Requirement Description

In current model design, no matter changing style or data, zss model will send a model event to notify spreadsheet about range of content change. It doesn't differentiate between data and style. (refer to ModelUpdateWrapper.doNotify() inside org.zkoss.zss.range.impl.RangeImpl) Therefore, CellOpertaionUtil.applyBorder() and range.setCellStyle() both trigger a model event.

If users have custom formulas that retrieve data from a database, and they might not be re-evaluated all the time. The re-evaluation triggered by changing a style will cause a problem. Hence, The benefits of changing style doesn't trigger recalculation of a formula:

• avoid formula calculation effort for a style change