weblayer: adds @NonNull/@Nullable to public API

I only added this to the public API as that is the important
part.

BUG=none
TEST=none

Change-Id: I2369ea07fcac9e3bb87632f6235f11e37d5283a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1874587
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708402}

weblayer/public/java/BUILD.gn

@@ -44,6 +44,7 @@ template("weblayer_java") {
 
     deps = [
       ":weblayer_client_manifest",
+      "//third_party/android_deps:androidx_annotation_annotation_java",
       "//third_party/android_deps:com_android_support_support_fragment_java",
       "//weblayer/browser/java:client_java",
     ]

weblayer/public/java/org/chromium/weblayer/BrowserController.java

@@ -8,6 +8,9 @@ import android.net.Uri;
 import android.os.RemoteException;
 import android.webkit.ValueCallback;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import org.json.JSONException;
 import org.json.JSONObject;
 
@@ -19,6 +22,10 @@ import org.chromium.weblayer_private.aidl.IFullscreenDelegateClient;
 import org.chromium.weblayer_private.aidl.IObjectWrapper;
 import org.chromium.weblayer_private.aidl.ObjectWrapper;
 
+/**
+ * Represents a web-browser. More specifically, owns a NavigationController, and allows configuring
+ * state of the browser, such as delegates and observers.
+ */
 public final class BrowserController {
     /** The top level key of the JSON object returned by executeScript(). */
     public static final String SCRIPT_RESULT_KEY = "result";
@@ -41,7 +48,7 @@ public final class BrowserController {
         mNavigationController = NavigationController.create(mImpl);
     }
 
-    public void setDownloadDelegate(DownloadDelegate delegate) {
+    public void setDownloadDelegate(@Nullable DownloadDelegate delegate) {
         try {
             if (delegate != null) {
                 mDownloadDelegateClient = new DownloadDelegateClientImpl(delegate);
@@ -55,7 +62,7 @@ public final class BrowserController {
         }
     }
 
-    public void setFullscreenDelegate(FullscreenDelegate delegate) {
+    public void setFullscreenDelegate(@Nullable FullscreenDelegate delegate) {
         try {
             if (delegate != null) {
                 mFullscreenDelegateClient = new FullscreenDelegateClientImpl(delegate);
@@ -78,7 +85,8 @@ public final class BrowserController {
      * callback if provided. The object passed to the callback will have a single key
      * SCRIPT_RESULT_KEY which will hold the result of running the script.
      */
-    public void executeScript(String script, ValueCallback<JSONObject> callback) {
+    public void executeScript(
+            @NonNull String script, @Nullable ValueCallback<JSONObject> callback) {
         try {
             ValueCallback<String> stringCallback = (String result) -> {
                 if (callback == null) {
@@ -99,6 +107,7 @@ public final class BrowserController {
         }
     }
 
+    @Nullable
     public FullscreenDelegate getFullscreenDelegate() {
         return mFullscreenDelegateClient != null ? mFullscreenDelegateClient.getDelegate() : null;
     }
@@ -108,15 +117,16 @@ public final class BrowserController {
         // TODO(sky): figure out right assertion here if mProfile is non-null.
     }
 
+    @NonNull
     public NavigationController getNavigationController() {
         return mNavigationController;
     }
 
-    public void addObserver(BrowserObserver observer) {
+    public void addObserver(@Nullable BrowserObserver observer) {
         mObservers.addObserver(observer);
     }
 
-    public void removeObserver(BrowserObserver observer) {
+    public void removeObserver(@Nullable BrowserObserver observer) {
         mObservers.removeObserver(observer);
     }
 

weblayer/public/java/org/chromium/weblayer/BrowserFragment.java

@@ -16,6 +16,8 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+import androidx.annotation.NonNull;
+
 import org.chromium.weblayer_private.aidl.APICallException;
 import org.chromium.weblayer_private.aidl.IBrowserFragment;
 import org.chromium.weblayer_private.aidl.IObjectWrapper;
@@ -149,6 +151,7 @@ public final class BrowserFragment extends Fragment {
      * Returns the {@link BrowserFragmentController} associated with this fragment.
      * The controller is available only between BrowserFragment's onCreate() and onDestroy().
      */
+    @NonNull
     public BrowserFragmentController getController() {
         if (mBrowserFragmentController == null) {
             throw new RuntimeException("BrowserFragmentController is available only between "

weblayer/public/java/org/chromium/weblayer/BrowserFragmentController.java

@@ -8,6 +8,9 @@ import android.os.RemoteException;
 import android.view.View;
 import android.webkit.ValueCallback;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import org.chromium.weblayer_private.aidl.APICallException;
 import org.chromium.weblayer_private.aidl.IBrowserFragmentController;
 import org.chromium.weblayer_private.aidl.ObjectWrapper;
@@ -27,6 +30,7 @@ public final class BrowserFragmentController {
     }
 
