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