Allow geoJson.clip to be set after add.

Setting geoJson.tile(false) also explicitly, rather than implicitly, disables
clipping. The size of the clipping rect is inferred from the tile size when the
map is set (as before); this may change in the future if the map dispatches an
event when the tile size changes.

Also in this commit, the features associated with a geoJson tile are now
accessible as the `features` attribute of the tile. This is distinct from the
`features` attribute of the event, which only includes the updated features.

polymaps.js

@@ -2,7 +2,7 @@ if (!org) var org = {};
 if (!org.polymaps) org.polymaps = {};
 (function(po){
 
-  po.version = "2.1+2.1"; // This fork not semver!
+  po.version = "2.1+2.1+1"; // This fork not semver!
 
   var zero = {x: 0, y: 0};
 po.id = (function() {
@@ -1123,14 +1123,15 @@ po.geoJson = function(fetch) {
       container = geoJson.container(),
       url = "about:blank",
       clip = true,
-      clipId,
-      clipPath,
-      clipRect,
+      clipId = "org.polymaps." + po.id(),
+      clipHref = "url(#" + clipId + ")",
+      clipPath = container.insertBefore(po.svg("clipPath"), container.firstChild),
+      clipRect = clipPath.appendChild(po.svg("rect")),
       zoom = null,
-      tiles = {},
       features;
 
   container.setAttribute("fill-rule", "evenodd");
+  clipPath.setAttribute("id", clipId);
 
   if (!arguments.length) fetch = po.queue.json;
 
@@ -1220,6 +1221,7 @@ po.geoJson = function(fetch) {
 
   function load(tile, proj) {
     var g = tile.element = po.svg("g");
+    tile.features = [];
 
     proj = proj(tile);
 
@@ -1252,7 +1254,7 @@ po.geoJson = function(fetch) {
       }
 
       tile.ready = true;
-      updated.push.apply(tiles[tile.key] || (tiles[tile.key] = []), updated);
+      updated.push.apply(tile.features, updated);
       geoJson.dispatch({type: "load", tile: tile, features: updated});
     }
 
@@ -1261,13 +1263,10 @@ po.geoJson = function(fetch) {
     } else {
       tile.request = fetch(typeof url == "function" ? url(tile) : url, update);
     }
-
-    if (clipId) g.setAttribute("clip-path", "url(#" + clipId + ")");
   }
 
   function unload(tile) {
     if (tile.request) tile.request.abort(true);
-    delete tiles[tile.key];
   }
 
   geoJson.url = function(x) {
@@ -1286,32 +1285,36 @@ po.geoJson = function(fetch) {
 
   geoJson.clip = function(x) {
     if (!arguments.length) return clip;
-    clip = x;
+    if (clip) container.removeChild(clipPath);
+    if (clip = x) container.insertBefore(clipPath, container.firstChild);
+    var locks = geoJson.cache.locks();
+    for (var key in locks) {
+      if (clip) locks[key].element.setAttribute("clip-path", clipHref);
+      else locks[key].element.removeAttribute("clip-path");
+    }
     return geoJson;
   };
 
+  var __tile__ = geoJson.tile;
+  geoJson.tile = function(x) {
+    if (arguments.length && !x) geoJson.clip(x);
+    return __tile__.apply(geoJson, arguments);
+  };
+
   var __map__ = geoJson.map;
   geoJson.map = function(x) {
-    if (x) {
-      if (clip && geoJson.tile()) {
-        if (!clipPath) {
-          clipPath = container.insertBefore(po.svg("clipPath"), container.firstChild);
-          clipRect = clipPath.appendChild(po.svg("rect"));
-          clipPath.setAttribute("id", clipId = "org.polymaps." + po.id());
-        }
-        var size = x.tileSize();
-        clipRect.setAttribute("width", size.x);
-        clipRect.setAttribute("height", size.y);
-      } else if (clipPath) {
-        container.removeChild(clipPath);
-        clipPath = clipRect = clipId = null;
-      }
+    if (x && clipRect) {
+      var size = x.tileSize();
+      clipRect.setAttribute("width", size.x);
+      clipRect.setAttribute("height", size.y);
     }
     return __map__.apply(geoJson, arguments);
   };
 
   geoJson.show = function(tile) {
-    geoJson.dispatch({type: "show", tile: tile, features: tiles[tile.key] || []});
+    if (clip) tile.element.setAttribute("clip-path", clipHref);
+    else tile.element.removeAttribute("clip-path");
+    geoJson.dispatch({type: "show", tile: tile, features: tile.features});
     return geoJson;
   };