backend/internal/system/canvasbox.go

package system

import "git.tebibyte.media/tomo/tomo"
import "git.tebibyte.media/tomo/tomo/canvas"

type canvasBox struct {
	*box
	userDrawer canvas.Drawer
}

func (this *System) NewCanvasBox () tomo.CanvasBox {
	box := &canvasBox { }
	box.box = this.newBox(box)
	box.drawer = box
	return box
}

func (this *canvasBox) Box () tomo.Box {
	return this
}

func (this *canvasBox) SetDrawer (drawer canvas.Drawer) {
	this.userDrawer = drawer
	this.invalidateDraw()
}

func (this *canvasBox) Invalidate () {
	this.invalidateDraw()
}

func (this *canvasBox) Draw (can canvas.Canvas) {
	this.box.Draw(can)
	if this.userDrawer != nil {
		this.userDrawer.Draw (
			can.SubCanvas(this.padding.Apply(this.innerClippingBounds)))
	}
}