datagrid scrolling question

Brian Milby brian at milby7.com
Sat Aug 4 19:18:32 EDT 2018


My question is why use the button? Loop through the data in the grid and make the tsnet call manually for each line. If the button is calling a script outside of the DG, then you can use the same call. Then you don’t have to do any of those things to figure out the name of the row group.
On Aug 4, 2018, 5:39 PM -0500, Douglas Ruisaard via use-livecode <use-livecode at lists.runrev.com>, wrote:
> I sent a badly constructed message with this content (more or less) a few days ago. I am re-posting it in the hope that anyone who tried to decipher those two messages will give this another consideration.
>
> So pardon the repeat, but I'm quite sure someone from this group can lend me a hand on this issue.
>
> Using LC v8.1.9 on Windows 7 pro
>
> Using a datagrid form, each row has 1 checkbox, 3 fields and 2 buttons.
>
> One of the buttons (the one I need assistance with), named "Query" calls the "tsnet" library to query a remote WiFi module (esp8266) which returns the status of one of its IO pins. Works like a charm on ALL rows, scrolled or not... because (I reckon) the button is actually *IN* the grid, so there's no issue with the group name (as will become clear in a moment).. it is always "me".
>
> I also want to "automate" the queries (there are 8 such wifi modules involved). So I have a button outside of the datagrid which selects each row of the populated datagrid in a "repeat" statement and sends a "mouseUp" message to the datagrid.
>
> What I discovered is that (apparently) I have to "manufacture" the group name of each row to which I want to send the "mouseUp" message. So as I progress through the populated rows of the grid the "pseudo" group name of each row basically becomes the row number along with a prefix of "Row Template"... i.e. row 1's group name/label is "Row Template 0001", row 2 is "Row Template 0002", etc.
>
> Great... but once the grid starts to scroll, strange things start to happen. The pseudo-group name will "wrap"... and where it wraps depends on the number of rows which are initially visible on the grid.
>
> For example, if there are 8 populated rows and the DataGrid is sized to only show 3 rows at a time, upon the initialization of the Datagrid, the "pseudo" Row templates groups are named:
>
> row 1: "Row Template 0001"
> row 2: "Row Template 0002"
> row 3: "Row Template 0003"
> row 4: "Row Template 0004"
> row 5: "Row Template 0005"
> row 6: "Row Template 0001"
> row 7: "Row Template 0002"
> row 8: "Row Template 0003"
>
> this is demonstrated by putting a "put me" in the Behavior Script within the MouseUp handler to which I am sending the "mouseUp" message in order to "process" that row's content... i.e.
>
> on mouseUp
> put me
> ...do something
> end mouseUp
>
> What is interesting (and confusing at the same time), if I use a specific "wrapping pattern" (such as the one described above) and mutually "wrap" the name of the group to which I am about to send the "mouseUp" message, it works! ... i.e. from within the button outside of the datagrid:
> ... (in this example, the serverList array holds the 8 wifi module names I need to query with tsnet)
>
> put "0000" into pad
> put 0 into q
> repeat with y = 1 to (the number of lines in the keys of serverList)
> set the dgHilitedLines of group "DataGrid 1" to y
> add 1 to q
> if q > 5 then put 1 into q
> put char 1 to (4 - length(q)) of pad & q into z
> put char 1 to (4 - length(y)) of pad & y into z
> put "Row Template " & z into z
> send "mouseUp" to button "Query" of group z
> end repeat
>
> THIS is confusing because, although I am sending the same message to what appears to be the same pseudo-group name, once the grid scrolls beyond row 5, LC manages to know that I am actually referencing another grid row than the one(s) with the same pseudo-group names.
>
> To scroll the grid, programatically, I used:
> set the dgHilitedLines of group "DataGrid 1" to y
> to accomplish this.
>
> I also tried the more "seemingly appropriate":
> dispatch "ScrollLineIntoView" to group "DataGrid 1" with pLine"
>
> but this command changes the highlight of one of my fields which I have customized to have red text in case of an error. Regardless, using either method for scrolling does NOT seem to have any effect on the wrapping of the pseudo group name.
>
> Since this "wrap-point" changes based on the "amount" of the datagrid I "expose", this doesn't lend itself to portable or supportable code.
>
> If I don't "wrap" my group names according to this sort of pattern, once my code reaches the 6th line (in my example), I get a:
> " ... Chunk: can't find background), char 1 " error ... because "Row Template 0006" does not exist... it is "Row Template 0001"
>
> No doubt I'm approaching this wrong but I'm trying to teach myself datagrids and it's a struggle for this old brain!
> Is there another method for sending a "mouseUp" to a button on a datagrid form row?
>
> Douglas Ruisaard
> Trilogy Software
> (250) 573-3935
>
>
>
> Douglas Ruisaard
> Trilogy Software
> (250) 573-3935
>
>
>
>
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