Recover tabs in the event of a crash

Change-Id: Ia47a5bc1e659e46e7f29a8cec52b6fd2ed675be4

5 files changed, 144 insertions, 9 deletions

diff --git a/src/com/android/browser/BaseUi.java b/src/com/android/browser/BaseUi.java
index 548292a..b7964dc 100644
--- a/src/com/android/browser/BaseUi.java
+++ b/src/com/android/browser/BaseUi.java
@@ -226,7 +226,7 @@ public abstract class BaseUi implements UI, WebViewFactory {
 
     @Override
     public boolean needsRestoreAllTabs() {
-        return false;
+        return true;
     }
 
     @Override
diff --git a/src/com/android/browser/Controller.java b/src/com/android/browser/Controller.java
index e8e13d1..2f47cad 100644
--- a/src/com/android/browser/Controller.java
+++ b/src/com/android/browser/Controller.java
@@ -47,6 +47,7 @@ import android.os.Bundle;
 import android.os.Environment;
 import android.os.Handler;
 import android.os.Message;
+import android.os.Parcel;
 import android.os.PowerManager;
 import android.os.PowerManager.WakeLock;
 import android.preference.PreferenceActivity;
@@ -83,6 +84,7 @@ import android.widget.Toast;
 
 import java.io.ByteArrayOutputStream;
 import java.io.File;
+import java.io.FileOutputStream;
 import java.net.URLEncoder;
 import java.util.Calendar;
 import java.util.HashMap;
@@ -198,6 +200,7 @@ public class Controller
     // Tabs' notion of whether they represent bookmarked sites.
     private ContentObserver mBookmarksObserver;
     private DataController mDataController;
+    private CrashRecoveryHandler mCrashRecoveryHandler;
 
     private static class ClearThumbnails extends AsyncTask<File, Void, Void> {
         @Override
@@ -219,6 +222,7 @@ public class Controller
         mDataController = DataController.getInstance(mActivity);
         mTabControl = new TabControl(this);
         mSettings.setController(this);
+        mCrashRecoveryHandler = new CrashRecoveryHandler(this);
 
         mUrlHandler = new UrlHandler(this);
         mIntentHandler = new IntentHandler(mActivity, this);
@@ -252,6 +256,15 @@ public class Controller
     }
 
     void start(final Bundle icicle, final Intent intent) {
+        if (icicle != null) {
+            mCrashRecoveryHandler.clearState();
+            doStart(icicle, intent);
+        } else {
+            mCrashRecoveryHandler.startRecovery(intent);
+        }
+    }
+
+    void doStart(final Bundle icicle, final Intent intent) {
         // Unless the last browser usage was within 24 hours, destroy any
         // remaining incognito tabs.
 
@@ -279,12 +292,12 @@ public class Controller
         GoogleAccountLogin.startLoginIfNeeded(mActivity,
                 new Runnable() {
                     @Override public void run() {
-                        start(icicle, intent, currentTab, restoreIncognitoTabs);
+                        onPreloginFinished(icicle, intent, currentTab, restoreIncognitoTabs);
                     }
                 });
     }
 
-    private void start(Bundle icicle, Intent intent, int currentTab,
+    private void onPreloginFinished(Bundle icicle, Intent intent, int currentTab,
             boolean restoreIncognitoTabs) {
         if (currentTab == -1) {
             final Bundle extra = intent.getExtras();
@@ -610,6 +623,7 @@ public class Controller
         mNetworkHandler.onPause();
 
         WebView.disablePlatformNotifications();
+        mCrashRecoveryHandler.clearState();
     }
 
     void onSaveInstanceState(Bundle outState) {
@@ -911,6 +925,11 @@ public class Controller
         }
         mDataController.updateVisitedHistory(url);
         WebIconDatabase.getInstance().retainIconForPageUrl(url);
+        if (!mActivityPaused) {
+            // Since we clear the state in onPause, don't backup the current
+            // state if we are already paused
+            mCrashRecoveryHandler.backupState();
+        }
     }
 
