gallery/drawing.js

   1 Gallery.register(
   2   'drawing',
   3   {
   4     name: 'Time Series Drawing Demo',
   5     title: 'Time Series Drawing Demo',
   6     setup: function(parent) {
   7       parent.innerHTML = [
   8           "<div id='toolbar'>",
   9           "<div id='tool_zoom'></div>",
  10           "<div id='tool_pencil'></div>",
  11           "<div id='tool_eraser'></div>",
  12           "</div>",
  13           "<div id='draw_div' style='width: 600px; height: 300px;'></div>",
  14           "<p style='font-size: 10pt'>Toolbar/cursor icons are CC-licensed from ",
  15           "<a href='http://www.fatcow.com/free-icons'>FatCow</a>.</p>"].join("\n");
  16     },
  17
  18     run: function() {
  19       var zoom = document.getElementById('tool_zoom');
  20       zoom.onclick = function() { change_tool(zoom) };
  21       var pencil = document.getElementById('tool_pencil');
  22       pencil.onclick = function() { change_tool(pencil) };
  23       var eraser = document.getElementById('tool_eraser');
  24       eraser.onclick = function() { change_tool(eraser) };
  25
  26       var start_date = new Date("2002/12/29").getTime();
  27       var end_date = new Date().getTime();
  28       var data = [];
  29       for (var d = start_date; d < end_date; d += 604800 * 1000) {
  30         var millis = d + 2 * 3600 * 1000;
  31         data.push( [ new Date(new Date(millis).strftime("%Y/%m/%d")), 50 ]);
  32       }
  33
  34       var isDrawing = false;
  35       var lastDrawRow = null, lastDrawValue = null;
  36       var tool = 'pencil';
  37       var valueRange = [0, 100];
  38
  39       function setPoint(event, g, context) {
  40         var canvasx = Dygraph.pageX(event) - Dygraph.findPosX(g.graphDiv);
  41         var canvasy = Dygraph.pageY(event) - Dygraph.findPosY(g.graphDiv);
  42         var xy = g.toDataCoords(canvasx, canvasy);
  43         var x = xy[0], value = xy[1];
  44         var rows = g.numRows();
  45         var closest_row = -1;
  46         var smallest_diff = -1;
  47         // TODO(danvk): binary search
  48         for (var row = 0; row < rows; row++) {
  49           var date = g.getValue(row, 0);  // millis
  50           var diff = Math.abs(date - x);
  51           if (smallest_diff < 0 || diff < smallest_diff) {
  52             smallest_diff = diff;
  53             closest_row = row;
  54           }
  55         }
  56
  57         if (closest_row != -1) {
  58           if (lastDrawRow === null) {
  59             lastDrawRow = closest_row;
  60             lastDrawValue = value;
  61           }
  62           var coeff = (value - lastDrawValue) / (closest_row - lastDrawRow);
  63           if (closest_row == lastDrawRow) coeff = 0.0;
  64           var minRow = Math.min(lastDrawRow, closest_row);
  65           var maxRow = Math.max(lastDrawRow, closest_row);
  66           for (var row = minRow; row <= maxRow; row++) {
  67             if (tool == 'pencil') {
  68               var val = lastDrawValue + coeff * (row - lastDrawRow);
  69               val = Math.max(valueRange[0], Math.min(val, valueRange[1]));
  70               data[row][1] = val;
  71               if (val == null || isNaN(val)) console.log(val);
  72             } else if (tool == 'eraser') {
  73               data[row][1] = null;
  74             }
  75           }
  76           lastDrawRow = closest_row;
  77           lastDrawValue = value;
  78           g.updateOptions({ file: data });
  79           g.setSelection(closest_row);  // prevents the dot from being finnicky.
  80         }
  81       }
  82
  83       function finishDraw() {
  84         isDrawing = false;
  85         lastDrawRow = null;
  86         lastDrawValue = null;
  87       }
  88
  89       var change_tool = function(tool_div) {
  90         var ids = ['tool_zoom', 'tool_pencil', 'tool_eraser'];
  91         for (var i = 0; i < ids.length; i++) {
  92           var div = document.getElementById(ids[i]);
  93           if (div == tool_div) {
  94             div.style.backgroundPosition = -(i * 32) + 'px -32px';
  95           } else {
  96             div.style.backgroundPosition = -(i * 32) + 'px 0px';
  97           }
  98         }
  99         tool = tool_div.id.replace('tool_', '');
 100
 101         var dg_div = document.getElementById("draw_div");
 102         if (tool == 'pencil') {
 103           dg_div.style.cursor = 'url(images/cursor-pencil.png) 2 30, auto';
 104         } else if (tool == 'eraser') {
 105           dg_div.style.cursor = 'url(images/cursor-eraser.png) 10 30, auto';
 106         } else if (tool == 'zoom') {
 107           dg_div.style.cursor = 'crosshair';
 108         }
 109       }
 110       change_tool(document.getElementById("tool_pencil"));
 111
 112       g = new Dygraph(document.getElementById("draw_div"), data,
 113           {
 114             valueRange: valueRange,
 115             labels: [ 'Date', 'Value' ],
 116             interactionModel: {
 117               mousedown: function (event, g, context) {
 118                 if (tool == 'zoom') {
 119                   Dygraph.defaultInteractionModel.mousedown(event, g, context);
 120                 } else {
 121                   // prevents mouse drags from selecting page text.
 122                   if (event.preventDefault) {
 123                     event.preventDefault();  // Firefox, Chrome, etc.
 124                   } else {
 125                     event.returnValue = false;  // IE
 126                     event.cancelBubble = true;
 127                   }
 128                   isDrawing = true;
 129                   setPoint(event, g, context);
 130                 }
 131               },
 132               mousemove: function (event, g, context) {
 133                 if (tool == 'zoom') {
 134                   Dygraph.defaultInteractionModel.mousemove(event, g, context);
 135                 } else {
 136                   if (!isDrawing) return;
 137                   setPoint(event, g, context);
 138                 }
 139               },
 140               mouseup: function(event, g, context) {
 141                 if (tool == 'zoom') {
 142                   Dygraph.defaultInteractionModel.mouseup(event, g, context);
 143                 } else {
 144                   finishDraw();
 145                 }
 146               },
 147               mouseout: function(event, g, context) {
 148                 if (tool == 'zoom') {
 149                   Dygraph.defaultInteractionModel.mouseout(event, g, context);
 150                 }
 151               },
 152               dblclick: function(event, g, context) {
 153                 Dygraph.defaultInteractionModel.dblclick(event, g, context);
 154               },
 155               mousewheel: function(event, g, context) {
 156                 var normal = event.detail ? event.detail * -1 : event.wheelDelta / 40;
 157                 var percentage = normal / 50;
 158                 var axis = g.xAxisRange();
 159                 var xOffset = g.toDomCoords(axis[0], null)[0];
 160                 var x = event.offsetX - xOffset;
 161                 var w = g.toDomCoords(axis[1], null)[0] - xOffset;
 162                 var xPct = w == 0 ? 0 : (x / w);
 163
 164                 var delta = axis[1] - axis[0];
 165                 var increment = delta * percentage;
 166                 var foo = [increment * xPct, increment * (1 - xPct)];
 167                 var dateWindow = [ axis[0] + foo[0], axis[1] - foo[1] ];
 168
 169                 g.updateOptions({
 170                   dateWindow: dateWindow
 171                 });
 172                 Dygraph.cancelEvent(event);
 173               }
 174             },
 175             strokeWidth: 1.5,
 176             gridLineColor: 'rgb(196, 196, 196)',
 177             drawYGrid: false,
 178             drawYAxis: false
 179           });
 180           window.onmouseup = finishDraw;
 181       }
 182   });