Add org.freedesktop.Telepathy.Channel.Interface.LocalFile interface

Submitted by Guillaume Desmottes @gdesmott

Assigned to Telepathy bugs list

Link to original bug (#18527)

Description

We need a FileTransfer LocalFile interface for CM that can't implement the socket one because of the underlying IM library.

Such interface would depend on org.freedesktop.Telepathy.Channel.Type.FileTransfer.DRAFT and would have these 2 methods:

• ProvideLocalFile(v: path)
• AcceptLocalFile(v: path)

We should probably define a "LocalFilePath" new TP type as a variant which can be 's' if the path is in UTF-8 and 'ay' if it's not.

This interface would also have a "LocalFileOnly" boolean property set to TRUE.

Clients would be able to detect if a CM support this interface by looking at RequestableChannelClasses:

• if the CM implements just the 'normal' FT mode: {ChannelType: FileTransfer}
• if the CM doesn't support Socket FT: {ChannelType: FileTransfer, LocalFileOnly: True}
• if the CM implements both it announces the 2 channel classes above.