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(Dygraph.dateString_(millis)), 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 graphPos = Dygraph.findPos(g.graphDiv);
  41         var canvasx = Dygraph.pageX(event) - graphPos.x;
  42         var canvasy = Dygraph.pageY(event) - graphPos.y;
  43         var xy = g.toDataCoords(canvasx, canvasy);
  44         var x = xy[0], value = xy[1];
  45         var rows = g.numRows();
  46         var closest_row = -1;
  47         var smallest_diff = -1;
  48         // TODO(danvk): binary search
  49         for (var row = 0; row < rows; row++) {
  50           var date = g.getValue(row, 0);  // millis
  51           var diff = Math.abs(date - x);
  52           if (smallest_diff < 0 || diff < smallest_diff) {
  53             smallest_diff = diff;
  54             closest_row = row;
  55           }
  56         }
  57
  58         if (closest_row != -1) {
  59           if (lastDrawRow === null) {
  60             lastDrawRow = closest_row;
  61             lastDrawValue = value;
  62           }
  63           var coeff = (value - lastDrawValue) / (closest_row - lastDrawRow);
  64           if (closest_row == lastDrawRow) coeff = 0.0;
  65           var minRow = Math.min(lastDrawRow, closest_row);
  66           var maxRow = Math.max(lastDrawRow, closest_row);
  67           for (var row = minRow; row <= maxRow; row++) {
  68             if (tool == 'pencil') {
  69               var val = lastDrawValue + coeff * (row - lastDrawRow);
  70               val = Math.max(valueRange[0], Math.min(val, valueRange[1]));
  71               data[row][1] = val;
  72               if (val === null || value === undefined || isNaN(val)) {
  73                 console.log(val);
  74               }
  75             } else if (tool == 'eraser') {
  76               data[row][1] = null;
  77             }
  78           }
  79           lastDrawRow = closest_row;
  80           lastDrawValue = value;
  81           g.updateOptions({ file: data });
  82           g.setSelection(closest_row);  // prevents the dot from being finnicky.
  83         }
  84       }
  85
  86       function finishDraw() {
  87         isDrawing = false;
  88         lastDrawRow = null;
  89         lastDrawValue = null;
  90       }
  91
  92       var change_tool = function(tool_div) {
  93         var ids = ['tool_zoom', 'tool_pencil', 'tool_eraser'];
  94         for (var i = 0; i < ids.length; i++) {
  95           var div = document.getElementById(ids[i]);
  96           if (div == tool_div) {
  97             div.style.backgroundPosition = -(i * 32) + 'px -32px';
  98           } else {
  99             div.style.backgroundPosition = -(i * 32) + 'px 0px';
 100           }
 101         }
 102         tool = tool_div.id.replace('tool_', '');
 103
 104         var dg_div = document.getElementById("draw_div");
 105         if (tool == 'pencil') {
 106           dg_div.style.cursor = 'url(images/cursor-pencil.png) 2 30, auto';
 107         } else if (tool == 'eraser') {
 108           dg_div.style.cursor = 'url(images/cursor-eraser.png) 10 30, auto';
 109         } else if (tool == 'zoom') {
 110           dg_div.style.cursor = 'crosshair';
 111         }
 112       };
 113       change_tool(document.getElementById("tool_pencil"));
 114
 115       g = new Dygraph(document.getElementById("draw_div"), data,
 116           {
 117             valueRange: valueRange,
 118             labels: [ 'Date', 'Value' ],
 119             interactionModel: {
 120               mousedown: function (event, g, context) {
 121                 if (tool == 'zoom') {
 122                   Dygraph.defaultInteractionModel.mousedown(event, g, context);
 123                 } else {
 124                   // prevents mouse drags from selecting page text.
 125                   if (event.preventDefault) {
 126                     event.preventDefault();  // Firefox, Chrome, etc.
 127                   } else {
 128                     event.returnValue = false;  // IE
 129                     event.cancelBubble = true;
 130                   }
 131                   isDrawing = true;
 132                   setPoint(event, g, context);
 133                 }
 134               },
 135               mousemove: function (event, g, context) {
 136                 if (tool == 'zoom') {
 137                   Dygraph.defaultInteractionModel.mousemove(event, g, context);
 138                 } else {
 139                   if (!isDrawing) return;
 140                   setPoint(event, g, context);
 141                 }
 142               },
 143               mouseup: function(event, g, context) {
 144                 if (tool == 'zoom') {
 145                   Dygraph.defaultInteractionModel.mouseup(event, g, context);
 146                 } else {
 147                   finishDraw();
 148                 }
 149               },
 150               mouseout: function(event, g, context) {
 151                 if (tool == 'zoom') {
 152                   Dygraph.defaultInteractionModel.mouseout(event, g, context);
 153                 }
 154               },
 155               dblclick: function(event, g, context) {
 156                 Dygraph.defaultInteractionModel.dblclick(event, g, context);
 157               },
 158               mousewheel: function(event, g, context) {
 159                 var normal = event.detail ? event.detail * -1 : event.wheelDelta / 40;
 160                 var percentage = normal / 50;
 161                 var axis = g.xAxisRange();
 162                 var xOffset = g.toDomCoords(axis[0], null)[0];
 163                 var x = event.offsetX - xOffset;
 164                 var w = g.toDomCoords(axis[1], null)[0] - xOffset;
 165                 var xPct = w === 0 ? 0 : (x / w);
 166
 167                 var delta = axis[1] - axis[0];
 168                 var increment = delta * percentage;
 169                 var foo = [increment * xPct, increment * (1 - xPct)];
 170                 var dateWindow = [ axis[0] + foo[0], axis[1] - foo[1] ];
 171
 172                 g.updateOptions({
 173                   dateWindow: dateWindow
 174                 });
 175                 Dygraph.cancelEvent(event);
 176               }
 177             },
 178             strokeWidth: 1.5,
 179             gridLineColor: 'rgb(196, 196, 196)',
 180             drawYGrid: false,
 181             drawYAxis: false
 182           });
 183           window.onmouseup = finishDraw;
 184       }
 185   });