Add support for feedback icons

Author: tagliala

dist/select2-bootstrap4.css

@@ -52,20 +52,24 @@
   border-color: #ced4da;
   box-shadow: none; }
 
-select.is-invalid ~ .select2-container--bootstrap4 .select2-selection,
-form.was-validated select:invalid ~ .select2-container--bootstrap4 .select2-selection {
-  border-color: #dc3545; }
-  select.is-invalid ~ .select2-container--bootstrap4 .select2-selection:focus,
-  form.was-validated select:invalid ~ .select2-container--bootstrap4 .select2-selection:focus {
-    border-color: #dc3545;
-    box-shadow: 0 0 0 0.2rem rgba(220, 53, 69, 0.25); }
-
 select.is-valid ~ .select2-container--bootstrap4 .select2-selection,
 form.was-validated select:valid ~ .select2-container--bootstrap4 .select2-selection {
-  border-color: #28a745; }
+  border-color: #28a745;
+  padding-right: calc(1em + 2.3125rem) !important;
+  background: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='4' height='5' viewBox='0 0 4 5'%3e%3cpath fill='%23343a40' d='M2 0L0 2h4zm0 5L0 3h4z'/%3e%3c/svg%3e") right 0.75rem center/8px 10px no-repeat, #fff url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='8' height='8' viewBox='0 0 8 8'%3e%3cpath fill='%2328a745' d='M2.3 6.73L.6 4.53c-.4-1.04.46-1.4 1.1-.8l1.1 1.4 3.4-3.8c.6-.63 1.6-.27 1.2.7l-4 4.6c-.43.5-.8.4-1.1.1z'/%3e%3c/svg%3e") center right 1.75rem/calc(0.75em + 0.375rem) calc(0.75em + 0.375rem) no-repeat; }
   select.is-valid ~ .select2-container--bootstrap4 .select2-selection:focus,
   form.was-validated select:valid ~ .select2-container--bootstrap4 .select2-selection:focus {
     border-color: #28a745;
+    box-shadow: 0 0 0 0.2rem rgba(40, 167, 69, 0.25); }
+
+select.is-invalid ~ .select2-container--bootstrap4 .select2-selection,
+form.was-validated select:invalid ~ .select2-container--bootstrap4 .select2-selection {
+  border-color: #dc3545;
+  padding-right: calc(1em + 2.3125rem) !important;
+  background: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='4' height='5' viewBox='0 0 4 5'%3e%3cpath fill='%23343a40' d='M2 0L0 2h4zm0 5L0 3h4z'/%3e%3c/svg%3e") right 0.75rem center/8px 10px no-repeat, #fff url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='none' stroke='%23dc3545' viewBox='0 0 12 12'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3e%3ccircle cx='6' cy='8.2' r='.6' fill='%23dc3545' stroke='none'/%3e%3c/svg%3e") center right 1.75rem/calc(0.75em + 0.375rem) calc(0.75em + 0.375rem) no-repeat; }
+  select.is-invalid ~ .select2-container--bootstrap4 .select2-selection:focus,
+  form.was-validated select:invalid ~ .select2-container--bootstrap4 .select2-selection:focus {
+    border-color: #dc3545;
     box-shadow: 0 0 0 0.2rem rgba(220, 53, 69, 0.25); }
 
 .select2-container--bootstrap4 .select2-dropdown {

dist/select2-bootstrap4.min.css

@@ -192,6 +192,14 @@ <h3>Example of <a href="https://github.com/ttskch/select2-bootstrap4-theme" targ
 
     <div class="form-group">
       <label>Example of validated select</label>
+      <select data-placeholder="Valid example" class="form-control is-valid" data-allow-clear="1">
+        <option></option>
+      </select>
+      <div class="valid-feedback">
+        Everything is fine.
+      </div>
+    </div>
+    <div class="form-group">
       <select data-placeholder="Invalid example" class="form-control is-invalid" data-allow-clear="1">
         <option></option>
       </select>