From 70e7cf02585589448e17752063d5006f4bb7a14f Mon Sep 17 00:00:00 2001
From: Bret Ikehara <bret@coverhound.com>
Date: Thu, 25 Aug 2016 11:28:29 -0700
Subject: [PATCH 1/4] cancel the jump animation

---
 src/jump.js | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/jump.js b/src/jump.js
index 9e59114..abeed48 100644
--- a/src/jump.js
+++ b/src/jump.js
@@ -23,6 +23,8 @@ const jumper = () => {
 
   let callback        // to call when done scrolling            (function)
 
+  let requestID       // requestAnimationFrame id               (number)
+
   // scroll position helper
 
   function location() {
@@ -53,9 +55,13 @@ const jumper = () => {
     window.scrollTo(0, next)
 
     // check progress
-    timeElapsed < duration
-      ? requestAnimationFrame(loop)       // continue scroll loop
-      : done()                            // scrolling is done
+    if (timeElapsed < duration) {
+      // continue scroll loop
+      requestID = requestAnimationFrame(loop)
+    } else {
+      // scrolling is done
+      done();
+    }
   }
 
   // scroll finished helper
@@ -82,6 +88,12 @@ const jumper = () => {
     timeStart = false
   }
 
+  // cancels the requestAnimationFrame
+
+  function cancel() {
+    cancelAnimationFrame(requestID);
+  }
+
   // API
 
   function jump(target, options = {}) {
@@ -136,7 +148,9 @@ const jumper = () => {
     }
 
     // start the loop
-    requestAnimationFrame(loop)
+    requestID = requestAnimationFrame(loop)
+
+    return cancel
   }
 
   // expose only the jump method

From 60303346e9f7553cafd57ac86070970af79e4b2a Mon Sep 17 00:00:00 2001
From: Bret Ikehara <bret@coverhound.com>
Date: Tue, 30 Aug 2016 14:22:54 -0700
Subject: [PATCH 2/4] return the cancel jump

---
 src/jump.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/jump.js b/src/jump.js
index abeed48..15e5660 100644
--- a/src/jump.js
+++ b/src/jump.js
@@ -154,7 +154,10 @@ const jumper = () => {
   }
 
   // expose only the jump method
-  return jump
+  return {
+    jump,
+    cancel,
+  };
 }
 
 // export singleton

From b72c2fa37f8811515f5910067f697d3be6df1c98 Mon Sep 17 00:00:00 2001
From: Bret Ikehara <bret@coverhound.com>
Date: Tue, 30 Aug 2016 15:30:21 -0700
Subject: [PATCH 3/4] restart the jump start

---
 src/jump.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/jump.js b/src/jump.js
index 15e5660..f2c1fc6 100644
--- a/src/jump.js
+++ b/src/jump.js
@@ -91,6 +91,8 @@ const jumper = () => {
   // cancels the requestAnimationFrame
 
   function cancel() {
+    timeStart = false;
+
     cancelAnimationFrame(requestID);
   }
 

From e8f5e69f23f3908578909e10ac1066e356ef8425 Mon Sep 17 00:00:00 2001
From: Bret Ikehara <bret@coverhound.com>
Date: Thu, 1 Sep 2016 17:08:39 -0700
Subject: [PATCH 4/4] expose whether the jumper is running

---
 src/jump.js | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/jump.js b/src/jump.js
index f2c1fc6..fb13bd0 100644
--- a/src/jump.js
+++ b/src/jump.js
@@ -96,6 +96,12 @@ const jumper = () => {
     cancelAnimationFrame(requestID);
   }
 
+  // indicates whether jumper is executing
+
+  function isJumping() {
+    return !!timeStart;
+  }
+
   // API
 
   function jump(target, options = {}) {
@@ -159,6 +165,7 @@ const jumper = () => {
   return {
     jump,
     cancel,
+    isJumping,
   };
 }