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