Clean up WebVR RequestPresent and make callback asynchronous.

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.vr_shell;
 
 import android.app.Activity;
 import android.app.PendingIntent;
 import android.content.ComponentName;
 import android.content.Intent;
@@ skipping 22 matching lines @@
 
 /**
  * Manages interactions with the VR Shell.
  */
 @JNINamespace("vr_shell")
 public class VrShellDelegate {
     private static final String TAG = "VrShellDelegate";
     // Pseudo-random number to avoid request id collisions.
     public static final int EXIT_VR_RESULT = 721251;
 
+    public static final int ENTER_VR_NOT_NECESSARY = 0;

[Ted C, 2016/11/16 22:20:51]

For these, take a look at IntDef's as a way of making a pseudo enum that you
would then annotate your methods with to ensure the return/passed in values are
correct.

https://cs.chromium.org/search/?q=@IntDef+lang:java&sq=package:chromium&type=cs

+    public static final int ENTER_VR_CANCELLED = 1;
+    public static final int ENTER_VR_REQUESTED = 2;
+
     // TODO(bshe): These should be replaced by string provided by NDK. Currently, it only available
     // in SDK and we don't want add dependency to SDK just to get these strings.
     private static final String DAYDREAM_VR_EXTRA = "android.intent.extra.VR_LAUNCH";
     private static final String DAYDREAM_CATEGORY = "com.google.intent.category.DAYDREAM";
     private static final String CARDBOARD_CATEGORY = "com.google.intent.category.CARDBOARD";
 
     private static final String VR_ACTIVITY_ALIAS =
             "org.chromium.chrome.browser.VRChromeTabbedActivity";
-    private static final String DAYDREAM_DON_TYPE = "DAYDREAM_DON_TYPE";
-
-    private static final int DAYDREAM_DON_TYPE_VR_SHELL = 0;
-    private static final int DAYDREAM_DON_TYPE_WEBVR = 1;
-    private static final int DAYDREAM_DON_TYPE_AUTO = 2;
 
     private static final long REENTER_VR_TIMEOUT_MS = 1000;
 
     private final ChromeTabbedActivity mActivity;
     private final TabObserver mTabObserver;
+    private final Intent mEnterVRIntent;
 
     private boolean mVrAvailable;
     private Boolean mVrShellEnabled;
 
     private Class<? extends VrShell> mVrShellClass;
     private Class<? extends NonPresentingGvrContext> mNonPresentingGvrContextClass;
     private Class<? extends VrDaydreamApi> mVrDaydreamApiClass;
     private Class<? extends VrCoreVersionChecker> mVrCoreVersionCheckerClass;
     private VrShell mVrShell;
     private NonPresentingGvrContext mNonPresentingGvrContext;
     private VrDaydreamApi mVrDaydreamApi;
     private VrCoreVersionChecker mVrCoreVersionChecker;
     private boolean mInVr;
     private int mRestoreSystemUiVisibilityFlag = -1;
     private int mRestoreOrientation = ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
     private long mNativeVrShellDelegate;
     private Tab mTab;
     private boolean mRequestedWebVR;
     private long mLastVRExit;
 
     public VrShellDelegate(ChromeTabbedActivity activity) {
         mActivity = activity;
-        mVrAvailable = maybeFindVrClasses() && isVrCoreCompatible();
-        createVrDaydreamApi();
+        mVrAvailable = maybeFindVrClasses() && isVrCoreCompatible() && createVrDaydreamApi();
+        if (mVrAvailable) {
+            mEnterVRIntent = mVrDaydreamApi.createVrIntent(
+                    new ComponentName(mActivity, VR_ACTIVITY_ALIAS));
+        } else {
+            mEnterVRIntent = null;
+        }
         mTabObserver = new EmptyTabObserver() {
             @Override
             public void onContentChanged(Tab tab) {
                 if (tab.getNativePage() != null || tab.isShowingSadTab()) {
                     // For now we don't handle native pages. crbug.com/661609
                     exitVRIfNecessary(true);
                 }
             }
 
