From 1e1bf7dfc2628a153f6b6b8c9b2b6b6d74390e6c Mon Sep 17 00:00:00 2001
From: Dan Vanderkam <danvdk@gmail.com>
Date: Mon, 13 Sep 2010 18:02:04 -0700
Subject: [PATCH] add pointClickCallback

---
 dygraph.js          | 32 ++++++++++++++++++++++++++------
 tests/callback.html |  4 ++++
 2 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/dygraph.js b/dygraph.js
index 4d086f7..8c9f2df 100644
--- a/dygraph.js
+++ b/dygraph.js
@@ -727,7 +727,7 @@ Dygraph.prototype.createDragInterface_ = function() {
   var px = 0;
   var py = 0;
   var getX = function(e) { return Dygraph.pageX(e) - px };
-  var getY = function(e) { return Dygraph.pageX(e) - py };
+  var getY = function(e) { return Dygraph.pageY(e) - py };
 
   // Draw zoom rectangles when the mouse is down and the user moves around
   Dygraph.addEvent(this.mouseEventElement_, 'mousemove', function(event) {
@@ -803,11 +803,31 @@ Dygraph.prototype.createDragInterface_ = function() {
       var regionWidth = Math.abs(dragEndX - dragStartX);
       var regionHeight = Math.abs(dragEndY - dragStartY);
 
-      if (regionWidth < 2 && regionHeight < 2 &&
-          self.attr_('clickCallback') != null &&
-          self.lastx_ != undefined) {
-        // TODO(danvk): pass along more info about the points.
-        self.attr_('clickCallback')(event, self.lastx_, self.selPoints_);
+      if (regionWidth < 2 && regionHeight < 2 && self.lastx_ != undefined) {
+        if (self.attr_('clickCallback') != null) {
+          // TODO(danvk): pass along more info about the points.
+          self.attr_('clickCallback')(event, self.lastx_, self.selPoints_);
+        }
+        if (self.attr_('pointClickCallback')) {
+          // check if the click was on a particular point.
+          var closestIdx = -1;
+          var closestDistance = 0;
+          for (var i = 0; i < self.selPoints_.length; i++) {
+            var p = self.selPoints_[i];
+            var distance = Math.pow(p.canvasx - dragEndX, 2) +
+                           Math.pow(p.canvasy - dragEndY, 2);
+            if (closestIdx == -1 || distance < closestDistance) {
+              closestDistance = distance;
+              closestIdx = i;
+            }
+          }
+
+          // Allow any click within two pixels of the dot.
+          var radius = this.attr_('highlightCircleSize') + 2;
+          if (closestDistance <= 5 * 5) {
+            self.attr_('pointClickCallback')(event, self.selPoints_[closestIdx]);
+          }
+        }
       }
 
       if (regionWidth >= 10) {
diff --git a/tests/callback.html b/tests/callback.html
index 5a08409..64e9777 100644
--- a/tests/callback.html
+++ b/tests/callback.html
@@ -76,6 +76,10 @@
                 s.innerHTML += "<b>Click</b> " + pts_info(e,x,pts) + "<br/>";
               },
 
+              pointClickCallback: function(e, p) {
+                s.innerHTML += "<b>Point Click</b> " + p.name + ": " + p.x + "<br/>";
+              },
+
               zoomCallback: function(minX, maxX) {
                 s.innerHTML += "<b>Zoom</b> [" + minX + ", " + maxX + "]<br/>";
               },
-- 
2.7.4