base

type Control interface {
	// Traverse is register sub controls to FocusManager by the order by focus.
	Traverse(fm *FocusManager)

	// Update is prepare for draw to terminal.
	Update()

	// Draw is rendering Control as text, to terminal.
	Draw(g *Graphics)

	// MinimumSize is provide size of needs to print Control.
	MinimumSize(width int, height int) (Width int, Height int)

	// Move is move a Control to specified position.
	Move(x int, y int)

	// Layout is relayout sub controls within specified size.
	Layout(w int, h int)

	// IsFlexibleWidth is returns true if Control is flexible on horizontal.
	IsFlexibleWidth() bool

	// IsFlexibleHeight is returns true if Control is flexible on vertical.
	IsFlexibleHeight() bool
}

type Event struct {
	// contains filtered or unexported fields
}

type FocusManager struct {
	// contains filtered or unexported fields
}

type Focusable interface {
	Handle(ev Event)
	Focus(on bool)
}

type FocusableTree interface {
	Focusable

	// SubFocusFirst is focus to first children.
	SubFocusFirst()

	// SubFocusPrev is focus to previous children.
	SubFocusPrev() bool

	// SubFocusNext is focus to next children.
	SubFocusNext() bool

	// SubFocusLast is focus to last children.
	SubFocusLast()
}

type Graphics struct {
	// contains filtered or unexported fields
}

type Layer struct {
	Control         Control
	ClearBackground bool
	OnPop           func(returnCode int)
}

type Runtime interface {
	Stackable

	// BeginBackground is increment number of background tasks.
	// Runtime is ignore events while zero than bigger of number of background tasks.
	BeginBackground()

	// EndBackground is decrement number of background tasks.
	EndBackground()

	// Repaint is do request rerender terminal.
	Repaint()
}

type Stackable interface {
	// Push is stack a layer.
	Push(layer Layer)

	// Pop is remove layer from stack top.
	Pop(returnCode int)
}