             @Override
             public void onWebContentsSwapped(Tab tab, boolean didStartLoad, boolean didFinishLoad) {
                 // TODO(mthiesse): Update the native WebContents pointer and compositor. This
                 // doesn't seem to get triggered in VR Shell currently, but that's likely to change
                 // when we have omnibar navigation.
             }
         };
     }
 
     /**
      * Should be called once the native library is loaded so that the native portion of this
      * class can be initialized.
      */
     public void onNativeLibraryReady() {
-        if (mVrAvailable) {
-            mNativeVrShellDelegate = nativeInit();
-        }
+        if (!mVrAvailable) return;
+        mNativeVrShellDelegate = nativeInit();
     }
 
     @SuppressWarnings("unchecked")
     private boolean maybeFindVrClasses() {
         try {
             mVrShellClass = (Class<? extends VrShell>) Class.forName(
                     "org.chromium.chrome.browser.vr_shell.VrShellImpl");
             mNonPresentingGvrContextClass =
                     (Class<? extends NonPresentingGvrContext>) Class.forName(
                             "org.chromium.chrome.browser.vr_shell.NonPresentingGvrContextImpl");
             mVrDaydreamApiClass = (Class<? extends VrDaydreamApi>) Class.forName(
                     "org.chromium.chrome.browser.vr_shell.VrDaydreamApiImpl");
             mVrCoreVersionCheckerClass = (Class<? extends VrCoreVersionChecker>) Class.forName(
                     "org.chromium.chrome.browser.vr_shell.VrCoreVersionCheckerImpl");
             return true;
         } catch (ClassNotFoundException e) {
             mVrShellClass = null;
             mNonPresentingGvrContextClass = null;
             mVrDaydreamApiClass = null;
             mVrCoreVersionCheckerClass = null;
             return false;
         }
     }
 
     /**
      * Handle a VR intent, entering VR in the process.
      */
-    public boolean enterVRFromIntent(Intent intent) {
+    public void enterVRFromIntent(Intent intent) {
+        if (!mVrAvailable) return;
         assert isVrIntent(intent);
-        int transitionType = intent.getIntExtra(DAYDREAM_DON_TYPE, DAYDREAM_DON_TYPE_VR_SHELL);
-        if (!isVrShellEnabled()) {
-            assert transitionType != DAYDREAM_DON_TYPE_VR_SHELL;
+        if (enterVR()) {
+            nativeSetPresentResult(mNativeVrShellDelegate, true);
+            if (mRequestedWebVR) mVrShell.setWebVrModeEnabled(true);
+        } else {
+            nativeSetPresentResult(mNativeVrShellDelegate, false);
+            mVrDaydreamApi.exitFromVr(EXIT_VR_RESULT, new Intent());
         }
 
-        boolean inWebVR = transitionType == DAYDREAM_DON_TYPE_WEBVR
-                || (transitionType == DAYDREAM_DON_TYPE_AUTO
-                        && (!isVrShellEnabled() || mRequestedWebVR));
-        Tab tab = mActivity.getActivityTab();
-        if (!canEnterVR(inWebVR, tab)) return false;
+        mRequestedWebVR = false;
+    }
 
-        // TODO(mthiesse): We should handle switching between webVR and VR Shell mode through
-        // intents.
+    private boolean enterVR() {
         if (mInVr) return true;
-
         mVrDaydreamApi.setVrModeEnabled(true);
 
-        mTab = tab;
-        mTab.addObserver(mTabObserver);
+        Tab tab = mActivity.getActivityTab();
+        if (!canEnterVR(tab)) return false;
 
         mRestoreOrientation = mActivity.getRequestedOrientation();
         mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
         if (!createVrShell()) {
             mActivity.setRequestedOrientation(mRestoreOrientation);
             return false;
         }
+        mInVr = true;
+        mTab = tab;
+        mTab.addObserver(mTabObserver);
         addVrViews();
         setupVrModeWindowFlags();
         mVrShell.initializeNative(mTab, this);
-        if (inWebVR) mVrShell.setWebVrModeEnabled(true);
         // onResume needs to be called on GvrLayout after initialization to make sure DON flow work
         // properly.
         mVrShell.resume();
-        mInVr = true;
         mTab.updateFullscreenEnabledState();
         return true;
     }
 
