components.go

package rty

import (
	"math"

	"github.com/gdamore/tcell"
)

// Components are able to render themselves onto a screen

type RTY interface {
	Render(c Component)

	// Register must be called before Render
	RegisterElementScroll(name string, children []string) (l *ElementScrollLayout, selectedChild string)

	// *Scroller must be called after Render (each call to Render invalidates previous Crollers)
	ElementScroller(name string) ElementScroller
	TextScroller(name string) TextScroller
}

type ElementScroller interface {
	Up()
	Down()
	Top()
	Bottom()
	GetSelectedIndex() int
}

type TextScroller interface {
	Up()
	Down()
	Top()
	Bottom()

	ToggleFollow()
	SetFollow(following bool)
}

// Component renders onto a canvas
type Component interface {
	Size(availWidth, availHeight int) (int, int, error)
	Render(w Writer, width, height int) error
}

type Writer interface {
	SetContent(x int, y int, mainc rune, combc []rune)

	Divide(x, y, width, height int) (Writer, error)
	Foreground(c tcell.Color) Writer
	Background(c tcell.Color) Writer
	Invert() Writer
	Fill() (Writer, error)

	RenderChild(c Component) int

	RenderChildInTemp(c Component) Canvas
	Embed(src Canvas, srcY, srcHeight int) error

	RenderStateful(c StatefulComponent, name string)
}

const GROW = math.MaxInt32