reverted view update delay, BEFORE_RESUME can not be delayed

platform/xdebugger-impl/src/com/intellij/xdebugger/impl/frame/XDebugView.java

@@ -20,7 +20,7 @@ import com.intellij.ide.DataManager;
 import com.intellij.openapi.Disposable;
 import com.intellij.openapi.actionSystem.DataContext;
 import com.intellij.ui.content.ContentManager;
-import com.intellij.util.Alarm;
+import com.intellij.util.SingleAlarm;
 import com.intellij.xdebugger.XDebugSession;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -34,26 +34,29 @@ import java.util.EventObject;
 public abstract class XDebugView implements Disposable {
   public enum SessionEvent {PAUSED, BEFORE_RESUME, RESUMED, STOPPED, FRAME_CHANGED, SETTINGS_CHANGED}
 
-  private final Alarm myUpdateAlarm;
-  private static final int VIEW_UPDATE_DELAY = 100; //ms
+  private final SingleAlarm myClearAlarm;
+  private static final int VIEW_CLEAR_DELAY = 100; //ms
 
   public XDebugView() {
-    myUpdateAlarm = new Alarm(this);
+    myClearAlarm = new SingleAlarm(new Runnable() {
+      @Override
+      public void run() {
+        clear();
+      }
+    }, VIEW_CLEAR_DELAY, this);
+  }
+
+  protected final void requestClear() {
+    myClearAlarm.cancelAndRequest();
+  }
+
+  protected final void cancelClear() {
+    myClearAlarm.cancel();
   }
 
   protected abstract void clear();
 
-  public void onSessionEvent(@NotNull final SessionEvent event) {
-    myUpdateAlarm.cancelAllRequests();
-    myUpdateAlarm.addRequest(new Runnable() {
-      @Override
-      public void run() {
-        processSessionEvent(event);
-      }
-    }, VIEW_UPDATE_DELAY);
-  }
-
-  protected abstract void processSessionEvent(@NotNull SessionEvent event);
+  public abstract void processSessionEvent(@NotNull SessionEvent event);
 
   @Nullable
   protected static XDebugSession getSession(@NotNull EventObject e) {

platform/xdebugger-impl/src/com/intellij/xdebugger/impl/frame/XDebugViewSessionListener.java

@@ -36,7 +36,7 @@ public class XDebugViewSessionListener extends XDebugSessionAdapter {
     AppUIUtil.invokeLaterIfProjectAlive(session.getProject(), new Runnable() {
       @Override
       public void run() {
-        myDebugView.onSessionEvent(event);
+        myDebugView.processSessionEvent(event);
       }
     });
   }

platform/xdebugger-impl/src/com/intellij/xdebugger/impl/frame/XFramesView.java

@@ -221,11 +221,13 @@ public class XFramesView extends XDebugView {
     mySelectedStack = null;
     XSuspendContext suspendContext = session == null ? null : session.getSuspendContext();
     if (suspendContext == null) {
-      clear();
+      requestClear();
       return;
     }
 
     if (event == SessionEvent.PAUSED) {
+      // clear immediately
+      cancelClear();
       clear();
     }
 

platform/xdebugger-impl/src/com/intellij/xdebugger/impl/frame/XVariablesView.java

@@ -57,10 +57,11 @@ public class XVariablesView extends XVariablesViewBase {
 
     tree.markNodesObsolete();
     if (stackFrame != null) {
+      cancelClear();
       buildTreeAndRestoreState(stackFrame);
     }
     else {
-      clear();
+      requestClear();
     }
   }
 

platform/xdebugger-impl/src/com/intellij/xdebugger/impl/frame/XWatchesViewImpl.java

@@ -275,6 +275,7 @@ public class XWatchesViewImpl extends XDebugView implements DnDNativeTarget, XWa
     XDebugSession session = getSession(getMainPanel());
     XStackFrame stackFrame = session == null ? null : session.getCurrentStackFrame();
     if (stackFrame != null) {
+      cancelClear();
       tree.setSourcePosition(stackFrame.getSourcePosition());
       myRootNode.updateWatches(stackFrame.getEvaluator());
       if (myTreeState != null) {
@@ -282,7 +283,7 @@ public class XWatchesViewImpl extends XDebugView implements DnDNativeTarget, XWa
       }
     }
     else {
-      clear();
+      requestClear();
     }
   }
 

platform/xdebugger-impl/src/com/intellij/xdebugger/impl/ui/XDebugSessionTab.java

@@ -197,7 +197,7 @@ public class XDebugSessionTab extends DebuggerSessionTabBase {
       @Override
       public void run() {
         for (XDebugView view : myViews) {
-          view.onSessionEvent(XDebugView.SessionEvent.SETTINGS_CHANGED);
+          view.processSessionEvent(XDebugView.SessionEvent.SETTINGS_CHANGED);
         }
       }
     });