-    private boolean canEnterVR(boolean inWebVR, Tab tab) {
+    private boolean canEnterVR(Tab tab) {
         if (!LibraryLoader.isInitialized()) {
             return false;
         }
         // If vr isn't in the build, or we haven't initialized yet, or vr shell is not enabled and
         // this is not a web vr request, then return immediately.
-        if (!mVrAvailable || mNativeVrShellDelegate == 0 || (!isVrShellEnabled() && !inWebVR)) {
+        if (!mVrAvailable || mNativeVrShellDelegate == 0
+                || (!isVrShellEnabled() && !mRequestedWebVR)) {
             return false;
         }
         // TODO(mthiesse): When we have VR UI for opening new tabs, etc., allow VR Shell to be
         // entered without any current tabs.
         if (tab == null || tab.getContentViewCore() == null) {
             return false;
         }
 
         // For now we don't handle native pages. crbug.com/661609
         if (tab.getNativePage() != null || tab.isShowingSadTab()) {
             return false;
         }
         return true;
     }
 
+    @CalledByNative
+    private void presentRequested(boolean inWebVR) {
+        switch (enterVRIfNecessary()) {
+            case ENTER_VR_NOT_NECESSARY:
+                mVrShell.setWebVrModeEnabled(true);
+                nativeSetPresentResult(mNativeVrShellDelegate, true);
+                break;
+            case ENTER_VR_CANCELLED:
+                nativeSetPresentResult(mNativeVrShellDelegate, false);
+                break;
+            case ENTER_VR_REQUESTED:
+                // TODO(mthiesse): There's a GVR bug where they're not calling us back with the
+                // intent we ask them to when we call DaydreamApi#launchInVr. As a temporary hack,
+                // remember locally that we want to enter webVR.
+                mRequestedWebVR = inWebVR;
+                break;
+        }
+    }
+
     /**
-     * Enters VR Shell, displaying browser UI and tab contents in VR.
-     *
-     * @param inWebVR If true should begin displaying WebVR content rather than the VrShell UI.
+     * Enters VR Shell if necessary, displaying browser UI and tab contents in VR.
      */
-    @CalledByNative
-    public void enterVRIfNecessary(boolean inWebVR) {
-        if (mInVr) {
-            if (inWebVR) mVrShell.setWebVrModeEnabled(true);
-            return;
-        }
-        if (!canEnterVR(inWebVR, mActivity.getActivityTab())) return;
+    public int enterVRIfNecessary() {
+        if (!mVrAvailable) return ENTER_VR_CANCELLED;
+        if (mInVr) return ENTER_VR_NOT_NECESSARY;
+        if (!canEnterVR(mActivity.getActivityTab())) return ENTER_VR_CANCELLED;
 
-        // TODO(mthiesse): There's a GVR bug where they're not calling us back with the intent we
-        // ask them to when we call DaydreamApi#launchInVr. As a temporary hack, remember locally
-        // that we want to enter webVR.
-        mRequestedWebVR = inWebVR;
-        Intent intent = createDaydreamIntent(
-                inWebVR ? DAYDREAM_DON_TYPE_WEBVR : DAYDREAM_DON_TYPE_VR_SHELL);
-
-        mVrDaydreamApi.launchInVr(
-                PendingIntent.getActivity(mActivity, 0, intent, PendingIntent.FLAG_ONE_SHOT));
+        mVrDaydreamApi.launchInVr(getPendingEnterVRIntent());
+        return ENTER_VR_REQUESTED;
     }
 
     @CalledByNative
     private boolean exitWebVR() {
         if (!mInVr) return false;
         mVrShell.setWebVrModeEnabled(false);
         // TODO(bajones): Once VR Shell can be invoked outside of WebVR this
         // should no longer exit the shell outright. Need a way to determine
         // how VrShell was created.
         shutdownVR(true);
         return true;
     }
 
