Interface Widget

widgetapi/widgetapi.go:165–202

Widget is a single widget on the dashboard. Implementations must be thread safe.

// Widget is a single widget on the dashboard.
// Implementations must be thread safe.
type Widget interface {
	// When the infrastructure calls Draw(), the widget must block on the call
	// until it finishes drawing onto the provided canvas. When given the
	// canvas, the widget must first determine its size by calling
	// Canvas.Size(), then limit all its drawing to this area.
	//
	// The widget must not assume that the size of the canvas or its content
	// remains the same between calls.
	//
	// The argument meta is guaranteed to be valid (i.e. non-nil).
	Draw(cvs *canvas.Canvas, meta *Meta) error

	// Keyboard is called with every keyboard event whose scope the widget
	// registered for.
	//
	// The argument meta is guaranteed to be valid (i.e. non-nil).
	Keyboard(k *terminalapi.Keyboard, meta *EventMeta) error

	// Mouse is called with every mouse event whose scope the widget registered
	// for.
	//
	// The argument meta is guaranteed to be valid (i.e. non-nil).
	Mouse(m *terminalapi.Mouse, meta *EventMeta) error

	// Options returns registration options for the widget.
	// This is how the widget indicates to the infrastructure whether it is
	// interested in keyboard or mouse shortcuts, what is its minimum canvas
	// size, etc.
	//
	// Most widgets will return statically compiled options (minimum and
	// maximum size, etc.). If the returned options depend on the runtime state
	// of the widget (e.g. the user data provided to the widget), the widget
	// must protect against a case where the infrastructure calls the Draw
	// method with a canvas that doesn't meet the requested options. This is
	// because the data in the widget might change between calls to Options and
	// Draw.
	Options() Options
}