     // TODO(pshmakov): rename this to BrowserTabController.
+    @NonNull
     public BrowserController getBrowserController() {
         if (mController == null) {
             try {
@@ -38,7 +42,7 @@ public final class BrowserFragmentController {
         return mController;
     }
 
-    public void setTopView(View view) {
+    public void setTopView(@Nullable View view) {
         try {
             mImpl.setTopView(ObjectWrapper.wrap(view));
         } catch (RemoteException e) {
@@ -55,6 +59,7 @@ public final class BrowserFragmentController {
      * @return a ListenableResult of whether the request succeeded. A request might fail if it is
      * subsumed by a subsequent request, or if this object is destroyed.
      */
+    @NonNull
     public ListenableResult<Boolean> setSupportsEmbedding(boolean enable) {
         try {
             final ListenableResult<Boolean> listenableResult = new ListenableResult<Boolean>();
@@ -75,6 +80,7 @@ public final class BrowserFragmentController {
      * Returns {@link Profile} associated with this Browser Fragment. Multiple fragments can share
      * the same Profile.
      */
+    @NonNull
     public Profile getProfile() {
         try {
             return mProfileManager.getProfileFor(mImpl.getProfile());

weblayer/public/java/org/chromium/weblayer/BrowserObserver.java

@@ -6,6 +6,8 @@ package org.chromium.weblayer;
 
 import android.net.Uri;
 
+import androidx.annotation.NonNull;
+
 /**
  * Informed of interesting events that happen during the lifetime of a BrowserController.
  */
@@ -15,7 +17,7 @@ public abstract class BrowserObserver {
      *
      * @param url The new user-visible url.
      */
-    public void visibleUrlChanged(Uri url) {}
+    public void visibleUrlChanged(@NonNull Uri url) {}
 
     /**
      * The load state of the document has changed.

weblayer/public/java/org/chromium/weblayer/DownloadDelegate.java

@@ -4,6 +4,8 @@
 
 package org.chromium.weblayer;
 
+import androidx.annotation.NonNull;
+
 /**
  * An interface that allows clients to handle download requests originating in the browser.
  */
@@ -17,6 +19,6 @@ public abstract class DownloadDelegate {
      * @param mimetype the mimetype of the content reported by the server
      * @param contentLength the file size reported by the server
      */
-    public abstract void downloadRequested(String url, String userAgent, String contentDisposition,
-            String mimetype, long contentLength);
+    public abstract void downloadRequested(@NonNull String url, @NonNull String userAgent,
+            @NonNull String contentDisposition, @NonNull String mimetype, long contentLength);
 }

weblayer/public/java/org/chromium/weblayer/FullscreenDelegate.java

@@ -4,6 +4,8 @@
 
 package org.chromium.weblayer;
 
+import androidx.annotation.NonNull;
+
 /**
  * Used to configure fullscreen related state. HTML fullscreen support is only enabled if a
  * FullscreenDelegate is set.
@@ -17,7 +19,7 @@ public abstract class FullscreenDelegate {
      *
      * NOTE: the Runnable must not be used synchronously.
      */
-    public abstract void enterFullscreen(Runnable exitFullscreenRunner);
+    public abstract void enterFullscreen(@NonNull Runnable exitFullscreenRunner);
 
     /**
      * The page has exited fullscreen mode and the system should be moved out of fullscreen mode.

weblayer/public/java/org/chromium/weblayer/ListenableResult.java

@@ -4,6 +4,8 @@
 
 package org.chromium.weblayer;
 
+import androidx.annotation.NonNull;
+
 import java.util.ArrayList;
 
 /**
@@ -21,7 +23,7 @@ public class ListenableResult<V> {
      * Call the callback with the result of computation.
      * Note callback may be called immediately.
      */
-    public void addCallback(Callback<V> callback) {
+    public void addCallback(@NonNull Callback<V> callback) {
         if (mHasResult) {
             callback.onResult(mResult);
             return;

weblayer/public/java/org/chromium/weblayer/Navigation.java

@@ -7,6 +7,8 @@ package org.chromium.weblayer;
 import android.net.Uri;
 import android.os.RemoteException;
 
+import androidx.annotation.NonNull;
+
 import org.chromium.weblayer_private.aidl.APICallException;
 import org.chromium.weblayer_private.aidl.IClientNavigation;
 import org.chromium.weblayer_private.aidl.INavigation;
@@ -58,6 +60,7 @@ public final class Navigation extends IClientNavigation.Stub {
      * The uri the main frame is navigating to. This may change during the navigation when
      * encountering a server redirect.
      */
+    @NonNull
     public Uri getUri() {
         try {
             return Uri.parse(mNavigationImpl.getUri());
@@ -70,6 +73,7 @@ public final class Navigation extends IClientNavigation.Stub {
      * Returns the redirects that occurred on the way to the current page. The current page is the
      * last one in the list (so even when there's no redirect, there will be one entry in the list).
      */
+    @NonNull
     public List<Uri> getRedirectChain() {
         try {
             List<Uri> redirects = new ArrayList<Uri>();

weblayer/public/java/org/chromium/weblayer/NavigationController.java

@@ -7,6 +7,8 @@ package org.chromium.weblayer;
 import android.net.Uri;
 import android.os.RemoteException;
 
