Mega Code Archive
Clock animation
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/* Quote from
Programming .NET Windows Applications
By Jesse Liberty, Dan Hurwitz
First Edition October 2003
Pages: 1246 (More details)
*/
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Timers;
using System.Windows.Forms;
namespace Clock3CS
{
// Rename the class
public class ClockFace : System.Windows.Forms.Form
{
// Required designer variable.
private System.ComponentModel.Container components = null;
private int FaceRadius = 450; // size of the clock face
private bool b24Hours = false; // 24 hour clock face?
private System.Windows.Forms.Button btnClockFormat;
private DateTime currentTime; // used in more than one method
// new
private int xCenter; // center of the clock
private int yCenter;
private static int DateRadius = 600; // outer circumference for date
private static int Offset = 0; // for moving the text
Font font = new Font("Arial", 40); // use the same font throughout
private StringDraw sdToday; // the text to animate
public ClockFace()
{
// Required for Windows Form Designer support
InitializeComponent();
// use the user's choice of colors
BackColor = SystemColors.Window;
ForeColor = SystemColors.WindowText;
// *** begin new
string today = System.DateTime.Now.ToLongDateString();
today = " " + today.Replace(",","");
// create a new stringdraw object with today's date
sdToday = new StringDraw(today,this);
currentTime = DateTime.Now;
// set the current center based on the
// client area
xCenter = Width / 2;
yCenter = Height / 2;
// *** end new
// update the clock by timer
System.Timers.Timer timer = new System.Timers.Timer();
timer.Elapsed += new System.Timers.ElapsedEventHandler(OnTimer);
timer.Interval = 20; // shorter interval - more movement
timer.Enabled = true;
}
protected override void OnPaint ( PaintEventArgs e )
{
base.OnPaint(e);
Graphics g = e.Graphics;
SetScale(g);
DrawFace(g);
DrawTime(g,true); // force an update
}
// every time the timer event fires, update the clock
public void OnTimer(Object source, ElapsedEventArgs e)
{
Graphics g = this.CreateGraphics();
SetScale(g);
DrawFace(g);
DrawTime(g,false);
DrawDate(g);
g.Dispose();
}
#region Windows Form Designer generated code
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.btnClockFormat = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// btnClockFormat
//
this.btnClockFormat.Location = new System.Drawing.Point(8, 8);
this.btnClockFormat.Name = "btnClockFormat";
this.btnClockFormat.TabIndex = 1;
this.btnClockFormat.Text = "24 Hours";
this.btnClockFormat.Click += new System.EventHandler(this.btnClockFormat_Click);
//
// ClockFace
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.btnClockFormat});
this.Name = "ClockFace";
this.Text = "Clock3CS";
this.MouseDown += new System.Windows.Forms.MouseEventHandler(this.ClockFace_MouseDown);
this.ResumeLayout(false);
}
#endregion
[STAThread]
static void Main()
{
Application.Run(new ClockFace());
}
private void SetScale(Graphics g)
{
// if the form is too small, do nothing
if ( Width == 0 || Height == 0 )
return;
// set the origin at the center
g.TranslateTransform(xCenter, yCenter); // use the members vars
// set inches to the minimum of the width
// or height dividedby the dots per inch
float inches = Math.Min(Width / g.DpiX, Height / g.DpiX);
// set the scale to a grid of 2000 by 2000 units
g.ScaleTransform(
inches * g.DpiX / 2000, inches * g.DpiY / 2000);
}
private void DrawFace(Graphics g)
{
// numbers are in forecolor except flash number in green
// as the seconds go by.
