Lecture: Allow instructors to remove solution slides when processing units

src/main/java/de/tum/in/www1/artemis/service/LectureUnitProcessingService.java

@@ -70,8 +70,8 @@
 
                 List<PDDocument> documentUnits = pdfSplitter.split(document);
                 pdDocumentInformation.setTitle(lectureUnit.unitName());
-                if (lectureUnitInformationDTO.removeBreakSlides()) {
-                    removeBreakSlides(documentUnits.get(0));
+                if (lectureUnitInformationDTO.removeBreakSlides() || lectureUnitInformationDTO.removeSolutionSlides()) {
+                    removeBreakOrSolutionSlides(documentUnits.get(0), lectureUnitInformationDTO.removeBreakSlides(), lectureUnitInformationDTO.removeSolutionSlides());
                 }
                 documentUnits.get(0).setDocumentInformation(pdDocumentInformation);
                 documentUnits.get(0).save(outputStream);
@@ -96,28 +96,30 @@
     }
 
     /**
-     * Removes the break slides from the given document.
+     * Removes the break slides or solution slides from the given document.
      *
      * @param document document to remove break slides from
      */
-    private void removeBreakSlides(PDDocument document) {
+    private void removeBreakOrSolutionSlides(PDDocument document, boolean removeBreakSlides, boolean removeSolutionSlides) {
 
         try {
             PDFTextStripper pdfTextStripper = new PDFTextStripper();
             Splitter pdfSplitter = new Splitter();
             List<PDDocument> pages = pdfSplitter.split(document);
-            Iterator<PDDocument> iterator = pages.listIterator();
 
-            int index = 0;
-            while (iterator.hasNext()) {
-                PDDocument currentPage = iterator.next();
+            // Uses a decrementing loop (starting from the last index) to ensure that the
+            // index values are adjusted correctly when removing pages.
+            for (int index = pages.size() - 1; index >= 0; index--) {
+                PDDocument currentPage = pages.get(index);
                 String slideText = pdfTextStripper.getText(currentPage);
-                if (isBreakSlide(slideText)) {
+
+                if (isBreakSlide(slideText) && removeBreakSlides) {
+                    document.removePage(index);
+                }
+                else if (isSolutionSlide(slideText) && removeSolutionSlides) {
                     document.removePage(index);
-                    break;
                 }
                 currentPage.close(); // make sure to close the document
-                index++;
             }
         }
         catch (IOException e) {
@@ -130,6 +132,10 @@
         return slideText.contains("Break") || slideText.contains("Pause");
     }
 
+    private boolean isSolutionSlide(String slideText) {
+        return slideText.contains("Example solution") || slideText.contains("Example solution (with comments)") || slideText.contains("Example solution: model");
+    }
+
     /**
      * Prepare information of split units for client
      *
@@ -147,8 +153,8 @@
             List<LectureUnitSplitDTO> units = unitsDocumentMap.values().stream()
                     .map(lectureUnitSplit -> new LectureUnitSplitDTO(lectureUnitSplit.unitName, ZonedDateTime.now(), lectureUnitSplit.startPage, lectureUnitSplit.endPage))
                     .toList();
-            // return units information, maximum number of pages and by default remove break slides is false
-            return new LectureUnitInformationDTO(units, numberOfPages, false);
+            // return units information, maximum number of pages and by default remove break slides and remove solution slides are false
+            return new LectureUnitInformationDTO(units, numberOfPages, false, false);
         }
         catch (IOException e) {
             log.error("Error while preparing the map with information", e);

src/main/java/de/tum/in/www1/artemis/web/rest/dto/LectureUnitInformationDTO.java

@@ -2,5 +2,5 @@
 
 import java.util.List;
 
-public record LectureUnitInformationDTO(List<LectureUnitSplitDTO> units, int numberOfPages, boolean removeBreakSlides) {
+public record LectureUnitInformationDTO(List<LectureUnitSplitDTO> units, int numberOfPages, boolean removeBreakSlides, boolean removeSolutionSlides) {
 }

src/main/webapp/app/lecture/lecture-unit/lecture-unit-management/attachment-units/attachment-units.component.html

@@ -78,6 +78,22 @@ <h2 id="page-heading">
         <input class="form-check-input" type="checkbox" name="processUnit" [disabled]="units.length < 1" (change)="onSelectRemoveBreakSlides()" />
         <span class="px-1">{{ 'artemisApp.attachmentUnit.createAttachmentUnits.removeBreakSlide' | artemisTranslate }}</span>
         <fa-icon [icon]="faQuestionCircle" [ngbTooltip]="'artemisApp.attachmentUnit.createAttachmentUnits.removeBreakSlideTooltip' | artemisTranslate"></fa-icon>
+        <div *ngIf="removeBreakSlides" class="alert alert-warning mt-3 ml-3">
+            <span>
+                {{ 'artemisApp.attachmentUnit.createAttachmentUnits.removeBreakSlideInfo' | artemisTranslate }}
+            </span>
+        </div>
+    </div>
+
+    <div class="mt-3 mb-3">
+        <input class="form-check-input" type="checkbox" name="processUnit" [disabled]="units.length < 1" (change)="onSelectRemoveSolutionSlides()" />
+        <span class="px-1">{{ 'artemisApp.attachmentUnit.createAttachmentUnits.removeSolutionSlide' | artemisTranslate }}</span>
+        <fa-icon [icon]="faQuestionCircle" [ngbTooltip]="'artemisApp.attachmentUnit.createAttachmentUnits.removeSolutionSlideTooltip' | artemisTranslate"></fa-icon>
+        <div *ngIf="removeSolutionSlides" class="alert alert-warning mt-3 ml-3">
+            <span>
+                {{ 'artemisApp.attachmentUnit.createAttachmentUnits.removeSolutionSlideInfo' | artemisTranslate }}
+            </span>
+        </div>
     </div>
 
     <div *ngIf="units && units.length < 1" class="alert alert-danger mt-3">

src/main/webapp/app/lecture/lecture-unit/lecture-unit-management/attachment-units/attachment-units.component.ts

@@ -21,6 +21,7 @@ type LectureUnitInformationDTO = {
     units: LectureUnitDTOS[];
     numberOfPages: number;
     removeBreakSlides: boolean;
+    removeSolutionSlides: boolean;
 };
 
 @Component({
@@ -48,6 +49,7 @@ export class AttachmentUnitsComponent implements OnInit {
     fileName: string;
     invalidUnitTableMessage?: string;
     removeBreakSlides: boolean;
+    removeSolutionSlides: boolean;
 
     constructor(
         private activatedRoute: ActivatedRoute,
@@ -67,6 +69,7 @@ export class AttachmentUnitsComponent implements OnInit {
 
     ngOnInit(): void {
         this.removeBreakSlides = false;
+        this.removeSolutionSlides = false;
         this.isLoading = true;
         this.isProcessingMode = true;
 
@@ -95,7 +98,12 @@ export class AttachmentUnitsComponent implements OnInit {
     createAttachmentUnits(): void {
         if (this.validUnitInformation()) {
             this.isLoading = true;
-            const lectureUnitInformationDTOObj: LectureUnitInformationDTO = { units: this.units, numberOfPages: this.numberOfPages, removeBreakSlides: this.removeBreakSlides };
+            const lectureUnitInformationDTOObj: LectureUnitInformationDTO = {
+                units: this.units,
+                numberOfPages: this.numberOfPages,
+                removeBreakSlides: this.removeBreakSlides,
+                removeSolutionSlides: this.removeSolutionSlides,
+            };
             const formData: FormData = new FormData();
             formData.append('file', this.file);
             formData.append('lectureUnitInformationDTO', objectToJsonBlob(lectureUnitInformationDTOObj));
@@ -199,4 +207,8 @@ export class AttachmentUnitsComponent implements OnInit {
     onSelectRemoveBreakSlides() {
         this.removeBreakSlides = !this.removeBreakSlides;
     }
+
+    onSelectRemoveSolutionSlides() {
+        this.removeSolutionSlides = !this.removeSolutionSlides;
+    }
 }

src/main/webapp/i18n/de/lectureUnit.json

@@ -127,6 +127,10 @@
                 "processAutomatically": "Automatische Einheitenverarbeitung",
                 "removeBreakSlide": "Entferne Pausenfolien",
                 "removeBreakSlideTooltip": "Folien, die 'Break' enthalten, werden entfernt.",
+                "removeBreakSlideInfo": "Alle Pausenfolien werden aus allen Einheiten entfernt.",
+                "removeSolutionSlide": "Folien mit Beispiellösungen entfernen",
+                "removeSolutionSlideTooltip": "Wenn die Folie das Wort \"Example solution\" enthält, wird die Folie entfernt.",
+                "removeSolutionSlideInfo": "Alle Folien mit Beispiellösungen werden entfernt.",
                 "validation": {
                     "invalidPages": "Die Startseite oder die letzte Seite von {{ unitName }} sind falsch eingestellt.",
                     "empty": {

src/main/webapp/i18n/en/lectureUnit.json

@@ -127,8 +127,12 @@
                 "lectureFileToolTip": "Please select to enable the automatic separation of lecture units.",
                 "processUnits": "Process units",
                 "processAutomatically": "Automatic unit processing",
-                "removeBreakSlide": "Remove Break slide",
+                "removeBreakSlide": "Remove Break slides",
                 "removeBreakSlideTooltip": "If the slide contains the word 'Break' it will remove the slide from the unit.",
+                "removeBreakSlideInfo": "All Break slides will be removed from all units.",
+                "removeSolutionSlide": "Remove Example Solution slides",
+                "removeSolutionSlideTooltip": "If the slide contains the word 'Example solution' it will remove the slide from the unit.",
+                "removeSolutionSlideInfo": "All Example solution slides will be removed from all units.",
                 "validation": {
                     "invalidPages": "The start page or end page of {{ unitName }} are set incorrectly.",
                     "empty": {

src/test/java/de/tum/in/www1/artemis/lecture/AttachmentUnitsIntegrationTest.java

@@ -56,7 +56,7 @@
         userUtilService.addUsers(TEST_PREFIX, 1, 1, 0, 1);
         this.lecture1 = lectureUtilService.createCourseWithLecture(true);
         List<LectureUnitSplitDTO> units = new ArrayList<>();
-        this.lectureUnitSplits = new LectureUnitInformationDTO(units, 1, true);
+        this.lectureUnitSplits = new LectureUnitInformationDTO(units, 1, true, false);
         // Add users that are not in the course
         userUtilService.createAndSaveUser(TEST_PREFIX + "student42");
         userUtilService.createAndSaveUser(TEST_PREFIX + "tutor42");
@@ -106,7 +106,7 @@
         assertThat(lectureUnitSplitInfo.units()).hasSize(2);
         assertThat(lectureUnitSplitInfo.numberOfPages()).isEqualTo(20);
 
-        lectureUnitSplitInfo = new LectureUnitInformationDTO(lectureUnitSplitInfo.units(), lectureUnitSplitInfo.numberOfPages(), false);
+        lectureUnitSplitInfo = new LectureUnitInformationDTO(lectureUnitSplitInfo.units(), lectureUnitSplitInfo.numberOfPages(), false, false);
 
