The SMS protocol does not support sending a message longer than 160 characters. Android's SmsManager.sendTextMessage(..) fails to send in case the message is too long.
Instead of failing, check the message length. If it is longer than 160 characters, break it up and send it as several messages
On receive, collect the list of messages, then combine their bodies
Send a long message via KDE Connect and verify that it is actually sent
Send a short message via KDE Connect and verify that it can also be sent
Ideally: Test sending a message which is the maximum length for an SMS (160 characters) and verify that it is sent as exactly one SMS (And billed properly)
Receive a long message and verify that it is delivered as a single long message, even though we all know that it was transmitted as a multi-part SMS
Receive a short message and verify that it is correctly delivered
| Automatic diff as part of commit; lint not applicable. |
| Automatic diff as part of commit; unit tests not applicable. |
Thanks for the patch! This was something really missing in KDE Connect :)
If you fix the small issue I commented inline, the rest looks good to me.
| src/org/kde/kdeconnect/Plugins/TelepathyPlugin/TelepathyPlugin.java | ||
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| 71 | SMS lenght is more difficult to calculate than just checking the length of the string: it depends on the encoding used and the size of each specific character in that encoding (see [1]). Luckily enough, looks like there is a really easy solution. We can just always call smsManager.divideMessage and then smsManager.sendMultipartTextMessage regardless of the size and number of parts. Viewing the source code from Android [2], it looks like sendMultipartTextMessage handles correctly the case of short SMS that fit in a single message. [1] https://messente.com/documentation/tools/sms-length-calculator | |
Oops. Hold everything. I just realized you linked me to the SmsManager source, not the default messanging app. I need to learn to read more carefully! Let me amend the commit to not bother checking, since SmsManager is doing that for us.
I'm glad you knew to look for that -- That would have been a real nasty bug to find. But not for me, since I don't have an easy way to type non-ascii characters :)
One thing I was worried about is messages which are 160 bytes long -- Since the multi-part SMS protocol adds a header, this might get sent as two -- Happily, Android's SmsManager.divideMessage does correctly account for this as far as I can tell from looking at my bill, and a 160 byte message is "divided" into a single 160 byte message.