     /**
      * Resumes VR Shell.
      */
     public void maybeResumeVR() {
+        if (!mVrAvailable) return;
+        // TODO(mthiesse): Register the intent when on a page that supports WebVR, even if VrShell
+        // isn't enabled.
         if (isVrShellEnabled()) {
             registerDaydreamIntent();
         }
 
         // TODO(bshe): Ideally, we do not need two gvr context exist at the same time. We can
         // probably shutdown non presenting gvr when presenting and create a new one after exit
         // presenting. See crbug.com/655242
         if (mNonPresentingGvrContext != null) {
             StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
             try {
                 mNonPresentingGvrContext.resume();
             } catch (IllegalArgumentException e) {
                 Log.e(TAG, "Unable to resume mNonPresentingGvrContext", e);
             } finally {
                 StrictMode.setThreadPolicy(oldPolicy);
             }
         }
 
         if (mInVr) {
             setupVrModeWindowFlags();
             StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
             try {
                 mVrShell.resume();
             } catch (IllegalArgumentException e) {
                 Log.e(TAG, "Unable to resume VrShell", e);
             } finally {
                 StrictMode.setThreadPolicy(oldPolicy);
             }
         } else if (mLastVRExit + REENTER_VR_TIMEOUT_MS > SystemClock.uptimeMillis()) {
-            enterVRIfNecessary(mRequestedWebVR);
+            enterVRIfNecessary();
         }
     }
 
     /**
      * Pauses VR Shell.
      */
     public void maybePauseVR() {
-        if (isVrShellEnabled()) {
-            unregisterDaydreamIntent();
-        }
+        if (!mVrAvailable) return;
+        unregisterDaydreamIntent();
 
         if (mNonPresentingGvrContext != null) {
             mNonPresentingGvrContext.pause();
         }
 
         // TODO(mthiesse): When VR Shell lives in its own activity, and integrates with Daydream
         // home, pause instead of exiting VR here. For now, because VR Apps shouldn't show up in the
         // non-VR recents, and we don't want ChromeTabbedActivity disappearing, exit VR.
         exitVRIfNecessary(false);
     }
 
     /**
      * Exits the current VR mode (WebVR or VRShell)
      * @return Whether or not we exited VR.
      */
     public boolean exitVRIfNecessary(boolean returnTo2D) {
+        if (!mVrAvailable) return false;
         if (!mInVr) return false;
         // If WebVR is presenting instruct it to exit.
         nativeExitWebVRIfNecessary(mNativeVrShellDelegate);
         shutdownVR(returnTo2D);
         return true;
     }
 
     public void onExitVRResult(int resultCode) {
+        assert mVrAvailable;
         if (resultCode == Activity.RESULT_OK) {
             mVrDaydreamApi.setVrModeEnabled(false);
         } else {
             // For now, we don't handle re-entering VR when exit fails, so keep trying to exit.
             mVrDaydreamApi.exitFromVr(EXIT_VR_RESULT, new Intent());
         }
     }
 
-    private Intent createDaydreamIntent(int transitionType) {
-        if (mVrDaydreamApi == null) return null;
-        // TODO(bshe): Ideally, this should go through ChromeLauncherActivity. To avoid polluting
-        // metrics, use the VR Activity alias for now.
-        Intent intent = mVrDaydreamApi.createVrIntent(
-                new ComponentName(mActivity, VR_ACTIVITY_ALIAS));
-        intent.putExtra(DAYDREAM_DON_TYPE, transitionType);
-        return intent;
+    private PendingIntent getPendingEnterVRIntent() {
+        return PendingIntent.getActivity(mActivity, 0, mEnterVRIntent, PendingIntent.FLAG_ONE_SHOT);
     }
 
     /**
      * Registers the Intent to fire after phone inserted into a headset.
      */
     private void registerDaydreamIntent() {
-        if (mVrDaydreamApi == null) return;
-        Intent intent = createDaydreamIntent(DAYDREAM_DON_TYPE_AUTO);
-        mVrDaydreamApi.registerDaydreamIntent(
-                PendingIntent.getActivity(mActivity, 0, intent, PendingIntent.FLAG_ONE_SHOT));
+        mVrDaydreamApi.registerDaydreamIntent(getPendingEnterVRIntent());
     }
 