         List<AttachmentUnit> attachmentUnits = List.of(request.postWithMultipartFile("/api/lectures/" + lecture1.getId() + "/attachment-units/split", lectureUnitSplitInfo,
                 "lectureUnitInformationDTO", filePart, AttachmentUnit[].class, HttpStatus.OK));
@@ -153,7 +153,7 @@
                 LectureUnitInformationDTO.class, HttpStatus.OK);
         assertThat(lectureUnitSplitInfo.units()).hasSize(2);
         assertThat(lectureUnitSplitInfo.numberOfPages()).isEqualTo(20);
-        lectureUnitSplitInfo = new LectureUnitInformationDTO(lectureUnitSplitInfo.units(), lectureUnitSplitInfo.numberOfPages(), true);
+        lectureUnitSplitInfo = new LectureUnitInformationDTO(lectureUnitSplitInfo.units(), lectureUnitSplitInfo.numberOfPages(), true, false);
 
         List<AttachmentUnit> attachmentUnits = List.of(request.postWithMultipartFile("/api/lectures/" + lecture1.getId() + "/attachment-units/split", lectureUnitSplitInfo,
                 "lectureUnitInformationDTO", filePart, AttachmentUnit[].class, HttpStatus.OK));
@@ -166,14 +166,57 @@
         byte[] fileBytes = request.get(attachmentPath, HttpStatus.OK, byte[].class);
 
         try (PDDocument document = PDDocument.load(fileBytes)) {
-            // 12 is the number of pages for the first unit without the break slide
-            assertThat(document.getNumberOfPages()).isEqualTo(12);
+            // 6 is the number of pages for the first unit without the break slides
+            assertThat(document.getNumberOfPages()).isEqualTo(6);
             document.close();
         }
         assertThat(attachmentUnitList).hasSize(2);
         assertThat(attachmentUnitList).isEqualTo(attachmentUnits);
     }
 
+    @Test
+    @WithMockUser(username = TEST_PREFIX + "instructor1", roles = "INSTRUCTOR")
+    void splitLectureFile_asInstructor_shouldRemoveSolutionSlides_and_removeBreakSlides() throws Exception {
+        var filePart = createLectureFile(true);
+
+        LectureUnitInformationDTO lectureUnitSplitInfo = request.postWithMultipartFile("/api/lectures/" + lecture1.getId() + "/process-units", null, "process-units", filePart,
+                LectureUnitInformationDTO.class, HttpStatus.OK);
+        assertThat(lectureUnitSplitInfo.units()).hasSize(2);
+        assertThat(lectureUnitSplitInfo.numberOfPages()).isEqualTo(20);
+        lectureUnitSplitInfo = new LectureUnitInformationDTO(lectureUnitSplitInfo.units(), lectureUnitSplitInfo.numberOfPages(), true, true);
+
+        List<AttachmentUnit> attachmentUnits = List.of(request.postWithMultipartFile("/api/lectures/" + lecture1.getId() + "/attachment-units/split", lectureUnitSplitInfo,
+                "lectureUnitInformationDTO", filePart, AttachmentUnit[].class, HttpStatus.OK));
+        assertThat(attachmentUnits).hasSize(2);
+        assertThat(slideRepository.findAll()).hasSize(18); // 18 slides should be created for 2 attachment units (1 break slide is removed and 1 solution slide is removed)
+
+        List<Long> attachmentUnitIds = attachmentUnits.stream().map(AttachmentUnit::getId).toList();
+        List<AttachmentUnit> attachmentUnitList = attachmentUnitRepository.findAllById(attachmentUnitIds);
+
+        assertThat(attachmentUnitList).hasSize(2);
+        assertThat(attachmentUnitList).isEqualTo(attachmentUnits);
+
+        // first unit
+        String attachmentPathFirstUnit = attachmentUnitList.get(0).getAttachment().getLink();
+        byte[] fileBytesFirst = request.get(attachmentPathFirstUnit, HttpStatus.OK, byte[].class);
+
+        try (PDDocument document = PDDocument.load(fileBytesFirst)) {
+            // 5 is the number of pages for the first unit (after break and solution are removed)
+            assertThat(document.getNumberOfPages()).isEqualTo(5);
+            document.close();
+        }
+
+        // second unit
+        String attachmentPathSecondUnit = attachmentUnitList.get(1).getAttachment().getLink();
+        byte[] fileBytesSecond = request.get(attachmentPathSecondUnit, HttpStatus.OK, byte[].class);
+
+        try (PDDocument document = PDDocument.load(fileBytesSecond)) {
+            // 13 is the number of pages for the second unit
+            assertThat(document.getNumberOfPages()).isEqualTo(13);
+            document.close();
+        }
+    }
+
     private void testAllPreAuthorize() throws Exception {
         request.postWithMultipartFile("/api/lectures/" + lecture1.getId() + "/process-units", null, "process-units", createLectureFile(true), LectureUnitInformationDTO.class,
                 HttpStatus.FORBIDDEN);
@@ -192,23 +235,39 @@
         try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); PDDocument document = new PDDocument()) {
             if (shouldBePDF) {
                 for (int i = 1; i <= 20; i++) {
                     document.addPage(new PDPage());
                     PDPageContentStream contentStream = new PDPageContentStream(document, document.getPage(i - 1));
 
