Hello, thanks for a very in depth request description! It also came at a great point in time, as we're just working on the trade listing for the next release these days, and we've played around with various UI versions of the card listing.
I will start by acknowledging the reason for cancellation idea as cool. It's on the list now, probably not for this release, but for the next one. Secondly, I'd like to ask you to clarify what the adjust wishlist and tradelist mean in your flow description, i'm not 100% sure I get it right.
On to the cool part: the listing. The current version of our in-development listing on the trade page looks something like this:
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Cards are separated based on their details, so I have here added an "Alpha, German, Played Lightning Bolt" and an "M11 English Foil near mint Lightning Bolt" to this trade.
The counts on the left have tooltips explaining what they represent, but since there's no tooltips in a screenshot, I'll summarise
. In green is the editable number of cards you intend to trade. Then follow the number in your inventory, your tradelist and the other person's wishlist. (it's 0 all the way, ignore that, normally it would show matching numbers there).
The red background cells are highlighted because you have 1 Aethersnipe from Commander in this trade, but none in your inventory. And here comes in a problem we still have with this listing. While you dont' have that exact type of Aethersnipe, you do have some Athersnipes with no specified edition, and a couple (not visible here) from Lorwyn.
We still have to find a way to enable you to see this information (all other aethersnipes you have in your inv/tradelist) and edit your traded counts quickly to show that you actually want to trade a Lorwyn Aethersnipe.
You could of course just put 0 instead of 1 in the count and then add your Lorwyn Aethersnipe with the autocompleted input above, but that is slow and awkward. I'm currently leaning in favor of somehow providing a button that would expand the listing adding your other Aethersnipes here, even if they have a 0 in the for trade count. You could then edit everything to the desired counts.
Lastly, to address your suggested "pending in-trade" counts, I can see why it would be a very useful information, but I'm a bit unsure if we can add many more other count columns to this listing without making it very confusing. We'll try out some things, but I'm a little skeptical. Maybe we find another way to show that info (in a "more information" tooltip somewhere maybe....).
I'm aware my previous description, with no actual website to click on might be a bit hard to read, and also that the listing might end up too confusing, which is what we're trying to avoid
. Let us know what you think. We'll post more info as we go along.
Thank you very much for your feedback and interest!