Fix displayed identical fonts in sign PDF (#2751)

# Description of Changes

### Changes:
- Add a new custom select to display fonts correctly and to allow more
styling flexibility in Sign PDF feature by hiding the original
`<select>` element (`display: none;`) and wrap it with a `<div>` and
then create a custom selection menu using `<div>`s and CSS to achieve
the required results due to the limitations of `<select>` and `<option>`
while still preserving the hidden `<select>` for form submission.

### Why was the change made?
1. A bug that caused font families to not be displayed in Firefox.
2. Select/Option element are not flexible when it comes to styling
(compared to DIVs for example) but bullet point `1.` is of higher
priority.

### UI Changes:
- Dark Mode:
   - Before:

![image](https://github.com/user-attachments/assets/37f79c81-8155-4430-9e36-2b4cc2a442e6)

   - After:

![image](https://github.com/user-attachments/assets/e6a2b209-0d8f-4ff2-94ea-54827706d0cd)

- Light Mode:
   - Before:

![image](https://github.com/user-attachments/assets/c5356899-6be9-497b-8ad9-d50e6bd077d5)

   - After: 

![image](https://github.com/user-attachments/assets/29373b1a-cfa1-48a2-9040-3ed2fd5f7fd3)

Note:
- Changes in `sign.js` are between the lines 95-228, as it seems the
file was auto-formatted affecting whitespaces and
single_quotes/double_quotes.


#### Useful quotes from MDN:

> [Styling with
CSS](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/option#styling_with_css)
Styling the <option> element is highly limited. Options don't inherit
the font set on the parent. In Firefox, only
[color](https://developer.mozilla.org/en-US/docs/Web/CSS/color) and
[background-color](https://developer.mozilla.org/en-US/docs/Web/CSS/background-color)
can be set, however in Chrome and Safari it's not possible to set any
properties. You can find more details about styling in [our guide to
advanced form
styling](https://developer.mozilla.org/en-US/docs/Learn_web_development/Extensions/Forms/Advanced_form_styling).

#### Useful references:
- [Option
Element](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/option#styling_with_css)
- [Select
Element](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/select)
- [Advanced Form
Styling](https://developer.mozilla.org/en-US/docs/Learn_web_development/Extensions/Forms/Advanced_form_styling)

Closes #1575

---

## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md)
(if applicable)
- [x] I have performed a self-review of my own code
- [x] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [x] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [x] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md#6-testing)
for more details.

src/main/resources/static/css/sign.css

@@ -40,7 +40,6 @@ select#font-select option {
   max-width: 4rem;
 }
 
-
 .rotation-handle {
   width: 20px;
   height: 20px;
@@ -163,3 +162,76 @@ select#font-select option {
 .small-file-container-saved:hover .drag-icon {
   display: flex;
 }
+
+/* The container must be positioned relative: */
+.custom-select {
+  position: relative;
+  font-family: inherit;
+}
+
+.custom-select select {
+  display: none; /*hide original SELECT element: */
+}
+
+.select-selected {
+  background-color: inherit;
+  line-height: 30px;
+  font-size: 30px;
+  border-radius: 3rem !important;
+}
+
+/* Style the arrow inside the select element: */
+.select-selected:after {
+  position: absolute;
+  content: "";
+  top: 50%;
+  right: 10px;
+  translate: 0 -50%;
+  width: 0;
+  height: 0;
+  border: 6px solid transparent;
+  border-color: #fff transparent transparent transparent;
+}
+
+/* Point the arrow upwards when the select box is open (active): */
+.select-selected.select-arrow-active:after {
+  border-color: transparent transparent #fff transparent;
+  translate: 0 -75%;
+}
+
+/* style the items (options), including the selected item: */
+.select-items div,
+.select-selected {
+  color: inherit;
+  padding: 8px 16px;
+  cursor: pointer;
+}
+
+.select-items div {
+  border: 1px solid transparent;
+  border-color: transparent transparent transparent transparent;
+
+  line-height: 30px;
+  font-size: 30px;
+}
+
+/* Style items (options): */
+.select-items {
+  position: absolute;
+  background-color: inherit;
+  top: 100%;
+  left: 0;
+  right: 0;
+  z-index: 101;
+  border: inherit;
+}
+
+/* Hide the items when the select box is closed: */
+.select-hide {
+  display: none;
+}
+
+.select-items div:hover,
+.same-as-selected {
+  background-color: rgba(54, 54, 54, 0.1);
+}

