Chapter 1

iSmsMsg-
>SmsPDU().SetServiceCenterAddressL(KServiceCenterNumber);
// Convert data into unicode as CSmsBuffer will convert to
appropriate
// format for us.
TBuf buf;
buf.Copy(aData);
// Insert our SMS pattern header so that our receiver is able
to detect
// the incoming message, and then append the data.
smsBuffer->InsertL(0, KGdpSmsHeaderTag);
smsBuffer->InsertL(KGdpSmsPatternLen, buf);
iRetries = KGdpSmsSendRetries;
Reset();
ReEnterCurrentState(); // Kick us off again.
}
If we're already busy sending an SMS message, we simply give up on this new request and
return – it is up to the client to ensure we're not given more packets than we can cope with.
We create a CSmsBuffer object to contain the text contents of our message. CSmsBuffer
maintains the text content of the message in an array of TText objects, and provides
functions to modify the content.
We then create a CSmsMessage object. This object helps to hide the underlying complexity
of ensuring that the message is structured in the correct network format of an SMS
message. TSmsUserDataSettings allows us to specify that the message is stored in 7-bit
format. SMS supports both 7-bit and 8-bit data transport, but only 7-bit is universally
implemented, so that's what I've chosen to use here. SMS supports a maximum message
length of 160 7-bit characters.
aAddress contains the telephone number of the receiver. The only test we do with this
number is to see that it does not exceed a certain size.
Interestingly, CSmsMessage accepts a Unicode string for the address to which the SMS will
be sent, so we must convert the address from narrow text. We can do this by copying it into
a Unicode descriptor. We then set the service center number.
Before inserting aData into the CSmsBuffer object, we have to ensure that we first insert
the pattern that will enable the receiver to recognize the message as a GDP SMS message.
We then set up how many times we're going to retry sending if the first attempt fails and then
set the state machine going.
The first time a packet is sent, the current state (iState) will already be set to
TSendMsgState, so ReEnterCurrentState() will cause us to enter that state: