From 87e3b928d038be757ba0a7c7076af9dc4a18e1d0 Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@mapbox.com>
Date: Wed, 3 Apr 2019 23:26:26 -0400
Subject: [PATCH] Reduce drawing during history changes (closes #6086)

---
 modules/renderer/map.js       |  8 +++-----
 modules/ui/entity_editor.js   |  3 ++-
 modules/ui/selection_list.js  | 12 +++++++-----
 modules/ui/tools/save.js      |  9 ++++++---
 modules/ui/tools/undo_redo.js |  4 +++-
 5 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/modules/renderer/map.js b/modules/renderer/map.js
index 64f360483..7b1ec28b6 100644
--- a/modules/renderer/map.js
+++ b/modules/renderer/map.js
@@ -263,7 +263,7 @@ export function rendererMap(context) {
     }
 
 
-    function drawVector(difference, extent) {
+    function drawEditable(difference, extent) {
         var mode = context.mode();
         var graph = context.graph();
         var features = context.features();
@@ -576,15 +576,13 @@ export function rendererMap(context) {
 
         if (!difference) {
             supersurface.call(context.background());
+            wrapper.call(drawLayers);
         }
 
-        wrapper
-            .call(drawLayers);
-
         // OSM
         if (map.editable()) {
             context.loadTiles(projection);
-            drawVector(difference, extent);
+            drawEditable(difference, extent);
         } else {
             editOff();
         }
diff --git a/modules/ui/entity_editor.js b/modules/ui/entity_editor.js
index 1a58a27d2..6690297c0 100644
--- a/modules/ui/entity_editor.js
+++ b/modules/ui/entity_editor.js
@@ -239,8 +239,9 @@ export function uiEntityEditor(context) {
             .on('change.entity-editor', historyChanged);
 
 
-        function historyChanged() {
+        function historyChanged(difference) {
             if (_state === 'hide') return;
+            if (!difference || !difference.didChange.properties) return;
 
             var entity = context.hasEntity(_entityID);
             var graph = context.graph();
diff --git a/modules/ui/selection_list.js b/modules/ui/selection_list.js
index 0380f856b..031b75025 100644
--- a/modules/ui/selection_list.js
+++ b/modules/ui/selection_list.js
@@ -1,7 +1,4 @@
-import {
-    event as d3_event,
-    select as d3_select
-} from 'd3-selection';
+import { event as d3_event, select as d3_select } from 'd3-selection';
 
 import { t } from '../util/locale';
 import { modeSelect } from '../modes';
@@ -46,7 +43,12 @@ export function uiSelectionList(context, selectedIDs) {
             .append('div')
             .attr('class', 'feature-list cf');
 
-        context.history().on('change.selection-list', drawList);
+
+        context.history()
+            .on('change.selectionList', function(difference) {
+                if (difference) drawList();
+            });
+
         drawList();
 
 
diff --git a/modules/ui/tools/save.js b/modules/ui/tools/save.js
index f84bbf5c6..89fe4ea5b 100644
--- a/modules/ui/tools/save.js
+++ b/modules/ui/tools/save.js
@@ -16,8 +16,8 @@ export function uiToolSave(context) {
         label: t('save.title')
     };
 
-    var button = null,
-        tooltipBehavior = null;
+    var button = null;
+    var tooltipBehavior = null;
     var history = context.history();
     var key = uiCmd('⌘S');
     var _numChanges = 0;
@@ -102,8 +102,11 @@ export function uiToolSave(context) {
         context.keybinding()
             .on(key, save, true);
 
+
         context.history()
-            .on('change.save', updateCount);
+            .on('change.save', function(difference) {
+                if (difference) updateCount();
+            });
 
         context
             .on('enter.save', function() {
diff --git a/modules/ui/tools/undo_redo.js b/modules/ui/tools/undo_redo.js
index 3e61b8767..a46a9c7da 100644
--- a/modules/ui/tools/undo_redo.js
+++ b/modules/ui/tools/undo_redo.js
@@ -81,7 +81,9 @@ export function uiToolUndoRedo(context) {
             .on('drawn.undo_redo', debouncedUpdate);
 
         context.history()
-            .on('change.undo_redo', update);
+            .on('change.undo_redo', function(difference) {
+                if (difference) update();
+            });
 
         context
             .on('enter.undo_redo', update);