[debugger] Add listener to track the start of debugger stepping actions

IJ-MR-145237

GitOrigin-RevId: dea3c2e4e005df9531867830284af76d45891579

java/debugger/impl/src/com/intellij/debugger/engine/DebugProcessImpl.java

@@ -2162,6 +2162,13 @@ public abstract class DebugProcessImpl extends UserDataHolderBase implements Deb
           (context.getSuspendPolicy() == EventRequest.SUSPEND_EVENT_THREAD || isResumeOnlyCurrentThread())) {
         myThreadBlockedMonitor.startWatching(myContextThread);
       }
+
+      if (context != null) {
+        ApplicationManager.getApplication().getMessageBus().syncPublisher(SteppingListener.TOPIC)
+          .beforeSteppingStarted(context, getSteppingAction());
+      }
+
+
       if (context != null
           && isResumeOnlyCurrentThread()
           && context.getSuspendPolicy() == EventRequest.SUSPEND_ALL

java/debugger/impl/src/com/intellij/debugger/engine/SteppingListener.kt

@@ -0,0 +1,16 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.debugger.engine
+
+import com.intellij.util.messages.Topic
+import org.jetbrains.annotations.ApiStatus
+
+@ApiStatus.Internal
+interface SteppingListener {
+  companion object {
+    @Topic.AppLevel
+    @JvmField
+    val TOPIC: Topic<SteppingListener> = Topic(SteppingListener::class.java, Topic.BroadcastDirection.NONE)
+  }
+
+  fun beforeSteppingStarted(suspendContext: SuspendContextImpl, steppingAction: SteppingAction) { }
+}