plugins/chart-labels.js

   1 /**
   2  * @license
   3  * Copyright 2012 Dan Vanderkam (danvdk@gmail.com)
   4  * MIT-licensed (http://opensource.org/licenses/MIT)
   5  */
   6 /*global Dygraph:false */
   7
   8 Dygraph.Plugins.ChartLabels = (function() {
   9
  10 "use strict";
  11
  12 // TODO(danvk): move chart label options out of dygraphs and into the plugin.
  13 // TODO(danvk): only tear down & rebuild the DIVs when it's necessary.
  14
  15 var chart_labels = function() {
  16   this.title_div_ = null;
  17   this.xlabel_div_ = null;
  18   this.ylabel_div_ = null;
  19   this.y2label_div_ = null;
  20 };
  21
  22 chart_labels.prototype.toString = function() {
  23   return "ChartLabels Plugin";
  24 };
  25
  26 chart_labels.prototype.activate = function(g) {
  27   return {
  28     layout: this.layout,
  29     // clearChart: this.clearChart,
  30     didDrawChart: this.didDrawChart
  31   };
  32 };
  33
  34 // QUESTION: should there be a plugin-utils.js?
  35 var createDivInRect = function(r) {
  36   var div = document.createElement('div');
  37   div.style.position = 'absolute';
  38   div.style.left = r.x + 'px';
  39   div.style.top = r.y + 'px';
  40   div.style.width = r.w + 'px';
  41   div.style.height = r.h + 'px';
  42   return div;
  43 };
  44
  45 // Detach and null out any existing nodes.
  46 chart_labels.prototype.detachLabels_ = function() {
  47   var els = [ this.title_div_,
  48               this.xlabel_div_,
  49               this.ylabel_div_,
  50               this.y2label_div_ ];
  51   for (var i = 0; i < els.length; i++) {
  52     var el = els[i];
  53     if (!el) continue;
  54     if (el.parentNode) el.parentNode.removeChild(el);
  55   }
  56
  57   this.title_div_ = null;
  58   this.xlabel_div_ = null;
  59   this.ylabel_div_ = null;
  60   this.y2label_div_ = null;
  61 };
  62
  63 var createRotatedDiv = function(g, box, axis, classes, html) {
  64   // TODO(danvk): is this outer div actually necessary?
  65   var div = document.createElement("div");
  66   div.style.position = 'absolute';
  67   if (axis == 1) {
  68     // NOTE: this is cheating. Should be positioned relative to the box.
  69     div.style.left = '0px';
  70   } else {
  71     div.style.left = box.x + 'px';
  72   }
  73   div.style.top = box.y + 'px';
  74   div.style.width = box.w + 'px';
  75   div.style.height = box.h + 'px';
  76   div.style.fontSize = (g.getOption('yLabelWidth') - 2) + 'px';
  77
  78   var inner_div = document.createElement("div");
  79   inner_div.style.position = 'absolute';
  80   inner_div.style.width = box.h + 'px';
  81   inner_div.style.height = box.w + 'px';
  82   inner_div.style.top = (box.h / 2 - box.w / 2) + 'px';
  83   inner_div.style.left = (box.w / 2 - box.h / 2) + 'px';
  84   inner_div.style.textAlign = 'center';
  85
  86   // CSS rotation is an HTML5 feature which is not standardized. Hence every
  87   // browser has its own name for the CSS style.
  88   var val = 'rotate(' + (axis == 1 ? '-' : '') + '90deg)';
  89   inner_div.style.transform = val;        // HTML5
  90   inner_div.style.WebkitTransform = val;  // Safari/Chrome
  91   inner_div.style.MozTransform = val;     // Firefox
  92   inner_div.style.OTransform = val;       // Opera
  93   inner_div.style.msTransform = val;      // IE9
  94
  95   var class_div = document.createElement("div");
  96   class_div.className = classes;
  97   class_div.innerHTML = html;
  98
  99   inner_div.appendChild(class_div);
 100   div.appendChild(inner_div);
 101   return div;
 102 };
 103
 104 chart_labels.prototype.layout = function(e) {
 105   this.detachLabels_();
 106
 107   var g = e.dygraph;
 108   var div = e.chart_div;
 109   if (g.getOption('title')) {
 110     // QUESTION: should this return an absolutely-positioned div instead?
