From 168cda4f75d3a55d2596eda25dcee42eaaa85b15 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 18 Apr 2014 13:23:20 -0600
Subject: [PATCH] Pause measurement on overflowchanged during updates

Content updates trigger overflowchanged, but we're mainly using it to
detect when the editor component has been resized. Pausing measurement
during content updates makes them faster.
---
 src/editor-scroll-view-component.coffee | 32 ++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/editor-scroll-view-component.coffee b/src/editor-scroll-view-component.coffee
index 1ee1a6f92..b4e099166 100644
--- a/src/editor-scroll-view-component.coffee
+++ b/src/editor-scroll-view-component.coffee
@@ -1,5 +1,6 @@
 React = require 'react'
 {div} = require 'reactionary'
+{debounce} = require 'underscore-plus'
 
 InputComponent = require './input-component'
 LinesComponent = require './lines-component'
@@ -10,6 +11,10 @@ module.exports =
 EditorScrollViewComponent = React.createClass
   displayName: 'EditorScrollViewComponent'
 
+  measurementPaused: false
+  measurementPending: false
+  measurementRequested: false
+
   render: ->
     {editor, fontSize, fontFamily, lineHeight, showIndentGuide, cursorBlinkPeriod, cursorBlinkResumeDelay} = @props
     {visibleRowRange, preservedScreenRow, pendingChanges, cursorsMoved, onInputFocused, onInputBlurred} = @props
@@ -38,9 +43,34 @@ EditorScrollViewComponent = React.createClass
           SelectionsComponent({editor})
 
   componentDidMount: ->
-    @getDOMNode().addEventListener 'overflowchanged', @measureHeightAndWidth
+    @getDOMNode().addEventListener 'overflowchanged', @requestMeasurement
     @measureHeightAndWidth()
 
+  componentDidUpdate: ->
+    @pauseMeasurement()
+
+  requestMeasurement: ->
+    if @measurementPaused
+      @measurementRequested = true
+    else unless @measurementPending
+      @measurementPending = true
+      requestAnimationFrame =>
+        @measurementPending = false
+        @measureHeightAndWidth()
+
+  pauseMeasurement: ->
+    @measurementPaused = true
+    @resumeOverflowChangedEventsAfterDelay ?= debounce(@resumeMeasurement, 500)
+    @resumeOverflowChangedEventsAfterDelay()
+
+  resumeMeasurement: ->
+    @measurementPaused = false
+    if @measurementRequested
+      @measurementRequested = false
+      @requestMeasurement()
+
+  resumeMeasurementAfterDelay: null
+
   onInput: (char, replaceLastCharacter) ->
     {editor} = @props