src/main/resources/static/js/pages/sign.js

@@ -8,21 +8,21 @@ window.goToFirstOrLastPage = goToFirstOrLastPage;
 let currentPreviewSrc = null;
 
 function toggleSignatureView() {
-  const gridView = document.getElementById('gridView');
+  const gridView = document.getElementById("gridView");
-  const listView = document.getElementById('listView');
+  const listView = document.getElementById("listView");
-  const gridText = document.querySelector('.grid-view-text');
+  const gridText = document.querySelector(".grid-view-text");
-  const listText = document.querySelector('.list-view-text');
+  const listText = document.querySelector(".list-view-text");
 
-  if (gridView.style.display !== 'none') {
+  if (gridView.style.display !== "none") {
-    gridView.style.display = 'none';
+    gridView.style.display = "none";
-    listView.style.display = 'block';
+    listView.style.display = "block";
-    gridText.style.display = 'none';
+    gridText.style.display = "none";
-    listText.style.display = 'inline';
+    listText.style.display = "inline";
   } else {
-    gridView.style.display = 'block';
+    gridView.style.display = "block";
-    listView.style.display = 'none';
+    listView.style.display = "none";
-    gridText.style.display = 'inline';
+    gridText.style.display = "inline";
-    listText.style.display = 'none';
+    listText.style.display = "none";
   }
 }
 
@@ -30,63 +30,204 @@ function previewSignature(element) {
   const src = element.dataset.src;
   currentPreviewSrc = src;
 
-  const filename = element.querySelector('.signature-list-name').textContent;
+  const filename = element.querySelector(".signature-list-name").textContent;
 
-  const previewImage = document.getElementById('previewImage');
+  const previewImage = document.getElementById("previewImage");
-  const previewFileName = document.getElementById('previewFileName');
+  const previewFileName = document.getElementById("previewFileName");
 
   previewImage.src = src;
   previewFileName.textContent = filename;
 
-  const modal = new bootstrap.Modal(document.getElementById('signaturePreview'));
+  const modal = new bootstrap.Modal(
+    document.getElementById("signaturePreview")
+  );
   modal.show();
 }
 
 function addSignatureFromPreview() {
   if (currentPreviewSrc) {
     DraggableUtils.createDraggableCanvasFromUrl(currentPreviewSrc);
-    bootstrap.Modal.getInstance(document.getElementById('signaturePreview')).hide();
+    bootstrap.Modal.getInstance(
+      document.getElementById("signaturePreview")
+    ).hide();
   }
 }
 
-let originalFileName = '';
+let originalFileName = "";
-document.querySelector('input[name=pdf-upload]').addEventListener('change', async (event) => {
+document
+  .querySelector("input[name=pdf-upload]")
+  .addEventListener("change", async (event) => {
     const fileInput = event.target;
-  fileInput.addEventListener('file-input-change', async (e) => {
+    fileInput.addEventListener("file-input-change", async (e) => {
       const { allFiles } = e.detail;
       if (allFiles && allFiles.length > 0) {
         const file = allFiles[0];
-      originalFileName = file.name.replace(/\.[^/.]+$/, '');
+        originalFileName = file.name.replace(/\.[^/.]+$/, "");
         const pdfData = await file.arrayBuffer();
-      pdfjsLib.GlobalWorkerOptions.workerSrc = './pdfjs-legacy/pdf.worker.mjs';
+        pdfjsLib.GlobalWorkerOptions.workerSrc =
+          "./pdfjs-legacy/pdf.worker.mjs";
         const pdfDoc = await pdfjsLib.getDocument({ data: pdfData }).promise;
         await DraggableUtils.renderPage(pdfDoc, 0);
 
-      document.querySelectorAll('.show-on-file-selected').forEach((el) => {
+        document.querySelectorAll(".show-on-file-selected").forEach((el) => {
-        el.style.cssText = '';
+          el.style.cssText = "";
         });
       }
     });
   });
 