+import androidx.annotation.NonNull;
+
 import org.chromium.weblayer_private.aidl.APICallException;
 import org.chromium.weblayer_private.aidl.IBrowserController;
 import org.chromium.weblayer_private.aidl.IClientNavigation;
@@ -37,7 +39,7 @@ public final class NavigationController {
         mObservers = new ObserverList<NavigationObserver>();
     }
 
-    public void navigate(Uri uri) {
+    public void navigate(@NonNull Uri uri) {
         try {
             mNavigationController.navigate(uri.toString());
         } catch (RemoteException e) {
@@ -109,6 +111,7 @@ public final class NavigationController {
         }
     }
 
+    @NonNull
     public Uri getNavigationEntryDisplayUri(int index) {
         try {
             return Uri.parse(mNavigationController.getNavigationEntryDisplayUri(index));
@@ -117,11 +120,11 @@ public final class NavigationController {
         }
     }
 
-    public void addObserver(NavigationObserver observer) {
+    public void addObserver(@NonNull NavigationObserver observer) {
         mObservers.addObserver(observer);
     }
 
-    public void removeObserver(NavigationObserver observer) {
+    public void removeObserver(@NonNull NavigationObserver observer) {
         mObservers.removeObserver(observer);
     }
 

weblayer/public/java/org/chromium/weblayer/NavigationObserver.java

@@ -4,6 +4,8 @@
 
 package org.chromium.weblayer;
 
+import androidx.annotation.NonNull;
+
 /**
  * Informed of interesting events that happen during the lifetime of NavigationController. This
  * interface is only notified of main frame navigations.
@@ -37,14 +39,14 @@ public abstract class NavigationObserver {
      *
      * @param navigation the unique object for this navigation.
      */
-    public void navigationStarted(Navigation navigation) {}
+    public void navigationStarted(@NonNull Navigation navigation) {}
 
     /**
      * Called when a navigation encountered a server redirect.
      *
      * @param navigation the unique object for this navigation.
      */
-    public void navigationRedirected(Navigation navigation) {}
+    public void navigationRedirected(@NonNull Navigation navigation) {}
 
     /**
      * Called when the navigation is ready to be committed in a renderer. A navigation is considered
@@ -59,7 +61,7 @@ public abstract class NavigationObserver {
      *
      * @param navigation the unique object for this navigation.
      */
-    public void navigationCommitted(Navigation navigation) {}
+    public void navigationCommitted(@NonNull Navigation navigation) {}
 
     /**
      * Called when a navigation completes successfully in the BrowserController.
@@ -77,7 +79,7 @@ public abstract class NavigationObserver {
      *
      * @param navigation the unique object for this navigation.
      */
-    public void navigationCompleted(Navigation navigation) {}
+    public void navigationCompleted(@NonNull Navigation navigation) {}
 
     /**
      * Called when a navigation aborts in the BrowserController.
@@ -87,7 +89,7 @@ public abstract class NavigationObserver {
      *
      * @param navigation the unique object for this navigation.
      */
-    public void navigationFailed(Navigation navigation) {}
+    public void navigationFailed(@NonNull Navigation navigation) {}
 
     /**
      * This is fired after each navigation has completed to indicate that the first paint after a

weblayer/public/java/org/chromium/weblayer/WebLayer.java

@@ -16,6 +16,8 @@ import android.webkit.ValueCallback;
 import android.webkit.WebViewDelegate;
 import android.webkit.WebViewFactory;
 
+import androidx.annotation.NonNull;
+
 import org.chromium.weblayer_private.aidl.APICallException;
 import org.chromium.weblayer_private.aidl.BrowserFragmentArgs;
 import org.chromium.weblayer_private.aidl.IBrowserFragment;
@@ -104,6 +106,7 @@ public final class WebLayer {
      * @return a ListenableFuture whose value will contain the WebLayer once initialization
      * completes
      */
+    @NonNull
     public static ListenableFuture<WebLayer> create(Context appContext)
             throws UnsupportedVersionException {
         if (sFuture == null) {
@@ -182,6 +185,7 @@ public final class WebLayer {
         mImpl = iWebLayer;
     }
 
+    @NonNull
     public static BrowserFragment createBrowserFragment(String profilePath) {
         // TODO: use a profile id instead of the path to the actual file.
         Bundle args = new Bundle();