Pull request #3109: 无JIRA任务 resizeObserver

Merge in VISUAL/fineui from ~GUY/fineui:master to master

* commit 'b08014b5946ba933323d0b69bd486807d4e648b7':
  resizeObserver

src/core/platform/web/detectElementResize.js

@@ -112,7 +112,21 @@
     };
 
     var addResizeListener = function (element, fn) {
-        if (attachEvent) {
+        if (window.ResizeObserver) {
+            if (!element.__resizeObserver__) {
+                var resizeObserver = new window.ResizeObserver(function () {
+                    element.__resizeListeners__.forEach(function (listener) {
+                        listener();
+                    });
+                });
+                resizeObserver.observe(element);
+                element.__resizeObserver__ = resizeObserver;
+            }
+            if (!element.__resizeListeners__) {
+                element.__resizeListeners__ = [];
+            }
+            element.__resizeListeners__.push(fn);
+        } else if (attachEvent) {
             element.attachEvent("onresize", fn);
             BI.nextTick(fn);
         } else {
@@ -137,8 +151,17 @@
         }
     };
     var removeResizeListener = function (element, fn) {
-        if (attachEvent) element.detachEvent("onresize", fn);
-        else {
+        if (window.ResizeObserver) {
+            var index = element.__resizeListeners__.indexOf(fn);
+            if (index >= 0) {
+                element.__resizeListeners__.splice(index, 1);
+                if (!element.__resizeListeners__.length) {
+                    element.__resizeObserver__ && element.__resizeObserver__.unobserve(element);
+                }
+            }
+        } else if (attachEvent) {
+            element.detachEvent("onresize", fn);
+        } else {
             element.__resizeListeners__.splice(element.__resizeListeners__.indexOf(fn), 1);
             if (!element.__resizeListeners__.length) {
                 element.removeEventListener("scroll", scrollListener);