Brush brush = new SolidBrush(ForeColor);
float x, y;
// new code
int numHours = b24Hours ? 24 : 12;
int deg = 360 / numHours;
// for each of the hours on the clock face
for (int i = 1; i <= numHours; i++)
{
// i = hour 30 degrees = offset per hour
// +90 to make 12 straight up
x = GetCos(i*deg + 90) * FaceRadius;
y = GetSin(i*deg + 90) * FaceRadius;
StringFormat format = new StringFormat();
format.Alignment = StringAlignment.Center;
format.LineAlignment = StringAlignment.Center;
g.DrawString(
i.ToString(), font, brush, -x, -y,format);
} // end for loop
} // end drawFace
private void DrawTime(Graphics g, bool forceDraw)
{
// length of the hands
float hourLength = FaceRadius * 0.5f;
float minuteLength = FaceRadius * 0.7f;
float secondLength = FaceRadius * 0.9f;
// set to back color to erase old hands first
Pen hourPen = new Pen(BackColor);
Pen minutePen = new Pen(BackColor);
Pen secondPen = new Pen(BackColor);
// set the arrow heads
hourPen.EndCap = LineCap.ArrowAnchor;
minutePen.EndCap = LineCap.ArrowAnchor;
// hour hand is thicker
hourPen.Width = 30;
minutePen.Width = 20;
// second hand
Brush secondBrush = new SolidBrush(BackColor);
const int EllipseSize = 50;
GraphicsState state; // to to protect and to serve
// 1 - delete the old time
// delete the old second hand
// figure out how far around to rotate to draw the second hand
// save the current state, rotate, draw and then restore the state
float rotation = GetSecondRotation();
state = g.Save();
g.RotateTransform(rotation);
g.FillEllipse(
secondBrush,
-(EllipseSize/2),
-secondLength,
EllipseSize,
EllipseSize);
g.Restore(state);
DateTime newTime = DateTime.Now;
bool newMin = false; // has the minute changed?
// if the minute has changed, set the flag
if ( newTime.Minute != currentTime.Minute )
newMin = true;
// if the minute has changed or you must draw anyway then you
// must first delete the old minute and hour hand
if ( newMin || forceDraw )
{
// figure out how far around to rotate to draw the minute hand
// save the current state, rotate, draw and then restore the state
rotation = GetMinuteRotation();
state = g.Save();
g.RotateTransform(rotation);
g.DrawLine(minutePen,0,0,0,-minuteLength);
g.Restore(state);
// figure out how far around to rotate to draw the hour hand
// save the current state, rotate, draw and then restore the state
rotation = GetHourRotation();
state = g.Save();
g.RotateTransform(rotation);
g.DrawLine(hourPen,0,0,0,-hourLength);
g.Restore(state);
}
// step 2 - draw the new time
currentTime = newTime;
hourPen.Color = Color.Red;
minutePen.Color = Color.Blue;
secondPen.Color = Color.Green;
secondBrush = new SolidBrush(Color.Green);
// draw the new second hand
// figure out how far around to rotate to draw the second hand
// save the current state, rotate, draw and then restore the state
state = g.Save();
rotation = GetSecondRotation();
g.RotateTransform(rotation);
g.FillEllipse(
secondBrush,
-(EllipseSize/2),
-secondLength,
EllipseSize,
EllipseSize);
g.Restore(state);
// if the minute has changed or you must draw anyway then you
// must draw the new minute and hour hand
if ( newMin || forceDraw )
{
// figure out how far around to rotate to draw the minute hand
// save the current state, rotate, draw and then restore the state
state = g.Save();
rotation = GetMinuteRotation();
g.RotateTransform(rotation);
g.DrawLine(minutePen,0,0,0,-minuteLength);
g.Restore(state);
// figure out how far around to rotate to draw the hour hand
// save the current state, rotate, draw and then restore the state
state = g.Save();
rotation = GetHourRotation();
g.RotateTransform(rotation);
g.DrawLine(hourPen,0,0,0,-hourLength);
g.Restore(state);
}
}
// determine the rotation to draw the hour hand
private float GetHourRotation()
{
