Changeset 53167 in webkit

Timestamp:

Jan 12, 2010 3:34:20 PM (14 years ago)

Author:

eric@webkit.org

Message:

2010-01-12 Alexander Pavlov <​apavlov@chromium.org>

Reviewed by Timothy Hatcher.

Optimize WebInspector.TimelineGrid.prototype.updateDividers()

DOM element property access and modification are slow and should be done as lazily as possible.
​https://bugs.webkit.org/show_bug.cgi?id=33536

• inspector/front-end/TimelineGrid.js: (WebInspector.TimelineGrid.prototype.updateDividers): (WebInspector.TimelineGrid.prototype._setDividerAndBarLeft):

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• inspector/front-end/TimelineGrid.js (modified) (5 diffs)

trunk/WebCore/ChangeLog

@@ +1 @@
+2010-01-12  Alexander Pavlov  <apavlov@chromium.org>
+
+        Reviewed by Timothy Hatcher.
+
+        Optimize WebInspector.TimelineGrid.prototype.updateDividers()
+
+        DOM element property access and modification are slow and should be done as lazily as possible.
+        https://bugs.webkit.org/show_bug.cgi?id=33536
+
+        * inspector/front-end/TimelineGrid.js:
+        (WebInspector.TimelineGrid.prototype.updateDividers):
+        (WebInspector.TimelineGrid.prototype._setDividerAndBarLeft):
+
 2010-01-12  Beth Dakin  <bdakin@apple.com>
 

trunk/WebCore/inspector/front-end/TimelineGrid.js

@@ -63 +63 @@
             return false;
 
-        if (!(typeof paddingLeft === "number"))
+        if (typeof paddingLeft !== "number")
             paddingLeft = 0;
         this._currentDividerSlice = slice;
@@ -72 +72 @@
         var dividerLabelBar = this._dividersLabelBarElement.firstChild;
 
-        var clientWidth = this._dividersLabelBarElement.clientWidth - paddingLeft;
+        var dividersLabelBarElementClientWidth = this._dividersLabelBarElement.clientWidth;
+        var clientWidth = dividersLabelBarElementClientWidth - paddingLeft;
         for (var i = paddingLeft ? 0 : 1; i <= dividerCount; ++i) {
             if (!divider) {
@@ -86 +87 @@
                 dividerLabelBar.appendChild(label);
                 this._dividersLabelBarElement.appendChild(dividerLabelBar);
+                dividersLabelBarElementClientWidth = this._dividersLabelBarElement.clientWidth;
             }
 
@@ -94 +96 @@
 
             var left = paddingLeft + clientWidth * (i / dividerCount);
-            var percentLeft = 100 * left / this._dividersLabelBarElement.clientWidth + "%";
-            divider.style.left = percentLeft;
-            dividerLabelBar.style.left = percentLeft;
+            var percentLeft = 100 * left / dividersLabelBarElementClientWidth;
+            this._setDividerAndBarLeft(divider, dividerLabelBar, percentLeft);
 
             if (!isNaN(slice))
@@ -119 +120 @@
     },
 
+    _setDividerAndBarLeft: function(divider, dividerLabelBar, percentLeft)
+    {
+        var percentStyleLeft = parseFloat(divider.style.left);
+        if (!isNaN(percentStyleLeft) && Math.abs(percentStyleLeft - percentLeft) < 0.1)
+            return;
+        divider.style.left = percentLeft + "%";
+        dividerLabelBar.style.left = percentLeft + "%";
+    },
+
     addEventDivider: function(divider)
     {