Multi page layout init for #212

src/main/java/stirling/software/SPDF/controller/api/other/MultiPageLayoutController.java

@@ -0,0 +1,100 @@
+package stirling.software.SPDF.controller.api.other;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.multipart.MultipartFile;
+
+import com.itextpdf.kernel.geom.PageSize;
+import com.itextpdf.kernel.geom.Rectangle;
+import com.itextpdf.kernel.pdf.PdfDocument;
+import com.itextpdf.kernel.pdf.PdfPage;
+import com.itextpdf.kernel.pdf.PdfReader;
+import com.itextpdf.kernel.pdf.PdfWriter;
+import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
+import com.itextpdf.kernel.pdf.xobject.PdfFormXObject;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@RestController
+public class MultiPageLayoutController {
+
+	private static final Logger logger = LoggerFactory.getLogger(MultiPageLayoutController.class);
+
+	@PostMapping(value = "/multi-page-layout", consumes = "multipart/form-data")
+	@Operation(summary = "Merge multiple pages of a PDF document into a single page", description = "This operation takes an input PDF file and the number of pages to merge into a single sheet in the output PDF file.")
+	public ResponseEntity<byte[]> mergeMultiplePagesIntoOne(
+			@Parameter(description = "The input PDF file", required = true) @RequestParam("fileInput") MultipartFile file,
+			@Parameter(description = "The number of pages to fit onto a single sheet in the output PDF. Acceptable values are 2, 3, 4, 9, 16.", required = true, schema = @Schema(type = "integer", allowableValues = {
+					"2", "3", "4", "9", "16" })) @RequestParam("pagesPerSheet") int pagesPerSheet)
+			throws IOException {
+
+		if (pagesPerSheet != 2 && pagesPerSheet != 3
+				&& pagesPerSheet != (int) Math.sqrt(pagesPerSheet) * Math.sqrt(pagesPerSheet)) {
+			throw new IllegalArgumentException("pagesPerSheet must be 2, 3 or a perfect square");
+		}
+
+		int cols = pagesPerSheet == 2 || pagesPerSheet == 3 ? pagesPerSheet : (int) Math.sqrt(pagesPerSheet);
+		int rows = pagesPerSheet == 2 || pagesPerSheet == 3 ? 1 : (int) Math.sqrt(pagesPerSheet);
+
+		byte[] bytes = file.getBytes();
+		PdfReader reader = new PdfReader(new ByteArrayInputStream(bytes));
+		PdfDocument pdfDoc = new PdfDocument(reader);
+
+		ByteArrayOutputStream baos = new ByteArrayOutputStream();
+		PdfWriter writer = new PdfWriter(baos);
+		PdfDocument outputPdf = new PdfDocument(writer);
+		PageSize pageSize = new PageSize(PageSize.A4.rotate());
+
+		int totalPages = pdfDoc.getNumberOfPages();
+		float cellWidth = pageSize.getWidth() / cols;
+		float cellHeight = pageSize.getHeight() / rows;
+
+		for (int i = 1; i <= totalPages; i += pagesPerSheet) {
+			PdfPage page = outputPdf.addNewPage(pageSize);
+			PdfCanvas pdfCanvas = new PdfCanvas(page);
+
+			for (int row = 0; row < rows; row++) {
+				for (int col = 0; col < cols; col++) {
+					int index = i + row * cols + col;
+					if (index <= totalPages) {
+						// Get the page and calculate scaling factors
+						Rectangle rect = pdfDoc.getPage(index).getPageSize();
+						float scaleWidth = cellWidth / rect.getWidth();
+						float scaleHeight = cellHeight / rect.getHeight();
+						float scale = Math.min(scaleWidth, scaleHeight);
+
+						PdfFormXObject formXObject = pdfDoc.getPage(index).copyAsFormXObject(outputPdf);
+						float x = col * cellWidth + (cellWidth - rect.getWidth() * scale) / 2;
+						float y = (rows - 1 - row) * cellHeight + (cellHeight - rect.getHeight() * scale) / 2;
+
+						// Save the graphics state, apply the transformations, add the object, and then
+						// restore the graphics state
+						pdfCanvas.saveState();
+						pdfCanvas.concatMatrix(scale, 0, 0, scale, x, y);
+						pdfCanvas.addXObject(formXObject, 0, 0);
+						pdfCanvas.restoreState();
+					}
+				}
+			}
+		}
+
+		outputPdf.close();
+		byte[] pdfContent = baos.toByteArray();
+		pdfDoc.close();
+		return ResponseEntity.ok()
+				.header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"modifiedDocument.pdf\"")
+				.body(pdfContent);
+	}
+
+}

