Enable masonry layout for photos

assets/js/photos.js

@@ -0,0 +1,79 @@
+/**
+ * Set appropriate spanning to any masonry item
+ *
+ * Get different properties we already set for the masonry, calculate 
+ * height or spanning for any cell of the masonry grid based on its 
+ * content-wrapper's height, the (row) gap of the grid, and the size 
+ * of the implicit row tracks.
+ *
+ * @param item Object A brick/tile/cell inside the masonry
+ */
+function resizeMasonryItem(item){
+  /* Get the grid object, its row-gap, and the size of its implicit rows */
+  var grid = document.getElementsByClassName('photo-list')[0],
+      rowGap = parseInt(window.getComputedStyle(grid).getPropertyValue('grid-row-gap')),
+      rowHeight = parseInt(window.getComputedStyle(grid).getPropertyValue('grid-auto-rows'));
+
+  /*
+   * Spanning for any brick = S
+   * Grid's row-gap = G
+   * Size of grid's implicitly create row-track = R
+   * Height of item content = H
+   * Net height of the item = H1 = H + G
+   * Net height of the implicit row-track = T = G + R
+   * S = H1 / T
+   */
+  var rowSpan = Math.ceil((item.querySelector('a').getBoundingClientRect().height+rowGap)/(rowHeight+rowGap));
+
+  /* Set the spanning as calculated above (S) */
+  item.style.gridRowEnd = 'span '+rowSpan;
+}
+
+/**
+ * Apply spanning to all the masonry items
+ *
+ * Loop through all the items and apply the spanning to them using 
+ * `resizeMasonryItem()` function.
+ *
+ * @uses resizeMasonryItem
+ */
+function resizeAllMasonryItems(){
+  // Get all item class objects in one list
+  var allItems = document.getElementsByClassName('photo-item');
+
+  /*
+   * Loop through the above list and execute the spanning function to
+   * each list-item (i.e. each masonry item)
+   */
+  for(var i=0;i<allItems.length;i++){
+    resizeMasonryItem(allItems[i]);
+  }
+}
+
+/**
+ * Resize the items when all the images inside the masonry grid 
+ * finish loading. This will ensure that all the content inside our
+ * masonry items is visible.
+ *
+ * @uses ImagesLoaded
+ * @uses resizeMasonryItem
+ */
+function waitForImages() {
+  var allItems = document.getElementsByClassName('photo-item');
+  for(var i=0;i<allItems.length;i++){
+    imagesLoaded( allItems[i], function(instance) {
+      var item = instance.elements[0];
+      resizeMasonryItem(item);
+    } );
+  }
+  imagesLoaded(allItems).on("always", resizeAllMasonryItems);
+}
+
+/* Resize all the grid items on the load and resize events */
+var masonryEvents = ['load', 'resize'];
+masonryEvents.forEach( function(event) {
+  window.addEventListener(event, resizeAllMasonryItems);
+} );
+
+/* Do a resize once more when all the images finish loading */
+waitForImages();