Hovercards - make 'em work a bit better

Summary:
this diff makes hovercards load and draw but a single time as appropos; pre-diff we could hammer the server by moving the mouse a bunch before the initial load and the re-draw event was continuously firing.

also makes hovercards work inside whacked out divs like the Conpherence message panel. Fixes T2949.

Test Plan: played with conpherence and phriction, observing hovercards showing up like they should

Reviewers: epriestley, chad

Reviewed By: epriestley

CC: AnhNhan, aran, Korvin

Maniphest Tasks: T2949

Differential Revision: https://secure.phabricator.com/D5719

webroot/rsrc/externals/javelin/lib/Vector.js

@@ -238,9 +238,16 @@ JX.install('Vector', {
       var x = 0;
       var y = 0;
       do {
-        x += node.offsetLeft;
+        var offsetParent = node.offsetParent;
-        y += node.offsetTop;
+        var scrollLeft = 0;
-        node = node.offsetParent;
+        var scrollTop = 0;
+        if (offsetParent && offsetParent != document.body) {
+          scrollLeft = offsetParent.scrollLeft;
+          scrollTop = offsetParent.scrollTop;
+        }
+        x += (node.offsetLeft - scrollLeft);
+        y += (node.offsetTop - scrollTop);
+        node = offsetParent;
       } while (node && node != document.body);
 
       return new JX.Vector(x, y);

webroot/rsrc/js/application/core/Hovercard.js

@@ -27,18 +27,21 @@ JX.install('Hovercard', {
     },
 
     getCard : function() {
-      return this._node;
+      var self = JX.Hovercard;
+      return self._node;
     },
 
     show : function(root, phid) {
       var self = JX.Hovercard;
+      // Already displaying
+      if (self.getCard() && phid == self._visiblePHID) {
+        return;
+      }
       self.hide();
 
       self._visiblePHID = phid;
       self._activeRoot = root;
 
-      // Hovercards are all loaded by now, but when somebody previews a comment
-      // for example it may not be loaded yet.
       if (!(phid in self._cards)) {
         self._load([phid]);
       } else {
@@ -48,8 +51,8 @@ JX.install('Hovercard', {
 
     _drawCard : function(phid) {
       var self = JX.Hovercard;
-      // Already displaying
+      // card is loading...
-      if (self.getCard() && phid == self._visiblePHID) {
+      if (self._cards[phid] === true) {
         return;
       }
       // Not the current requested card
@@ -74,7 +77,6 @@ JX.install('Hovercard', {
 
       // Retrieve size from child (wrapper), since node gives wrong dimensions?
       var child = node.firstChild;
-
       var p = JX.$V(root);
       var d = JX.Vector.getDim(root);
       var n = JX.Vector.getDim(child);
@@ -122,8 +124,20 @@ JX.install('Hovercard', {
       var self = JX.Hovercard;
       var uri = JX.$U(self.fetchUrl);
 
+      var send = false;
       for (var ii = 0; ii < phids.length; ii++) {
+        var phid = phids[ii];
+        if (phid in self._cards) {
+          continue;
+        }
+        self._cards[phid] = true; // means "loading"
         uri.setQueryParam("phids["+ii+"]", phids[ii]);
+        send = true;
+      }
+
+      if (!send) {
+        // already loaded / loading everything!
+        return;
       }
 
       new JX.Request(uri, function(r) {