Canvas Limited to 32767

Richard Gaskin ambassador at
Tue Oct 6 14:50:08 EDT 2020

Glad it's not the funky mobile field workaround.  That's such a horrible 
experience for developers that even the act of documenting it should 
have been a red flag to go back and refine the field buffering for the 
few cases where that put-it-in-a-group recommendation is actually needed.

In your case, you have a huuuuuuge canvas, with users expected to scroll 
a region about 32 feet.  That's a lot of scrolling.

So in addition to the memory hit of buffering such a large region (32767 
* 32767 * 4 + whatever other overhead comes into play with buffering), 
in most layouts it would be a usability impairment to ask users to keep 
scrolling that much.

So maybe the team could switch the address from 32 to 64, but it still 
leave us with the question:

- Would a user have that much RAM?

- Would the user be able to use such a large canvas without acquiring
   RSI? ;)

I don't know your layout, but I do know you, and you're not the type to 
make things hard for users, so I'm assuming there's something about this 
uncommonly-large scrolling that fits well with the app's requirements.

But what we do know is no monitor can show it all, so the content is 
already effectively paged into view as-needed.

Could the content paging be provided through some other UI? For example, 
if those controls fit into logical groupings, might different sets of 
them be placed into separate physical groups, perhaps accessed via tabs 
or a list?

If it's truly necessary to have one vast plane to hold everything, could 
you handle paging internally while still providing the appearance of a 
contiguous group, similar to how the DataGrid does it?

  Richard Gaskin
  Fourth World Systems

Ralph DiMola wrote:
 > Desktop and mobile. It's a scrolling group with many sub-groups each
 > with 1 or more fields. Sometimes the height of the main group > 32767.
 > It's the result of a proximity search and in dense areas users are
 > getting hosed by this limit. Customer is screaming (but don't they
 > always).
 > Ralph DiMola
 > IT Director

-----Original Message-----
From: use-livecode [mailto:use-livecode-bounces at] On 
Of Richard Gaskin via use-livecode

Ralph DiMola wrote:

 > I just ran head first into this. Could someone explain why other than 
   > moving from an int16 to an int32 this is such a challenge? This 
should  > have been addressed during the refactoring of the engine.

Is this for the weird recommended mobile workaround of putting a text 
field into a group just to have it scroll, or something else?

   Richard Gaskin
   Fourth World Systems

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