gui_plan

-Planned-
Interface to Gui

	-> Basic primitives and layer handling (via groups.py and primitives.py)
		- Objects for groups and basic primitives
		- Design class containing primitives and design information
		- Groups are determined after the fact, objects are not to be sorted initially
	
	-> Open Design (via default `importer` class)
		- Supported formats list
			- GLIF native format

		- Open design function
		
	-> Save Design (via default `exporter` class)
		- Supported formats list
			- GLIF native format
			
		- Open file function
		
	-> Import (via `importer` base class)
		- Supported formats list
			- Gerber RS-274X
			- gEDA Netlist file
			- (contrib/optional) gEDA Schematic
			- (contrib/optional) PCB format
			- (contrib/optional) Others such as EagleXML and Kicad via contributed scripts.
			
		- Import design function
	
	-> Export (via `exporter` base class)
		- Supported formats list
			- Gerber RS-274X
			- (optional) PCB format
			- (optional) gEDA Netlist file
			- (optional) Others such as EagleXML and Kicad via contributed scripts.
			
		- Export design function
		
Library support (via `library` base class)
	- Read
		- GLIF native format
		- PCB footprint
		- EagleXML library
		
	- Write
		- GLIF native format
		- PCB footprint (contrib/optional)
		- EagleXML library (contrib/optional)
	

Class Hierarchy

	importer	-> importer_glif
			-> importer_rs274
			-> importer_geda_net
			-> importer_geda_pcb (contrib/optional)
			-> importer_eagle_xml (contrib/optional)
			-> importer_kicad (contrib/optional)
	
	exporter	-> exporter_glif
			-> exporter_rs274
			-> exporter_geda_net
			-> exporter_geda_pcb (contrib/optional)
			-> exporter_eagle_xml (contrib/optional)
			-> exporter_kicad (contrib/optional)

	group	-> pin
			- Net
			- Pin number
			- Pin name
			
		-> footprint
			- At least one pin is expected to be among the various graphical elements in the group
			- `Flipped?` For simplicity, a footprint may only be on the top or the bottom