Lectures: Add hide/show functionality to PDF Preview Component

src/main/java/de/tum/cit/aet/artemis/lecture/domain/Slide.java

@@ -1,5 +1,7 @@
 package de.tum.cit.aet.artemis.lecture.domain;
 
+import java.util.Date;
+
 import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
 import jakarta.persistence.JoinColumn;
@@ -27,6 +29,9 @@ public class Slide extends DomainObject {
     @Column(name = "slide_number")
     private int slideNumber;
 
+    @Column(name = "hidden")
+    private Date hidden;
+
     public AttachmentUnit getAttachmentUnit() {
         return attachmentUnit;
     }
@@ -50,4 +55,12 @@ public int getSlideNumber() {
     public void setSlideNumber(int slideNumber) {
         this.slideNumber = slideNumber;
     }
+
+    public Date getHidden() {
+        return hidden;
+    }
+
+    public void setHidden(Date hidden) {
+        this.hidden = hidden;
+    }
 }

src/main/java/de/tum/cit/aet/artemis/lecture/repository/SlideRepository.java

@@ -2,7 +2,11 @@
 
 import static de.tum.cit.aet.artemis.core.config.Constants.PROFILE_CORE;
 
+import java.util.List;
+
 import org.springframework.context.annotation.Profile;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
 import de.tum.cit.aet.artemis.core.repository.base.ArtemisJpaRepository;
@@ -17,4 +21,17 @@ public interface SlideRepository extends ArtemisJpaRepository<Slide, Long> {
 
     Slide findSlideByAttachmentUnitIdAndSlideNumber(Long attachmentUnitId, Integer slideNumber);
 
+    /**
+     * Finds the list of hidden slide IDs for a specific attachment unit ID.
+     *
+     * @param attachmentUnitId The ID of the attachment unit.
+     * @return List of hidden slide IDs.
+     */
+    @Query("""
+            SELECT s.slideNumber
+            FROM Slide s
+            WHERE s.attachmentUnit.id = :attachmentUnitId AND s.hidden IS NOT NULL
+            """)
+    List<Integer> findHiddenSlideNumbersByAttachmentUnitId(@Param("attachmentUnitId") Long attachmentUnitId);
+
 }

src/main/java/de/tum/cit/aet/artemis/lecture/service/AttachmentUnitService.java

@@ -108,10 +108,11 @@ public AttachmentUnit createAttachmentUnit(AttachmentUnit attachmentUnit, Attach
      * @param updateAttachment       The new attachment data.
      * @param updateFile             The optional file.
      * @param keepFilename           Whether to keep the original filename or not.
+     * @param hiddenPages            The hidden pages of attachment unit.
      * @return The updated attachment unit.
      */
     public AttachmentUnit updateAttachmentUnit(AttachmentUnit existingAttachmentUnit, AttachmentUnit updateUnit, Attachment updateAttachment, MultipartFile updateFile,
-            boolean keepFilename) {
+            boolean keepFilename, String hiddenPages) {
         Set<CompetencyLectureUnitLink> existingCompetencyLinks = new HashSet<>(existingAttachmentUnit.getCompetencyLinks());
 
         existingAttachmentUnit.setDescription(updateUnit.getDescription());
@@ -144,7 +145,7 @@ public AttachmentUnit updateAttachmentUnit(AttachmentUnit existingAttachmentUnit
             }
             // Split the updated file into single slides only if it is a pdf
             if (Objects.equals(FilenameUtils.getExtension(updateFile.getOriginalFilename()), "pdf")) {
-                slideSplitterService.splitAttachmentUnitIntoSingleSlides(savedAttachmentUnit);
+                slideSplitterService.splitAttachmentUnitIntoSingleSlides(savedAttachmentUnit, hiddenPages);
             }
             if (pyrisWebhookService.isPresent() && irisSettingsRepository.isPresent()) {
                 pyrisWebhookService.get().autoUpdateAttachmentUnitsInPyris(savedAttachmentUnit.getLecture().getCourse().getId(), List.of(savedAttachmentUnit));

src/main/java/de/tum/cit/aet/artemis/lecture/service/LectureUnitImportService.java

