Paint2/Paint_2/Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Paint_2
{
    public partial class PaintForm : Form
    {
        const int DEFAULT_PENCIL = 0;
        const int DOT_PENCIL = 1;

        const string DEFAULT_FILEPATH = "C:/Paint2/Drawings/";
        Sketch sketch;
        List<PaintTool> toolList;
        bool drawing = false;
        Random rnd;
        Color hoveringColor;
        public PaintForm()
        {
            InitializeComponent();

            rnd = new Random();
            nupWidth.Value = canvas.Width;
            nupHeight.Value = canvas.Height;
            toolList = new List<PaintTool>();
            toolList.Add(new Pencil());
            toolList.Add(new DotPencil());
            sketch = new Sketch(new Size((int)nupWidth.Value, (int)nupHeight.Value), toolList);
            canvas.Image = sketch.Drawing;
            tmrRefresh.Enabled = true;
        }
        private Point MousePositionToCanvasPosition()
        {
            //return new Point(MousePosition.X - canvas.Location.X, MousePosition.Y - canvas.Location.Y);
            return canvas.PointToClient(MousePosition);
        }
        private void canvas_MouseDown(object sender, MouseEventArgs e)
        {
            drawing = true;
            sketch.StartDrawing(MousePositionToCanvasPosition(), Color.FromArgb(rnd.Next(0, 256), rnd.Next(0, 256), rnd.Next(0, 256)), (int)nupPencilWidth.Value);
        }
        private void canvas_MouseUp(object sender, MouseEventArgs e)
        {
            sketch.AddDrawingPoint(MousePositionToCanvasPosition());
            drawing = false;
            RefreshUi();
        }

        private void tmrRefresh_Tick(object sender, EventArgs e)
        {
            if (drawing)
            {
                sketch.AddDrawingPoint(MousePositionToCanvasPosition());
            }
            RefreshUi();
        }
        private void BtnColor_Click(object sender, EventArgs e)
        {
            Button button = sender as Button;
            sketch.ChangePaintToolColor(button.BackColor);
            tmrRefresh_Tick(sender, e);
        }
        private string ColorToString(Color color)
        {
            // Expected Hex:FFFFFF R:255 G:255 B:255
            string result = "";
            int toBase = 16;
            result += "Hex:" + Convert.ToString(color.R, toBase) + Convert.ToString(color.G, toBase) + Convert.ToString(color.B, toBase) + " ";
            result += "R:" + color.R + " G:" + color.G + " B:" + color.B;
            return result;
        }
        private void RefreshUi()
        {
            canvas.Image = sketch.Paint();
            lblSelectedColor.Text = ColorToString(sketch.CurrentTool.Color);
            btnSelectedColor.BackColor = sketch.CurrentTool.Color;
            hoveringColor = GetHoverColor();
            lblHoveringColor.Text = ColorToString(hoveringColor);
            btnHoveringColor.BackColor = hoveringColor;

            List<Color> colorHistory = sketch.CurrentTool.GetLastColors(4);
            btnColorHistory1.BackColor = colorHistory[0];
            btnColorHistory2.BackColor = colorHistory[1];
            btnColorHistory3.BackColor = colorHistory[2];
            btnColorHistory4.BackColor = colorHistory[3];
        }
        private Color GetHoverColor()
        {
            Point cursorLocation = MousePositionToCanvasPosition();
            Color pixel;
            if (cursorLocation.X > 0 && cursorLocation.X < canvas.Width && cursorLocation.Y > 0 && cursorLocation.Y < canvas.Height)
            {
                pixel = (canvas.Image as Bitmap).GetPixel(cursorLocation.X, cursorLocation.Y);
            }
            else
            {
                pixel = Color.FromArgb(0x00, 0x00, 0x00);
            }
            return pixel;

        }
        private void btnClear_Click(object sender, EventArgs e)
        {
            sketch.Clear();
            RefreshUi();
        }

        private void nupPencilWidth_ValueChanged(object sender, EventArgs e)
        {
            sketch.ChangePaintToolWidth((int)nupPencilWidth.Value);
        }

        private void btnSetColor_Click(object sender, EventArgs e)
        {
            string value = tbxColorHex.Text;
            value = value.Replace("#", String.Empty);
            int R, G, B;
            try
            {
                R = Convert.ToInt32(value[0] + value[1]);
                G = Convert.ToInt32(value[2] + value[3]);
                B = Convert.ToInt32(value[4] + value[5]);
            }
            catch (Exception exception)
            {
                MessageBox.Show("Please enter a valid hexadecimal value");
                tbxColorHex.Text = "#FFFFFF";
                R = 255;
                G = 255;
                B = 255;
            }
            sketch.ChangePaintToolColor(Color.FromArgb(R, G, B));
        }

        private void button1_Click(object sender, EventArgs e)
        {
            int R, G, B;
            R = (int)nupRed.Value;
            G = (int)nupGreen.Value;
            B = (int)nupBlue.Value;
            if (R > 255)
            {
                R = 255;
            }
            if (G > 255)
            {
                G = 25;
            }
            if (B > 255)
            {
                B = 255;
            }
            sketch.ChangePaintToolColor(Color.FromArgb(R, G, B));
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            string fileName = tbxProjectName.Text;
            Bitmap image = (Bitmap)canvas.Image;

            if (!Directory.Exists(DEFAULT_FILEPATH))
            {
                Directory.CreateDirectory(DEFAULT_FILEPATH);
            }
            if (!Directory.Exists(DEFAULT_FILEPATH + fileName))
            {
                Directory.CreateDirectory(DEFAULT_FILEPATH + fileName);
            }

            image.Save(DEFAULT_FILEPATH + fileName + "/" + fileName + ".png", System.Drawing.Imaging.ImageFormat.Png);
        }

        private void btnSaveCopy_Click(object sender, EventArgs e)
        {
            string fileName = tbxProjectName.Text + "_copy";
            Bitmap image = (Bitmap)canvas.Image;

            if (!Directory.Exists(DEFAULT_FILEPATH))
            {
                Directory.CreateDirectory(DEFAULT_FILEPATH);
            }
            if (!Directory.Exists(DEFAULT_FILEPATH + fileName))
            {
                Directory.CreateDirectory(DEFAULT_FILEPATH + fileName);
            }

            image.Save(DEFAULT_FILEPATH + fileName + "/" + fileName + ".png", System.Drawing.Imaging.ImageFormat.Png);
        }

        private void btnDotTracer_Click(object sender, EventArgs e)
        {
            sketch.ChangeTool(DOT_PENCIL);
            RefreshUi();
        }

        private void btnPencil_Click(object sender, EventArgs e)
        {
            sketch.ChangeTool(DEFAULT_PENCIL);
            RefreshUi();
        }
    }
}