use butterknife to bind view and modify the click methods.

app/build.gradle

@@ -1,12 +1,11 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.2"
+    compileSdkVersion 27
     defaultConfig {
         applicationId "com.example.android.emojify"
         minSdkVersion 15
-        targetSdkVersion 25
+        targetSdkVersion 27
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -24,6 +23,8 @@ dependencies {
     androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
         exclude group: 'com.android.support', module: 'support-annotations'
     })
+
+
     compile 'com.android.support:design:25.2.0'
     compile 'com.android.support:appcompat-v7:25.2.0'
     compile 'com.google.android.gms:play-services-vision:10.2.0'

app/src/main/java/com/example/android/emojify/MainActivity.java

@@ -42,7 +42,12 @@
 import butterknife.BindView;
 import butterknife.ButterKnife;
 import butterknife.OnClick;
-import timber.log.Timber;
+
+
+public class MainActivity extends AppCompatActivity {
+
+    //  (2): Replace all View declarations with Butterknife annotations
+
 
 public class MainActivity extends AppCompatActivity {
 
@@ -52,14 +57,25 @@ public class MainActivity extends AppCompatActivity {
 
     private static final String FILE_PROVIDER_AUTHORITY = "com.example.android.fileprovider";
 
-    @BindView(R.id.image_view) ImageView mImageView;
 
-    @BindView(R.id.emojify_button) Button mEmojifyButton;
-    @BindView(R.id.share_button) FloatingActionButton mShareFab;
-    @BindView(R.id.save_button) FloatingActionButton mSaveFab;
-    @BindView(R.id.clear_button) FloatingActionButton mClearFab;
+    @BindView(R.id.image_view)
+    ImageView mImageView;
+
+    @BindView(R.id.emojify_button)
+    Button mEmojifyButton;
+
+    @BindView(R.id.share_button)
+    FloatingActionButton mShareFab;
+
+    @BindView(R.id.save_button)
+    FloatingActionButton mSaveFab;
+
+    @BindView(R.id.clear_button)
+    FloatingActionButton mClearFab;
+
+    @BindView(R.id.title_text_view)
+    TextView mTitleTextView;
 
-    @BindView(R.id.title_text_view) TextView mTitleTextView;
 
     private String mTempPhotoPath;
 
@@ -71,11 +87,12 @@ protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
 
-        // Bind the views
         ButterKnife.bind(this);
+        //  (3): Replace the findViewById calls with the Butterknife data binding
+        // Bind the views
+
+
 
-        // Set up Timber
-        Timber.plant(new Timber.DebugTree());
     }
 
     /**
@@ -100,7 +117,7 @@ public void emojifyMe() {
 
     @Override
     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
-            @NonNull int[] grantResults) {
+                                           @NonNull int[] grantResults) {
         // Called when you request permission to read and write to external storage
         switch (requestCode) {
             case REQUEST_STORAGE_PERMISSION: {
@@ -193,6 +210,9 @@ private void processAndSetImage() {
     }
 
 
+
+    //  (4): Replace OnClick methods with Butterknife annotations for OnClicks
+
     /**
      * OnClick method for the save button.
      */

app/src/main/res/layout/activity_main.xml

@@ -14,6 +14,7 @@
  limitations under the License.-->
 
 
+
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"

build.gradle

@@ -3,9 +3,10 @@
 buildscript {
     repositories {
         jcenter()
+        google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.2.3'
+        classpath 'com.android.tools.build:gradle:3.0.1'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -15,6 +16,7 @@ buildscript {
 allprojects {
     repositories {
         jcenter()
+        google()
     }
 }
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Mon Dec 28 10:00:20 PST 2015
+#Tue Aug 21 15:57:55 CST 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.14.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip