feat: add WalletResetEventListener for wallet.reset()

core/src/main/java/org/bitcoinj/wallet/Wallet.java

@@ -72,6 +72,7 @@
 import org.bitcoinj.wallet.listeners.WalletCoinsReceivedEventListener;
 import org.bitcoinj.wallet.listeners.WalletCoinsSentEventListener;
 import org.bitcoinj.wallet.listeners.WalletReorganizeEventListener;
+import org.bitcoinj.wallet.listeners.WalletResetEventListener;
 import org.slf4j.*;
 import org.bouncycastle.crypto.params.*;
 
@@ -203,6 +204,8 @@ protected boolean removeEldestEntry(Map.Entry<Sha256Hash, Transaction> eldest) {
         = new CopyOnWriteArrayList<>();
     private final CopyOnWriteArrayList<ListenerRegistration<WalletReorganizeEventListener>> reorganizeListeners
         = new CopyOnWriteArrayList<>();
+    private final CopyOnWriteArrayList<ListenerRegistration<WalletResetEventListener>> resetListeners
+        = new CopyOnWriteArrayList<>();
     private final CopyOnWriteArrayList<ListenerRegistration<ScriptsChangeEventListener>> scriptChangeListeners
         = new CopyOnWriteArrayList<>();
     private final CopyOnWriteArrayList<ListenerRegistration<TransactionConfidenceEventListener>> transactionConfidenceListeners
@@ -3041,6 +3044,14 @@ public void addReorganizeEventListener(Executor executor, WalletReorganizeEventL
         reorganizeListeners.add(new ListenerRegistration<>(listener, executor));
     }
 
+    /**
+     * Adds an event listener object. Methods on this object are called when something interesting happens,
+     * like receiving money. The listener is executed by the given executor.
+     */
+    public void addResetEventListener(Executor executor, WalletResetEventListener listener) {
+        // This is thread safe, so we don't need to take the lock.
+        resetListeners.add(new ListenerRegistration<>(listener, executor));
+    }
     /**
      * Adds an event listener object. Methods on this object are called when scripts
      * watched by this wallet change. Runs the listener methods in the user thread.
@@ -3122,6 +3133,14 @@ public boolean removeReorganizeEventListener(WalletReorganizeEventListener liste
         return ListenerRegistration.removeFromList(listener, reorganizeListeners);
     }
 
+    /**
+     * Removes the given event listener object. Returns true if the listener was removed, false if that listener
+     * was never added.
+     */
+    public boolean removeResetEventListener(WalletResetEventListener listener) {
+        return ListenerRegistration.removeFromList(listener, resetListeners);
+    }
+
     /**
      * Removes the given event listener object. Returns true if the listener was removed, false if that listener
      * was never added.
@@ -3208,6 +3227,18 @@ public void run() {
         }
     }
 
+    protected void queueOnReset() {
+        checkState(lock.isHeldByCurrentThread());
+        for (final ListenerRegistration<WalletResetEventListener> registration : resetListeners) {
+            registration.executor.execute(new Runnable() {
+                @Override
+                public void run() {
+                    registration.listener.onWalletReset(Wallet.this);
+                }
+            });
+        }
+    }
+
     protected void queueOnScriptsChanged(final List<Script> scripts, final boolean isAddingScripts) {
         for (final ListenerRegistration<ScriptsChangeEventListener> registration : scriptChangeListeners) {
             registration.executor.execute(new Runnable() {
@@ -3424,6 +3455,7 @@ public void reset() {
             lastBlockSeenHeight = -1; // Magic value for 'never'.
             lastBlockSeenTimeSecs = 0;
             saveLater();
+            queueOnReset();
             maybeQueueOnWalletChanged();
         } finally {
             lock.unlock();

core/src/main/java/org/bitcoinj/wallet/listeners/WalletResetEventListener.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2024 Dash Core Group
+ *
+ * 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 org.bitcoinj.wallet.listeners;
+
+import org.bitcoinj.wallet.Wallet;
+
+public interface WalletResetEventListener {
+    /**
+     * <p>This is called when the wallet is reset and all transactions are removed.</p>
+     *
+     */
+    void onWalletReset(Wallet wallet);
+}