"address unknown" for tx inputs in txdetails on android

[pony-montana]

Hi, when I click to a tx to see the details of the inputs and the outputs, I see for most txs "address unknown" and "unknown amount" in the inputs. The outputs, instead, always shows correctly.

The only cases where the inputs shows correctly are for the address that belong to my wallet (so all the outgoing txs basically).

[SomberNight]

The difference between tx inputs and outputs here is that the transaction itself contains all data about the outputs, but not for the inputs. The inputs are only referred to by prevout, so to be able to display an "input address" or an "input amount", the parent/prev txs are also required.

When we have the prev tx, the input address/amount are displayed, otherwise "unknown" is shown. The prev txs should always be already available for "outgoing" txs (sends) but typically they are not available locally for "incoming" txs (receives).

The desktop Qt gui has the same behaviour, except there there is an opt-in option "Download missing data" (added in d83863c), which when enabled, missing prev txs are requested from the electrum server.

[pony-montana]

do you think would be a good option to add the "download missing data" function also on android? It would be a per tx switch or a global state that apply to all tx?