src/main/java/stirling/software/SPDF/controller/web/OtherWebController.java

@@ -108,4 +108,13 @@ public class OtherWebController {
         return "other/remove-blanks";
     }
     
+    @GetMapping("/multi-page-layout")
+    @Hidden
+    public String multiPageLayoutForm(Model model) {
+        model.addAttribute("currentPage", "multi-page-layout");
+        return "other/multi-page-layout";
+    }
+    
+    
+    
 }

src/main/resources/messages_en_GB.properties

@@ -128,6 +128,10 @@ home.compare.desc=Compares and shows the differences between 2 PDF Documents
 home.certSign.title=Sign with Certificate
 home.certSign.desc=Signs a PDF with a Certificate/Key (PEM/P12)
 
+home.pageLayout.title=Multi-Page Layout
+home.pageLayout.desc=Merge multiple pages of a PDF document into a single page
+
+
 
 downloadPdf=Download PDF
 text=Text
@@ -135,6 +139,11 @@ font=Font
 selectFillter=-- Select --
 pageNum=Page Number 
 
+pageLayout.title=Multi Page Layout
+pageLayout.header=Multi Page Layout
+pageLayout.pagesPerSheet=Pages per sheet:
+pageLayout.submit=Submit
+
 certSign.title=Certificate Signing
 certSign.header=Sign a PDF with your certificate (Work in progress)
 certSign.selectPDF=Select a PDF File for Signing: 

src/main/resources/static/images/page-layout.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" fill="currentColor" class="bi bi-grid" viewBox="0 0 16 16">
+  <path d="M1 2.5A1.5 1.5 0 0 1 2.5 1h3A1.5 1.5 0 0 1 7 2.5v3A1.5 1.5 0 0 1 5.5 7h-3A1.5 1.5 0 0 1 1 5.5v-3zM2.5 2a.5.5 0 0 0-.5.5v3a.5.5 0 0 0 .5.5h3a.5.5 0 0 0 .5-.5v-3a.5.5 0 0 0-.5-.5h-3zm6.5.5A1.5 1.5 0 0 1 10.5 1h3A1.5 1.5 0 0 1 15 2.5v3A1.5 1.5 0 0 1 13.5 7h-3A1.5 1.5 0 0 1 9 5.5v-3zm1.5-.5a.5.5 0 0 0-.5.5v3a.5.5 0 0 0 .5.5h3a.5.5 0 0 0 .5-.5v-3a.5.5 0 0 0-.5-.5h-3zM1 10.5A1.5 1.5 0 0 1 2.5 9h3A1.5 1.5 0 0 1 7 10.5v3A1.5 1.5 0 0 1 5.5 15h-3A1.5 1.5 0 0 1 1 13.5v-3zm1.5-.5a.5.5 0 0 0-.5.5v3a.5.5 0 0 0 .5.5h3a.5.5 0 0 0 .5-.5v-3a.5.5 0 0 0-.5-.5h-3zm6.5.5A1.5 1.5 0 0 1 10.5 9h3a1.5 1.5 0 0 1 1.5 1.5v3a1.5 1.5 0 0 1-1.5 1.5h-3A1.5 1.5 0 0 1 9 13.5v-3zm1.5-.5a.5.5 0 0 0-.5.5v3a.5.5 0 0 0 .5.5h3a.5.5 0 0 0 .5-.5v-3a.5.5 0 0 0-.5-.5h-3z"/>
+</svg>