-document.addEventListener('DOMContentLoaded', () => {
+document.addEventListener("DOMContentLoaded", () => {
-  document.querySelectorAll('.show-on-file-selected').forEach((el) => {
+  document.querySelectorAll(".show-on-file-selected").forEach((el) => {
-    el.style.cssText = 'display:none !important';
+    el.style.cssText = "display:none !important";
   });
-  document.querySelectorAll('.small-file-container-saved img ').forEach((img) => {
+  document
-    img.addEventListener('dragstart', (e) => {
+    .querySelectorAll(".small-file-container-saved img ")
-      e.dataTransfer.setData('fileUrl', img.src);
+    .forEach((img) => {
+      img.addEventListener("dragstart", (e) => {
+        e.dataTransfer.setData("fileUrl", img.src);
       });
     });
-  document.addEventListener('keydown', (e) => {
+  document.addEventListener("keydown", (e) => {
-    if (e.key === 'Delete') {
+    if (e.key === "Delete") {
       DraggableUtils.deleteDraggableCanvas(DraggableUtils.getLastInteracted());
     }
   });
+
+  addCustomSelect();
 });
 
-const imageUpload = document.querySelector('input[name=image-upload]');
+function addCustomSelect() {
-imageUpload.addEventListener('change', (e) => {
+  let customSelectElementContainer =
+    document.getElementById("signFontSelection");
+  let originalSelectElement =
+    customSelectElementContainer.querySelector("select");
+
+  let optionsCount = originalSelectElement.length;
+
+  let selectedItem = createAndStyleSelectedItem();
+
+  customSelectElementContainer.appendChild(selectedItem);
+
+  let customSelectionsOptionsContainer = createCustomOptionsContainer();
+  createAndAddCustomOptions();
+  customSelectElementContainer.appendChild(customSelectionsOptionsContainer);
+
+  selectedItem.addEventListener("click", function (e) {
+    /* When the select box is clicked, close any other select boxes,
+      and open/close the current select box: */
+    e.stopPropagation();
+    closeAllSelect(this);
+    this.nextSibling.classList.toggle("select-hide");
+    this.classList.toggle("select-arrow-active");
+  });
+
+  function createAndAddCustomOptions() {
+    for (let j = 0; j < optionsCount; j++) {
+      /* For each option in the original select element,
+        create a new DIV that will act as an option item: */
+      let customOptionItem = createAndStyleCustomOption(j);
+
+      customOptionItem.addEventListener("click", onCustomOptionClick);
+      customSelectionsOptionsContainer.appendChild(customOptionItem);
+    }
+  }
+
+  function createCustomOptionsContainer() {
+    let customSelectionsOptionsContainer = document.createElement("DIV");
+    customSelectionsOptionsContainer.setAttribute(
+      "class",
+      "select-items select-hide"
+    );
+    return customSelectionsOptionsContainer;
+  }
+
+  function createAndStyleSelectedItem() {
+    let selectedItem = document.createElement("DIV");
+    selectedItem.setAttribute("class", "select-selected");
+    selectedItem.innerHTML =
+      originalSelectElement.options[
+        originalSelectElement.selectedIndex
+      ].innerHTML;
+
+    selectedItem.style.fontFamily = window.getComputedStyle(
+      originalSelectElement.options[originalSelectElement.selectedIndex]
+    ).fontFamily;
+    return selectedItem;
+  }
+
+  function onCustomOptionClick(e) {
+    /* When an item is clicked, update the original select box,
+          and the selected item: */
+    let selectElement =
+      this.parentNode.parentNode.getElementsByTagName("select")[0];
+    let optionsCount = selectElement.length;
+    let currentlySelectedCustomOption = this.parentNode.previousSibling;
+    for (let i = 0; i < optionsCount; i++) {
+      if (selectElement.options[i].innerHTML == this.innerHTML) {
+        selectElement.selectedIndex = i;
+        currentlySelectedCustomOption.innerHTML = this.innerHTML;
+        currentlySelectedCustomOption.style.fontFamily = this.style.fontFamily;
+
+        let previouslySelectedOption =
+          this.parentNode.getElementsByClassName("same-as-selected");
+
+        if (previouslySelectedOption && previouslySelectedOption.length > 0)
+          previouslySelectedOption[0].classList.remove("same-as-selected");
+
+        this.classList.add("same-as-selected");
+        break;
+      }
+    }
+    currentlySelectedCustomOption.click();
+  }
+
+  function createAndStyleCustomOption(j) {
+    let customOptionItem = document.createElement("DIV");
+    customOptionItem.innerHTML = originalSelectElement.options[j].innerHTML;
+    customOptionItem.classList.add(originalSelectElement.options[j].className);
+    customOptionItem.style.fontFamily = window.getComputedStyle(
+      originalSelectElement.options[j]
+    ).fontFamily;
+
+    if (j == originalSelectElement.selectedIndex)
+      customOptionItem.classList.add("same-as-selected");
+    return customOptionItem;
+  }
+
+  function closeAllSelect(element) {
+    /* A function that will close all select boxes in the document,
+    except the current select box: */
+    let allSelectedOptions = document.getElementsByClassName("select-selected");
+    let allSelectedOptionsCount = allSelectedOptions.length;
+    let indicesOfContainersToHide = [];
+    for (let i = 0; i < allSelectedOptionsCount; i++) {
+      if (element == allSelectedOptions[i]) {
+        indicesOfContainersToHide.push(i);
+      } else {
+        allSelectedOptions[i].classList.remove("select-arrow-active");
+      }
+    }
+
+    hideOptionsContainers(indicesOfContainersToHide);
+  }
+
+  /* If the user clicks anywhere outside the select box,
+  then close all select boxes: */
+  document.addEventListener("click", closeAllSelect);
+
+  function hideOptionsContainers(containersIndices) {
+    let allOptionsContainers = document.getElementsByClassName("select-items");
+    let allSelectionListsContainerCount = allOptionsContainers.length;
+    for (let i = 0; i < allSelectionListsContainerCount; i++) {
+      if (containersIndices.indexOf(i)) {
+        allOptionsContainers[i].classList.add("select-hide");
+      }
+    }
+  }
+}
+
+const imageUpload = document.querySelector("input[name=image-upload]");
+imageUpload.addEventListener("change", (e) => {
   if (!e.target.files) return;
   for (const imageFile of e.target.files) {
     var reader = new FileReader();
@@ -97,11 +238,11 @@ imageUpload.addEventListener('change', (e) => {
   }
 });
 
