutor;
-        this.preferences = preferences;
-        this.abbreviationRepository = abbreviationRepository;
+        this.clipboardContentGenerator = new ClipboardContentGenerator(preferences.getPreviewPreferences(), preferences.getLayoutFormatterPreferences(), abbreviationRepository);
 
         this.executable.bind(ActionHelper.needsEntriesSelected(stateManager));
     }
@@ -77,106 +63,12 @@ public void execute() {
                       .executeWith(taskExecutor);
     }
 
-    private List<String> generateCitations() throws IOException {
-        // This worker stored the style as filename. The CSLAdapter and the CitationStyleCache store the source of the
-        // style. Therefore, we extract the style source from the file.
-        String styleSource = null;
-        PreviewLayout previewLayout = preferences.getPreviewPreferences().getSelectedPreviewLayout();
-
-        if (previewLayout instanceof CitationStylePreviewLayout citationStyleLayout) {
-            styleSource = citationStyleLayout.getText();
-        }
-
-        if (styleSource != null) {
-            return CitationStyleGenerator.generateBibliographies(
-                    selectedEntries,
-                    styleSource,
-                    outputFormat,
-                    stateManager.getActiveDatabase().get(),
-                    Injector.instantiateModelOrService(BibEntryTypesManager.class));
-        } else {
-            return generateTextBasedPreviewLayoutCitations();
-        }
-    }
-
-    private List<String> generateTextBasedPreviewLayoutCitations() throws IOException {
-        if (stateManager.getActiveDatabase().isEmpty()) {
-            return Collections.emptyList();
-        }
-
-        TextBasedPreviewLayout customPreviewLayout = preferences.getPreviewPreferences().getCustomPreviewLayout();
-        StringReader customLayoutReader = new StringReader(customPreviewLayout.getText().replace("__NEWLINE__", "\n"));
-        Layout layout = new LayoutHelper(customLayoutReader, preferences.getLayoutFormatterPreferences(), abbreviationRepository)
-                .getLayoutFromText();
-
-        List<String> citations = new ArrayList<>(selectedEntries.size());
-        for (BibEntry entry : selectedEntries) {
-            citations.add(layout.doLayout(entry, stateManager.getActiveDatabase().get().getDatabase()));
-        }
-        return citations;
-    }
-
-    /**
-     * Generates a plain text string out of the preview and copies it additionally to the html to the clipboard (WYSIWYG Editors use the HTML, plain text editors the text)
-     */
-    protected static ClipboardContent processPreview(List<String> citations) {
-        ClipboardContent content = new ClipboardContent();
-        content.putHtml(String.join(CitationStyleOutputFormat.HTML.getLineSeparator(), citations));
-        content.putString(String.join(CitationStyleOutputFormat.HTML.getLineSeparator(), citations));
-        return content;
+    private ClipboardContent generateCitations() throws IOException {
+        return clipboardContentGenerator.generate(selectedEntries, outputFormat, stateManager.getActiveDatabase().get());
     }
 
-    /**
-     * Joins every citation with a newline and returns it.
-     */
-    protected static ClipboardContent processText(List<String> citations) {
-        ClipboardContent content = new ClipboardContent();
-        content.putString(String.join(CitationStyleOutputFormat.TEXT.getLineSeparator(), citations));
-        return content;
-    }
-
-    /**
-     * Inserts each citation into a HTML body and copies it to the clipboard
-     */
-    protected static ClipboardContent processHtml(List<String> citations) {
-        String result = "<!DOCTYPE html>" + OS.NEWLINE +
-                "<html>" + OS.NEWLINE +
-                "   <head>" + OS.NEWLINE +
-                "      <meta charset=\"utf-8\">" + OS.NEWLINE +
-                "   </head>" + OS.NEWLINE +
-                "   <body>" + OS.NEWLINE + OS.NEWLINE;
-
-        result += String.join(CitationStyleOutputFormat.HTML.getLineSeparator(), citations);
-        result += OS.NEWLINE +
-                "   </body>" + OS.NEWLINE +
-                "</html>" + OS.NEWLINE;
-
-        ClipboardContent content = new ClipboardContent();
-        content.putString(result);
-        content.putHtml(result);
-        return content;
-    }
-
-    private void setClipBoardContent(List<String> citations) {
-        PreviewLayout previewLayout = preferences.getPreviewPreferences().getSelectedPreviewLayout();
-
-        // if it's not a citation style take care of the preview
-        if (!(previewLayout instanceof CitationStylePreviewLayout)) {
-            clipBoardManager.setContent(processPreview(citations));
-        } else {
-            // if it's generated by a citation style take care of each output format
-            ClipboardContent content;
-            switch (outputFormat) {
-                case HTML -> content = processHtml(citations);
-                case TEXT -> content = processText(citations);
-                default -> {
-                    LOGGER.warn("unknown output format: '{}', processing it via the default.", outputFormat);
-                    content = processText(citations);
-                }
-            }
-            clipBoardManager.setContent(content);
-        }
-
+    private void setClipBoardContent(ClipboardContent clipBoardContent) {
+        clipBoardManager.setContent(clipBoardContent);
         dialogService.notify(Localization.lang("Copied %0 citations.", String.valueOf(selectedEntries.size())));
     }
 }