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I have a page with about 500 elements, that support drag/drop. When I start dragging any element in Internet Explorer (6 or 7), it takes approximately 1 minute before the drag outline appears. Same page when loaded in Firefox takes about a second to start drag. When the element count is around 100 same action in IE takes about 3-4 seconds.
I am using BB 4.2.1 optimized without the debugger.
How do I go about finding out the cause of the delay in IE?
More On Performance Root Cause
22 July, 2008 - 01:42 — risalaWell, since I could not get any help from Backbase, it was back to good ol tracing. Turns out in dragAndDrop.xml there is a block of code
btl.drag._savedStyle = bb.html.addStyle('html * {...}')that applies to all elements in the document. Internet Explorer takes good number of seconds to process the style changes. As the number of elements grow, this gets progessively worse. The style change is a neat feature where the cursor indicates no drop but the implementation has to change!
For a quick solution, just comment out the code. You won't get the cursor effect but the performance is great! If you want the cursor effect you may be able to get it by handling dragOver and dragLeave events yourself.
Thank You
22 July, 2008 - 16:18 — nbeverThank you risala for your post and fix tips. We're seeing the same problem on our application and it was making some people pretty nervous since the crux of our user experience is D&D. I really appreciate the time you took to find the issue and post a quick fix.
-Nate
Thank you for reporting /
22 July, 2008 - 08:57 — SjoerdThank you for reporting / finding the issue, i have added it to our bug tracking system to make sure it gets picked up in a future release.
computer specs
22 July, 2008 - 16:40 — tordonarisala and nate, could you post the specs of your development/test machines? I'd like to get some basic references with regards to the performance. thanks.