JabRef · damgam0288 · Nov 11, 2024 · Nov 11, 2024 · Nov 11, 2024 · Nov 11, 2024
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -48,6 +48,7 @@ Note that this project **does not** adhere to [Semantic Versioning](https://semv
 - By double clicking on a local citation in the Citation Relations Tab you can now jump the linked entry. [#11955](https://github.com/JabRef/jabref/pull/11955)
 - We use the menu icon for background tasks as a progress indicator to visualise an import's progress when dragging and dropping several PDF files into the main table. [#12072](https://github.com/JabRef/jabref/pull/12072)
 - The PDF content importer now supports importing title from upto the second page of the PDF. [#12139](https://github.com/JabRef/jabref/issues/12139)
+- We added the ability for users to display a cover image in the preview panel of the entry editor for book, in-book and booklet citations. [#10120](https://github.com/JabRef/jabref/issues/10120)
 
 ### Changed
 

diff --git a/src/main/java/org/jabref/gui/preview/PreviewViewer.java b/src/main/java/org/jabref/gui/preview/PreviewViewer.java
@@ -218,14 +218,35 @@ private void setPreviewText(String text) {
         layoutText = """
                 <html>
                     <body id="previewBody">
-                        <div id="content"> %s </div>
+                        <div style="display: flex;">
+                            <div id="content" style="flex: 1;">
+                                %s
+                            </div>
+                            <div id="bookCover" style="flex: 1;">
+                                <img
+                                    src="%s"
+                                    style="width: 75vh; height: auto; max-height: 100vh;"
+                                    align="right";
+                                >
+                            </div>
+                        </div>
                     </body>
                 </html>
-                """.formatted(text);
+                """.formatted(text, getBookCoverURI());
         highlightLayoutText();
         this.setHvalue(0);
     }
 
+    private String getBookCoverURI() {
+        if (entry != null) {
+            if (entry.getCoverImageFile().isPresent()) {
+                return "file:///" + entry.getCoverImageFile().get().getLink();
+            }
+        }
+
+        return "";
+    }
+
     private void highlightLayoutText() {
         if (layoutText == null) {
             return;

diff --git a/src/main/java/org/jabref/model/entry/BibEntry.java b/src/main/java/org/jabref/model/entry/BibEntry.java
@@ -99,6 +99,16 @@
 public class BibEntry implements Cloneable {
 
     public static final EntryType DEFAULT_TYPE = StandardEntryType.Misc;
+
+    private static final HashSet<EntryType> COVERABLE_TYPES = new HashSet<>();
+    static {
+        COVERABLE_TYPES.add(StandardEntryType.Book);
+        COVERABLE_TYPES.add(StandardEntryType.InBook);
+        COVERABLE_TYPES.add(StandardEntryType.Booklet);
+    }
+
+    private static final String COVER_TAG = "cover";
+
     private static final Logger LOGGER = LoggerFactory.getLogger(BibEntry.class);
     private final SharedBibEntryData sharedBibEntryData;
 
@@ -1124,6 +1134,36 @@ public Optional<FieldChange> addFiles(List<LinkedFile> filesToAdd) {
         currentFiles.addAll(filesToAdd);
         return setFiles(currentFiles);
     }
+
+    /**
+     * @return <code>LinkedFile</code> that contains the cover image
+     * if the <code>BibEntry</code> is a Book or other <code>COVERABLE_TYPES</code>
+     */
+    public Optional<LinkedFile> getCoverImageFile() {
+        if (!isCoverable()) {
+            return Optional.empty();
+        }
+
+        List<LinkedFile> files = getFiles();
+
+        if (files == null) {
+            return Optional.empty();
+        }
+
+        if (files.isEmpty()) {
+            return Optional.empty();
+        }
+
+        for (LinkedFile file : getFiles()) {
+            if (file.getDescription().equalsIgnoreCase(COVER_TAG)) {
+                if (file.isImage()) {
+                    return Optional.of(file);
+                }
+            }
+        }
+
+        return Optional.empty();
+    }
     // endregion
 
     /**
@@ -1253,4 +1293,11 @@ public boolean isEmpty() {
         }
         return StandardField.AUTOMATIC_FIELDS.containsAll(this.getFields());
     }
+
+    /**
+     * @return <code>true</code> if this entry's <code>type</code> is a Book or one of <code>COVERABLE_TYPES</code>
+     */
+    private boolean isCoverable() {
+        return COVERABLE_TYPES.contains(getType());
+    }
 }
diff --git a/src/main/java/org/jabref/model/entry/LinkedFile.java b/src/main/java/org/jabref/model/entry/LinkedFile.java
@@ -220,6 +220,14 @@ public boolean isOnlineLink() {
         return isOnlineLink(link.get());
     }
 
