package tui

// View defines the behavior of any element displayable on screen.
// To define custom Views, it is recommended to add ViewTmpl
// as the promoted anonymous field for your custom View struct.
// It implements the View interface with useful default behavior
type View interface {
	Events

	SetStyle(s Style)
	Style() Style

	// Layout is usually called by the parent view to ask the view's preferred size.
	// If the parent view does not care about its preferred size, it might not be called at all.
	// Negative values indicate as much space as possible.
	Layout() (prefWidth, prefHeight int)

	// Draw is called for each view when it should print itself onto the screen.
	// The parent view has full control of the ViewBuffer size
	// and may or may not use the values returned from Layout() to set the size.
	Draw(buf *ViewBuffer)
}

// Group defines the behavior of a View which can hold multiple sub views
type Group interface {
	View

	Views() []View
}

// Wrapper defines the behavior of a GroupView which can hold exactly one sub view.
// To define custom Wrappers, it is recommended to add WrapperTmpl
// as the promoted anonymous field for your custom Wrapper struct.
// It implements the Wrapper interface with useful default behavior
type Wrapper interface {
	Group

	SetView(View)
	View() View
}