From 6fa719df2a1e30383ec4ddb529c73c7a835a6aa4 Mon Sep 17 00:00:00 2001
From: Mike Hearn <mike@plan99.net>
Date: Sun, 22 Sep 2013 14:45:05 +0200
Subject: [PATCH] Wallet template: some improvements to crash handling.

---
 .../src/main/java/wallettemplate/Main.java    |  9 ++++---
 .../wallettemplate/SendMoneyController.java   |  2 +-
 .../java/wallettemplate/utils/GuiUtils.java   | 25 ++++++++++++++++---
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/wallettemplate/src/main/java/wallettemplate/Main.java b/wallettemplate/src/main/java/wallettemplate/Main.java
index 25fefa1e..29fd7ceb 100644
--- a/wallettemplate/src/main/java/wallettemplate/Main.java
+++ b/wallettemplate/src/main/java/wallettemplate/Main.java
@@ -7,6 +7,7 @@ import com.google.bitcoin.params.RegTestParams;
 import com.google.bitcoin.store.BlockStoreException;
 import com.google.bitcoin.utils.BriefLogFormatter;
 import com.google.bitcoin.utils.Threading;
+import com.google.common.base.Throwables;
 import javafx.application.Application;
 import javafx.application.Platform;
 import javafx.fxml.FXMLLoader;
@@ -35,16 +36,16 @@ public class Main extends Application {
     @Override
     public void start(Stage mainWindow) throws Exception {
         instance = this;
+        GuiUtils.handleCrashesOnThisThread();
         try {
             init(mainWindow);
         } catch (Throwable t) {
-            final Throwable cause = t.getCause();
-            if (cause != null && cause.getCause() instanceof BlockStoreException) {
+            // Nicer message for the case where the block store file is locked.
+            if (Throwables.getRootCause(t) instanceof BlockStoreException) {
                 GuiUtils.informationalAlert("Already running", "This application is already running and cannot be started twice.");
             } else {
-                GuiUtils.crashAlert(t.getLocalizedMessage());
+                throw t;
             }
-            Platform.exit();
         }
     }
 
diff --git a/wallettemplate/src/main/java/wallettemplate/SendMoneyController.java b/wallettemplate/src/main/java/wallettemplate/SendMoneyController.java
index eaa69367..4b354f30 100644
--- a/wallettemplate/src/main/java/wallettemplate/SendMoneyController.java
+++ b/wallettemplate/src/main/java/wallettemplate/SendMoneyController.java
@@ -52,7 +52,7 @@ public class SendMoneyController {
                 @Override
                 public void onFailure(Throwable t) {
                     // We died trying to empty the wallet.
-                    Platform.runLater(() -> GuiUtils.crashAlert(t.getMessage()));
+                    GuiUtils.crashAlert(t);
                 }
             });
             sendBtn.setDisable(true);
diff --git a/wallettemplate/src/main/java/wallettemplate/utils/GuiUtils.java b/wallettemplate/src/main/java/wallettemplate/utils/GuiUtils.java
index c686eb28..d1c5d371 100644
--- a/wallettemplate/src/main/java/wallettemplate/utils/GuiUtils.java
+++ b/wallettemplate/src/main/java/wallettemplate/utils/GuiUtils.java
@@ -1,6 +1,8 @@
 package wallettemplate.utils;
 
+import com.google.common.base.Throwables;
 import javafx.animation.*;
+import javafx.application.Platform;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Node;
 import javafx.scene.Scene;
@@ -33,12 +35,29 @@ public class GuiUtils {
         }
     }
 
-    public static void crashAlert(String alert) {
-        runAlert((stage, controller) -> controller.crashAlert(stage, alert));
+    public static void crashAlert(Throwable t) {
+        t.printStackTrace();
+        Throwable rootCause = Throwables.getRootCause(t);
+        Runnable r = () -> runAlert((stage, controller) -> controller.crashAlert(stage, rootCause.toString()));
+        if (Platform.isFxApplicationThread())
+            r.run();
+        else
+            Platform.runLater(r);
+    }
+
+    /** Show a GUI alert box for any unhandled exceptions that propagate out of this thread. */
+    public static void handleCrashesOnThisThread() {
+        Thread.currentThread().setUncaughtExceptionHandler((thread, exception) -> {
+            GuiUtils.crashAlert(Throwables.getRootCause(exception));
+        });
     }
 
     public static void informationalAlert(String message, String details) {
-        runAlert((stage, controller) -> controller.informational(stage, message, details));
+        Runnable r = () -> runAlert((stage, controller) -> controller.informational(stage, message, details));
+        if (Platform.isFxApplicationThread())
+            r.run();
+        else
+            Platform.runLater(r);
     }
 
     private static final int UI_ANIMATION_TIME_MSEC = 350;