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 Dygraph.Plugins.ChartLabels = (function() {
   7
   8 // TODO(danvk): move chart label options out of dygraphs and into the plugin.
   9
  10 var chart_labels = function() {
  11   this.title_div_ = null;
  12   this.xlabel_div_ = null;
  13   this.ylabel_div_ = null;
  14   this.y2label_div_ = null;
  15 };
  16
  17 chart_labels.prototype.toString = function() {
  18   return "ChartLabels Plugin";
  19 };
  20
  21 chart_labels.prototype.activate = function(g) {
  22   return {
  23     layout: this.layout,
  24     // clearChart: this.clearChart,
  25     drawChart: this.drawChart
  26   };
  27 };
  28
  29 // QUESTION: should there be a plugin-utils.js?
  30 var createDivInRect = function(r) {
  31   var div = document.createElement('div');
  32   div.style.position = 'absolute';
  33   div.style.left = r.x + 'px';
  34   div.style.top = r.y + 'px';
  35   div.style.width = r.w + 'px';
  36   div.style.height = r.h + 'px';
  37   return div;
  38 };
  39
  40 // Detach and null out any existing nodes.
  41 chart_labels.prototype.detachLabels_ = function() {
  42   var els = [ this.title_div_,
  43               this.xlabel_div_,
  44               this.ylabel_div_,
  45               this.y2label_div_ ];
  46   for (var i = 0; i < els.length; i++) {
  47     var el = els[i];
  48     if (!el) continue;
  49     if (el.parentNode) el.parentNode.removeChild(el);
  50   }
  51
  52   this.title_div_ = null;
  53   this.xlabel_div_ = null;
  54   this.ylabel_div_ = null;
  55   this.y2label_div_ = null;
  56 };
  57
  58 chart_labels.prototype.layout = function(e) {
  59   this.detachLabels_();
  60
  61   var g = e.dygraph;
  62   var div = e.chart_div;
  63   if (g.getOption('title')) {
  64     // QUESTION: should this return an absolutely-positioned div instead?
  65     var title_rect = e.reserveSpaceTop(g.getOption('titleHeight'));
  66     this.title_div_ = createDivInRect(title_rect);
  67     this.title_div_.innerHTML = g.getOption('title');
  68     this.title_div_.style.textAlign = 'center';
  69     this.title_div_.style.fontSize = (g.getOption('titleHeight') - 8) + 'px';
  70     this.title_div_.style.fontWeight = 'bold';
  71     div.appendChild(this.title_div_);
  72   }
  73
  74 /*
  75   if (g.getOption('xlabel')) {
  76     var x_rect = e.reserveSpaceBottom(g.getOption('xLabelHeight'));
  77   }
  78
  79   if (g.getOption('ylabel')) {
  80     var y_rect = e.reserveSpaceLeft(0);
  81   }
  82
  83   if (g.getOption('y2label')) {
  84     var y2_rect = e.reserveSpaceRight(0);
  85   }
  86   */
  87 };
  88
  89 chart_labels.prototype.drawChart = function(e) {
  90   var g = e.dygraph;
  91   if (this.title_div_) {
  92     this.title_div_.innerHTML = g.getOption('title');
  93   }
  94 };
  95
  96 chart_labels.prototype.clearChart = function() {
  97 };
  98
  99 chart_labels.prototype.destroy = function() {
 100   detachLabels();
 101 };
 102
 103
 104 return chart_labels;
 105 })();