visualizer: render CondensationRequest nicely (#1113)

Co-authored-by: openhands <openhands@all-hands.dev>
Co-authored-by: Xingyao Wang <xingyao@all-hands.dev>

Author: 3 people

openhands-sdk/openhands/sdk/conversation/visualizer/default.py

@@ -17,7 +17,7 @@
     UserRejectObservation,
 )
 from openhands.sdk.event.base import Event
-from openhands.sdk.event.condenser import Condensation
+from openhands.sdk.event.condenser import Condensation, CondensationRequest
 
 
 # These are external inputs
@@ -252,6 +252,19 @@ def _create_event_panel(self, event: Event) -> Panel | None:
                 border_style=_SYSTEM_COLOR,
                 expand=True,
             )
+
+        elif isinstance(event, CondensationRequest):
+            title = f"[bold {_SYSTEM_COLOR}]"
+            if self._name:
+                title += f"{self._name} "
+            title += f"Condensation Request[/bold {_SYSTEM_COLOR}]"
+            return Panel(
+                content,
+                title=title,
+                border_style=_SYSTEM_COLOR,
+                padding=_PANEL_PADDING,
+                expand=True,
+            )
         else:
             # Fallback panel for unknown event types
             title = f"[bold {_ERROR_COLOR}]"

openhands-sdk/openhands/sdk/event/condenser.py

@@ -55,6 +55,17 @@ class CondensationRequest(Event):
 
     source: SourceType = "environment"
 
+    @property
+    def visualize(self) -> Text:
+        text = Text()
+        text.append("Conversation Condensation Requested\n", style="bold")
+        message = (
+            "A condensation of the conversation history has been requested to "
+            "manage context window usage.\n"
+        )
+        text.append(message)
+        return text
+
 
 class CondensationSummaryEvent(LLMConvertibleEvent):
     """This event represents a summary generated by a condenser."""

tests/sdk/conversation/test_visualizer.py

@@ -11,6 +11,7 @@
 from openhands.sdk.event import (
     ActionEvent,
     AgentErrorEvent,
+    CondensationRequest,
     MessageEvent,
     ObservationEvent,
     PauseEvent,
@@ -291,6 +292,24 @@ def test_visualizer_user_reject_observation_panel():
     assert "User rejected the proposed action." in renderable.plain
 
 
+def test_visualizer_condensation_request_panel():
+    """CondensationRequest should render a system-styled panel with friendly text."""
+    visualizer = DefaultConversationVisualizer()
+    event = CondensationRequest()
+    panel = visualizer._create_event_panel(event)
+    assert panel is not None
+    # Should not fall back to UNKNOWN
+    assert "UNKNOWN Event" not in str(panel.title)
+    # Title should indicate condensation request (case-insensitive check on substring)
+    assert "Condensation Request" in str(panel.title)
+    # Body should be the friendly visualize text
+    renderable = panel.renderable
+    assert isinstance(renderable, Text)
+    body = renderable.plain
+    assert "Conversation Condensation Requested" in body
+    assert "condensation of the conversation history" in body
+
+
 def test_metrics_formatting():
     """Test metrics subtitle formatting."""
     from unittest.mock import MagicMock