Subversion Repositories group.electronics

using System;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;
using System.Diagnostics;

namespace NITNavComm {

        /// <summary>
        /// The LEDBulb is a .Net control for Windows Forms that emulates an
        /// LED light with two states On and Off.  The purpose of the control is to 
        /// provide a sleek looking representation of an LED light that is sizable, 
        /// has a transparent background and can be set to different colors.  
        /// </summary>
        public partial class LedLight : UserControl {

                #region Public and Private Members

                private Color _color;
                private bool _on = true;
                private Color _reflectionColor = Color.FromArgb(180, 255, 255, 255);
                private Color[] _surroundColor = new Color[] { Color.FromArgb(0, 255, 255, 255) };
                private Timer _timer = new Timer();

                /// <summary>
                /// Gets or Sets the color of the LED light
                /// </summary>
                [DefaultValue(typeof(Color), "153, 255, 54")]
                public Color Color { 
                        get { return _color; } 
                        set { 
                                _color = value;
                                this.DarkColor = ControlPaint.Dark(_color);
                                this.DarkDarkColor = ControlPaint.DarkDark(_color);
                                this.Invalidate();      // Redraw the control
                        } 
                }
                
                /// <summary>
                /// Dark shade of the LED color used for gradient
                /// </summary>
                public Color DarkColor { get; protected set; }
                
                /// <summary>
                /// Very dark shade of the LED color used for gradient
                /// </summary>
                public Color DarkDarkColor { get; protected set; }

                /// <summary>
                /// Gets or Sets whether the light is turned on
                /// </summary>
                public bool On { 
                        get { return _on; } 
                        set { _on = value; this.Invalidate(); } 
                }

                #endregion

                #region Constructor
                
                public LedLight() {
                        SetStyle(ControlStyles.DoubleBuffer
                        | ControlStyles.AllPaintingInWmPaint
                        | ControlStyles.ResizeRedraw
                        | ControlStyles.UserPaint
                        | ControlStyles.SupportsTransparentBackColor, true);
                        
                        this.Color = Color.FromArgb(255, 153, 255, 54);
                        _timer.Tick += new EventHandler(
                                (object sender, EventArgs e) => { this.On = !this.On; }
                        );
                }
                
                #endregion

                #region Methods

                /// <summary>
                /// Handles the Paint event for this UserControl
                /// </summary>
                protected override void OnPaint(PaintEventArgs e){
                        // Create an offscreen graphics object for double buffering
                        Bitmap offScreenBmp = new Bitmap(this.ClientRectangle.Width, this.ClientRectangle.Height);
                        using (System.Drawing.Graphics g = Graphics.FromImage(offScreenBmp)) {
                                g.SmoothingMode = SmoothingMode.HighQuality;
                                // Draw the control
                                drawControl(g, this.On);
                                // Draw the image to the screen
                                e.Graphics.DrawImageUnscaled(offScreenBmp, 0, 0);
                        }
                }

                /// <summary>
                /// Renders the control to an image
                /// </summary>
                private void drawControl(Graphics g, bool on) {
                        // Is the bulb on or off
                        Color lightColor = (on)? this.Color : Color.FromArgb(150, this.DarkColor);
                        Color darkColor = (on) ? this.DarkColor : this.DarkDarkColor;
                        
                        // Calculate the dimensions of the bulb
                        int width = this.Width - (this.Padding.Left + this.Padding.Right);
                        int height = this.Height - (this.Padding.Top + this.Padding.Bottom);
                        // Diameter is the lesser of width and height
                        int diameter = Math.Min(width, height);
                        // Subtract 1 pixel so ellipse doesn't get cut off
                        diameter = Math.Max(diameter - 1, 1);

                        // Draw the background ellipse
                        var rectangle = new Rectangle(this.Padding.Left, this.Padding.Top, diameter, diameter);
                        g.FillEllipse(new SolidBrush(darkColor), rectangle);

                        // Draw the glow gradient
                        var path = new GraphicsPath();
                        path.AddEllipse(rectangle);
                        var pathBrush = new PathGradientBrush(path);
                        pathBrush.CenterColor = lightColor;
                        pathBrush.SurroundColors = new Color[] { Color.FromArgb(0, lightColor) };
                        g.FillEllipse(pathBrush, rectangle);

                        // Draw the white reflection gradient
                        var offset = Convert.ToInt32(diameter * .15F);
                        var diameter1 = Convert.ToInt32(rectangle.Width * .8F);
                        var whiteRect = new Rectangle(rectangle.X - offset, rectangle.Y - offset, diameter1, diameter1);
                        var path1 = new GraphicsPath();
                        path1.AddEllipse(whiteRect);
                        var pathBrush1 = new PathGradientBrush(path);
                        pathBrush1.CenterColor = _reflectionColor;
                        pathBrush1.SurroundColors = _surroundColor;
                        g.FillEllipse(pathBrush1, whiteRect);

                        // Draw the border
                        g.SetClip(this.ClientRectangle);
                        if (this.On) g.DrawEllipse(new Pen(Color.FromArgb(85, Color.Black),1F), rectangle);
                }

                /// <summary>
                /// Causes the Led to start blinking
                /// </summary>
                /// <param name="milliseconds">Number of milliseconds to blink for. 0 stops blinking</param>
                public void Blink(int milliseconds) {
                        if (milliseconds > 0) {
                                this.On = true;
                                _timer.Interval = milliseconds;
                                _timer.Enabled = true;
                        }
                        else {
                                _timer.Enabled = false;
                                this.On = false;
                        }
                }

                #endregion
        }
}