Added Kotlin to project and converted SearchSuggestionManager to Kotlin

app/build.gradle

@@ -1,4 +1,5 @@
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
 apply plugin: 'com.getkeepsafe.dexcount'
 
 android {
@@ -108,4 +109,7 @@ dependencies {
     def leakCanaryVersion = '1.5.1'
     debugCompile "com.squareup.leakcanary:leakcanary-android:$leakCanaryVersion"
     releaseCompile "com.squareup.leakcanary:leakcanary-android-no-op:$leakCanaryVersion"
+
+    // Kotlin
+    compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
 }

app/src/main/java/acr/browser/lightning/search/SuggestionsAdapter.java

@@ -302,11 +302,11 @@ public class SuggestionsAdapter extends BaseAdapter implements Filterable {
     @NonNull
     private Single<List<HistoryItem>> getSuggestionsForQuery(@NonNull final String query) {
         if (mSuggestionChoice == PreferenceManager.Suggestion.SUGGESTION_GOOGLE) {
-            return SuggestionsManager.createGoogleQueryObservable(query, mApplication);
+            return SuggestionsManager.INSTANCE.createGoogleQueryObservable(query, mApplication);
         } else if (mSuggestionChoice == PreferenceManager.Suggestion.SUGGESTION_DUCK) {
-            return SuggestionsManager.createDuckQueryObservable(query, mApplication);
+            return SuggestionsManager.INSTANCE.createDuckQueryObservable(query, mApplication);
         } else if (mSuggestionChoice == PreferenceManager.Suggestion.SUGGESTION_BAIDU) {
-            return SuggestionsManager.createBaiduQueryObservable(query, mApplication);
+            return SuggestionsManager.INSTANCE.createBaiduQueryObservable(query, mApplication);
         } else {
             return Single.empty();
         }

app/src/main/java/acr/browser/lightning/search/SuggestionsManager.java

@@ -1,70 +0,0 @@
-package acr.browser.lightning.search;
-
-import android.app.Application;
-import android.support.annotation.NonNull;
-
-import com.anthonycr.bonsai.Single;
-import com.anthonycr.bonsai.SingleAction;
-import com.anthonycr.bonsai.SingleSubscriber;
-
-import java.util.List;
-
-import acr.browser.lightning.database.HistoryItem;
-import acr.browser.lightning.search.suggestions.BaiduSuggestionsModel;
-import acr.browser.lightning.search.suggestions.DuckSuggestionsModel;
-import acr.browser.lightning.search.suggestions.GoogleSuggestionsModel;
-
-class SuggestionsManager {
-
-    private static volatile boolean sIsTaskExecuting;
-
-    static boolean isRequestInProgress() {
-        return sIsTaskExecuting;
-    }
-
-    @NonNull
-    static Single<List<HistoryItem>> createGoogleQueryObservable(@NonNull final String query,
-                                                                 @NonNull final Application application) {
-        return Single.create(new SingleAction<List<HistoryItem>>() {
-            @Override
-            public void onSubscribe(@NonNull final SingleSubscriber<List<HistoryItem>> subscriber) {
-                sIsTaskExecuting = true;
-                List<HistoryItem> results = new GoogleSuggestionsModel(application).fetchResults(query);
-                subscriber.onItem(results);
-                subscriber.onComplete();
-                sIsTaskExecuting = false;
-            }
-        });
-    }
-
-    @NonNull
-    static Single<List<HistoryItem>> createBaiduQueryObservable(@NonNull final String query,
-                                                                 @NonNull final Application application) {
-        return Single.create(new SingleAction<List<HistoryItem>>() {
-            @Override
-            public void onSubscribe(@NonNull final SingleSubscriber<List<HistoryItem>> subscriber) {
-                sIsTaskExecuting = true;
-                List<HistoryItem> results = new BaiduSuggestionsModel(application).fetchResults(query);
-                subscriber.onItem(results);
-                subscriber.onComplete();
-                sIsTaskExecuting = false;
-            }
-        });
-    }
-
-    @NonNull
-    static Single<List<HistoryItem>> createDuckQueryObservable(@NonNull final String query,
-                                                               @NonNull final Application application) {
-        return Single.create(new SingleAction<List<HistoryItem>>() {
-            @Override
-            public void onSubscribe(@NonNull final SingleSubscriber<List<HistoryItem>> subscriber) {
-                sIsTaskExecuting = true;
-                List<HistoryItem> results = new DuckSuggestionsModel(application).fetchResults(query);
-                subscriber.onItem(results);
-                subscriber.onComplete();
-                sIsTaskExecuting = false;
-            }
-        });
-    }
-
-}

app/src/main/java/acr/browser/lightning/search/SuggestionsManager.kt

@@ -0,0 +1,43 @@
+package acr.browser.lightning.search
+
+import acr.browser.lightning.database.HistoryItem
+import acr.browser.lightning.search.suggestions.BaiduSuggestionsModel
+import acr.browser.lightning.search.suggestions.DuckSuggestionsModel
+import acr.browser.lightning.search.suggestions.GoogleSuggestionsModel
+import android.app.Application
+import com.anthonycr.bonsai.Single
+import com.anthonycr.bonsai.SingleAction
+
+internal object SuggestionsManager {
+
+    @JvmStatic
+    @Volatile var isRequestInProgress: Boolean = false
+
+    fun createGoogleQueryObservable(query: String, application: Application) =
+            Single.create(SingleAction<List<HistoryItem>> { subscriber ->
+                isRequestInProgress = true
+                val results = GoogleSuggestionsModel(application).fetchResults(query)
+                subscriber.onItem(results)
+                subscriber.onComplete()
+                isRequestInProgress = false
+            })
+
+    fun createBaiduQueryObservable(query: String, application: Application) =
+            Single.create(SingleAction<List<HistoryItem>> { subscriber ->
+                isRequestInProgress = true
+                val results = BaiduSuggestionsModel(application).fetchResults(query)
+                subscriber.onItem(results)
+                subscriber.onComplete()
+                isRequestInProgress = false
+            })
+
+    fun createDuckQueryObservable(query: String, application: Application) =
+            Single.create(SingleAction<List<HistoryItem>> { subscriber ->
+                isRequestInProgress = true
+                val results = DuckSuggestionsModel(application).fetchResults(query)
+                subscriber.onItem(results)
+                subscriber.onComplete()
+                isRequestInProgress = false
+            })
+
+}

build.gradle

@@ -1,10 +1,12 @@
 buildscript {
+    ext.kotlin_version = '1.1.3'
     repositories {
         jcenter()
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:2.3.3'
         classpath 'com.getkeepsafe.dexcount:dexcount-gradle-plugin:0.6.3'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }