Some experiences of broadcast and command in powerplant

Lbroadcaster and llistener are paired. messages can be obtained and processed from classes inherited by llistener. Classes inherited from lbroadcaster can
To broadcast messages. Therefore, the view class can be inherited from the llistener, the control class on the view can be inherited from the lbroadcaster, and then the control
Addlistener goes to view, so that when the control has a message, it can be processed in listentomesseng of llistener.

Lcommander is a class used to process the menu interface. when processing a menu, findcommandstatus can be used to set the menu status. You can use processcommand to send commands, and then accept and process the commands in obeycommand. However, this can also be used outside the menu.