added some missing nullable annotation additions, switched to compat implementations of some methods, fixed some lint warnings

app/src/main/java/acr/browser/lightning/activity/BrowserActivity.java

@@ -313,7 +313,7 @@ public abstract class BrowserActivity extends ThemableBrowserActivity implements
         }
 
         setNavigationDrawerWidth();
-        mDrawerLayout.setDrawerListener(new DrawerLocker());
+        mDrawerLayout.addDrawerListener(new DrawerLocker());
 
         mWebpageBitmap = ThemeUtils.getThemedBitmap(this, R.drawable.ic_webpage, mDarkTheme);
 
@@ -541,12 +541,10 @@ public abstract class BrowserActivity extends ThemableBrowserActivity implements
         }
 
         @Override
-        public void onDrawerSlide(View v, float arg) {
+        public void onDrawerSlide(View v, float arg) {}
-        }
 
         @Override
-        public void onDrawerStateChanged(int arg) {
+        public void onDrawerStateChanged(int arg) {}
-        }
 
     }
 

app/src/main/java/acr/browser/lightning/activity/TabsManager.java

@@ -54,7 +54,7 @@ public class TabsManager {
     @Nullable private TabNumberChangedListener mTabNumberListener;
 
     private boolean mIsInitialized = false;
-    private List<Runnable> mPostInitializationWorkList = new ArrayList<>();
+    private final List<Runnable> mPostInitializationWorkList = new ArrayList<>();
 
     @Inject PreferenceManager mPreferenceManager;
     @Inject BookmarkManager mBookmarkManager;

app/src/main/java/acr/browser/lightning/browser/BrowserPresenter.java

@@ -30,7 +30,7 @@ public class BrowserPresenter {
 
     private static final String TAG = BrowserPresenter.class.getSimpleName();
 
-    private TabsManager mTabsModel;
+    @NonNull private final TabsManager mTabsModel;
     @Inject PreferenceManager mPreferences;
     @Inject Bus mEventBus;
 

app/src/main/java/acr/browser/lightning/fragment/TabsFragment.java

@@ -19,6 +19,7 @@ import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v4.app.Fragment;
 import android.support.v4.view.ViewCompat;
+import android.support.v4.widget.TextViewCompat;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.RecyclerView.LayoutManager;
@@ -316,11 +317,7 @@ public class TabsFragment extends Fragment implements View.OnClickListener, View
 
             final Bitmap favicon = web.getFavicon();
             if (web.isForegroundTab()) {
-                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+                TextViewCompat.setTextAppearance(holder.txtTitle, R.style.boldText);
-                    holder.txtTitle.setTextAppearance(R.style.boldText);
-                } else {
-                    holder.txtTitle.setTextAppearance(getContext(), R.style.boldText);
-                }
                 Drawable foregroundDrawable;
                 if (!mDrawerTabs) {
                     foregroundDrawable = new BitmapDrawable(getResources(), mForegroundTabBitmap);
@@ -340,11 +337,7 @@ public class TabsFragment extends Fragment implements View.OnClickListener, View
                 }
                 holder.favicon.setImageBitmap(favicon);
             } else {
-                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+                TextViewCompat.setTextAppearance(holder.txtTitle, R.style.normalText);
-                    holder.txtTitle.setTextAppearance(R.style.normalText);
-                } else {
-                    holder.txtTitle.setTextAppearance(getContext(), R.style.normalText);
-                }
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                     holder.layout.setBackground(mBackgroundTabDrawable);
                 } else {

app/src/main/java/acr/browser/lightning/preference/PreferenceManager.java

@@ -63,7 +63,7 @@ public class PreferenceManager {
         public static final String INITIAL_CHECK_FOR_I2P = "checkForI2P";
     }
 
-    private final SharedPreferences mPrefs;
+    @NonNull private final SharedPreferences mPrefs;
 
     private static final String PREFERENCES = "settings";
 
@@ -255,7 +255,7 @@ public class PreferenceManager {
         return mPrefs.getBoolean(Name.DO_NOT_TRACK, false);
     }
 
-    public boolean getRemoveIdentifyingHeadersEnabled(){
+    public boolean getRemoveIdentifyingHeadersEnabled() {
         return mPrefs.getBoolean(Name.IDENTIFYING_HEADERS, false);
     }
 
@@ -271,7 +271,7 @@ public class PreferenceManager {
         mPrefs.edit().putString(name, value).apply();
     }
 
-    public void setRemoveIdentifyingHeadersEnabled(boolean enabled){
+    public void setRemoveIdentifyingHeadersEnabled(boolean enabled) {
         putBoolean(Name.IDENTIFYING_HEADERS, enabled);
     }
 
@@ -331,7 +331,7 @@ public class PreferenceManager {
         putBoolean(Name.COOKIES, enable);
     }
 
