custom_widget.go

package main

// An attempt to figure out the minimum boilplate needed for implementing a
// widget in Ebitenui

import (
	"image"
	"image/color"

	"github.com/ebitenui/ebitenui/widget"
	"github.com/hajimehoshi/ebiten/v2"
	"github.com/hajimehoshi/ebiten/v2/vector"
)

type CustomWidget struct {
	widget *widget.Widget

	init *widget.MultiOnce
}

type CustomWidgetOpt func(o *CustomWidget)

type CustomWidgetOptions struct {
}

var CustomWidgetOpts CustomWidgetOptions

func (o *CustomWidget) createWidget() {
	o.widget = widget.NewWidget()
}

func (o *CustomWidget) Render(screen *ebiten.Image, def widget.DeferredRenderFunc) {
	vector.DrawFilledCircle(screen, 15+float32(o.widget.Rect.Min.X), 15+float32(o.widget.Rect.Min.Y), 5, color.White, false)
}

func NewCustomWidget(opts ...CustomWidgetOpt) *CustomWidget {
	obj := &CustomWidget{
		init: &widget.MultiOnce{},
	}

	obj.init.Append(obj.createWidget)

	for _, opt := range opts {
		opt(obj)
	}

	return obj
}

// GetWidget implements widget.PreferredSizeLocateableWidget.
func (o *CustomWidget) GetWidget() *widget.Widget {
	o.init.Do()
	return o.widget
}

// PreferredSize implements widget.PreferredSizeLocateableWidget.
func (o *CustomWidget) PreferredSize() (int, int) {
	o.init.Do()

	return ebiten.WindowSize()
}

// SetLocation implements widget.PreferredSizeLocateableWidget.
func (o *CustomWidget) SetLocation(rect image.Rectangle) {
	o.init.Do()
	o.widget.SetLocation(rect)
}