Non null annotations in LightningWebClient/ChromeClient

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

@@ -0,0 +1,16 @@
+package acr.browser.lightning.utils;
+
+public class Preconditions {
+    /**
+     * Ensure that an object is not null
+     * and throw a RuntimeException if it
+     * is null.
+     *
+     * @param object check nullness on this object.
+     */
+    public static void checkNonNull(Object object) {
+        if (object == null) {
+            throw new RuntimeException("Object must not be null");
+        }
+    }
+}

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

@@ -9,6 +9,8 @@ import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.net.Uri;
 import android.os.Message;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.v7.app.AlertDialog;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -17,30 +19,28 @@ import android.webkit.ValueCallback;
 import android.webkit.WebChromeClient;
 import android.webkit.WebView;
 
+import com.anthonycr.grant.PermissionsManager;
+import com.anthonycr.grant.PermissionsResultAction;
 import com.squareup.otto.Bus;
 
 import acr.browser.lightning.R;
 import acr.browser.lightning.app.BrowserApp;
 import acr.browser.lightning.bus.BrowserEvents;
 import acr.browser.lightning.controller.UIController;
+import acr.browser.lightning.utils.Preconditions;
 
-import com.anthonycr.grant.PermissionsManager;
-import com.anthonycr.grant.PermissionsResultAction;
-
-/**
- * @author Stefano Pacifici based on Anthony C. Restaino code
- * @date 2015/09/21
- */
 class LightningChromeClient extends WebChromeClient {
 
     private static final String[] PERMISSIONS = new String[]{Manifest.permission.ACCESS_FINE_LOCATION};
 
-    private final Activity mActivity;
-    private final LightningView mLightningView;
-    private final UIController mUIController;
-    private final Bus eventBus;
+    @NonNull private final Activity mActivity;
+    @NonNull private final LightningView mLightningView;
+    @NonNull private final UIController mUIController;
+    @NonNull private final Bus eventBus;
 
-    LightningChromeClient(Activity activity, LightningView lightningView) {
+    LightningChromeClient(@NonNull Activity activity, @NonNull LightningView lightningView) {
+        Preconditions.checkNonNull(activity);
+        Preconditions.checkNonNull(lightningView);
         mActivity = activity;
         mUIController = (UIController) activity;
         mLightningView = lightningView;
@@ -55,7 +55,7 @@ class LightningChromeClient extends WebChromeClient {
     }
 
     @Override
-    public void onReceivedIcon(WebView view, Bitmap icon) {
+    public void onReceivedIcon(@NonNull WebView view, Bitmap icon) {
         mLightningView.getTitleInfo().setFavicon(icon);
         eventBus.post(new BrowserEvents.TabsChanged());
         cacheFavicon(view.getUrl(), icon, mActivity);
@@ -66,7 +66,7 @@ class LightningChromeClient extends WebChromeClient {
      *
      * @param icon the icon to cache
      */
-    private static void cacheFavicon(final String url, final Bitmap icon, final Context context) {
+    private static void cacheFavicon(final String url, @Nullable final Bitmap icon, @NonNull final Context context) {
         if (icon == null) return;
         final Uri uri = Uri.parse(url);
         if (uri.getHost() == null) {
@@ -77,7 +77,7 @@ class LightningChromeClient extends WebChromeClient {
 
 
     @Override
-    public void onReceivedTitle(WebView view, String title) {
+    public void onReceivedTitle(@Nullable WebView view, @Nullable String title) {
         if (title != null && !title.isEmpty()) {
             mLightningView.getTitleInfo().setTitle(title);
         } else {
@@ -90,8 +90,8 @@ class LightningChromeClient extends WebChromeClient {
     }
 
     @Override
-    public void onGeolocationPermissionsShowPrompt(final String origin,
-                                                   final GeolocationPermissions.Callback callback) {
+    public void onGeolocationPermissionsShowPrompt(@NonNull final String origin,
+                                                   @NonNull final GeolocationPermissions.Callback callback) {
         PermissionsManager.getInstance().requestPermissionsIfNecessaryForResult(mActivity, PERMISSIONS, new PermissionsResultAction() {
             @Override
             public void onGranted() {
@@ -170,11 +170,9 @@ class LightningChromeClient extends WebChromeClient {
      *
      * @return a Bitmap that can be used as a place holder for videos.
      */
+    @Nullable
     @Override
     public Bitmap getDefaultVideoPoster() {
-        if (mActivity == null) {
-            return null;
-        }
         final Resources resources = mActivity.getResources();
         return BitmapFactory.decodeResource(resources, android.R.drawable.spinner_background);
     }

