      1 /**
      2  * @license
      3  * Copyright 2011 Dan Vanderkam (danvdk@gmail.com)
      4  * MIT-licenced: https://opensource.org/licenses/MIT
      5  */
      6
      7 /**
      8  * @fileoverview Based on PlotKitLayout, but modified to meet the needs of
      9  * dygraphs.
     10  */
     11
     12 /*global Dygraph:false */
     13 "use strict";
     14
     15 import * as utils from './dygraph-utils';
     16
     17 /**
     18  * Creates a new DygraphLayout object.
     19  *
     20  * This class contains all the data to be charted.
     21  * It uses data coordinates, but also records the chart range (in data
     22  * coordinates) and hence is able to calculate percentage positions ('In this
     23  * view, Point A lies 25% down the x-axis.')
     24  *
     25  * Two things that it does not do are:
     26  * 1. Record pixel coordinates for anything.
     27  * 2. (oddly) determine anything about the layout of chart elements.
     28  *
     29  * The naming is a vestige of Dygraph's original PlotKit roots.
     30  *
     31  * @constructor
     32  */
     33 var DygraphLayout = function(dygraph) {
     34   this.dygraph_ = dygraph;
     35   /**
     36    * Array of points for each series.
     37    *
     38    * [series index][row index in series] = |Point| structure,
     39    * where series index refers to visible series only, and the
     40    * point index is for the reduced set of points for the current
     41    * zoom region (including one point just outside the window).
     42    * All points in the same row index share the same X value.
     43    *
     44    * @type {Array.<Array.<Dygraph.PointType>>}
     45    */
     46   this.points = [];
     47   this.setNames = [];
     48   this.annotations = [];
     49   this.yAxes_ = null;
     50
     51   // TODO(danvk): it's odd that xTicks_ and yTicks_ are inputs, but xticks and
     52   // yticks are outputs. Clean this up.
     53   this.xTicks_ = null;
     54   this.yTicks_ = null;
     55 };
     56
     57 /**
     58  * Add points for a single series.
     59  *
     60  * @param {string} setname Name of the series.
     61  * @param {Array.<Dygraph.PointType>} set_xy Points for the series.
     62  */
     63 DygraphLayout.prototype.addDataset = function(setname, set_xy) {
     64   this.points.push(set_xy);
     65   this.setNames.push(setname);
     66 };
     67
     68 /**
     69  * Returns the box which the chart should be drawn in. This is the canvas's
     70  * box, less space needed for the axis and chart labels.
     71  *
     72  * @return {{x: number, y: number, w: number, h: number}}
     73  */
     74 DygraphLayout.prototype.getPlotArea = function() {
     75   return this.area_;
     76 };
     77
     78 // Compute the box which the chart should be drawn in. This is the canvas's
     79 // box, less space needed for axis, chart labels, and other plug-ins.
     80 // NOTE: This should only be called by Dygraph.predraw_().
     81 DygraphLayout.prototype.computePlotArea = function() {
     82   var area = {
     83     // TODO(danvk): per-axis setting.
     84     x: 0,
     85     y: 0
     86   };
     87
     88   area.w = this.dygraph_.width_ - area.x - this.dygraph_.getOption('rightGap');
     89   area.h = this.dygraph_.height_;
     90
     91   // Let plugins reserve space.
     92   var e = {
     93     chart_div: this.dygraph_.graphDiv,
     94     reserveSpaceLeft: function(px) {
     95       var r = {
     96         x: area.x,
     97         y: area.y,
     98         w: px,
     99         h: area.h
    100       };
    101       area.x += px;
    102       area.w -= px;
    103       return r;
    104     },
    105     reserveSpaceRight: function(px) {
    106       var r = {
    107         x: area.x + area.w - px,
    108         y: area.y,
    109         w: px,
    110         h: area.h
    111       };
    112       area.w -= px;
    113       return r;
    114     },
    115     reserveSpaceTop: function(px) {
    116       var r = {
    117         x: area.x,
    118         y: area.y,
    119         w: area.w,
    120         h: px
    121       };
    122       area.y += px;
    123       area.h -= px;
    124       return r;
    125     },
    126     reserveSpaceBottom: function(px) {
    127       var r = {
    128         x: area.x,
    129         y: area.y + area.h - px,
    130         w: area.w,
    131         h: px
    132       };
    133       area.h -= px;
    134       return r;
    135     },
    136     chartRect: function() {
    137       return {x:area.x, y:area.y, w:area.w, h:area.h};
    138     }
    139   };
    140   this.dygraph_.cascadeEvents_('layout', e);
    141
    142   this.area_ = area;
    143 };
    144
    145 DygraphLayout.prototype.setAnnotations = function(ann) {
    146   // The Dygraph object's annotations aren't parsed. We parse them here and
    147   // save a copy. If there is no parser, then the user must be using raw format.
