From 6b194ed6278d4b05a04a20d6907203ed329bef77 Mon Sep 17 00:00:00 2001
From: Tom Hughes <tom@compton.nu>
Date: Sun, 14 Oct 2018 12:28:26 +0100
Subject: [PATCH 1/1] Resize change bounding boxes on a zoom change

---
 app/assets/javascripts/index/history.js | 56 ++++++++++++++-----------
 1 file changed, 31 insertions(+), 25 deletions(-)

diff --git a/app/assets/javascripts/index/history.js b/app/assets/javascripts/index/history.js
index b0f34a2ad..6274c135f 100644
--- a/app/assets/javascripts/index/history.js
+++ b/app/assets/javascripts/index/history.js
@@ -89,36 +89,30 @@ OSM.History = function(map) {
     });
   }
 
-  function updateMap() {
-    group.clearLayers();
-
-    var changesets = [];
-
-    $("[data-changeset]").each(function () {
-      var changeset = $(this).data('changeset');
-      if (changeset.bbox) {
-        var bottomLeft = map.project(L.latLng(changeset.bbox.minlat, changeset.bbox.minlon)),
-            topRight = map.project(L.latLng(changeset.bbox.maxlat, changeset.bbox.maxlon)),
-            width = topRight.x - bottomLeft.x,
-            height = bottomLeft.y - topRight.y,
-            minSize = 20;  // Min width/height of changeset in pixels
+  var changesets = [];
 
-        if (width < minSize) {
-          bottomLeft.x -= ((minSize - width) / 2);
-          topRight.x += ((minSize - width) / 2);
-        }
+  function updateBounds() {
+    group.clearLayers();
 
-        if (height < minSize) {
-          bottomLeft.y += ((minSize - height) / 2);
-          topRight.y -= ((minSize - height) / 2);
-        }
+    changesets.forEach(function(changeset) {
+      var bottomLeft = map.project(L.latLng(changeset.bbox.minlat, changeset.bbox.minlon)),
+          topRight = map.project(L.latLng(changeset.bbox.maxlat, changeset.bbox.maxlon)),
+          width = topRight.x - bottomLeft.x,
+          height = bottomLeft.y - topRight.y,
+          minSize = 20;  // Min width/height of changeset in pixels
 
-        var bounds = [map.unproject(bottomLeft),
-                      map.unproject(topRight)];
+      if (width < minSize) {
+        bottomLeft.x -= ((minSize - width) / 2);
+        topRight.x += ((minSize - width) / 2);
+      }
 
-        changeset.bounds = L.latLngBounds(bounds);
-        changesets.push(changeset);
+      if (height < minSize) {
+        bottomLeft.y += ((minSize - height) / 2);
+        topRight.y -= ((minSize - height) / 2);
       }
+
+      changeset.bounds = L.latLngBounds(map.unproject(bottomLeft),
+                                        map.unproject(topRight));
     });
 
     changesets.sort(function (a, b) {
@@ -132,6 +126,16 @@ OSM.History = function(map) {
       rect.id = changeset.id;
       rect.addTo(group);
     }
+  }
+
+  function updateMap() {
+    changesets = $("[data-changeset]").map(function (index,element) {
+      return $(element).data('changeset');
+    }).get().filter(function (changeset) {
+      return changeset.bbox;
+    });
+
+    updateBounds();
 
     if (window.location.pathname !== '/history') {
       var bounds = group.getBounds();
@@ -151,6 +155,8 @@ OSM.History = function(map) {
       map.on("moveend", update);
     }
 
+    map.on("zoomend", updateBounds);
+
     update();
   };
 
-- 
2.43.2