I'll try to post one for you.
Actually, with some of the changes in PowerApps, (there are still some issues with flexible height galleries), I had to change my approach, but what I've settled on seems to consistently work, regardless of the platform it was running on.
With the other approach (posted above), I later discovered the sizing would be different depending on whether it was run as an app in Chrome/Chromium or Edge, whether it was running the web development environment, or if running on iOS or Android.
I'm now using a rectangle object (either as a separator (height=1, Y=max height) or bounding rectangle (X=0, Y=0, height = max location of other controls) instead of the HTML. This seems to work much better now. I think the HTML approach differed between environments perhaps due to different assumptions those browsers/etc made about HTML spacing.
To use the "bounding rectangle" approach, I set the X and Y of the rectangle to 0, and then for Height do something like the following:
Max(
If( 'FFG - CTRL TEXT INPUT'.Visible, 'FFG - CTRL TEXT INPUT'.Y + 'FFG - CTRL TEXT INPUT'.Height, 0 ),
If( 'FFG - CTRL DATE'.Visible, 'FFG - CTRL DATE'.Y + 'FFG - CTRL DATE'.Height, 0 ),
If( 'FFG - CTRL DATE RANGE START'.Visible, 'FFG - CTRL DATE RANGE START'.Y + 'FFG - CTRL DATE RANGE START'.Height, 0 ),
If( 'FFG - CTRL DROPDOWN'.Visible, 'FFG - CTRL DROPDOWN'.Y + 'FFG - CTRL DROPDOWN'.Height, 0 ),
If( 'FFG - CTRL COMBOBOX'.Visible, 'FFG - CTRL COMBOBOX'.Y + 'FFG - CTRL COMBOBOX'.Height, 0 ),
If( 'FFG - CTRL CHECKBOX'.Visible, 'FFG - CTRL CHECKBOX'.Y + 'FFG - CTRL CHECKBOX'.Height, 0 ),
If( 'FFG - ERROR MSG Txt'.Visible, 'FFG - ERROR MSG Txt'.Y + 'FFG - ERROR MSG Txt'.Height, 0 ),
If( 'FFG - HEADER Txt'.Visible, 'FFG - HEADER Txt'.Y + 'FFG - HEADER Txt'.Height, 0 ),
If( 'FFG - textValue RESULT'.Visible, 'FFG - textValue RESULT'.Y + 'FFG - textValue RESULT'.Height, 0 ), // Should only be visible if Debug is enabled
/* Default */ 'FFG - NAME Txt'.Y + 'FFG - NAME Txt'.Height
) + 5
So in the above, my gallery is actually used to collect a user supplied range of filter criteria. This is done in a custom control (FlexibleFilterGallery), I created, and the above is a snippet from it. When using the control, it is passed in a table of "filter criteria" that specifies the type of control for the filter, the available values (for comboboxes, list boxes, drop downs), defaults, ranges (ie: start/end dates, numerical ranges, etc) that the control will use to provide the user the correct type of control, as well as limit options / validate user input.
The template includes all those controls (combos, LBs, checkboxes, text entry, date, date range, etc), but only the one specified by the specific record in the table is set to Visible.
BTW - you'll also notice the check for the 'FFG - ERROR MSG Txt'.Visible. This is only Visible if there was an error, and actually will increase the size of that cell to display the error message (ie: if for date range, end date is before start date) and once the error is corrected, the error message will then have Visible set to false, and thus the height of the cell will be reduced again automatically.
Thus, the code above with the If()s determine which one is visible, and then get its current Height - which depending on the control could be variable height (especially for text with autoheight set, etc).
So this grabs the Max position from each of the Visible controls (in some other uses there might be multiple that are visible), adds 5 to this, and sets it to the height of the rectangle. The flexible gallery control then correctly sizes itself, meaning that each record may be displayed in the gallery with a different height.
A slightly more complex way I use this is in a gallery or items (customer records) where each record may have multiple underlying records that I wish to display in the same template. While I could do this with nested galleries (a gallery contained in a gallery), instead I'm using an HTML text field (with an HTML table) that is set to autoheight for the sub record. (while this is not my specific use, consider this like a customer record, where perhaps the customer own multiple vehicles, so the "subrecord" is about the vehicles). Initially the HTML is hidden, unless the user clicks on the "Show Details" button, which will then cause it to be set to Visible, and thus PowerApps will recalculate the size of that record in the template dynamically - expanding it as necessary. You can show details of only the records you want which will only resize that one in the gallery accordingly. Some have only 0, 1, or many subrecords (ie: vehicles in my example) - so the size will differ based on the record itself (number of rows as well as size of that row).
Here I'm using the separator line approach (no difference in function, just visual appearance) with the HTML text set to autoheight. So the Y for the separator (which is the bottom most control in the template) is:
If( 'AT - Usage Details Html_1'.Visible,
'AT - Usage Details Html_1'.Y + 'AT - Usage Details Html_1'.Height,
'AT - Usage Details Html_1'.Y
) + 5
Works VERY well. Sorry if the explanation was confusing - was typing this up between morning meetings (have to run for one). Will see if I can post some screenshots later.
But hopefully the above gives you some ideas.