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

@@ -11,6 +11,7 @@ import android.net.http.SslError;
 import android.os.Build;
 import android.os.Message;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.v7.app.AlertDialog;
 import android.text.InputType;
 import android.text.method.PasswordTransformationMethod;
@@ -41,23 +42,26 @@ import acr.browser.lightning.constant.Constants;
 import acr.browser.lightning.controller.UIController;
 import acr.browser.lightning.utils.AdBlock;
 import acr.browser.lightning.utils.IntentUtils;
+import acr.browser.lightning.utils.Preconditions;
 import acr.browser.lightning.utils.ProxyUtils;
 import acr.browser.lightning.utils.Utils;
 
 public class LightningWebClient extends WebViewClient {
 
 
-    private final Activity mActivity;
-    private final LightningView mLightningView;
-    private final UIController mUIController;
-    private final Bus mEventBus;
-    private final IntentUtils mIntentUtils;
+    @NonNull private final Activity mActivity;
+    @NonNull private final LightningView mLightningView;
+    @NonNull private final UIController mUIController;
+    @NonNull private final Bus mEventBus;
+    @NonNull private final IntentUtils mIntentUtils;
 
     @Inject ProxyUtils mProxyUtils;
     @Inject AdBlock mAdBlock;
 
-    LightningWebClient(Activity activity, LightningView lightningView) {
+    LightningWebClient(@NonNull Activity activity, @NonNull LightningView lightningView) {
         BrowserApp.getAppComponent().inject(this);
+        Preconditions.checkNonNull(activity);
+        Preconditions.checkNonNull(lightningView);
         mActivity = activity;
         mUIController = (UIController) activity;
         mLightningView = lightningView;
@@ -68,7 +72,7 @@ public class LightningWebClient extends WebViewClient {
 
     @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     @Override
-    public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
+    public WebResourceResponse shouldInterceptRequest(WebView view, @NonNull WebResourceRequest request) {
         if (mAdBlock.isAd(request.getUrl().toString())) {
             ByteArrayInputStream EMPTY = new ByteArrayInputStream("".getBytes());
             return new WebResourceResponse("text/plain", "utf-8", EMPTY);
@@ -76,6 +80,7 @@ public class LightningWebClient extends WebViewClient {
         return super.shouldInterceptRequest(view, request);
     }
 
+    @Nullable
     @SuppressWarnings("deprecation")
     @TargetApi(Build.VERSION_CODES.KITKAT_WATCH)
     @Override
@@ -89,7 +94,7 @@ public class LightningWebClient extends WebViewClient {
 
     @TargetApi(Build.VERSION_CODES.KITKAT)
     @Override
-    public void onPageFinished(WebView view, String url) {
+    public void onPageFinished(@NonNull WebView view, String url) {
         if (view.isShown()) {
             mUIController.updateUrl(url, true);
             view.postInvalidate();
@@ -166,7 +171,7 @@ public class LightningWebClient extends WebViewClient {
 
     @TargetApi(Build.VERSION_CODES.KITKAT)
     @Override
-    public void onScaleChanged(final WebView view, final float oldScale, final float newScale) {
+    public void onScaleChanged(@NonNull final WebView view, final float oldScale, final float newScale) {
         if (view.isShown() && mLightningView.mPreferences.getTextReflowEnabled() &&
                 Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
             if (mIsRunning)
@@ -187,7 +192,8 @@ public class LightningWebClient extends WebViewClient {
         }
     }
 
-    private static List<Integer> getAllSslErrorMessageCodes(SslError error) {
+    @NonNull
+    private static List<Integer> getAllSslErrorMessageCodes(@NonNull SslError error) {
         List<Integer> errorCodeMessageCodes = new ArrayList<>();
 
         if (error.hasError(SslError.SSL_DATE_INVALID)) {
@@ -213,7 +219,7 @@ public class LightningWebClient extends WebViewClient {
     }
 
     @Override
-    public void onReceivedSslError(WebView view, @NonNull final SslErrorHandler handler, SslError error) {
+    public void onReceivedSslError(WebView view, @NonNull final SslErrorHandler handler, @NonNull SslError error) {
         List<Integer> errorCodeMessageCodes = getAllSslErrorMessageCodes(error);
 
         StringBuilder stringBuilder = new StringBuilder();
@@ -245,7 +251,7 @@ public class LightningWebClient extends WebViewClient {
     }
 
     @Override
-    public void onFormResubmission(WebView view, @NonNull final Message dontResend, final Message resend) {
+    public void onFormResubmission(WebView view, @NonNull final Message dontResend, @NonNull final Message resend) {
         AlertDialog.Builder builder = new AlertDialog.Builder(mActivity);
         builder.setTitle(mActivity.getString(R.string.title_form_resubmission));
         builder.setMessage(mActivity.getString(R.string.message_form_resubmission))
@@ -269,7 +275,7 @@ public class LightningWebClient extends WebViewClient {
     }
 
     @Override
-    public boolean shouldOverrideUrlLoading(WebView view, String url) {
+    public boolean shouldOverrideUrlLoading(@NonNull WebView view, @NonNull String url) {
         // Check if configured proxy is available
         if (!mProxyUtils.isProxyReady()) {
             // User has been notified