// degrees depend on 24 vs. 12 hour clock
float deg = b24Hours ? 15 : 30;
float numHours = b24Hours ? 24 : 12;
return( 360f * currentTime.Hour / numHours +
deg * currentTime.Minute / 60f);
}
private float GetMinuteRotation()
{
return( 360f * currentTime.Minute / 60f );
}
private float GetSecondRotation()
{
return(360f * currentTime.Second / 60f);
}
private static float GetSin(float degAngle)
{
return (float) Math.Sin(Math.PI * degAngle / 180f);
}
private static float GetCos(float degAngle)
{
return (float) Math.Cos(Math.PI * degAngle / 180f);
}
private void btnClockFormat_Click(object sender, System.EventArgs e)
{
btnClockFormat.Text = b24Hours ? "24 Hour" : "12 Hour";
b24Hours = ! b24Hours;
this.Invalidate();
}
private void DrawDate(Graphics g)
{
Brush brush = new SolidBrush(ForeColor);
sdToday.DrawString(g,brush);
}
private void ClockFace_MouseDown(
object sender, System.Windows.Forms.MouseEventArgs e)
{
xCenter = e.X;
yCenter = e.Y;
this.Invalidate();
}
// each letter in the outer string knows how to draw itself
private class LtrDraw
{
char myChar; // the actual letter i draw
float x; // current x coordinate
float y; // current y coordinate
float oldx; // old x coordinate (to delete)
float oldy; // old y coordinate (to delete)
// constructor
public LtrDraw(char c)
{
myChar = c;
}
// property for X coordinate
public float X
{
get { return x; }
set { oldx = x; x = value; }
}
// property for Y coordinate
public float Y
{
get { return y; }
set { oldy = y; y = value; }
}
// get total width of the string
public float GetWidth(Graphics g, Font font)
{
SizeF stringSize = g.MeasureString(myChar.ToString(),font);
return stringSize.Width;
}
// get total height of the string
public float GetHeight(Graphics g, Font font)
{
SizeF stringSize = g.MeasureString(myChar.ToString(),font);
return stringSize.Height;
}
// get the font from the control and draw the current character
// First delete the old and then draw the new
public void DrawString(Graphics g, Brush brush, ClockFace cf)
{
Font font = cf.font;
Brush blankBrush = new SolidBrush(cf.BackColor);
g.DrawString(myChar.ToString(),font,blankBrush,oldx,oldy);
g.DrawString(myChar.ToString(),font,brush,x,y);
}
}
// holds an array of LtrDraw objects
// and knows how to tell them to draw
private class StringDraw
{
ArrayList theString = new ArrayList();
LtrDraw l;
ClockFace theControl;
// constructor takes a string, populates the array
// and stashes away the calling control (ClockFace)
public StringDraw(string s, ClockFace theControl)
{
this.theControl = theControl;
foreach (char c in s)
{
l = new LtrDraw(c);
theString.Add(l);
}
}
// divide the circle by the number of letters
// and draw each letter in position
public void DrawString(Graphics g, Brush brush)
{
int angle = 360 / theString.Count;
int counter = 0;
foreach (LtrDraw theLtr in theString)
{
// 1. To find the X coordinate, take the Cosine of the angle
// and multiply by the radius.
// 2. To compute the angle, start with the base angle
// (360 divided by the number of letters)
// and multiply by letter position.
// Thus if each letter is 10 degrees, and this is the third
// letter, you get 30 degrees. Add 90 to start at 12 O'clock.
// Each time through, subtract the clockFace offset to move
// the entire string around the clock on each timer call
float newX = GetCos(angle * counter + 90 - ClockFace.Offset) * ClockFace.DateRadius ;
float newY = GetSin(angle * counter + 90 - ClockFace.Offset) * ClockFace.DateRadius ;
theLtr.X =
newX - (theLtr.GetWidth(g,theControl.font) / 2);
theLtr.Y =
newY - (theLtr.GetHeight(g,theControl.font) / 2);
counter++;
theLtr.DrawString(g,brush,theControl);
}
ClockFace.Offset += 1; // rotate the entire string
}
}
} // end class
} // end namespace
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