The Clock

The Clock - Javascript

// JavaScript Scripting Example 04
//
// "The Clock"
//

// Don't cache the image
Response.Cachecontrol = "No-cache";
Response.Expires = -1440;
Response.AddHeader("pragma", "no-cache");

var errormsg = new String("");
errormsg = DrawClock();

// Check if errors occured
if (errormsg != "")
DisplayError(errormsg);

// Draw the clock
function DrawClock()
{
try
{
  var xCenter;
  var yCenter;
  var path;

  // Fix path
  path = Server.MapPath("..\\..\\images") + "\\";

  // Since the clock consists of four images, we will create
  // four image objects.
  var imageobj = Server.CreateObject("W3Image.Image");
  var imageobj2 = Server.CreateObject("W3Image.Image");
  var imageobj3 = Server.CreateObject("W3Image.Image");
  var imageobj4 = Server.CreateObject("W3Image.Image");

  // Set the backgroundcolours to black.
  // We will use the black colour as transparent when blitting.
  imageobj.BkColor = 0x000000;
  imageobj2.BkColor = 0x000000;
  imageobj3.BkColor = 0x000000;
  imageobj4.BkColor = 0x000000;

  // Load the four bitmaps.
  if (imageobj.LoadImage(path + "background.bmp") == false)
  {
   // Do your error handling here...
   return "Error when loading image 'background.bmp'.";
  }

  if (imageobj2.LoadImage(path + "hour.bmp") == false)
  {
   // Do your error handling here...
   return "Error when loading image 'hour.bmp'.";
  }

  if (imageobj3.LoadImage(path + "minute.bmp") == false)
  {
   // Do your error handling here...
   return "Error when loading image 'minute.bmp'.";
  }

  if (imageobj4.LoadImage(path + "second.bmp") == false)
  {
   // Do your error handling here...
   return "Error when loading image 'second.bmp'.";
  }

  // Get the current time.
  var date = new Date();
  var hours = date.getHours();
  var minutes = date.getMinutes();
  var seconds = date.getSeconds();


  // Add the seconds
  xCenter = imageobj4.Width / 2;
  yCenter = imageobj4.Height / 2;

  seconds = seconds * 6;

  imageobj4.Rotate(seconds, xCenter, yCenter);
  imageobj4.StretchBltExt(imageobj, 0, 0, imageobj.Width, imageobj.Height, 0, 0, imageobj.Width, imageobj.Height, "transparent");


  // Add the minutes
  xCenter = imageobj3.Width / 2;
  yCenter = imageobj3.Height / 2;

  minutes = minutes * 6;

  imageobj3.Rotate(minutes, xCenter, yCenter);
  imageobj3.StretchBltExt(imageobj, 0, 0, imageobj.Width, imageobj.Height, 0, 0, imageobj.Width, imageobj.Height, "transparent");


  // Add the hours
  xCenter = imageobj2.Width / 2;
  yCenter = imageobj2.Height / 2;

  if(hours >= 12)
  hours -= 12;

  hours = hours * 30;
  hours += (minutes / 12);

  imageobj2.Rotate(hours, xCenter, yCenter);
  imageobj2.StretchBltExt(imageobj, 0, 0, imageobj.Width, imageobj.Height, 0, 0, imageobj.Width, imageobj.Height, "transparent");


  // Stream imageobj as a JPG image.
  if (imageobj.StreamImage(Response, "JPG", 24) == false)
  {
   // Do your error handling here...
   return "Error when streaming image!";
  }

  // Sucess
  return "";
}
catch(err)
{
  // Do your error handling here...
  return "Error: " + (err.number & 0xFFFF) + " - " + err.description + ".";
}
}

// Example of a error handler - Displaying the error as a image
function DisplayError(msgcode)
{
// Create an error image
var errorimage = Server.CreateObject("W3Image.Image");
errorimage.CreateEmptySurface(1,1);

// Create and select the font
var fontobj = errorimage.CreateFont("Tahoma",24,0,"normal",0,0x000000,false,false,true);
errorimage.SetFont(fontobj);

// Get size of the text
var width = errorimage.GetTextWidth(msgcode);
var height = errorimage.GetTextHeight(msgcode);

// Create a surface as large as the error message
errorimage.CreateEmptySurface(width,height);

// Select the font again (font is deselected when creating a new surface)
errorimage.SetFont(fontobj);

// Write out error message
errorimage.DrawText(msgcode,0,0);

// Stream the image as a JPG image
errorimage.StreamImage(Response, "JPG", 24);
}