added html and css editors

shared/_base.ts

@@ -67,6 +67,22 @@ export class BaseElement extends HTMLElement {
 
         return null;
     }
+    
+    findVisible(tagName: string) {
+        var result = [];
+        
+        var elements = document.getElementsByTagName(tagName);
+
+        for (let i = 0; i < elements.length; i++) {
+            const element = <HTMLElement>elements[i];
+            
+            if (element.style.display !== "none") {
+                result.push(element);
+            }
+        }
+
+        return result;
+    }
 
     hasChild(element: Element, startsWidth: boolean = false): boolean {
         var ele = this;