Refactor Vr activity into ChromeTabbedActivity.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
new file mode 100644
index 0000000000000000000000000000000000000000..46a55a1fa806a86f66f032cb89be127d95396dac
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
@@ -0,0 +1,198 @@
+// 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.content.Intent;
+import android.content.pm.ActivityInfo;
+import android.os.StrictMode;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.ViewGroup.LayoutParams;
+import android.view.WindowManager;
+
+import org.chromium.base.Log;
+import org.chromium.chrome.browser.ChromeTabbedActivity;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+/**
+ * Manages interactions with the VR Shell.
+ */
+public class VrShellDelegate {
+    private static final String TAG = "VrShellDelegate";
+
+    private ChromeTabbedActivity mActivity;
+
+    private boolean mVrShellEnabled;
+
+    private Class<? extends VrShellInterface> mVrShellClass;
+    private VrShellInterface mVrShellView;
+    private boolean mInVr;
+    private int mRestoreSystemUiVisibilityFlag = -1;
+    private ViewGroup mParentView;
+    private String mVrExtra;
+
+    public VrShellDelegate(ChromeTabbedActivity activity, ViewGroup parentView) {
+        mActivity = activity;
+        mParentView = parentView;
+
+        mVrShellClass = maybeFindVrShell();
+        if (mVrShellClass != null) {
+            mVrShellEnabled = true;
+            try {
+                mVrExtra = (String) mVrShellClass.getField("VR_EXTRA").get(null);
+            } catch (IllegalAccessException | IllegalArgumentException | NoSuchFieldException e) {
+                Log.e(TAG, "Unable to read VR_EXTRA field", e);
+                mVrShellEnabled = false;
+            }
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private Class<? extends VrShellInterface> maybeFindVrShell() {
+        try {
+            return (Class<? extends VrShellInterface>) Class
+                    .forName("org.chromium.chrome.browser.vr_shell.VrShell");
+        } catch (ClassNotFoundException e) {
+            return null;
+        }
+    }
+
+    /**
+     * Enters VR Shell, displaying browser UI and tab contents in VR.
+     *
+     * This function performs native initialization, and so must only be called after native
+     * libraries are ready.
+     * @Returns Whether or not we are in VR when this function returns.
+     */
+    public boolean enterVRIfNecessary() {
+        if (!mVrShellEnabled) return false;
+        if (mInVr) return true;
+        // VrShell must be initialized in Landscape mode due to a bug in the GVR library.
+        mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
+        if (!createVrShell()) {
+            mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
+            return false;
+        }
+        addVrViews();
+        setupVrModeWindowFlags();
+        mVrShellView.onNativeLibraryReady();
+        mVrShellView.setVrModeEnabled(true);
+        mInVr = true;
+        return true;
+    }
+
+    /**
+     * Resumes VR Shell.
+     */
+    public void resumeVR() {
+        setupVrModeWindowFlags();
+        mVrShellView.resume();
+    }
+
+    /**
+     * Pauses VR Shell.
+     */
+    public void pauseVR() {
+        mVrShellView.pause();
+    }
+
+    /**
+     * Exits VR Shell, performing all necessary cleanup.
+     * @Returns Whether or not we exited VR.
+     */
+    public boolean exitVRIfNecessary() {
+        if (!mInVr) return false;
+        mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
+        mVrShellView.setVrModeEnabled(false);
+        mVrShellView.pause();
+        removeVrViews();
+        clearVrModeWindowFlags();
+        destroyVrShell();
+        mInVr = false;
+        return true;
+    }
+
+    private boolean createVrShell() {
+        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
+        try {
+            Constructor<?> vrShellConstructor = mVrShellClass.getConstructor(Activity.class);
+            mVrShellView = (VrShellInterface) vrShellConstructor.newInstance(mActivity);
+        } catch (InstantiationException | IllegalAccessException | IllegalArgumentException
+                | InvocationTargetException | NoSuchMethodException e) {
+            Log.e(TAG, "Unable to instantiate VrShell", e);
+            return false;
+        } finally {
+            StrictMode.setThreadPolicy(oldPolicy);
+        }
+        return true;
+    }
+
+    private void addVrViews() {
+        LayoutParams params = new LayoutParams(LayoutParams.MATCH_PARENT,
+                LayoutParams.MATCH_PARENT);
+        mParentView.addView(mVrShellView.getContainer(), mParentView.getChildCount(), params);
+    }
+
+    private void removeVrViews() {
+        ((ViewGroup) mVrShellView.getContainer().getParent())
+                .removeView(mVrShellView.getContainer());
+    }
+
+    private void setupVrModeWindowFlags() {
+        if (mRestoreSystemUiVisibilityFlag == -1) {
+            mRestoreSystemUiVisibilityFlag = mActivity.getWindow().getDecorView()
+                    .getSystemUiVisibility();
+        }
+        mActivity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
+        mActivity.getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE
+                | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
+                | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
+                | View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
+    }
+
+    private void clearVrModeWindowFlags() {
+        mActivity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
+        if (mRestoreSystemUiVisibilityFlag != -1) {
+            mActivity.getWindow().getDecorView()
+                    .setSystemUiVisibility(mRestoreSystemUiVisibilityFlag);
+        }
+        mRestoreSystemUiVisibilityFlag = -1;
+    }
+
+    /**
+     * Clean up VrShell, and associated native objects.
+     */
+    public void destroyVrShell() {
+        if (mVrShellView != null) {
+            mVrShellView.teardown();
+            mVrShellView = null;
+        }
+    }
+
+    /**
+     * Whether or not the intent is a Daydream VR Intent.
+     */
+    public boolean isVrIntent(Intent intent) {
+        if (intent == null) return false;
+        return intent.getBooleanExtra(mVrExtra, false);
+    }
+
+    /**
+     * Whether or not we are currently in VR.
+     */
+    public boolean isInVR() {
+        return mInVr;
+    }
+
+    /**
+     * @return Whether or not VR Shell is currently enabled.
+     */
+    public boolean isVrShellEnabled() {
+        return mVrShellEnabled;
+    }
+}