+    /**
+     * @return <code>true</code> if <code>fileType</code> contains the string "image"
+     */
+    public boolean isImage() {
+        // Cannot compare fileType to StandardExternalFileType enum since it is a StringProperty
+        return getFileType().toLowerCase().contains("image");
+    }
+
     public Optional<Path> findIn(BibDatabaseContext databaseContext, FilePreferences filePreferences) {
         List<Path> dirs = databaseContext.getFileDirectories(filePreferences);
         return findIn(dirs);

diff --git a/src/test/java/org/jabref/model/entry/BibEntryTest.java b/src/test/java/org/jabref/model/entry/BibEntryTest.java
@@ -1,6 +1,7 @@
 package org.jabref.model.entry;
 
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -813,6 +814,82 @@ void mergeEntriesWithOverlapAndPriorityGivenToOverlappingField() {
         assertEquals(expected.getFields(), copyEntry.getFields());
     }
 
+    @Test
+    void getCoverImageReturnsCorrectImage() {
+        LinkedFile cover1 = new LinkedFile("", Paths.get("JabRef-icon-128.png"), "PNG image");
+        LinkedFile cover2 = new LinkedFile("", Paths.get("JabRef-icon-64.png"), "PNG image");
+        LinkedFile cover3 = new LinkedFile("cover", Paths.get("wallpaper.jpg"), "JPG image");
+        BibEntry entry = new BibEntry(StandardEntryType.Book).withField(StandardField.AUTHOR, "value");
+        entry.addFile(cover1);
+        entry.addFile(cover2);
+        entry.addFile(cover3);
+        assertEquals(Optional.of(cover3), entry.getCoverImageFile());
+    }
+
+    @Test
+    void getCoverImageReturnsEmptyIfNoFiles() {
+        entry = new BibEntry(StandardEntryType.Book).withField(StandardField.AUTHOR, "value");
+        assertEquals(Optional.empty(), entry.getCoverImageFile());
+    }
+
+    @Test
+    void getCoverImageReturnsEmptyIfNoImageFiles() {
+        LinkedFile pdf = new LinkedFile("", Paths.get("Baldoni2002.pdf").toAbsolutePath().toString(), "pdf");
+        LinkedFile markdown = new LinkedFile("", "readme.md", "md");
+        entry = new BibEntry(StandardEntryType.Book).withField(StandardField.AUTHOR, "value");
+        entry.addFile(markdown);
+        entry.addFile(pdf);
+        assertEquals(Optional.empty(), entry.getCoverImageFile());
+    }
+
+    @ParameterizedTest
+    @MethodSource("nonCoverableEntryTypes")
+    void getCoverImageReturnsEmptyIfEntryIsNotCoverable(StandardEntryType entryType) {
+        BibEntry entry = new BibEntry(entryType).withField(StandardField.AUTHOR, "value");
+        assertEquals(Optional.empty(), entry.getCoverImageFile());
+    }
+
+    static Stream<StandardEntryType> nonCoverableEntryTypes() {
+        return Stream.of(
+                StandardEntryType.Proceedings,
+                StandardEntryType.Dataset,
+                StandardEntryType.Software
+        );
+    }
+
+    @ParameterizedTest
+    @MethodSource("imagesWithoutCoverDescription")
+    void getCoverImageDoesNotReturnImagesWithoutCoverDescription(LinkedFile image) {
+        entry = new BibEntry(StandardEntryType.Book).withField(StandardField.AUTHOR, "value");
+        entry.addFile(image);
+        assertEquals(Optional.empty(), entry.getCoverImageFile());
+    }
+
+    static Stream<LinkedFile> imagesWithoutCoverDescription() {
+        return Stream.of(
+                new LinkedFile("", Paths.get("JabRef-icon-128.png"), "PNG image"),
+                new LinkedFile("", Paths.get("JabRef-icon-64.png"), "PNG image"),
+                new LinkedFile("", Paths.get("JabRef-icon-32.png"), "PNG image")
+        );
+    }
+
+    @ParameterizedTest
+    @MethodSource("docsWithCoverDescription")
+    void getCoverImageDoesNotReturnDocumentsWithCoverDescription(LinkedFile file) {
+        entry = new BibEntry(StandardEntryType.Book).withField(StandardField.AUTHOR, "value");
+        entry.addFile(file);
+        assertEquals(Optional.empty(), entry.getCoverImageFile());
+    }
+
+    static Stream<LinkedFile> docsWithCoverDescription() {
+        return Stream.of(
+                new LinkedFile("cover", Paths.get("Baldoni2002.pdf"), "pdf"),
+                new LinkedFile("cover", Paths.get("readme.md"), "md"),
+                new LinkedFile("cover", Paths.get("BiblioscapeImporterTestArticleST.txt"), "txt"),
+                new LinkedFile("cover", Paths.get("emptyFile.xml"), "xml")
+        );
+    }
+
     public static Stream<BibEntry> isEmpty() {
         return Stream.of(
                 new BibEntry(),