theme: add modal to view large image

theme/default/home.hbs

@@ -25,6 +25,7 @@
                 </div>
             </div>
         </div>
+        {{> modal.hbs }}
         <script src="/static/script.js?ver={{ build_num }}"></script>
     </body>
 </html>

theme/default/modal.hbs

@@ -0,0 +1,11 @@
+<!-- The Modal -->
+<!-- https://www.w3schools.com/howto/howto_css_modal_images.asp -->
+<div id="myModal" class="modal">
+
+    <!-- The Close Button -->
+    <span class="close">&times;</span>
+
+    <!-- Modal Content (The Image) -->
+    <img class="modal-content" id="img01">
+
+</div>

theme/default/post.hbs

@@ -16,6 +16,7 @@
             <!-- We don't handle this in backend -->
             </div>
         </div>
+        {{> modal.hbs }}
         <script src="/static/script.js?ver={{ build_num }}"></script>
     </body>
 </html>

theme/default/static/script.js

@@ -16,6 +16,20 @@ window.onbeforeunload = (ev) => {
 window.onload = function() {
   let content = document.getElementsByClassName("content");
   if (content.length == 0) return;
+  // View large image in modal when clicked
+  var modal = document.getElementById("myModal");
+  var modalImg = document.getElementById("img01");
+  document.querySelectorAll(".content img").forEach((elem) => {
+    elem.onclick = (ev) => {
+      modal.style.display = "block";
+      modalImg.src = elem.src;
+    };
+  });
+  var span = document.getElementsByClassName("close")[0];
+  span.onclick = () => {
+    modal.style.display = "none";
+  };
+  // Table-of-Contents generation
   // Don't do this on mobile; it's horrible
   if (window.matchMedia("(max-width: 1000px)").matches) return;
 

theme/default/static/style.css

@@ -274,6 +274,13 @@ h5 {
 .content img {
     max-width: calc(100% - 10px);
     object-fit: contain;
+    cursor: pointer;
+    transition: opacity 0.3s;
+}
+
+.post img:hover,
+.content img:hover {
+    opacity: 0.7;
 }
 
 .toc-wrapper {
@@ -387,4 +394,76 @@ h5 {
     .with-divider.with-divider-center-mobile::after {
         margin-left: calc(50% - 20px) !important;
     }
-}
+}
+
+/* Modal <https://www.w3schools.com/howto/howto_css_modal_images.asp> */
+/* The Modal (background) */
+.modal {
+    display: none; /* Hidden by default */
+    position: fixed; /* Stay in place */
+    z-index: 1; /* Sit on top */
+    padding-top: 100px; /* Location of the box */
+    left: 0;
+    top: 0;
+    width: 100%; /* Full width */
+    height: 100%; /* Full height */
+    overflow: auto; /* Enable scroll if needed */
+    background-color: rgb(0,0,0); /* Fallback color */
+    background-color: rgba(0,0,0,0.9); /* Black w/ opacity */
+  }
+  
+  /* Modal Content (Image) */
+  .modal-content {
+    margin: auto;
+    display: block;
+    width: 80%;
+    max-width: 700px;
+  }
+  
+  /* Caption of Modal Image (Image Text) - Same Width as the Image */
+  #caption {
+    margin: auto;
+    display: block;
+    width: 80%;
+    max-width: 700px;
+    text-align: center;
+    color: #ccc;
+    padding: 10px 0;
+    height: 150px;
+  }
+  
+  /* Add Animation - Zoom in the Modal */
+  .modal-content, #caption {
+    animation-name: zoom;
+    animation-duration: 0.6s;
+  }
+  
+  @keyframes zoom {
+    from {transform:scale(0)}
+    to {transform:scale(1)}
+  }
+  
+  /* The Close Button */
+  .close {
+    position: absolute;
+    top: 15px;
+    right: 35px;
+    color: #f1f1f1;
+    font-size: 40px;
+    font-weight: bold;
+    transition: 0.3s;
+  }
+  
+  .close:hover,
+  .close:focus {
+    color: #bbb;
+    text-decoration: none;
+    cursor: pointer;
+  }
+  
+  /* 100% Image Width on Smaller Screens */
+  @media only screen and (max-width: 700px){
+    .modal-content {
+      width: 100%;
+    }
+  }