Generated columns are not rendered for few rows somtimes


I have developed a app using vaadin. We are showing a search result in a table ( with LCQ container) and we have one generated column which will show a popupbutton and on click of it, it will open a context menu with 4 other buttons to do various actions.

Today i faces a strange issue that for some of the rows the popupbutton (generatedcolumn) is not rendered at all. the column is just empty. No exceptions are thrown in the back end.

i have a attached a snapshot of the UI. Next week we are planning for a production release. Could anyone help me to solve this?
11822.bmp (2.72 MB)

What does Firebug say about the empty table cells? Does the problem appear with a different browser? Does the generator really work for those items (add some debug logging or System.out.println lines in the generator)?

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Hi Thanks for the quick reply. when i examined using IE developer tool bar those cells are empty. The problem occurs in FF as well. Unfortunately i haven’t installed firbug. So i couldn’t verify. This issue occurs when the scrolling is done in a fast manner and also when it takes more time to return the search result. I have attached attached the snapshots of the issue taken from IE.
11842.bmp (1.9 MB)


Have you tried to replace generated PopupButtons with normal Buttons to see if the problem is in PopupButton. If you open a debug window by adding ?debug to the URL, do you get any exceptions to the debug window when empty columns get rendered?


Hi Henri,

The issue occurs while using normal buttons also. I paid more attention and found that it occurs only when the scrolling is done using the mouse center wheel to scroll fast which results in a server event for every rotation. when we scroll fast so many server side calls occur for fetching the next pages. I assume once all the server side events respond asynchronously, the client engine is not able to render properly.