AppRTCDemo(android): uncaught exceptions now display a modal dialog box before killing the app.

BUG=2458
R=henrike@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2348004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/talk@4914 4adac7df-926f-26a2-2b94-8c16560cd09d

2 files changed, 104 insertions, 9 deletions

diff --git a/examples/android/src/org/appspot/apprtc/AppRTCDemoActivity.java b/examples/android/src/org/appspot/apprtc/AppRTCDemoActivity.java
index b89e9ac..8f1fecd 100644
--- a/examples/android/src/org/appspot/apprtc/AppRTCDemoActivity.java
+++ b/examples/android/src/org/appspot/apprtc/AppRTCDemoActivity.java
@@ -93,16 +93,8 @@ public class AppRTCDemoActivity extends Activity
   public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
 
-    // Since the error-handling of this demo consists of throwing
-    // RuntimeExceptions and we assume that'll terminate the app, we install
-    // this default handler so it's applied to background threads as well.
     Thread.setDefaultUncaughtExceptionHandler(
-        new Thread.UncaughtExceptionHandler() {
-          public void uncaughtException(Thread t, Throwable e) {
-            e.printStackTrace();
-            System.exit(-1);
-          }
-        });
+        new UnhandledExceptionHandler(this));
 
     PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
     wakeLock = powerManager.newWakeLock(
diff --git a/examples/android/src/org/appspot/apprtc/UnhandledExceptionHandler.java b/examples/android/src/org/appspot/apprtc/UnhandledExceptionHandler.java
new file mode 100644
index 0000000..502a5d5
--- /dev/null
+++ b/examples/android/src/org/appspot/apprtc/UnhandledExceptionHandler.java
@@ -0,0 +1,103 @@
+/*
+ * libjingle
+ * Copyright 2013, Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright notice,
+ *     this list of conditions and the following disclaimer in the documentation
+ *     and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.appspot.apprtc;
+
+import android.app.Activity;
+import android.app.AlertDialog;
+import android.content.DialogInterface;
+import android.util.Log;
+import android.util.TypedValue;
+import android.widget.ScrollView;
+import android.widget.TextView;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+
+/**
+ * Singleton helper: install a default unhandled exception handler which shows
+ * an informative dialog and kills the app.  Useful for apps whose
+ * error-handling consists of throwing RuntimeExceptions.
+ * NOTE: almost always more useful to
+ * Thread.setDefaultUncaughtExceptionHandler() rather than
+ * Thread.setUncaughtExceptionHandler(), to apply to background threads as well.
+ */
+public class UnhandledExceptionHandler
+    implements Thread.UncaughtExceptionHandler {
+  private static final String TAG = "AppRTCDemoActivity";
+  private final Activity activity;
+
+  public UnhandledExceptionHandler(final Activity activity) {
+    this.activity = activity;
+  }
+
+  public void uncaughtException(Thread unusedThread, final Throwable e) {
+    activity.runOnUiThread(new Runnable() {
+        @Override public void run() {
+          String title = "Fatal error: " + getTopLevelCauseMessage(e);
+          String msg = getRecursiveStackTrace(e);
+          TextView errorView = new TextView(activity);
+          errorView.setText(msg);
+          errorView.setTextSize(TypedValue.COMPLEX_UNIT_SP, 8);
+          ScrollView scrollingContainer = new ScrollView(activity);
+          scrollingContainer.addView(errorView);
+          Log.e(TAG, title + "\n\n" + msg);
+          DialogInterface.OnClickListener listener =
+              new DialogInterface.OnClickListener() {
+                @Override public void onClick(
+                    DialogInterface dialog, int which) {
+                  dialog.dismiss();
+                  System.exit(1);
+                }
+              };
+          AlertDialog.Builder builder =
+              new AlertDialog.Builder(activity);
+          builder
+              .setTitle(title)
+              .setView(scrollingContainer)
+              .setPositiveButton("Exit", listener).show();
+        }
+      });
+  }
+
+  // Returns the Message attached to the original Cause of |t|.
+  private static String getTopLevelCauseMessage(Throwable t) {
+    Throwable topLevelCause = t;
+    while (topLevelCause.getCause() != null) {
+      topLevelCause = topLevelCause.getCause();
+    }
+    return topLevelCause.getMessage();
+  }
+
+  // Returns a human-readable String of the stacktrace in |t|, recursively
+  // through all Causes that led to |t|.
+  private static String getRecursiveStackTrace(Throwable t) {
+    StringWriter writer = new StringWriter();
+    t.printStackTrace(new PrintWriter(writer));
+    return writer.toString();
+  }
+}