tests/underlay-callback.html

   1 <!DOCTYPE html>
   2 <html>
   3   <head>
   4     <meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7; IE=EmulateIE9">
   5     <title>Custom underlay callback</title>
   6     <!--[if IE]>
   7     <script type="text/javascript" src="../excanvas.js"></script>
   8     <![endif]-->
   9     <!--
  10     For production (minified) code, use:
  11     <script type="text/javascript" src="dygraph-combined.js"></script>
  12     -->
  13     <script type="text/javascript" src="../dygraph-dev.js"></script>
  14
  15     <script type="text/javascript" src="data.js"></script>
  16   </head>
  17   <body>
  18     <p>Should draw a three-colored background, split horizontally at y:2.25, and
  19     again on the top at x:19Nov:</p>
  20     <div id="div_g" style="width:600px; height:300px;"></div>
  21
  22     <div id="status" style="width:100%; height:200px;"></div>
  23
  24     <script type="text/javascript">
  25       s = document.getElementById("status");
  26
  27       g = new Dygraph(
  28             document.getElementById("div_g"),
  29             NoisyData, {
  30               rollPeriod: 7,
  31               showRoller: true,
  32               errorBars: true,
  33
  34               underlayCallback: function(canvas, area, g) {
  35                 // Selecting a date in the middle of the graph.
  36                 var splitDate = new Date("2006-11-19").getTime();
  37                 var coords = g.toDomCoords(splitDate, 2.25);
  38
  39                 // splitX and splitY are the coordinates on the canvas for (2006-11-19, 2.25).
  40                 var splitX = coords[0];
  41                 var splitY = coords[1];
  42
  43                 // The drawing area doesn't start at (0, 0), it starts at (area.x, area.y).
  44                 // That's why we subtract them from splitX and splitY. This gives us the
  45                 // actual distance from the upper-left hand corder of the graph itself.
  46                 var leftSideWidth = splitX - area.x;
  47                 var rightSideWidth = area.w - leftSideWidth;
  48                 var topHeight = splitY - area.y;
  49                 var bottomHeight = area.h - topHeight;
  50
  51                 // fillRect(x, y, width, height)
  52                 // Top section: y = (2.25, +Infinity)
  53                 // left: (x < 2006-11-19)
  54                 canvas.fillStyle = 'lightblue';
  55                 canvas.fillRect(area.x, area.y, leftSideWidth, topHeight);
  56
  57                 // right: (x > 2006-11-19)
  58                 canvas.fillStyle = 'orange';
  59                 canvas.fillRect(splitX, area.y, rightSideWidth, topHeight);
  60
  61                 // Bottom section: y = (-Infinity, 2.25)
  62                 canvas.fillStyle = 'pink';
  63                 canvas.fillRect(area.x, splitY, area.w, bottomHeight);
  64               }
  65             }
  66           );
  67     </script>
  68   </body>
  69 </html>