-                    if (i == 6 || i == 13) {
+                    if (i == 6) {
                         contentStream.beginText();
                         contentStream.setFont(PDType1Font.TIMES_ROMAN, 12);
                         contentStream.newLineAtOffset(25, -15);
                         contentStream.showText("itp20..");
                         contentStream.newLineAtOffset(25, 500);
                         contentStream.showText("Break");
                         contentStream.newLineAtOffset(0, -15);
                         contentStream.showText("Have fun");
                         contentStream.close();
                         continue;
                     }
 
-                    if (i == 7 || i == 14) {
+                    if (i == 7) {
+                        contentStream.beginText();
+                        contentStream.setFont(PDType1Font.TIMES_ROMAN, 12);
+                        contentStream.newLineAtOffset(25, -15);
+                        contentStream.showText("itp20..");
+                        contentStream.newLineAtOffset(25, 500);
+                        contentStream.showText("Example solution");
+                        contentStream.newLineAtOffset(0, -15);
+                        contentStream.showText("First Unit");
+                        contentStream.newLineAtOffset(0, -15);
+                        contentStream.showText("Second Unit");
+                        contentStream.endText();
+                        contentStream.close();
+                        continue;
+                    }
+
+                    if (i == 2 || i == 8) {
                         contentStream.beginText();
                         contentStream.setFont(PDType1Font.TIMES_ROMAN, 12);
                         contentStream.newLineAtOffset(25, -15);

src/test/javascript/spec/component/lecture-unit/attachment-unit/attachment-units.component.spec.ts

@@ -223,12 +223,21 @@ describe('AttachmentUnitsComponent', () => {
         expect(navigateSpy).toHaveBeenCalledOnce();
     }));
 
-    it('should select process units checkbox', fakeAsync(() => {
+    it('should select remove break slides checkbox', fakeAsync(() => {
         attachmentUnitsComponent.removeBreakSlides = false;
         const onSelectRemoveBreakSlides = jest.spyOn(attachmentUnitsComponent, 'onSelectRemoveBreakSlides');
         attachmentUnitsComponent.onSelectRemoveBreakSlides();
         tick();
         expect(onSelectRemoveBreakSlides).toHaveBeenCalledOnce();
         expect(attachmentUnitsComponent.removeBreakSlides).toBeTrue();
     }));
+
+    it('should select remove solution slides checkbox', fakeAsync(() => {
+        attachmentUnitsComponent.removeSolutionSlides = false;
+        const onSelectRemoveSolutionSlides = jest.spyOn(attachmentUnitsComponent, 'onSelectRemoveSolutionSlides');
+        attachmentUnitsComponent.onSelectRemoveSolutionSlides();
+        tick();
+        expect(onSelectRemoveSolutionSlides).toHaveBeenCalledOnce();
+        expect(attachmentUnitsComponent.removeSolutionSlides).toBeTrue();
+    }));
 });