From a5a507274e6a58f70f8c9017d063210c8b78583b Mon Sep 17 00:00:00 2001
From: Klaus Weidner <klausw@google.com>
Date: Fri, 11 May 2012 14:29:43 -0700
Subject: [PATCH] Requests from Dan's code review:

- rename the option to drawGapEdgePoints

- fix point lookup for isolated points. The code was getting the overall
  points[] array and limits confused with the subset intended for the
  current series.
---
 auto_tests/tests/callback.js |  8 ++++----
 dygraph-canvas.js            | 26 +++++++++++++++-----------
 dygraph-options-reference.js |  2 +-
 tests/isolated-points.html   |  2 +-
 4 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/auto_tests/tests/callback.js b/auto_tests/tests/callback.js
index e2f425f..6d3df1d 100644
--- a/auto_tests/tests/callback.js
+++ b/auto_tests/tests/callback.js
@@ -152,11 +152,11 @@ CallbackTestCase.prototype.testDrawPointCallback_isolated = function() {
   assertEquals(13, xvalues[0]);
   assertEquals(15, xvalues[1]);
 
-  // Test that isolated points + gap points get drawn when drawGapPoints is set.
-  // This should add one point at the right edge of the segment at x=11, but not
-  // at the graph edge at x=10.
+  // Test that isolated points + gap points get drawn when
+  // drawGapEdgePoints is set.  This should add one point at the right
+  // edge of the segment at x=11, but not at the graph edge at x=10.
   xvalues = []; // Reset for new test
-  graphOpts.drawGapPoints = true;
+  graphOpts.drawGapEdgePoints = true;
   g = new Dygraph(graph, testdata, graphOpts);
   assertEquals(3, xvalues.length);
   assertEquals(11, xvalues[0]);
diff --git a/dygraph-canvas.js b/dygraph-canvas.js
index e5939d0..0c44e84 100644
--- a/dygraph-canvas.js
+++ b/dygraph-canvas.js
@@ -661,11 +661,12 @@ DygraphCanvasRenderer.prototype._renderAnnotations = function() {
   }
 };
 
-DygraphCanvasRenderer.makeNextPointStep_ = function(connect, points, end) {
+DygraphCanvasRenderer.makeNextPointStep_ = function(
+    connect, points, start, end) {
   if (connect) {
     return function(j) {
-      while (++j < end) {
-        if (!(points[j].yval === null)) break;
+      while (++j + start < end) {
+        if (!(points[start + j].yval === null)) break;
       }
       return j;
     }
@@ -688,18 +689,22 @@ DygraphCanvasRenderer.prototype._drawStyledLine = function(
   var points = this.layout.points;
   var prevX = null;
   var prevY = null;
+  var nextY = null;
   var pointsOnLine = []; // Array of [canvasx, canvasy] pairs.
   if (!Dygraph.isArrayLike(strokePattern)) {
     strokePattern = null;
   }
-  var drawGapPoints = this.dygraph_.attr_('drawGapPoints', setName);
+  var drawGapPoints = this.dygraph_.attr_('drawGapEdgePoints', setName);
 
-  var point;
+  var point, nextPoint;
   var next = DygraphCanvasRenderer.makeNextPointStep_(
-      this.attr_('connectSeparatedPoints'), points, afterLastIndexInSet);
+      this.attr_('connectSeparatedPoints'), points, firstIndexInSet,
+      afterLastIndexInSet);
   ctx.save();
-  for (var j = firstIndexInSet; j < afterLastIndexInSet; j = next(j)) {
-    point = points[j];
+  for (var j = 0; j < setLength; j = next(j)) {
+    point = points[firstIndexInSet + j];
+    nextY = (next(j) < setLength) ?
+        points[firstIndexInSet + next(j)].canvasy : null;
     if (isNullOrNaN(point.canvasy)) {
       if (stepPlot && prevX !== null) {
         // Draw a horizontal line to the start of the missing data
@@ -714,13 +719,12 @@ DygraphCanvasRenderer.prototype._drawStyledLine = function(
     } else {
       // 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 ||
-                                   isNullOrNaN(points[j+1].canvasy)));
+      var isIsolated = (!prevX && isNullOrNaN(nextY));
       if (drawGapPoints) {
         // Also consider a point to be is "isolated" if it's adjacent to a
         // null point, excluding the graph edges.
         if ((j > 0 && !prevX) ||
-            (j < points.length - 1 && isNullOrNaN(points[j+1].canvasy))) {
+            (next(j) < setLength && isNullOrNaN(nextY))) {
           isIsolated = true;
         }
       }
diff --git a/dygraph-options-reference.js b/dygraph-options-reference.js
index 3fdd4ea..97b410f 100644
--- a/dygraph-options-reference.js
+++ b/dygraph-options-reference.js
@@ -43,7 +43,7 @@ Dygraph.OPTIONS_REFERENCE =  // <JSON>
     "type": "boolean",
     "description": "Draw a small dot at each point, in addition to a line going through the point. This makes the individual data points easier to see, but can increase visual clutter in the chart. The small dot can be replaced with a custom rendering by supplying a <a href='#drawPointCallback'>drawPointCallback</a>."
   },
-  "drawGapPoints": {
+  "drawGapEdgePoints": {
     "default": "false",
     "labels": ["Data Line display"],
     "type": "boolean",
diff --git a/tests/isolated-points.html b/tests/isolated-points.html
index 85e8fd8..f507fda 100644
--- a/tests/isolated-points.html
+++ b/tests/isolated-points.html
@@ -30,7 +30,7 @@
       {
         labels: ["X", "S1", "S2" ],
         S1: {
-          drawGapPoints: true
+          drawGapEdgePoints: true
         },
         pointSize: 4,
         showRoller: true
-- 
2.7.4