src/main/resources/templates/fragments/navbar.html

@@ -156,6 +156,7 @@ function compareVersions(version1, version2) {
         <div th:replace="~{fragments/navbarEntry :: navbarEntry ( 'pdf-organizer', 'images/sort-numeric-down.svg', 'home.pdfOrganiser.title', 'home.pdfOrganiser.desc')}"></div>
         <div th:replace="~{fragments/navbarEntry :: navbarEntry ( 'rotate-pdf', 'images/arrow-clockwise.svg', 'home.rotate.title', 'home.rotate.desc')}"></div>
         <div th:replace="~{fragments/navbarEntry :: navbarEntry ( 'remove-pages', 'images/file-earmark-x.svg', 'home.removePages.title', 'home.removePages.desc')}"></div>
+		<div th:replace="~{fragments/navbarEntry :: navbarEntry ( 'multi-page-layout', 'images/page-layout.svg', 'home.pageLayout.title', 'home.pageLayout.desc')}"></div>
 		
     </div>
 </li>

src/main/resources/templates/home.html

@@ -136,6 +136,9 @@ filter: invert(0.2) sepia(2) saturate(50) hue-rotate(190deg);
                 <div th:replace="~{fragments/card :: card(id='compare', cardTitle=#{home.compare.title}, cardText=#{home.compare.desc}, cardLink='compare', svgPath='images/scales.svg')}"></div>
                 
                 <div th:replace="~{fragments/card :: card(id='cert-sign', cardTitle=#{home.certSign.title}, cardText=#{home.certSign.desc}, cardLink='cert-sign', svgPath='images/award.svg')}"></div>
+                <div th:replace="~{fragments/card :: card(id='multi-page-layout', cardTitle=#{home.pageLayout.title}, cardText=#{home.pageLayout.desc}, cardLink='multi-page-layout', svgPath='images/page-layout.svg')}"></div>
+                
+                
 		
                 <script>
                 function toggleFavorite(element) {

src/main/resources/templates/other/multi-page-layout.html

@@ -0,0 +1,39 @@
+<!DOCTYPE html>
+<html th:lang="${#locale.toString()}" th:lang-direction="#{language.direction}" xmlns:th="http://www.thymeleaf.org">
+
+
+<th:block th:insert="~{fragments/common :: head(title=#{pageLayout.title})}"></th:block>
+
+
+<body>
+    <div id="page-container">
+        <div id="content-wrap">
+            <div th:insert="~{fragments/navbar.html :: navbar}"></div>
+            <br> <br>
+            <div class="container">
+                <div class="row justify-content-center">
+                    <div class="col-md-6">
+                        <h2 th:text="#{pageLayout.header}"></h2>
+                         <form id="multiPdfForm" th:action="@{multi-page-layout}" method="post" enctype="multipart/form-data">
+                            <div th:replace="~{fragments/common :: fileSelector(name='fileInput', multiple=false, accept='application/pdf')}"></div>
+                            <div class="form-group">
+	                            <label for="pagesPerSheet" th:text="#{pageLayout.pagesPerSheet}"></label>
+							    <select id="pagesPerSheet" name="pagesPerSheet" required>
+							        <option value="2">2</option>
+							        <option value="3">3</option>
+							        <option value="4">4</option>
+							        <option value="9">9</option>
+							        <option value="16">16</option>
+							    </select>
+						    </div>
+                            <button type="submit" id="submitBtn" class="btn btn-primary" th:text="#{pageLayout.submit}"></button> 
+                        </form>
+                    </div>
+                </div>
+            </div>
+        </div>
+        <div th:insert="~{fragments/footer.html :: footer}"></div>
+    </div>
+</body>
+
+</html>