@@ -119,7 +119,7 @@ public LectureUnit importLectureUnit(final LectureUnit importedLectureUnit) {
                 attachment.setAttachmentUnit(attachmentUnit);
                 attachmentRepository.save(attachment);
                 if (attachment.getLink().endsWith(".pdf")) {
-                    slideSplitterService.splitAttachmentUnitIntoSingleSlides(attachmentUnit);
+                    slideSplitterService.splitAttachmentUnitIntoSingleSlides(attachmentUnit, null);
                 }
                 attachmentUnit.setAttachment(attachment);
                 return attachmentUnit;

src/main/java/de/tum/cit/aet/artemis/lecture/service/LectureUnitProcessingService.java

@@ -109,7 +109,7 @@ public List<AttachmentUnit> splitAndSaveUnits(LectureUnitSplitInformationDTO lec
 
                 MultipartFile multipartFile = fileService.convertByteArrayToMultipart(lectureUnit.unitName(), ".pdf", outputStream.toByteArray());
                 AttachmentUnit savedAttachmentUnit = attachmentUnitService.createAttachmentUnit(attachmentUnit, attachment, lecture, multipartFile, true);
-                slideSplitterService.splitAttachmentUnitIntoSingleSlides(documentUnits.getFirst(), savedAttachmentUnit, multipartFile.getOriginalFilename());
+                slideSplitterService.splitAttachmentUnitIntoSingleSlides(documentUnits.getFirst(), savedAttachmentUnit, multipartFile.getOriginalFilename(), null);
                 documentUnits.getFirst().close(); // make sure to close the document
                 units.add(savedAttachmentUnit);
             }

src/main/java/de/tum/cit/aet/artemis/lecture/service/SlideSplitterService.java

@@ -8,6 +8,11 @@
 import java.io.IOException;
 import java.net.URI;
 import java.nio.file.Path;
+import java.time.LocalDate;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
 
 import javax.imageio.ImageIO;
 
@@ -39,6 +44,8 @@ public class SlideSplitterService {
 
     private static final Logger log = LoggerFactory.getLogger(SlideSplitterService.class);
 
+    static final LocalDate FOREVER = LocalDate.of(9999, 12, 31);
+
     private final FileService fileService;
 
     private final SlideRepository slideRepository;
@@ -52,14 +59,15 @@ public SlideSplitterService(FileService fileService, SlideRepository slideReposi
      * Splits an Attachment Unit file into single slides and saves them as PNG files asynchronously.
      *
      * @param attachmentUnit The attachment unit to which the slides belong.
+     * @param hiddenPages    The hidden pages of the attachment unit.
      */
     @Async
-    public void splitAttachmentUnitIntoSingleSlides(AttachmentUnit attachmentUnit) {
+    public void splitAttachmentUnitIntoSingleSlides(AttachmentUnit attachmentUnit, String hiddenPages) {
         Path attachmentPath = FilePathService.actualPathForPublicPath(URI.create(attachmentUnit.getAttachment().getLink()));
         File file = attachmentPath.toFile();
         try (PDDocument document = Loader.loadPDF(file)) {
             String pdfFilename = file.getName();
-            splitAttachmentUnitIntoSingleSlides(document, attachmentUnit, pdfFilename);
+            splitAttachmentUnitIntoSingleSlides(document, attachmentUnit, pdfFilename, hiddenPages);
         }
         catch (IOException e) {
             log.error("Error while splitting Attachment Unit {} into single slides", attachmentUnit.getId(), e);
@@ -68,19 +76,23 @@ public void splitAttachmentUnitIntoSingleSlides(AttachmentUnit attachmentUnit) {
     }
 
     /**
-     * Splits an Attachment Unit file into single slides and saves them as PNG files. Document is closed where this method is called.
+     * Splits an Attachment Unit file into single slides and saves them as PNG files or updates existing slides.
      *
      * @param attachmentUnit The attachment unit to which the slides belong.
      * @param document       The PDF document that is already loaded.
      * @param pdfFilename    The name of the PDF file.
+     * @param hiddenPages    The hidden pages of the attachment unit.
      */
-    public void splitAttachmentUnitIntoSingleSlides(PDDocument document, AttachmentUnit attachmentUnit, String pdfFilename) {
+    public void splitAttachmentUnitIntoSingleSlides(PDDocument document, AttachmentUnit attachmentUnit, String pdfFilename, String hiddenPages) {
         log.debug("Splitting Attachment Unit file {} into single slides", attachmentUnit.getAttachment().getName());
         try {
             String fileNameWithOutExt = FilenameUtils.removeExtension(pdfFilename);
             int numPages = document.getNumberOfPages();
             PDFRenderer pdfRenderer = new PDFRenderer(document);
 
