NonNull annotations
diff --git a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionCircleFragment.java b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionCircleFragment.java
index cb79bbe..cff6907 100644
--- a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionCircleFragment.java
+++ b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionCircleFragment.java
@@ -1,6 +1,7 @@
 package com.davemorrissey.labs.subscaleview.test.extension;
 
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -14,7 +15,7 @@
 public class ExtensionCircleFragment extends Fragment {
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View rootView = inflater.inflate(layout.extension_circle_fragment, container, false);
         rootView.findViewById(id.next).setOnClickListener(new View.OnClickListener() {
             @Override public void onClick(View v) { ((ExtensionActivity) ExtensionCircleFragment.this.getActivity()).next(); }
diff --git a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionFreehandFragment.java b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionFreehandFragment.java
index 73f35b1..d943fea 100644
--- a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionFreehandFragment.java
+++ b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionFreehandFragment.java
@@ -1,6 +1,7 @@
 package com.davemorrissey.labs.subscaleview.test.extension;
 
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -14,7 +15,7 @@
 public class ExtensionFreehandFragment extends Fragment {
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View rootView = inflater.inflate(layout.extension_freehand_fragment, container, false);
         rootView.findViewById(id.previous).setOnClickListener(new View.OnClickListener() {
             @Override public void onClick(View v) { ((ExtensionActivity) ExtensionFreehandFragment.this.getActivity()).previous(); }
diff --git a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionPinFragment.java b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionPinFragment.java
index 600b461..f5231c1 100644
--- a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionPinFragment.java
+++ b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/extension/ExtensionPinFragment.java
@@ -2,6 +2,7 @@
 
 import android.graphics.PointF;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -15,7 +16,7 @@
 public class ExtensionPinFragment extends Fragment {
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View rootView = inflater.inflate(layout.extension_pin_fragment, container, false);
         rootView.findViewById(id.next).setOnClickListener(new View.OnClickListener() {
             @Override public void onClick(View v) { ((ExtensionActivity) ExtensionPinFragment.this.getActivity()).next(); }
diff --git a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayLargeFragment.java b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayLargeFragment.java
index ee3ae8d..58f923e 100644
--- a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayLargeFragment.java
+++ b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayLargeFragment.java
@@ -1,6 +1,7 @@
 package com.davemorrissey.labs.subscaleview.test.imagedisplay;
 
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -14,7 +15,7 @@
 public class ImageDisplayLargeFragment extends Fragment {
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View rootView = inflater.inflate(layout.imagedisplay_large_fragment, container, false);
         rootView.findViewById(id.next).setOnClickListener(new View.OnClickListener() {
             @Override public void onClick(View v) { ((ImageDisplayActivity) ImageDisplayLargeFragment.this.getActivity()).next(); }
diff --git a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayRegionFragment.java b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayRegionFragment.java
index d360d67..5e6b1c8 100644
--- a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayRegionFragment.java
+++ b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayRegionFragment.java
@@ -3,6 +3,7 @@
 import android.graphics.Bitmap;
 import android.graphics.Rect;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -21,7 +22,7 @@
 public class ImageDisplayRegionFragment extends Fragment {
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View rootView = inflater.inflate(layout.imagedisplay_region_fragment, container, false);
         final SubsamplingScaleImageView imageView = rootView.findViewById(id.imageView);
         imageView.setBitmapDecoderFactory(new CompatDecoderFactory<ImageDecoder>(SkiaImageDecoder.class, Bitmap.Config.ARGB_8888));
diff --git a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayRotateFragment.java b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayRotateFragment.java
index e3a2584..c44627a 100644
--- a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayRotateFragment.java
+++ b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/imagedisplay/ImageDisplayRotateFragment.java
@@ -1,6 +1,7 @@
 package com.davemorrissey.labs.subscaleview.test.imagedisplay;
 
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -14,7 +15,7 @@
 public class ImageDisplayRotateFragment extends Fragment {
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View rootView = inflater.inflate(layout.imagedisplay_rotate_fragment, container, false);
         final SubsamplingScaleImageView imageView = rootView.findViewById(id.imageView);
         imageView.setImage(ImageSource.asset("swissroad.jpg"));
diff --git a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/viewpager/VerticalViewPager.java b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/viewpager/VerticalViewPager.java
index 3d64042..71131ea 100644
--- a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/viewpager/VerticalViewPager.java
+++ b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/viewpager/VerticalViewPager.java
@@ -1,6 +1,7 @@
 package com.davemorrissey.labs.subscaleview.test.viewpager;
 
 import android.content.Context;
+import android.support.annotation.NonNull;
 import android.support.v4.view.ViewPager;
 import android.util.AttributeSet;
 import android.view.MotionEvent;
@@ -29,7 +30,7 @@
     private class VerticalPageTransformer implements ViewPager.PageTransformer {
 
         @Override
-        public void transformPage(View view, float position) {
+        public void transformPage(@NonNull View view, float position) {
             if (position < -1) {
                 view.setAlpha(0);
             } else if (position <= 1) {
diff --git a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/viewpager/ViewPagerFragment.java b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/viewpager/ViewPagerFragment.java
index 9f7e86d..03e7155 100644
--- a/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/viewpager/ViewPagerFragment.java
+++ b/sample/src/main/java/com/davemorrissey/labs/subscaleview/test/viewpager/ViewPagerFragment.java
@@ -1,6 +1,7 @@
 package com.davemorrissey.labs.subscaleview.test.viewpager;
 
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -25,7 +26,7 @@
     }
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View rootView = inflater.inflate(layout.view_pager_page, container, false);
 
         if (savedInstanceState != null) {
@@ -42,7 +43,7 @@
     }
 
     @Override
-    public void onSaveInstanceState(Bundle outState) {
+    public void onSaveInstanceState(@NonNull Bundle outState) {
         super.onSaveInstanceState(outState);
         View rootView = getView();
         if (rootView != null) {