package tomo import "errors" import "git.tebibyte.media/sashakoshka/tomo/data" import "git.tebibyte.media/sashakoshka/tomo/theme" import "git.tebibyte.media/sashakoshka/tomo/config" import "git.tebibyte.media/sashakoshka/tomo/elements" // Backend represents a connection to a display server, or something similar. // It is capable of managing an event loop, and creating windows. type Backend interface { // Run runs the backend's event loop. It must block until the backend // experiences a fatal error, or Stop() is called. Run () (err error) // Stop stops the backend's event loop. Stop () // Do executes the specified callback within the main thread as soon as // possible. This method must be safe to call from other threads. Do (callback func ()) // NewWindow creates a new window with the specified width and height, // and returns a struct representing it that fulfills the Window // interface. NewWindow (width, height int) (window elements.Window, err error) // Copy puts data into the clipboard. Copy (data.Data) // Paste returns the data currently in the clipboard. Paste (accept []data.Mime) (data.Data) // SetTheme sets the theme of all open windows. SetTheme (theme.Theme) // SetConfig sets the configuration of all open windows. SetConfig (config.Config) } // BackendFactory represents a function capable of constructing a backend // struct. Any connections should be initialized within this function. If there // any errors encountered during this process, the function should immediately // stop, clean up any resources, and return an error. type BackendFactory func () (backend Backend, err error) // RegisterBackend registers a backend factory. When an application calls // tomo.Run(), the first registered backend that does not throw an error will be // used. func RegisterBackend (factory BackendFactory) { factories = append(factories, factory) } var factories []BackendFactory func instantiateBackend () (backend Backend, err error) { // find a suitable backend for _, factory := range factories { backend, err = factory() if err == nil && backend != nil { return } } // if none were found, but there was no error produced, produce an // error if err == nil { err = errors.New("no available backends") } return }