+            List<Integer> hiddenPagesList = hiddenPages != null && !hiddenPages.isEmpty() ? Arrays.stream(hiddenPages.split(",")).map(Integer::parseInt).toList()
+                    : Collections.emptyList();
+
             for (int page = 0; page < numPages; page++) {
                 BufferedImage bufferedImage = pdfRenderer.renderImageWithDPI(page, 72, ImageType.RGB);
                 byte[] imageInByte = bufferedImageToByteArray(bufferedImage, "png");
@@ -89,11 +101,15 @@ public void splitAttachmentUnitIntoSingleSlides(PDDocument document, AttachmentU
                 MultipartFile slideFile = fileService.convertByteArrayToMultipart(filename, ".png", imageInByte);
                 Path savePath = fileService.saveFile(slideFile, FilePathService.getAttachmentUnitFilePath().resolve(attachmentUnit.getId().toString()).resolve("slide")
                         .resolve(String.valueOf(slideNumber)).resolve(filename));
-                Slide slideEntity = new Slide();
-                slideEntity.setSlideImagePath(FilePathService.publicPathForActualPath(savePath, (long) slideNumber).toString());
-                slideEntity.setSlideNumber(slideNumber);
-                slideEntity.setAttachmentUnit(attachmentUnit);
-                slideRepository.save(slideEntity);
+
+                Optional<Slide> existingSlideOpt = Optional.ofNullable(slideRepository.findSlideByAttachmentUnitIdAndSlideNumber(attachmentUnit.getId(), slideNumber));
+                Slide slide = existingSlideOpt.orElseGet(Slide::new);
+                slide.setSlideImagePath(FilePathService.publicPathForActualPath(savePath, (long) slideNumber).toString());
+                slide.setSlideNumber(slideNumber);
+                slide.setAttachmentUnit(attachmentUnit);
+                slide.setHidden(hiddenPagesList.contains(slideNumber) ? java.sql.Date.valueOf(FOREVER) : null);
+                slideRepository.save(slide);
+
             }
         }
         catch (IOException e) {

src/main/java/de/tum/cit/aet/artemis/lecture/web/AttachmentUnitResource.java

@@ -44,6 +44,7 @@
 import de.tum.cit.aet.artemis.lecture.dto.LectureUnitSplitInformationDTO;
 import de.tum.cit.aet.artemis.lecture.repository.AttachmentUnitRepository;
 import de.tum.cit.aet.artemis.lecture.repository.LectureRepository;
+import de.tum.cit.aet.artemis.lecture.repository.SlideRepository;
 import de.tum.cit.aet.artemis.lecture.service.AttachmentUnitService;
 import de.tum.cit.aet.artemis.lecture.service.LectureUnitProcessingService;
 import de.tum.cit.aet.artemis.lecture.service.SlideSplitterService;
@@ -75,9 +76,11 @@ public class AttachmentUnitResource {
 
     private final FileService fileService;
 
+    private final SlideRepository slideRepository;
+
     public AttachmentUnitResource(AttachmentUnitRepository attachmentUnitRepository, LectureRepository lectureRepository, LectureUnitProcessingService lectureUnitProcessingService,
             AuthorizationCheckService authorizationCheckService, GroupNotificationService groupNotificationService, AttachmentUnitService attachmentUnitService,
-            CompetencyProgressService competencyProgressService, SlideSplitterService slideSplitterService, FileService fileService) {
+            CompetencyProgressService competencyProgressService, SlideSplitterService slideSplitterService, FileService fileService, SlideRepository slideRepository) {
         this.attachmentUnitRepository = attachmentUnitRepository;
         this.lectureUnitProcessingService = lectureUnitProcessingService;
         this.lectureRepository = lectureRepository;
@@ -87,6 +90,7 @@ public AttachmentUnitResource(AttachmentUnitRepository attachmentUnitRepository,
         this.competencyProgressService = competencyProgressService;
         this.slideSplitterService = slideSplitterService;
         this.fileService = fileService;
+        this.slideRepository = slideRepository;
     }
 