    148   this.annotations = [];
    149   var parse = this.dygraph_.getOption('xValueParser') || function(x) { return x; };
    150   for (var i = 0; i < ann.length; i++) {
    151     var a = {};
    152     if (!ann[i].xval && ann[i].x === undefined) {
    153       console.error("Annotations must have an 'x' property");
    154       return;
    155     }
    156     if (ann[i].icon &&
    157         !(ann[i].hasOwnProperty('width') &&
    158           ann[i].hasOwnProperty('height'))) {
    159       console.error("Must set width and height when setting " +
    160                     "annotation.icon property");
    161       return;
    162     }
    163     utils.update(a, ann[i]);
    164     if (!a.xval) a.xval = parse(a.x);
    165     this.annotations.push(a);
    166   }
    167 };
    168
    169 DygraphLayout.prototype.setXTicks = function(xTicks) {
    170   this.xTicks_ = xTicks;
    171 };
    172
    173 // TODO(danvk): add this to the Dygraph object's API or move it into Layout.
    174 DygraphLayout.prototype.setYAxes = function (yAxes) {
    175   this.yAxes_ = yAxes;
    176 };
    177
    178 DygraphLayout.prototype.evaluate = function() {
    179   this._xAxis = {};
    180   this._evaluateLimits();
    181   this._evaluateLineCharts();
    182   this._evaluateLineTicks();
    183   this._evaluateAnnotations();
    184 };
    185
    186 DygraphLayout.prototype._evaluateLimits = function() {
    187   var xlimits = this.dygraph_.xAxisRange();
    188   this._xAxis.minval = xlimits[0];
    189   this._xAxis.maxval = xlimits[1];
    190   var xrange = xlimits[1] - xlimits[0];
    191   this._xAxis.scale = (xrange !== 0 ? 1 / xrange : 1.0);
    192
    193   if (this.dygraph_.getOptionForAxis("logscale", 'x')) {
    194     this._xAxis.xlogrange = utils.log10(this._xAxis.maxval) - utils.log10(this._xAxis.minval);
    195     this._xAxis.xlogscale = (this._xAxis.xlogrange !== 0 ? 1.0 / this._xAxis.xlogrange : 1.0);
    196   }
    197   for (var i = 0; i < this.yAxes_.length; i++) {
    198     var axis = this.yAxes_[i];
    199     axis.minyval = axis.computedValueRange[0];
    200     axis.maxyval = axis.computedValueRange[1];
    201     axis.yrange = axis.maxyval - axis.minyval;
    202     axis.yscale = (axis.yrange !== 0 ? 1.0 / axis.yrange : 1.0);
    203
    204     if (this.dygraph_.getOption("logscale") || axis.logscale) {
    205       axis.ylogrange = utils.log10(axis.maxyval) - utils.log10(axis.minyval);
    206       axis.ylogscale = (axis.ylogrange !== 0 ? 1.0 / axis.ylogrange : 1.0);
    207       if (!isFinite(axis.ylogrange) || isNaN(axis.ylogrange)) {
    208         console.error('axis ' + i + ' of graph at ' + axis.g +
    209                       ' can\'t be displayed in log scale for range [' +
    210                       axis.minyval + ' - ' + axis.maxyval + ']');
    211       }
    212     }
    213   }
    214 };
    215
    216 DygraphLayout.calcXNormal_ = function(value, xAxis, logscale) {
    217   if (logscale) {
    218     return ((utils.log10(value) - utils.log10(xAxis.minval)) * xAxis.xlogscale);
    219   } else {
    220     return (value - xAxis.minval) * xAxis.scale;
    221   }
    222 };
    223
    224 /**
    225  * @param {DygraphAxisType} axis
    226  * @param {number} value
    227  * @param {boolean} logscale
    228  * @return {number}
    229  */
    230 DygraphLayout.calcYNormal_ = function(axis, value, logscale) {
    231   if (logscale) {
    232     var x = 1.0 - ((utils.log10(value) - utils.log10(axis.minyval)) * axis.ylogscale);
    233     return isFinite(x) ? x : NaN;  // shim for v8 issue; see pull request 276
    234   } else {
    235     return 1.0 - ((value - axis.minyval) * axis.yscale);
    236   }
    237 };
    238
    239 DygraphLayout.prototype._evaluateLineCharts = function() {
    240   var isStacked = this.dygraph_.getOption("stackedGraph");
    241   var isLogscaleForX = this.dygraph_.getOptionForAxis("logscale", 'x');
    242
    243   for (var setIdx = 0; setIdx < this.points.length; setIdx++) {
    244     var points = this.points[setIdx];
    245     var setName = this.setNames[setIdx];
    246     var connectSeparated = this.dygraph_.getOption('connectSeparatedPoints', setName);
    247     var axis = this.dygraph_.axisPropertiesForSeries(setName);
    248     // TODO (konigsberg): use optionsForAxis instead.
