We did something similar with colleague, some time ago, not in 4D, but idea would be similar:
1. we initialised arrays to proper size (amount of data was know beforehand). At that moment, user would see an area with empty lines 2. we run a process that calculated the lines and updated arrays and area. 3. as a optimisation, we did not calculated all lines, only a small part (256?) so the area would display something immediately. When the user scrolled down, process started to calculate lines from scroll position. Implementing it in 4D would be quite straightforward: process that display LB wold initialise empty arrays and will launch process or worker that calculates values. Worker then calls CALL FORM periodically with values - per line or group of lines - and called method inserts calculated values into displayed arrays. 4D would handle the update of LB, process with LB would not be frozen and user would be able to see how are the values filling the area. Using workers would allow implementation of point 3. quite straightforward, but it may not be necessary. As a first step, I would let worker calculate all lines. Only if calculation takes too long (minutes) I would try to adjust worker call so it calculates only displayed lines. HTH, Peter Bozek On Sun, Mar 8, 2020 at 7:38 PM John J Foster via 4D_Tech < 4d_tech@lists.4d.com> wrote: > Hi All, > > 4D v17 R5 (Mac and Windows single user standalone) > > I have a list box that needs to be built and available before the > calculation is complete. In this case I have some searches looking for > particular conditions and when found add them to the listbox. They could > easily take a few seconds to I’m guessing a minute or more. The searching > could span 50-60 sub searches within a 100 years of daily data (Think daily > stock market data but it’s not for the stock market). > > So I would like a strategy: > > - so that list box remains available as it’s being built. > > - the screen is not frozen as it’s being built. > > - The list box fills as each row is found/added and can be seen > rebuilding. > > I’ve seen this kind of thing in a windows app (not 4D) and I’d like to > emulate the behavior. > > I need a strategy I’m guessing that involves another process which knows > how to communicate back to this form/listbox. Is this where workers could > be helpful? > > Does anyone have some snippets of code I could see to visualize the > process? > > Appreciate, > John… > > > ********************************************************************** > 4D Internet Users Group (4D iNUG) > Archive: http://lists.4d.com/archives.html > Options: https://lists.4d.com/mailman/options/4d_tech > Unsub: mailto:4d_tech-unsubscr...@lists.4d.com > ********************************************************************** -- -- Peter Bozek ********************************************************************** 4D Internet Users Group (4D iNUG) Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:4d_tech-unsubscr...@lists.4d.com **********************************************************************