     /**
@@ -117,19 +121,20 @@ public ResponseEntity<AttachmentUnit> getAttachmentUnit(@PathVariable Long attac
      * @param file             the optional file to upload
      * @param keepFilename     specifies if the original filename should be kept or not
      * @param notificationText the text to be used for the notification. No notification will be sent if the parameter is not set
+     * @param hiddenPages      the pages to be hidden in the attachment unit. No hidden pages will be sent if the parameter is not set
      * @return the ResponseEntity with status 200 (OK) and with body the updated attachmentUnit
      */
     @PutMapping(value = "lectures/{lectureId}/attachment-units/{attachmentUnitId}", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
     @EnforceAtLeastEditor
     public ResponseEntity<AttachmentUnit> updateAttachmentUnit(@PathVariable Long lectureId, @PathVariable Long attachmentUnitId, @RequestPart AttachmentUnit attachmentUnit,
             @RequestPart Attachment attachment, @RequestPart(required = false) MultipartFile file, @RequestParam(defaultValue = "false") boolean keepFilename,
-            @RequestParam(value = "notificationText", required = false) String notificationText) {
+            @RequestParam(value = "notificationText", required = false) String notificationText, @RequestParam(value = "hiddenPages", required = false) String hiddenPages) {
         log.debug("REST request to update an attachment unit : {}", attachmentUnit);
         AttachmentUnit existingAttachmentUnit = attachmentUnitRepository.findOneWithSlidesAndCompetencies(attachmentUnitId);
         checkAttachmentUnitCourseAndLecture(existingAttachmentUnit, lectureId);
         authorizationCheckService.checkHasAtLeastRoleInCourseElseThrow(Role.EDITOR, existingAttachmentUnit.getLecture().getCourse(), null);
 
-        AttachmentUnit savedAttachmentUnit = attachmentUnitService.updateAttachmentUnit(existingAttachmentUnit, attachmentUnit, attachment, file, keepFilename);
+        AttachmentUnit savedAttachmentUnit = attachmentUnitService.updateAttachmentUnit(existingAttachmentUnit, attachmentUnit, attachment, file, keepFilename, hiddenPages);
 
         if (notificationText != null) {
             groupNotificationService.notifyStudentGroupAboutAttachmentChange(savedAttachmentUnit.getAttachment(), notificationText);
@@ -170,7 +175,7 @@ public ResponseEntity<AttachmentUnit> createAttachmentUnit(@PathVariable Long le
         AttachmentUnit savedAttachmentUnit = attachmentUnitService.createAttachmentUnit(attachmentUnit, attachment, lecture, file, keepFilename);
         lectureRepository.save(lecture);
         if (Objects.equals(FilenameUtils.getExtension(file.getOriginalFilename()), "pdf")) {
-            slideSplitterService.splitAttachmentUnitIntoSingleSlides(savedAttachmentUnit);
+            slideSplitterService.splitAttachmentUnitIntoSingleSlides(savedAttachmentUnit, null);
         }
         attachmentUnitService.prepareAttachmentUnitForClient(savedAttachmentUnit);
         competencyProgressService.updateProgressByLearningObjectAsync(savedAttachmentUnit);
@@ -332,4 +337,16 @@ private void checkFile(Path filePath) {
             throw new BadRequestAlertException("The file must be a pdf", ENTITY_NAME, "wrongFileType");
         }
     }
+
+    @GetMapping("lectures/{lectureId}/attachment-units/{attachmentUnitId}/hidden-slides")
+    @EnforceAtLeastEditor
+    public ResponseEntity<List<Integer>> getAttachmentUnitHiddenSlides(@PathVariable Long attachmentUnitId, @PathVariable Long lectureId) {
+        log.debug("REST request to get hidden slides of AttachmentUnit : {}", attachmentUnitId);
+        List<Integer> hiddenSlides = slideRepository.findHiddenSlideNumbersByAttachmentUnitId(attachmentUnitId);
+        AttachmentUnit attachmentUnit = attachmentUnitRepository.findByIdElseThrow(attachmentUnitId);
+        checkAttachmentUnitCourseAndLecture(attachmentUnit, lectureId);
+        authorizationCheckService.checkHasAtLeastRoleInCourseElseThrow(Role.EDITOR, attachmentUnit.getLecture().getCourse(), null);
+
+        return ResponseEntity.ok().body(hiddenSlides);
+    }
 }

