factor out logic for generating the html legend

[dygraphs.git] / dygraph-canvas.js

diff --git a/dygraph-canvas.js b/dygraph-canvas.js
index 29341e1..2f8821e 100644 (file)
--- a/dygraph-canvas.js
+++ b/dygraph-canvas.js
@@ -32,9 +32,9 @@ DygraphLayout.prototype.addDataset = function(setname, set_xy) {
 
 DygraphLayout.prototype.setAnnotations = function(ann) {
   // The Dygraph object's annotations aren't parsed. We parse them here and
-  // save a copy.
+  // save a copy. If there is no parser, then the user must be using raw format.
   this.annotations = [];
-  var parse = this.attr_('xValueParser');
+  var parse = this.attr_('xValueParser') || function(x) { return x; };
   for (var i = 0; i < ann.length; i++) {
     var a = {};
     if (!ann[i].xval && !ann[i].x) {
@@ -88,6 +88,16 @@ DygraphLayout.prototype._evaluateLimits = function() {
     axis.maxyval = axis.computedValueRange[1];
     axis.yrange = axis.maxyval - axis.minyval;
     axis.yscale = (axis.yrange != 0 ? 1.0 / axis.yrange : 1.0);
+
+    if (axis.g.attr_("logscale")) {
+      axis.ylogrange = Dygraph.log10(axis.maxyval) - Dygraph.log10(axis.minyval);
+      axis.ylogscale = (axis.ylogrange != 0 ? 1.0 / axis.ylogrange : 1.0);
+      if (!isFinite(axis.ylogrange) || isNaN(axis.ylogrange)) {
+        axis.g.error('axis ' + i + ' of graph at ' + axis.g +
+            ' can\'t be displayed in log scale for range [' +
+            axis.minyval + ' - ' + axis.maxyval + ']');
+      }
+    }
   }
 };
 
@@ -102,10 +112,17 @@ DygraphLayout.prototype._evaluateLineCharts = function() {
 
     for (var j = 0; j < dataset.length; j++) {
       var item = dataset[j];
+
+      var yval;
+      if (axis.logscale) {
+        yval = 1.0 - ((Dygraph.log10(parseFloat(item[1])) - Dygraph.log10(axis.minyval)) * axis.ylogscale); // really should just be yscale.
+      } else {
+        yval = 1.0 - ((parseFloat(item[1]) - axis.minyval) * axis.yscale);
+      }
       var point = {
         // TODO(danvk): here
         x: ((parseFloat(item[0]) - this.minxval) * this.xscale),
-        y: 1.0 - ((parseFloat(item[1]) - axis.minyval) * axis.yscale),
+        y: yval,
         xval: parseFloat(item[0]),
         yval: parseFloat(item[1]),
         name: setName
@@ -133,7 +150,7 @@ DygraphLayout.prototype._evaluateLineTicks = function() {
     for (var j = 0; j < axis.ticks.length; j++) {
       var tick = axis.ticks[j];
       var label = tick.label;
-      var pos = 1.0 - (axis.yscale * (tick.v - axis.minyval));
+      var pos = this.dygraph_.toPercentYCoord(tick.v, i);
       if ((pos >= 0.0) && (pos <= 1.0)) {
         this.yticks.push([i, pos, label]);
       }
@@ -393,7 +410,9 @@ DygraphCanvasRenderer.prototype.render = function() {
   function halfDown(y){return Math.round(y)-0.5};
 
   if (this.options.underlayCallback) {
-    this.options.underlayCallback(ctx, this.area, this.layout, this.dygraph_);
+    // NOTE: we pass the dygraph object to this callback twice to avoid breaking
+    // users who expect a deprecated form of this callback.
+    this.options.underlayCallback(ctx, this.area, this.dygraph_, this.dygraph_);
   }
 
   if (this.options.drawYGrid) {
@@ -720,8 +739,6 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() {
   }
 
   // create paths
-  var isOK = function(x) { return x && !isNaN(x); };
-
   var ctx = context;
   if (errorBars) {
     if (fillGraph) {
@@ -749,7 +766,7 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() {
       for (var j = 0; j < this.layout.points.length; j++) {
         var point = this.layout.points[j];
         if (point.name == setName) {
-          if (!isOK(point.y)) {
+          if (!Dygraph.isOK(point.y)) {
             prevX = NaN;
             continue;
           }
@@ -814,7 +831,7 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() {
       for (var j = 0; j < this.layout.points.length; j++) {
         var point = this.layout.points[j];
         if (point.name == setName) {
-          if (!isOK(point.y)) {
+          if (!Dygraph.isOK(point.y)) {
             prevX = NaN;
             continue;
           }
@@ -861,7 +878,7 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() {
     for (var j = 0; j < points.length; j++) {
       var point = points[j];
       if (point.name == setName) {
-        if (!isOK(point.canvasy)) {
+        if (!Dygraph.isOK(point.canvasy)) {
           if (stepPlot && prevX != null) {
             // Draw a horizontal line to the start of the missing data
             ctx.beginPath();
@@ -877,7 +894,7 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() {
           // A point is "isolated" if it is non-null but both the previous
           // and next points are null.
           var isIsolated = (!prevX && (j == points.length - 1 ||
-                                       !isOK(points[j+1].canvasy)));
+                                       !Dygraph.isOK(points[j+1].canvasy)));
 
           if (!prevX) {
             prevX = point.canvasx;