From a6f0e3c5b6a310bb57f86aa750c6005968e5943c Mon Sep 17 00:00:00 2001
From: bryan brancotte <bryan.brancotte@gmail.com>
Date: Thu, 14 Sep 2017 13:45:25 +0200
Subject: [PATCH] Ability to force the tip to remain visible

Can be used like this :
```javascript
svg.data(data)
  .enter()
    .append('svg:circle')
      .on('mouseenter', tip.show)
      .on('mouseleave', tip.hide)
      .on('click', tip.toggle_keep_visible);
```
---
 d3-tip.js | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/d3-tip.js b/d3-tip.js
index ddc6100..4c74cd6 100644
--- a/d3-tip.js
+++ b/d3-tip.js
@@ -44,6 +44,7 @@ d3.tip = function() {
         scrollLeft = document.documentElement.scrollLeft || document.body.scrollLeft
 
     nodel.html(content)
+      .attr("keep_visible", "false")
       .style('position', 'absolute')
       .style('opacity', 1)
       .style('pointer-events', 'all')
@@ -62,12 +63,21 @@ d3.tip = function() {
   // Returns a tip
   tip.hide = function() {
     var nodel = getNodeEl()
-    nodel
+    if (nodel.attr("keep_visible") != "true") nodel
       .style('opacity', 0)
       .style('pointer-events', 'none')
     return tip
   }
 
+  // Public - toggle foring or not the tip to remain visible
+  //
+  // Returns a tip
+  tip.toggle_keep_visible = function() {
+    var nodel = getNodeEl()
+    nodel.attr("keep_visible", nodel.attr("keep_visible") == "false")
+    return tip
+  }
+
   // Public: Proxy attr calls to the d3 tip container.  Sets or gets attribute value.
   //
   // n - name of the attribute