[rd debugger] XDebugProcess API to provide debug session events

(cherry picked from commit ea021a766d74f68ca6ca58f41159c4e826d0494f)


(cherry picked from commit 256519c7ac630edcf19d5a02a03798b0da22e4dd)

IJ-CR-182318

GitOrigin-RevId: 11dc0c87dc515e5ddce504aa98682a402a8a0f7c

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

@@ -78,6 +78,7 @@ public class JavaDebugProcess extends XDebugProcess {
   private final NodeManagerImpl myNodeManager;
   private final JvmSmartStepIntoActionHandler mySmartStepIntoActionHandler;
   private final JvmDropFrameActionHandler myDropFrameActionActionHandler;
+  private final JavaDebugSessionEventsProvider myJavaDebugSessionEventsProvider;
 
   private static final JavaBreakpointHandlerFactory[] ourDefaultBreakpointHandlerFactories = {
     process -> new JavaBreakpointHandler.JavaLineBreakpointHandler(process),
@@ -226,6 +227,7 @@ public class JavaDebugProcess extends XDebugProcess {
 
     mySmartStepIntoActionHandler = new JvmSmartStepIntoActionHandler(javaSession);
     myDropFrameActionActionHandler = new JvmDropFrameActionHandler(javaSession);
+    myJavaDebugSessionEventsProvider = new JavaDebugSessionEventsProvider(this);
   }
 
   private boolean shouldApplyContext(DebuggerContextImpl context) {
@@ -257,6 +259,11 @@ public class JavaDebugProcess extends XDebugProcess {
     return myJavaSession;
   }
 
+  @Override
+  public XDebugSessionEventsProvider getSessionEventsProvider() {
+    return myJavaDebugSessionEventsProvider;
+  }
+
   @Override
   public @NotNull XDebuggerEditorsProvider getEditorsProvider() {
     return myEditorsProvider;

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

@@ -0,0 +1,31 @@
+// Copyright 2000-2025 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.debugger.impl.DebuggerContextListener
+import com.intellij.debugger.impl.DebuggerSession
+import com.intellij.xdebugger.XDebugSessionEventsProvider
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.buffer
+import kotlinx.coroutines.flow.channelFlow
+import org.jetbrains.annotations.ApiStatus
+
+@ApiStatus.Internal
+class JavaDebugSessionEventsProvider(private val debugProcess: JavaDebugProcess) : XDebugSessionEventsProvider {
+  override fun getUiUpdateEventsFlow(): Flow<Unit> {
+    val stateManager = debugProcess.debuggerSession.contextManager
+    return channelFlow {
+      val listener = DebuggerContextListener { _, event ->
+        if (event == DebuggerSession.Event.THREADS_REFRESH) {
+          trySend(Unit)
+        }
+      }
+      stateManager.addListener(listener)
+
+      awaitClose {
+        stateManager.removeListener(listener)
+      }
+    }.buffer(Channel.CONFLATED)
+  }
+}

platform/xdebugger-api/src/com/intellij/xdebugger/XDebugProcess.java

@@ -295,6 +295,11 @@ public abstract class XDebugProcess {
     return frame == null ? null : frame.getEvaluator();
   }
 
+  @ApiStatus.Internal
+  public XDebugSessionEventsProvider getSessionEventsProvider() {
+    return null;
+  }
+
   /**
    * Whether the "isShowLibraryStackFrames" setting is respected.
    * If true, the ShowLibraryFramesAction will be shown, for example.

platform/xdebugger-api/src/com/intellij/xdebugger/XDebugSessionEventsProvider.kt

@@ -0,0 +1,13 @@
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.xdebugger
+
+import kotlinx.coroutines.flow.Flow
+import org.jetbrains.annotations.ApiStatus
+
+/**
+ * A provider of events from [XDebugSession] which could trigger UI updates.
+ */
+@ApiStatus.Internal
+interface XDebugSessionEventsProvider {
+  fun getUiUpdateEventsFlow(): Flow<Unit>
+}

platform/xdebugger-impl/backend/src/com/intellij/platform/debugger/impl/backend/BackendXDebugSessionApi.kt

@@ -240,6 +240,11 @@ internal class BackendXDebugSessionApi : XDebugSessionApi {
       session.setBreakpointMuted(muted)
     }
   }
+
+  override suspend fun getUiUpdateEventsFlow(sessionId: XDebugSessionId): Flow<Unit> {
+    val session = sessionId.findValue() ?: return emptyFlow()
+    return session.debugProcess.sessionEventsProvider.getUiUpdateEventsFlow()
+  }
 }
 
 internal suspend fun createBackendDocument(

platform/xdebugger-impl/rpc/src/com/intellij/platform/debugger/impl/rpc/XDebugSessionApi.kt

@@ -67,6 +67,8 @@ interface XDebugSessionApi : RemoteApi<Unit> {
 
   suspend fun muteBreakpoints(sessionDataId: XDebugSessionDataId, muted: Boolean)
 
+  suspend fun getUiUpdateEventsFlow(sessionId: XDebugSessionId): Flow<Unit>
+
   companion object {
     @JvmStatic
     suspend fun getInstance(): XDebugSessionApi {