Receiving Information

An application receives information in two ways: solicited and unsolicited. Solicited information is requested by the application through a function call such as lineGetDevCaps or lineGetAddressCaps. Unsolicited information arrives in the form of messagespics/TAPI00090000.gifmost importantly call-state messages. Often, the two mechanisms are used together, as when an application receives a LINE_CALLSTATE message, after which it checks the information contained in the LINECALLINFO structure by calling lineGetCallInfo.

An application can call lineGetDevCaps to learn more about available lines. The application determines the names of the lines and the number of addresses on those lines. (An important factor in the configuration of lines and addresses is the way the service provider chooses to map lines and addresses. Though the application has no control over this mapping, it can determine the details of the mapping by calling functions such as lineGetDevCaps.) Later, using this information, the application could allow the user to choose which line (and address) to use for an outgoing call, restricting the lines it displays (in a dialog box, for example) to those that support a specific media mode. As an example, an application designed to be used only for faxing may choose to let the user select only lines that support fax transmission.

Call lineGetAddressCaps to obtain information for a given address. The application can use the names of the addresses to let the user choose them in a popup menu, but other information is also reported, such as whether caller-ID is supported, what kinds of call states can be produced, and how many active calls can exist on that address.

Software for developers
Delphi Components
.Net Components
Software for Android Developers
More information resources
Unix Manual Pages
Delphi Examples