 111     var title_rect = e.reserveSpaceTop(g.getOption('titleHeight'));
 112     this.title_div_ = createDivInRect(title_rect);
 113     this.title_div_.style.textAlign = 'center';
 114     this.title_div_.style.fontSize = (g.getOption('titleHeight') - 8) + 'px';
 115     this.title_div_.style.fontWeight = 'bold';
 116     this.title_div_.style.zIndex = 10;
 117
 118     var class_div = document.createElement("div");
 119     class_div.className = 'dygraph-label dygraph-title';
 120     class_div.innerHTML = g.getOption('title');
 121     this.title_div_.appendChild(class_div);
 122     div.appendChild(this.title_div_);
 123   }
 124
 125   if (g.getOption('xlabel')) {
 126     var x_rect = e.reserveSpaceBottom(g.getOption('xLabelHeight'));
 127     this.xlabel_div_ = createDivInRect(x_rect);
 128     this.xlabel_div_.style.textAlign = 'center';
 129     this.xlabel_div_.style.fontSize = (g.getOption('xLabelHeight') - 2) + 'px';
 130
 131     var class_div = document.createElement("div");
 132     class_div.className = 'dygraph-label dygraph-xlabel';
 133     class_div.innerHTML = g.getOption('xlabel');
 134     this.xlabel_div_.appendChild(class_div);
 135     div.appendChild(this.xlabel_div_);
 136   }
 137
 138   if (g.getOption('ylabel')) {
 139     // It would make sense to shift the chart here to make room for the y-axis
 140     // label, but the default yAxisLabelWidth is large enough that this results
 141     // in overly-padded charts. The y-axis label should fit fine. If it
 142     // doesn't, the yAxisLabelWidth option can be increased.
 143     var y_rect = e.reserveSpaceLeft(0);
 144
 145     this.ylabel_div_ = createRotatedDiv(
 146         g, y_rect,
 147         1,  // primary (left) y-axis
 148         'dygraph-label dygraph-ylabel',
 149         g.getOption('ylabel'));
 150     div.appendChild(this.ylabel_div_);
 151   }
 152
 153   if (g.getOption('y2label') && g.numAxes() == 2) {
 154     // same logic applies here as for ylabel.
 155     var y2_rect = e.reserveSpaceRight(0);
 156     this.y2label_div_ = createRotatedDiv(
 157         g, y2_rect,
 158         2,  // secondary (right) y-axis
 159         'dygraph-label dygraph-y2label',
 160         g.getOption('y2label'));
 161     div.appendChild(this.y2label_div_);
 162   }
 163 };
 164
 165 chart_labels.prototype.didDrawChart = function(e) {
 166   var g = e.dygraph;
 167   if (this.title_div_) {
 168     this.title_div_.children[0].innerHTML = g.getOption('title');
 169   }
 170   if (this.xlabel_div_) {
 171     this.xlabel_div_.children[0].innerHTML = g.getOption('xlabel');
 172   }
 173   if (this.ylabel_div_) {
 174     this.ylabel_div_.children[0].children[0].innerHTML = g.getOption('ylabel');
 175   }
 176   if (this.y2label_div_) {
 177     this.y2label_div_.children[0].children[0].innerHTML = g.getOption('y2label');
 178   }
 179 };
 180
 181 chart_labels.prototype.clearChart = function() {
 182 };
 183
 184 chart_labels.prototype.destroy = function() {
 185   this.detachLabels_();
 186 };
 187
 188
 189 return chart_labels;
 190 })();