Is every thing need to be set in the Build(context *guigui.Context, adder *guigui.ChildAdder) error function every time

[udan-jayanith]

If i have a popup and a button that show the popup when the button is clicked, I would normally listn for button click and on that listner, OnClose function is set for popup.
Example:

// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: 2026 The Guigui Authors

package main

import (
	"fmt"
	"image"
	"os"

	"github.com/hajimehoshi/ebiten/v2"

	"github.com/guigui-gui/guigui"
	"github.com/guigui-gui/guigui/basicwidget"
)

type Root struct {
	guigui.DefaultWidget

	background basicwidget.Background

	popup      basicwidget.Popup
	show_popup basicwidget.Button
}

func (r *Root) Build(context *guigui.Context, adder *guigui.ChildAdder) error {
	adder.AddWidget(&r.background)

	if r.popup.IsOpen() {
		adder.AddWidget(&r.popup)
	}

	r.show_popup.SetText("Show popup")
	r.show_popup.OnDown(func(context *guigui.Context) {
		r.popup.SetModal(true)
		r.popup.SetCloseByClickingOutside(true)
		r.popup.SetBackgroundDark(true)
		r.popup.SetBackgroundBlurred(true)
		r.popup.OnClose(func(context *guigui.Context, reason basicwidget.PopupCloseReason)      {
			println("Popup closed")
		})
		r.popup.SetOpen(true)
	})
	adder.AddWidget(&r.show_popup)
	return nil
}

func (r *Root) Layout(context *guigui.Context, widgetBounds *guigui.WidgetBounds, layouter *guigui.ChildLayouter) {
	bounds := widgetBounds.Bounds()
	layouter.LayoutWidget(&r.background, bounds)

	if r.popup.IsOpen() {
		b := bounds
		w := 200
		h := 200
		b.Min.X += b.Dx()/2 - w/2
		b.Max.X = b.Min.X + w
		
		b.Min.Y += b.Dy()/2 - h/2
		b.Max.Y = b.Min.Y + h
		layouter.LayoutWidget(&r.popup, b)
	}
	layouter.LayoutWidget(&r.show_popup, bounds)
}

func main() {
	op := &guigui.RunOptions{
		Title:         "Popup",
		WindowMinSize: image.Pt(600, 400),
		RunGameOptions: &ebiten.RunGameOptions{
			ApplePressAndHoldEnabled: true,
		},
	}
	if err := guigui.Run(&Root{}, op); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}

Is that the right way or
need to run

r.popup.SetModal(true)
		r.popup.SetCloseByClickingOutside(true)
		r.popup.SetBackgroundDark(true)
		r.popup.SetBackgroundBlurred(true)
		r.popup.OnClose(func(context *guigui.Context, reason basicwidget.PopupCloseReason)      {
			println("Popup closed")
		})

in every build.

[udan-jayanith]

Note: OnClose function need to be set for popup in every build when the popup is opened otherwise OnClose function dosen't run. Is this a bug. If popup.SetOpen(true) runs in every build, popup gives a flickering effect.

[hajimehoshi]

	r.show_popup.SetText("Show popup")
	r.show_popup.OnDown(func(context *guigui.Context) {
		r.popup.SetModal(true)
		r.popup.SetCloseByClickingOutside(true)
		r.popup.SetBackgroundDark(true)
		r.popup.SetBackgroundBlurred(true)
		r.popup.OnClose(func(context *guigui.Context, reason basicwidget.PopupCloseReason)      {
			println("Popup closed")
		})
		r.popup.SetOpen(true)
	})

Not correct. This should be

	r.show_popup.SetText("Show popup")
	r.show_popup.OnDown(func(context *guigui.Context) {
		r.popup.SetOpen(true)
	})

	r.popup.SetModal(true)
	r.popup.SetCloseByClickingOutside(true)
	r.popup.SetBackgroundDark(true)
	r.popup.SetBackgroundBlurred(true)
	r.popup.OnClose(func(context *guigui.Context, reason basicwidget.PopupCloseReason)      {
		println("Popup closed")
	})

though I might be missing something.