    249     var logscale = this.dygraph_.attributes_.getForSeries("logscale", setName);
    250
    251     for (var j = 0; j < points.length; j++) {
    252       var point = points[j];
    253
    254       // Range from 0-1 where 0 represents left and 1 represents right.
    255       point.x = DygraphLayout.calcXNormal_(point.xval, this._xAxis, isLogscaleForX);
    256       // Range from 0-1 where 0 represents top and 1 represents bottom
    257       var yval = point.yval;
    258       if (isStacked) {
    259         point.y_stacked = DygraphLayout.calcYNormal_(
    260             axis, point.yval_stacked, logscale);
    261         if (yval !== null && !isNaN(yval)) {
    262           yval = point.yval_stacked;
    263         }
    264       }
    265       if (yval === null) {
    266         yval = NaN;
    267         if (!connectSeparated) {
    268           point.yval = NaN;
    269         }
    270       }
    271       point.y = DygraphLayout.calcYNormal_(axis, yval, logscale);
    272     }
    273
    274     this.dygraph_.dataHandler_.onLineEvaluated(points, axis, logscale);
    275   }
    276 };
    277
    278 DygraphLayout.prototype._evaluateLineTicks = function() {
    279   var i, tick, label, pos, v, has_tick;
    280   this.xticks = [];
    281   for (i = 0; i < this.xTicks_.length; i++) {
    282     tick = this.xTicks_[i];
    283     label = tick.label;
    284     has_tick = !('label_v' in tick);
    285     v = has_tick ? tick.v : tick.label_v;
    286     pos = this.dygraph_.toPercentXCoord(v);
    287     if ((pos >= 0.0) && (pos < 1.0)) {
    288       this.xticks.push({pos, label, has_tick});
    289     }
    290   }
    291
    292   this.yticks = [];
    293   for (i = 0; i < this.yAxes_.length; i++ ) {
    294     var axis = this.yAxes_[i];
    295     for (var j = 0; j < axis.ticks.length; j++) {
    296       tick = axis.ticks[j];
    297       label = tick.label;
    298       has_tick = !('label_v' in tick);
    299       v = has_tick ? tick.v : tick.label_v;
    300       pos = this.dygraph_.toPercentYCoord(v, i);
    301       if ((pos > 0.0) && (pos <= 1.0)) {
    302         this.yticks.push({axis: i, pos, label, has_tick});
    303       }
    304     }
    305   }
    306 };
    307
    308 DygraphLayout.prototype._evaluateAnnotations = function() {
    309   // Add the annotations to the point to which they belong.
    310   // Make a map from (setName, xval) to annotation for quick lookups.
    311   var i;
    312   var annotations = {};
    313   for (i = 0; i < this.annotations.length; i++) {
    314     var a = this.annotations[i];
    315     annotations[a.xval + "," + a.series] = a;
    316   }
    317
    318   this.annotated_points = [];
    319
    320   // Exit the function early if there are no annotations.
    321   if (!this.annotations || !this.annotations.length) {
    322     return;
    323   }
    324
    325   // TODO(antrob): loop through annotations not points.
    326   for (var setIdx = 0; setIdx < this.points.length; setIdx++) {
    327     var points = this.points[setIdx];
    328     for (i = 0; i < points.length; i++) {
    329       var p = points[i];
    330       var k = p.xval + "," + p.name;
    331       if (k in annotations) {
    332         p.annotation = annotations[k];
    333         this.annotated_points.push(p);
    334         //if there are multiple same x-valued points, the annotation would be rendered multiple times
    335         //remove already rendered annotation
    336         delete annotations[k];
    337       }
    338     }
    339   }
    340 };
    341
    342 /**
    343  * Convenience function to remove all the data sets from a graph
    344  */
    345 DygraphLayout.prototype.removeAllDatasets = function() {
    346   delete this.points;
    347   delete this.setNames;
    348   delete this.setPointsLengths;
    349   delete this.setPointsOffsets;
    350   this.points = [];
    351   this.setNames = [];
    352   this.setPointsLengths = [];
    353   this.setPointsOffsets = [];
    354 };
    355
    356 export default DygraphLayout;
    357