     @Override
diff --git a/src/com/android/browser/CrashRecoveryHandler.java b/src/com/android/browser/CrashRecoveryHandler.java
new file mode 100644
index 0000000..9e98e76
--- /dev/null
+++ b/src/com/android/browser/CrashRecoveryHandler.java
@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.browser;
+
+import android.app.AlertDialog;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.content.DialogInterface.OnClickListener;
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.Debug;
+import android.os.Parcel;
+import android.util.Log;
+
+import java.io.ByteArrayOutputStream;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+
+public class CrashRecoveryHandler {
+
+    private static final String LOGTAG = "BrowserCrashRecovery";
+    private static final String STATE_FILE = "browser_state.parcel";
+    private static final int BUFFER_SIZE = 4096;
+
+    private Controller mController;
+
+    public CrashRecoveryHandler(Controller controller) {
+        mController = controller;
+    }
+
+    public void backupState() {
+        final Bundle state = new Bundle();
+        mController.onSaveInstanceState(state);
+        final Context context = mController.getActivity();
+        new Thread() {
+            @Override
+            public void run() {
+                Parcel p = Parcel.obtain();
+                try {
+                    state.writeToParcel(p, 0);
+                    FileOutputStream fout = context.openFileOutput(STATE_FILE,
+                            Context.MODE_PRIVATE);
+                    fout.write(p.marshall());
+                    fout.close();
+                } catch (Exception e) {
+                    Log.i(LOGTAG, "Failed to save persistent state", e);
+                } finally {
+                    p.recycle();
+                }
+            }
+        }.start();
+    }
+
+    public void clearState() {
+        Context context = mController.getActivity();
+        context.deleteFile(STATE_FILE);
+    }
+
+    public void promptToRecover(final Bundle state, final Intent intent) {
+        new AlertDialog.Builder(mController.getActivity())
+                .setTitle(R.string.recover_title)
+                .setMessage(R.string.recover_prompt)
+                .setPositiveButton(R.string.recover_yes, new OnClickListener() {
+                    @Override
+                    public void onClick(DialogInterface dialog, int which) {
+                        mController.doStart(state, intent);
+                    }
+                })
+                .setNegativeButton(R.string.recover_no, new OnClickListener() {
+                    @Override
+                    public void onClick(DialogInterface dialog, int which) {
+                        clearState();
+                        mController.doStart(null, intent);
+                    }
+                })
+                .show();
+    }
+
+    public void startRecovery(Intent intent) {
+        Parcel parcel = Parcel.obtain();
+        try {
+            Context context = mController.getActivity();
+            FileInputStream fin = context.openFileInput(STATE_FILE);
+            ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
+            byte[] buffer = new byte[BUFFER_SIZE];
+            int read;
+            while ((read = fin.read(buffer)) > 0) {
+                dataStream.write(buffer, 0, read);
+            }
+            byte[] data = dataStream.toByteArray();
+            parcel.unmarshall(data, 0, data.length);
+            parcel.setDataPosition(0);
+            Bundle state = parcel.readBundle();
+            promptToRecover(state, intent);
+        } catch (FileNotFoundException e) {
+            // No state to recover
+            mController.doStart(null, intent);
+        } catch (Exception e) {
+            Log.w(LOGTAG, "Failed to recover state!", e);
+            mController.doStart(null, intent);
+        } finally {
+            parcel.recycle();
+        }
+    }
+}
diff --git a/src/com/android/browser/Tab.java b/src/com/android/browser/Tab.java
index 87aca57..8368c33 100644
--- a/src/com/android/browser/Tab.java
+++ b/src/com/android/browser/Tab.java
@@ -1299,7 +1299,8 @@ class Tab {
         mCloseOnExit = closeOnExit;
         mAppId = appId;
         mDataController = DataController.getInstance(mActivity);
-        mCurrentState = new PageState(mActivity, w.isPrivateBrowsingEnabled());
+        mCurrentState = new PageState(mActivity, w != null
+                ? w.isPrivateBrowsingEnabled() : false);
         mInPageLoad = false;
         mInForeground = false;
 
diff --git a/src/com/android/browser/XLargeUi.java b/src/com/android/browser/XLargeUi.java
index 4b06d28..39981b0 100644
--- a/src/com/android/browser/XLargeUi.java
+++ b/src/com/android/browser/XLargeUi.java
@@ -176,11 +176,6 @@ public class XLargeUi extends BaseUi implements ScrollListener {
     }
 
     @Override
-    public boolean needsRestoreAllTabs() {
-        return true;
-    }
-
-    @Override
     public void addTab(Tab tab) {
         mTabBar.onNewTab(tab);
     }