-    public void setDownloadDirectory(String directory) {
+    public void setDownloadDirectory(@NonNull String directory) {
         putString(Name.DOWNLOAD_DIRECTORY, directory);
     }
 
@@ -351,7 +351,7 @@ public class PreferenceManager {
         putBoolean(Name.HIDE_STATUS_BAR, enable);
     }
 
-    public void setHomepage(String homepage) {
+    public void setHomepage(@NonNull String homepage) {
         putString(Name.HOMEPAGE, homepage);
     }
 
@@ -438,7 +438,7 @@ public class PreferenceManager {
         putInt(Name.PROXY_CHOICE, choice);
     }
 
-    public void setProxyHost(String proxyHost) {
+    public void setProxyHost(@NonNull String proxyHost) {
         putString(Name.USE_PROXY_HOST, proxyHost);
     }
 
@@ -450,7 +450,7 @@ public class PreferenceManager {
         putInt(Name.USER_AGENT, choice);
     }
 
-    public void setUserAgentString(String agent) {
+    public void setUserAgentString(@Nullable String agent) {
         putString(Name.USER_AGENT_STRING, agent);
     }
 

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

@@ -33,7 +33,7 @@ import acr.browser.lightning.R;
 import acr.browser.lightning.database.HistoryItem;
 import acr.browser.lightning.utils.Utils;
 
-public class RetrieveSuggestionsTask extends AsyncTask<Void, Void, List<HistoryItem>> {
+class RetrieveSuggestionsTask extends AsyncTask<Void, Void, List<HistoryItem>> {
 
     private static final String TAG = RetrieveSuggestionsTask.class.getSimpleName();
 
@@ -42,12 +42,12 @@ public class RetrieveSuggestionsTask extends AsyncTask<Void, Void, List<HistoryI
     private static final String ENCODING = "ISO-8859-1";
     private static final long INTERVAL_DAY = 86400000;
     private static final String DEFAULT_LANGUAGE = "en";
-    private static XmlPullParser sXpp;
+    @Nullable private static XmlPullParser sXpp;
-    private static String sLanguage;
+    @Nullable private static String sLanguage;
-    private WeakReference<SuggestionsResult> mResultCallback;
+    @NonNull private final WeakReference<SuggestionsResult> mResultCallback;
-    private Application mApplication;
+    @NonNull private final Application mApplication;
-    private String mSearchSubtitle;
+    @NonNull private final String mSearchSubtitle;
-    private String mQuery;
+    @NonNull private String mQuery;
 
     public RetrieveSuggestionsTask(@NonNull String query,
                                    @NonNull SuggestionsResult callback,

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

@@ -6,7 +6,7 @@ import java.util.List;
 
 import acr.browser.lightning.database.HistoryItem;
 
-public interface SuggestionsResult {
+interface SuggestionsResult {
 
     /**
      * Called when the search suggestions have

app/src/main/java/acr/browser/lightning/utils/KeyboardHelper.java

@@ -19,7 +19,7 @@ public class KeyboardHelper {
         void keyboardVisibilityChanged(boolean visible);
     }
 
-    @NonNull private View mView;
+    @NonNull private final View mView;
     private int mLastRight = -1;
     private int mLastBottom = -1;
 

app/src/main/java/acr/browser/lightning/view/LightningView.java

@@ -40,7 +40,6 @@ import java.util.Map;
 
 import javax.inject.Inject;
 
-import acr.browser.lightning.R;
 import acr.browser.lightning.app.BrowserApp;
 import acr.browser.lightning.constant.BookmarkPage;
 import acr.browser.lightning.constant.Constants;
@@ -57,7 +56,6 @@ import acr.browser.lightning.react.Schedulers;
 import acr.browser.lightning.react.Subscriber;
 import acr.browser.lightning.react.OnSubscribe;
 import acr.browser.lightning.utils.ProxyUtils;
-import acr.browser.lightning.utils.ThemeUtils;
 import acr.browser.lightning.utils.UrlUtils;
 import acr.browser.lightning.utils.Utils;
 

app/src/main/java/acr/browser/lightning/view/LightningViewTitle.java

@@ -21,7 +21,7 @@ class LightningViewTitle {
 
     @Nullable private Bitmap mFavicon = null;
     @NonNull private String mTitle;
-    @NonNull Context mContext;
+    @NonNull private final Context mContext;
 
     public LightningViewTitle(@NonNull Context context) {
         mContext = context;

app/src/main/java/acr/browser/lightning/view/LightningWebClient.java

@@ -25,8 +25,6 @@ import android.webkit.WebViewClient;
 import android.widget.EditText;
 import android.widget.LinearLayout;
 
-import com.squareup.otto.Bus;
-
 import java.io.ByteArrayInputStream;
 import java.net.URISyntaxException;
 import java.util.ArrayList;