using System;
using System.Diagnostics;
using System.Drawing;
using System.Linq.Expressions;

namespace Graphics
{
    public partial class Form1 : Form
    {
        Color background = Color.FromArgb(0, 39, 104);
        Color stripes = Color.FromArgb(250, 204, 8);

        float size = 20;
        int startX = 100;
        int startY = 100;

        public Form1()
        {
            InitializeComponent();
            numericUpDown1.Value = (decimal)size; // init size
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);
            var g = e.Graphics;

            SolidBrush solidBrush = new SolidBrush(background);

            // background
            g.FillRectangle(
                solidBrush,
                startX,
                startY,
                16 * size, // x size
                10 * size // y size
            );

            solidBrush.Color = stripes;

            // horizontal stripe
            g.FillRectangle(
                 solidBrush,
                 startX,
                 startY + 4 * size, // y offset
                 16 * size, // x size
                 2 * size // y size
             );

            // vertical stripe
            g.FillRectangle(
                solidBrush,
                startX + 5 * size, // x offset
                startY,
                2 * size, // x size
                10 * size // y size
            );
        }

        private void btn_sverige_Click(object sender, EventArgs e)
        {
            background = Color.FromArgb(0, 39, 104);
            stripes = Color.FromArgb(250, 204, 8);
            Invalidate();
        }

        private void btn_danmark_Click(object sender, EventArgs e)
        {
            background = Color.FromArgb(198, 12, 48);
            stripes = Color.FromArgb(255, 255, 255);
            Invalidate();
        }

        private void btn_finland_Click(object sender, EventArgs e)
        {
            background = Color.FromArgb(255, 255, 255);
            stripes = Color.FromArgb(0, 53, 128);
            Invalidate();
        }

        private void numericUpDown1_ValueChanged(object sender, EventArgs e)
        {
            size = ((float)numericUpDown1.Value);
            Invalidate();
        }
    }
}