navigation

type Config struct {
	// Key binding.
	Binding cli.Handler
	// Underlying filesystem.
	Cursor Cursor
	// A function that returns the relative weights of the widths of the 3
	// columns. If unspecified, the ratio is 1:3:4.
	WidthRatio func() [3]int
}

type Cursor interface {
	// Current returns a File that represents the current directory.
	Current() (File, error)
	// Parent returns a File that represents the parent directory. It may return
	// nil if the current directory is the root of the filesystem.
	Parent() (File, error)
	// Ascend navigates to the parent directory.
	Ascend() error
	// Descend navigates to the named child directory.
	Descend(name string) error
}

type File interface {
	// Name returns the name of the file.
	Name() string
	// ShowName returns a styled filename.
	ShowName() ui.Text
	// IsDirDeep returns whether the file is itself a directory or a symlink to
	// a directory.
	IsDirDeep() bool
	// Read returns either a list of File's if the File represents a directory,
	// a (possibly incomplete) slice of bytes if the File represents a normal
	// file, or an error if the File cannot be read.
	Read() ([]File, []byte, error)
}