feat: implement split modes including presets and custom input

Added support for predefined split modes:
- Split all except first and last
- Split all except first
- Split all except last
- Split all

Also added a custom mode that enables users to specify exact pages to split via input field.

app/core/src/main/java/stirling/software/SPDF/controller/api/SplitPdfBySectionsController.java

@@ -33,6 +33,7 @@ import io.swagger.v3.oas.annotations.tags.Tag;
 
 import lombok.RequiredArgsConstructor;
 
+import stirling.software.SPDF.model.SplitTypes;
 import stirling.software.SPDF.model.api.SplitPdfBySectionsRequest;
 import stirling.software.common.service.CustomPDFDocumentFactory;
 import stirling.software.common.util.GeneralUtils;
@@ -51,6 +52,7 @@ public class SplitPdfBySectionsController {
             summary = "Split PDF pages into smaller sections",
             description =
                     "Split each page of a PDF into smaller sections based on the user's choice"
+                            + " which page to split, and how to split"
                             + " ( halves, thirds, quarters, etc.), both vertically and horizontally."
                             + " Input:PDF Output:ZIP-PDF Type:SISO")
     public ResponseEntity<byte[]> splitPdf(@ModelAttribute SplitPdfBySectionsRequest request)
@@ -59,13 +61,10 @@ public class SplitPdfBySectionsController {
 
         MultipartFile file = request.getFileInput();
         String pageNumbers = request.getPageNumbers();
+        String splitMode = request.getSplitMode();
         PDDocument sourceDocument = pdfDocumentFactory.load(file);
 
-        // Split the page order string into an array of page numbers or range of numbers
+        Set<Integer> pagesToSplit = getPagesToSplit(pageNumbers, splitMode, sourceDocument.getNumberOfPages());
-        String[] pageOrderArr = pageNumbers.split(",");
-        List<Integer> pageListToSplit =
-            GeneralUtils.parsePageList(pageOrderArr, sourceDocument.getNumberOfPages(), false);
-        Set<Integer> pagesToSplit = new HashSet<>(pageListToSplit);
 
         // Process the PDF based on split parameters
         int horiz = request.getHorizontalDivisions() + 1;
@@ -119,6 +118,52 @@ public class SplitPdfBySectionsController {
         }
     }
 
+    // Based on the mode, get the pages that need to be split and return the pages set
+    private Set<Integer> getPagesToSplit(String pageNumbers, String splitMode, int totalPages) {
+        Set<Integer> pagesToSplit = new HashSet<>();
+
+        switch (SplitTypes.valueOf(splitMode)) {
+            case CUSTOM:
+                if (pageNumbers == null || pageNumbers.isBlank()) {
+                    throw new IllegalArgumentException("Custom mode requires page numbers input.");
+                }
+                String[] pageOrderArr = pageNumbers.split(",");
+                List<Integer> pageListToSplit = GeneralUtils.parsePageList(pageOrderArr, totalPages, false);
+                pagesToSplit.addAll(pageListToSplit);
+                break;
+
+            case SPLIT_ALL:
+                for (int i = 0; i < totalPages; i++) {
+                    pagesToSplit.add(i);
+                }
+                break;
+
+            case SPLIT_ALL_EXCEPT_FIRST:
+                for (int i = 1; i < totalPages; i++) {
+                    pagesToSplit.add(i);
+                }
+                break;
+
+            case SPLIT_ALL_EXCEPT_LAST:
+                for (int i = 0; i < totalPages - 1; i++) {
+                    pagesToSplit.add(i);
+                }
+                break;
+
+            case SPLIT_ALL_EXCEPT_FIRST_AND_LAST:
+                for (int i = 1; i < totalPages - 1; i++) {
+                    pagesToSplit.add(i);
+                }
+                break;
+
+            default:
+                throw new IllegalArgumentException("Unsupported split mode: " + splitMode);
+        }
+
+        return pagesToSplit;
+    }
+
+
     public List<PDDocument> splitPdfPages(
             PDDocument document, int horizontalDivisions, int verticalDivisions, Set<Integer> pagesToSplit)
             throws IOException {

app/core/src/main/java/stirling/software/SPDF/model/SplitTypes.java

@@ -0,0 +1,9 @@
+package stirling.software.SPDF.model;
+
+public enum SplitTypes {
+    CUSTOM,
+    SPLIT_ALL_EXCEPT_FIRST_AND_LAST,
+    SPLIT_ALL_EXCEPT_FIRST,
+    SPLIT_ALL_EXCEPT_LAST,
+    SPLIT_ALL
+}

app/core/src/main/java/stirling/software/SPDF/model/api/SplitPdfBySectionsRequest.java