-const signaturePadCanvas = document.getElementById('drawing-pad-canvas');
+const signaturePadCanvas = document.getElementById("drawing-pad-canvas");
 const signaturePad = new SignaturePad(signaturePadCanvas, {
   minWidth: 1,
   maxWidth: 2,
-  penColor: 'black',
+  penColor: "black",
 });
 
 function addDraggableFromPad() {
@@ -113,7 +254,7 @@ function addDraggableFromPad() {
 }
 
 function getCroppedCanvasDataUrl(canvas) {
-  let originalCtx = canvas.getContext('2d');
+  let originalCtx = canvas.getContext("2d");
   let originalWidth = canvas.width;
   let originalHeight = canvas.height;
   let imageData = originalCtx.getImageData(0, 0, originalWidth, originalHeight);
@@ -129,7 +270,8 @@ function getCroppedCanvasDataUrl(canvas) {
   for (y = 0; y < originalHeight; y++) {
     for (x = 0; x < originalWidth; x++) {
       currentPixelColorValueIndex = (y * originalWidth + x) * 4;
-      let currentPixelAlphaValue = imageData.data[currentPixelColorValueIndex + 3];
+      let currentPixelAlphaValue =
+        imageData.data[currentPixelColorValueIndex + 3];
       if (currentPixelAlphaValue > 0) {
         if (minX > x) minX = x;
         if (maxX < x) maxX = x;
@@ -142,10 +284,15 @@ function getCroppedCanvasDataUrl(canvas) {
   let croppedWidth = maxX - minX;
   let croppedHeight = maxY - minY;
   if (croppedWidth < 0 || croppedHeight < 0) return null;
-  let cuttedImageData = originalCtx.getImageData(minX, minY, croppedWidth, croppedHeight);
+  let cuttedImageData = originalCtx.getImageData(
+    minX,
+    minY,
+    croppedWidth,
+    croppedHeight
+  );
 
-  let croppedCanvas = document.createElement('canvas'),
+  let croppedCanvas = document.createElement("canvas"),
-    croppedCtx = croppedCanvas.getContext('2d');
+    croppedCtx = croppedCanvas.getContext("2d");
 
   croppedCanvas.width = croppedWidth;
   croppedCanvas.height = croppedHeight;
@@ -158,9 +305,13 @@ function resizeCanvas() {
   var ratio = Math.max(window.devicePixelRatio || 1, 1);
   var additionalFactor = 10;
 