     /**
      * Unregisters the Intent which registered by this context if any.
      */
     private void unregisterDaydreamIntent() {
-        if (mVrDaydreamApi != null) {
-            mVrDaydreamApi.unregisterDaydreamIntent();
-        }
+        mVrDaydreamApi.unregisterDaydreamIntent();
     }
 
     @CalledByNative
     private long createNonPresentingNativeContext() {
         if (!mVrAvailable) return 0;
 
         try {
             Constructor<?> nonPresentingGvrContextConstructor =
                     mNonPresentingGvrContextClass.getConstructor(Activity.class);
             mNonPresentingGvrContext =
@@ skipping 11 matching lines @@
     private void shutdownNonPresentingNativeContext() {
         mNonPresentingGvrContext.shutdown();
         mNonPresentingGvrContext = null;
     }
 
     /**
      * Exits VR Shell, performing all necessary cleanup.
      */
     private void shutdownVR(boolean returnTo2D) {
         if (!mInVr) return;
+        mRequestedWebVR = false;
         if (returnTo2D) {
             mVrDaydreamApi.exitFromVr(EXIT_VR_RESULT, new Intent());
         } else {
             mVrDaydreamApi.setVrModeEnabled(false);
             mLastVRExit = SystemClock.uptimeMillis();
         }
         mActivity.setRequestedOrientation(mRestoreOrientation);
         mVrShell.pause();
         removeVrViews();
         clearVrModeWindowFlags();
@@ skipping 13 matching lines @@
             return false;
         }
 
         try {
             Constructor<?> mVrCoreVersionCheckerConstructor =
                     mVrCoreVersionCheckerClass.getConstructor();
             mVrCoreVersionChecker =
                     (VrCoreVersionChecker) mVrCoreVersionCheckerConstructor.newInstance();
         } catch (InstantiationException | IllegalAccessException | IllegalArgumentException
                 | InvocationTargetException | NoSuchMethodException e) {
-            Log.e(TAG, "Unable to instantiate VrCoreVersionChecker", e);
+            Log.d(TAG, "Unable to instantiate VrCoreVersionChecker", e);
             return false;
         }
         return mVrCoreVersionChecker.isVrCoreCompatible();
     }
 
     private boolean createVrDaydreamApi() {
-        if (!mVrAvailable) return false;
-
         try {
             Constructor<?> vrPrivateApiConstructor =
                     mVrDaydreamApiClass.getConstructor(Activity.class);
             mVrDaydreamApi = (VrDaydreamApi) vrPrivateApiConstructor.newInstance(mActivity);
         } catch (InstantiationException | IllegalAccessException | IllegalArgumentException
-                | InvocationTargetException | NoSuchMethodException e) {
-            Log.e(TAG, "Unable to instantiate VrDaydreamApi", e);
+                | InvocationTargetException | NoSuchMethodException | SecurityException e) {
+            Log.d(TAG, "Unable to instantiate VrDaydreamApi", e);
             return false;
         }
         return true;
     }
 
     private boolean createVrShell() {
         StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
         StrictMode.allowThreadDiskWrites();
         try {
             Constructor<?> vrShellConstructor = mVrShellClass.getConstructor(Activity.class);
@@ skipping 78 matching lines @@
         if (mVrShellEnabled == null) {
             if (!LibraryLoader.isInitialized()) {
                 return false;
             }
             mVrShellEnabled = ChromeFeatureList.isEnabled(ChromeFeatureList.VR_SHELL);
         }
         return mVrShellEnabled;
     }
 
     /**
-     * @return Whether or not VR Shell is currently enabled.
-     */
-    public boolean isVrInitialized() {
-        return mVrDaydreamApi != null;
-    }
-
-    /**
      * @return Pointer to the native VrShellDelegate object.
      */
     @CalledByNative
     private long getNativePointer() {
         return mNativeVrShellDelegate;
     }
 
     private native long nativeInit();
     private native void nativeExitWebVRIfNecessary(long nativeVrShellDelegate);
+    private native void nativeSetPresentResult(long nativeVrShellDelegate, boolean result);
 }