src/main/resources/config/liquibase/changelog/20241117234100_changelog.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
+                   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+                   xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog https://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd">
+    <changeSet id="20241117234100" author="ece.eren">
+        <addColumn tableName="slide">
+            <column name="hidden" type="datetime(3)"/>
+        </addColumn>
+    </changeSet>
+</databaseChangeLog>

src/main/resources/config/liquibase/master.xml

@@ -33,6 +33,7 @@
     <include file="classpath:config/liquibase/changelog/20241010101010_changelog.xml" relativeToChangelogFile="false"/>
     <include file="classpath:config/liquibase/changelog/20241018053210_changelog.xml" relativeToChangelogFile="false"/>
     <include file="classpath:config/liquibase/changelog/20241023456789_changelog.xml" relativeToChangelogFile="false"/>
+    <include file="classpath:config/liquibase/changelog/20241117234100_changelog.xml" relativeToChangelogFile="false"/>
 
     <!-- NOTE: please use the format "YYYYMMDDhhmmss_changelog.xml", i.e. year month day hour minutes seconds and not something else! -->
     <!-- we should also stay in a chronological order! -->

src/main/webapp/app/lecture/lecture-unit/lecture-unit-management/attachmentUnit.service.ts

@@ -31,11 +31,12 @@ export class AttachmentUnitService {
             .pipe(map((res: EntityResponseType) => this.lectureUnitService.convertLectureUnitResponseDatesFromServer(res)));
     }
 
-    update(lectureId: number, attachmentUnitId: number, formData: FormData, notificationText?: string): Observable<EntityResponseType> {
+    update(lectureId: number, attachmentUnitId: number, formData: FormData, notificationText?: string, hiddenPages?: string): Observable<EntityResponseType> {
         return this.httpClient
             .put<AttachmentUnit>(
                 `${this.resourceURL}/lectures/${lectureId}/attachment-units/${attachmentUnitId}?keepFilename=true` +
-                    (notificationText ? `&notificationText=${notificationText}` : ''),
+                    (notificationText ? `&notificationText=${notificationText}` : '') +
+                    (hiddenPages ? `&hiddenPages=${hiddenPages}` : ''),
                 formData,
                 { observe: 'response' },
             )
@@ -71,4 +72,15 @@ export class AttachmentUnitService {
     getAttachmentFile(courseId: number, attachmentUnitId: number): Observable<Blob> {
         return this.httpClient.get(`${this.resourceURL}/files/courses/${courseId}/attachment-units/${attachmentUnitId}`, { responseType: 'blob' });
     }
+
+    /**
+     * Retrieve the hidden slide numbers associated with a given attachment unit ID.
+     *
+     * @param lectureId The ID of the lecture that the Attachment Unit belongs to.
+     * @param attachmentUnitId The ID of the attachment unit.
+     * @returns An Observable that emits a list of integers representing hidden slide numbers.
+     */
+    getHiddenSlides(lectureId: number, attachmentUnitId: number): Observable<number[]> {
+        return this.httpClient.get<number[]>(`${this.resourceURL}/lectures/${lectureId}/attachment-units/${attachmentUnitId}/hidden-slides`);
+    }
 }

src/main/webapp/app/lecture/pdf-preview/pdf-preview-thumbnail-grid/pdf-preview-thumbnail-grid.component.html

@@ -1,3 +1,4 @@
+<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.0.0-beta3/css/all.min.css" />
 <div class="pdf-container" #pdfContainer>
     @if (isEnlargedView()) {
         <jhi-pdf-preview-enlarged-canvas-component