-  signaturePadCanvas.width = signaturePadCanvas.offsetWidth * ratio * additionalFactor;
+  signaturePadCanvas.width =
-  signaturePadCanvas.height = signaturePadCanvas.offsetHeight * ratio * additionalFactor;
+    signaturePadCanvas.offsetWidth * ratio * additionalFactor;
-  signaturePadCanvas.getContext('2d').scale(ratio * additionalFactor, ratio * additionalFactor);
+  signaturePadCanvas.height =
+    signaturePadCanvas.offsetHeight * ratio * additionalFactor;
+  signaturePadCanvas
+    .getContext("2d")
+    .scale(ratio * additionalFactor, ratio * additionalFactor);
 
   signaturePad.clear();
 }
@@ -174,12 +325,12 @@ new IntersectionObserver((entries, observer) => {
 new ResizeObserver(resizeCanvas).observe(signaturePadCanvas);
 
 function addDraggableFromText() {
-  const sigText = document.getElementById('sigText').value;
+  const sigText = document.getElementById("sigText").value;
-  const font = document.querySelector('select[name=font]').value;
+  const font = document.querySelector("select[name=font]").value;
   const fontSize = 100;
 
-  const canvas = document.createElement('canvas');
+  const canvas = document.createElement("canvas");
-  const ctx = canvas.getContext('2d');
+  const ctx = canvas.getContext("2d");
   ctx.font = `${fontSize}px ${font}`;
   const textWidth = ctx.measureText(sigText).width;
   const textHeight = fontSize;
@@ -190,7 +341,7 @@ function addDraggableFromText() {
   canvas.height = paragraphs.length * textHeight * 1.35; // for tails
   ctx.font = `${fontSize}px ${font}`;
 
-  ctx.textBaseline = 'top';
+  ctx.textBaseline = "top";
 
   let y = 0;
 
@@ -212,8 +363,8 @@ async function goToFirstOrLastPage(page) {
   }
 }
 
-document.getElementById('download-pdf').addEventListener('click', async () => {
+document.getElementById("download-pdf").addEventListener("click", async () => {
-  const downloadButton = document.getElementById('download-pdf');
+  const downloadButton = document.getElementById("download-pdf");
   const originalContent = downloadButton.innerHTML;
 
   downloadButton.disabled = true;
@@ -224,13 +375,13 @@ document.getElementById('download-pdf').addEventListener('click', async () => {
   try {
     const modifiedPdf = await DraggableUtils.getOverlayedPdfDocument();
     const modifiedPdfBytes = await modifiedPdf.save();
-    const blob = new Blob([modifiedPdfBytes], {type: 'application/pdf'});
+    const blob = new Blob([modifiedPdfBytes], { type: "application/pdf" });
-    const link = document.createElement('a');
+    const link = document.createElement("a");
     link.href = URL.createObjectURL(blob);
-    link.download = originalFileName + '_signed.pdf';
+    link.download = originalFileName + "_signed.pdf";
     link.click();
   } catch (error) {
-    console.error('Error downloading PDF:', error);
+    console.error("Error downloading PDF:", error);
   } finally {
     downloadButton.disabled = false;
     downloadButton.innerHTML = originalContent;

src/main/resources/templates/sign.html

@@ -15,7 +15,8 @@
 
       #font-select option[value="[[${font.name}]]"] {
         font-family: "[[${font.name}]]",
-        cursive;
+        cursive
+        !important;
       }
     </style>
   </th:block>
@@ -133,10 +134,12 @@
                 <label class="form-check-label" for="sigText" th:text="#{text}"></label>
                 <textarea class="form-control" id="sigText" name="sigText" rows="3"></textarea>
                 <label th:text="#{font}"></label>
+                <div id="signFontSelection" class="custom-select form-control">
                   <select class="form-control" name="font" id="font-select">
                     <option th:each="font : ${fonts}" th:value="${font.name}" th:text="${font.name}"
                       th:class="${font.name.toLowerCase()+'-font'}"></option>
                   </select>
+                </div>
                 <div class="margin-auto-parent">
                   <button id="save-text-signature" class="btn btn-outline-success mt-2 margin-center"
                     onclick="addDraggableFromText()" th:text="#{sign.add}"></button>