From bb0a0a8338c276a7b2bd6fe2d6580a1be2c806b3 Mon Sep 17 00:00:00 2001
From: tanem <tane.morgan@gmail.com>
Date: Wed, 30 Dec 2015 12:14:19 +1300
Subject: [PATCH] Add shouldComponentUpdate (closes #13)

---
 package.json    |  2 +-
 src/Salvager.js | 14 +++++++++-----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/package.json b/package.json
index 77a3a37..6c6b20d 100644
--- a/package.json
+++ b/package.json
@@ -93,4 +93,4 @@
     "clamp": "^1.0.1",
     "lodash.isfunction": "^3.0.6"
   }
-}
\ No newline at end of file
+}
diff --git a/src/Salvager.js b/src/Salvager.js
index 249e202..712c66f 100644
--- a/src/Salvager.js
+++ b/src/Salvager.js
@@ -11,7 +11,8 @@ export default class Salvager extends Component {
       bufferStart: 0,
       isUpdating: false,
       rowHeight: 0,
-      rowWrapperTransform: ''
+      rowWrapperTransform: '',
+      visibleAreaOffsetHeight: 0
     };
   }
 
@@ -52,6 +53,13 @@ export default class Salvager extends Component {
     });
   }
 
+  shouldComponentUpdate(nextProps, nextState) {
+    return (
+      nextState.bufferStart !== this.state.bufferStart ||
+      nextState.rowHeight !== this.state.rowHeight
+    );
+  }
+
   _buildRows() {
     let RenderedRow = Row;
     if (this.props.getRow) RenderedRow = this.props.getRow();
@@ -81,10 +89,6 @@ export default class Salvager extends Component {
     const bufferMidPoint = Math.floor(midPoint / this.state.rowHeight);
     let bufferStart = clamp(Math.floor(bufferMidPoint - this.props.bufferSize / 2), 0, this.props.data.length - this.props.bufferSize);
 
-    if (bufferStart === this.state.bufferStart) {
-      return this.setState({ isUpdating: false });
-    }
-
     this.setState({
       bufferStart,
       isUpdating: false,