remove slow cursor[style*] css rule

lib/ace/css/editor.css

@@ -63,6 +63,10 @@
     left: 0;
     cursor: default;
     z-index: 4;
+    -ms-user-select: none;
+    -moz-user-select: none;
+    -webkit-user-select: none;
+    user-select: none;
 }
 
 .ace_gutter-active-line {
@@ -227,10 +231,6 @@
             transition: opacity 0.18s;
 }
 
-.ace_cursor[style*="opacity: 0"]{
-    -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=0)";
-}
-
 .ace_editor.ace_multiselect .ace_cursor {
     border-left-width: 1px;
 }

lib/ace/layer/cursor.js

@@ -32,12 +32,16 @@ define(function(require, exports, module) {
 "use strict";
 
 var dom = require("../lib/dom");
+var IE8;
 
 var Cursor = function(parentEl) {
     this.element = dom.createElement("div");
     this.element.className = "ace_layer ace_cursor-layer";
     parentEl.appendChild(this.element);
     
+    if (IE8 === undefined)
+        IE8 = "opacity" in this.element;
+
     this.isVisible = false;
     this.isBlinking = true;
     this.blinkInterval = 1000;
@@ -46,10 +50,23 @@ var Cursor = function(parentEl) {
     this.cursors = [];
     this.cursor = this.addCursor();
     dom.addCssClass(this.element, "ace_hidden-cursors");
+    this.$updateCursors = this.$updateVisibility.bind(this);
 };
 
 (function() {
     
+    this.$updateVisibility = function(val) {
+        var cursors = this.cursors;
+        for (var i = cursors.length; i--; )
+            cursors[i].style.visibility = val ? "" : "hidden";
+    };
+    this.$updateOpacity = function(val) {
+        var cursors = this.cursors;
+        for (var i = cursors.length; i--; )
+            cursors[i].style.opacity = val ? "" : "0";
+    };
+    
+
     this.$padding = 0;
     this.setPadding = function(padding) {
         this.$padding = padding;
@@ -74,12 +91,13 @@ var Cursor = function(parentEl) {
     };
 
     this.setSmoothBlinking = function(smoothBlinking) {
-        if (smoothBlinking != this.smoothBlinking) {
+        if (smoothBlinking != this.smoothBlinking && !IE8) {
             this.smoothBlinking = smoothBlinking;
-            if (smoothBlinking)
+            dom.setCssClass(this.element, "ace_smooth-blinking", smoothBlinking);
-                dom.addCssClass(this.element, "ace_smooth-blinking");
+            this.$updateCursors(true);
-            else
+            this.$updateCursors = (smoothBlinking 
-                dom.removeCssClass(this.element, "ace_smooth-blinking");
+                ? this.$updateOpacity
+                : this.$updateVisibility).bind(this);
             this.restartTimer();
         }
     };
@@ -113,35 +131,34 @@ var Cursor = function(parentEl) {
     };
 
     this.restartTimer = function() {
+        var update = this.$updateCursors;
         clearInterval(this.intervalId);
         clearTimeout(this.timeoutId);
-        if (this.smoothBlinking)
+        if (this.smoothBlinking) {
             dom.removeCssClass(this.element, "ace_smooth-blinking");
-        for (var i = this.cursors.length; i--; )
+        }
-            this.cursors[i].style.opacity = "";
+        
+        update(true);
 
         if (!this.isBlinking || !this.blinkInterval || !this.isVisible)
             return;
 
-        if (this.smoothBlinking)
+        if (this.smoothBlinking) {
             setTimeout(function(){
                 dom.addCssClass(this.element, "ace_smooth-blinking");
             }.bind(this));
+        }
         
         var blink = function(){
             this.timeoutId = setTimeout(function() {
-                for (var i = this.cursors.length; i--; ) {
+                update(false);
-                    this.cursors[i].style.opacity = 0;
+            }, 0.6 * this.blinkInterval);
-                }
-            }.bind(this), 0.6 * this.blinkInterval);
         }.bind(this);
 
         this.intervalId = setInterval(function() {
-            for (var i = this.cursors.length; i--; ) {
+            update(true);
-                this.cursors[i].style.opacity = "";
-            }
             blink();
-        }.bind(this), this.blinkInterval);
+        }, this.blinkInterval);
 
         blink();
     };