fix: improve accuracy of moving img element classes (cotes2020#2399)

Author: cotes2020

_includes/refactor-content.html

@@ -88,9 +88,41 @@
     {% endfor %}
 
     <!-- take out classes -->
+    {% assign _wrapper_class = '' %}
+
     {% if _class %}
-      {% capture _old_class %}class="{{ _class }}"{% endcapture %}
-      {% assign _left = _left | remove: _old_class %}
+      {% assign _remain = _class %}
+      {% assign _class_array = _class | split: ' ' %}
+
+      {% for c in _class_array %}
+        {% assign _pick = false %}
+
+        {% case c %}
+          {% when 'preview-img', 'normal', 'left', 'right', 'light', 'dark' %}
+            {% assign _pick = true %}
+          {% else %}
+            {% if c contains '-' %}
+              {% assign start = c | split: '-' | first %}
+              {% if start == 'w' %}
+                {% assign _pick = true %}
+              {% endif %}
+            {% endif %}
+        {% endcase %}
+
+        {% if _pick %}
+          {% assign _remain = _remain | remove: c | strip %}
+          {% assign _wrapper_class = _wrapper_class | append: ' ' | append: c %}
+        {% endif %}
+      {% endfor %}
+
+      {% unless _wrapper_class == '' %}
+        {% capture _old_class %}class="{{ _class }}"{% endcapture %}
+        {% assign _left = _left | remove: _old_class %}
+        {% unless _remain == '' %}
+          {% capture _new_class %}class="{{ _remain }}"{% endcapture %}
+          {% assign _left = _left | append: _new_class %}
+        {% endunless %}
+      {% endunless %}
     {% endif %}
 
     {% assign _final_src = null %}
@@ -110,7 +142,7 @@
 
     {% if _lqip %}
       {% assign _lazyload = false %}
-      {% assign _class = _class | append: ' blur' %}
+      {% assign _wrapper_class = _wrapper_class | append: ' blur' %}
 
       {% unless _lqip contains 'data:' %}
         {% assign _lqip_alt = 'lqip="' | append: _path_prefix %}
@@ -121,7 +153,7 @@
       {% assign _left = _left | replace: 'src=', 'data-src=' | replace: ' lqip=', ' data-lqip="true" src=' %}
 
     {% else %}
-      {% assign _class = _class | append: ' shimmer' %}
+      {% assign _wrapper_class = _wrapper_class | append: ' shimmer' %}
     {% endif %}
 
     <!-- lazy-load images -->
@@ -153,8 +185,8 @@
         {% assign _wrapper_start = _final_src
           | default: _src
           | prepend: '<a href="'
-          | append: '" class="popup img-link '
-          | append: _class
+          | append: '" class="popup img-link'
+          | append: _wrapper_class
           | append: '">'
         %}