Scale Pages

src/main/java/stirling/software/SPDF/config/EndpointConfiguration.java

@@ -65,6 +65,7 @@ public void init() {
         addEndpointToGroup("PageOps", "pdf-organizer");
         addEndpointToGroup("PageOps", "rotate-pdf");
         addEndpointToGroup("PageOps", "multi-page-layout");
+        addEndpointToGroup("PageOps", "scale-pages");
 
         // Adding endpoints to "Convert" group
         addEndpointToGroup("Convert", "pdf-to-img");

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

@@ -0,0 +1,88 @@
+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 ScalePagesController {
+
+	private static final Logger logger = LoggerFactory.getLogger(ScalePagesController.class);
+
+	@PostMapping(value = "/scale-pages", consumes = "multipart/form-data")
+	@Operation(summary = "Change the size of a PDF page/document", description = "This operation takes an input PDF file and the size to scale the pages to in the output PDF file.")
+	public ResponseEntity<byte[]> mergeMultiplePagesIntoOne(
+			@Parameter(description = "The input PDF file", required = true) @RequestParam("fileInput") MultipartFile file,
+			@Parameter(description = "The scale of pages in the output PDF. Acceptable values are A4.", required = true, schema = @Schema(type = "String", allowableValues = { "A4" })) @RequestParam("pageSize") String targetPageSize,
+            @Parameter(description = "The scale of the content on the pages of the output PDF. Acceptable values are floats.", required = true, schema = @Schema(type = "float")) @RequestParam("scaleFactor") float scaleFactor)
+			throws IOException {
+
+		if (!targetPageSize.equals("A4")) {
+			throw new IllegalArgumentException("pageSize must be A4");
+		}
+
+		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); // TODO: This (and all other PageSize.A4) need to be dynamically changed in response to targetPageSize
+
+		int totalPages = pdfDoc.getNumberOfPages();
+
+		for (int i = 1; i <= totalPages; i++) {
+			PdfPage page = outputPdf.addNewPage(pageSize);
+			PdfCanvas pdfCanvas = new PdfCanvas(page);
+
+			// Get the page and calculate scaling factors
+			Rectangle rect = pdfDoc.getPage(i).getPageSize();
+			float scaleWidth = PageSize.A4.getWidth() / rect.getWidth();
+			float scaleHeight = PageSize.A4.getHeight() / rect.getHeight();
+			float scale = Math.min(scaleWidth, scaleHeight) * scaleFactor;
+            System.out.println("Scale: " + scale);
+
+			PdfFormXObject formXObject = pdfDoc.getPage(i).copyAsFormXObject(outputPdf);
+			float x = (PageSize.A4.getWidth() - rect.getWidth() * scale) / 2; // Center Page
+			float y = (PageSize.A4.getHeight() - 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=\"" + file.getOriginalFilename().replaceFirst("[.][^.]+$", "") + "_modified.pdf\"")
+				.body(pdfContent);
+	}
+}

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

@@ -115,6 +115,11 @@ public String multiPageLayoutForm(Model model) {
         return "other/multi-page-layout";
     }
 
-
+    @GetMapping("/scale-pages")
+    @Hidden
+    public String scalePagesFrom(Model model) {
+        model.addAttribute("currentPage", "scale-pages");
+        return "other/scale-pages";
+    }
 
 }

src/main/resources/messages_en_GB.properties

@@ -131,6 +131,9 @@ 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
 
+home.scalePages.title=Adjust page-scale
+home.scalePages.desc=Change the size of the pages of a PDF document
+
 error.pdfPassword=The PDF Document is passworded and either the password was not provided or was incorrect
 
 downloadPdf=Download PDF
@@ -144,6 +147,12 @@ pageLayout.header=Multi Page Layout
 pageLayout.pagesPerSheet=Pages per sheet:
 pageLayout.submit=Submit
 
+scalePages.title=Adjust page-scale
+scalePages.header=Adjust page-scale
+scalePages.pageSize=Size of a page of the document.
+scalePages.scaleFactor=Zoom level (crop) of a page.
+scalePages.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/templates/fragments/navbar.html

@@ -157,6 +157,7 @@
         <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 th:replace="~{fragments/navbarEntry :: navbarEntry ( 'scale-pages', 'images/scale-pages.svg', 'home.scalePages.title', 'home.scalePages.desc')}"></div>
 
     </div>
 </li>

src/main/resources/templates/home.html

@@ -137,7 +137,8 @@ <h1 class="display-4" th:text="${@appName}"></h1>
 
                 <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>
-
+                <div th:replace="~{fragments/card :: card(id='scale-pages', cardTitle=#{home.scalePages.title}, cardText=#{home.scalePages.desc}, cardLink='scale-pages', svgPath='images/scale-pages.svg')}"></div>
+
 
 
                 <script>

src/main/resources/templates/other/scale-pages.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="#{scalePages.header}"></h2>
+                         <form id="scalePagesFrom" th:action="@{scale-pages}" 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="pageSize" th:text="#{scalePages.pageSize}"></label>
+							    <select id="pageSize" name="pageSize" required>
+							        <option value="A4">A4</option>
+							    </select>
+						    </div>
+                            <div class="form-group">
+	                            <label for="scaleFactor" th:text="#{scalePages.scaleFactor}"></label>
+                                <input type="number" id="scaleFactor" name="scaleFactor" step="any" min="0" value="1">
+						    </div>
+                            <button type="submit" id="submitBtn" class="btn btn-primary" th:text="#{scalePages.submit}"></button> 
+                        </form>
+                    </div>
+                </div>
+            </div>
+        </div>
+        <div th:insert="~{fragments/footer.html :: footer}"></div>
+    </div>
+</body>
+
+</html>