Execute action upon listbox column resizing

The event On Column Resize is now triggered “live” during the resizing of the list boxes as long as the user modifies the column widths (previously, it was generated only once, at the end of the resizing).

Thanks to this feature, 4D programmers will have the opportunity to create live and responsive interfaces based on the actual width of columns!


When a column contains dates, the date format can be modified as the column is resized. So the date can be displayed first as “05/12/16” then “Dec. 05 2016” then “December 5th 2006” as the column width increases.

If a column contains huge numbers, they can be displayed first as “123465789” then as “123,456,789” (with the thousand separator) then as “123,456,789.55” (with the decimal part) then as “123,456,789.55 $” (with the unit).

A time column can be displayed with or without seconds, and so on.

In all these case, the only thing you have to do is to change the format of the column according to it’s width and the type of data it contains !

Here is a video that will show you an example of the way it works :

We also invite you to have a look at the Example Database.

For more details, please refer to the “Events, Objects and Properties” section from the “Form event” article in 4D v16 documentation.

Roland Lannuzel
• Product Owner & 4D Expert •After studying electronics, Roland went into industrial IT as a developer and consultant, building solutions for customers with a variety of databases and technologies. In the late 80’s he fell in love with 4D and has used it in writing business applications that include accounting, billing and email systems.Eventually joining the company in 1997, Roland’s valuable contributions include designing specifications, testing tools, demos as well as training and speaking to the 4D community at many conferences. He continues to actively shape the future of 4D by defining new features and database development tools.