@@ -5,6 +5,7 @@ import io.swagger.v3.oas.annotations.media.Schema;
 import lombok.Data;
 import lombok.EqualsAndHashCode;
 
+import stirling.software.SPDF.model.SplitTypes;
 import stirling.software.common.model.api.PDFFile;
 
 @Data
@@ -16,6 +17,17 @@ public class SplitPdfBySectionsRequest extends PDFFile {
         requiredMode = Schema.RequiredMode.REQUIRED)
     private String pageNumbers;
 
+    @Schema(
+        implementation = SplitTypes.class,
+        description =
+            "Modes for page split. Valid values are:\n"
+                + "SPLIT_ALL_EXCEPT_FIRST_AND_LAST: Splits all except the first and the last pages.\n"
+                + "SPLIT_ALL_EXCEPT_FIRST: Splits all except the first page.\n"
+                + "SPLIT_ALL_EXCEPT_LAST: Splits all except the last page.\n"
+                + "SPLIT_ALL: Splits all pages.\n"
+                + "CUSTOM: Custom split.\n")
+    private String splitMode;
+
     @Schema(
             description = "Number of horizontal divisions for each PDF page",
             defaultValue = "0",

app/core/src/main/resources/messages_en_GB.properties

@@ -1587,7 +1587,14 @@ split-by-sections.vertical.placeholder=Enter number of vertical divisions
 split-by-sections.submit=Split PDF
 split-by-sections.merge=Merge Into One PDF
 split-by-sections.pageToSplit=Pages to split (Enter a comma-separated list of page numbers) :
-split-by-sections.pageToSplit.placeholder=(e.g. 1,2,6 or 1-10,15-30)
+split-by-sections.pageToSplit.placeholder=(e.g. 1,2,6)
+split-by-sections.mode=Mode
+split-by-sections.mode.1=Split all except first and last
+split-by-sections.mode.2=Split all except first
+split-by-sections.mode.3=Split all except last
+split-by-sections.mode.4=Split all
+split-by-sections.mode.5=Custom. Specify pages to split
+
 
 
 #printFile

app/core/src/main/resources/templates/split-pdf-by-sections.html

@@ -20,6 +20,16 @@
               </div>
               <form method="post" enctype="multipart/form-data" th:action="@{'/api/v1/general/split-pdf-by-sections'}">
                 <div th:replace="~{fragments/common :: fileSelector(name='fileInput', multipleInputsForSingleRequest=false, accept='application/pdf')}"></div>
+                <div class="mb-3">
+                  <label for="splitMode" th:text="#{split-by-sections.mode}">Mode</label>
+                  <select class="form-control" id="splitMode" name="splitMode">
+                    <option value="SPLIT_ALL_EXCEPT_FIRST_AND_LAST" th:text="#{split-by-sections.mode.1}">Split all except first and last</option>
+                    <option value="SPLIT_ALL_EXCEPT_FIRST" th:text="#{split-by-sections.mode.2}">Split all except first</option>
+                    <option value="SPLIT_ALL_EXCEPT_LAST" th:text="#{split-by-sections.mode.3}">Split all except last</option>
+                    <option value="SPLIT_ALL" th:text="#{split-by-sections.mode.4}">Split all</option>
+                    <option value="CUSTOM" th:text="#{split-by-sections.mode.5}">Specify pages to split</option>
+                  </select>
+                </div>
                 <div class="mb-3">
                   <label for="pageToSplit" th:text="#{split-by-sections.pageToSplit}"></label>
                   <input type="text" class="form-control" id="pageToSplit" name="pageNumbers"
@@ -85,6 +95,16 @@
                     this.value = this.value.replace(/\s+/g, '');;
                   });
 
+                  // Only enable the page list input field when split mode is custom.
+                  function togglePageInput() {
+                    const mode = document.getElementById('splitMode').value;
+                    const pageListInput = document.getElementById('pageToSplit');
+                    pageListInput.disabled = mode !== "CUSTOM";
+                  }
+
+                  document.getElementById('splitMode').addEventListener('change', togglePageInput);
+                  window.addEventListener('DOMContentLoaded', togglePageInput);
+
                 </script>
                 <br>
                 <button type="submit" id="submitBtn" class="btn btn-primary" th:text="#{split-by-sections.submit}">Submit</button>