fix(editor_ui): resolve splitter and tab drag gesture conflict

new_editor/include/XCEditor/Collections/UIEditorTabStripInteraction.h

@@ -53,6 +53,10 @@ struct UIEditorTabStripInteractionFrame {
     bool focused = false;
 };
 
+// Clears transient pointer-driven state while preserving selection/navigation.
+void ClearUIEditorTabStripTransientInteraction(
+    UIEditorTabStripInteractionState& state);
+
 UIEditorTabStripInteractionFrame UpdateUIEditorTabStripInteraction(
     UIEditorTabStripInteractionState& state,
     std::string& selectedTabId,

new_editor/src/Collections/UIEditorTabStripInteraction.cpp

@@ -363,6 +363,14 @@ void CancelTabReorder(
 
 } // namespace
 
+void ClearUIEditorTabStripTransientInteraction(
+    UIEditorTabStripInteractionState& state) {
+    state.pressedTarget = {};
+    state.hasPointerPosition = false;
+    ClearHoverState(state);
+    ClearReorderState(state);
+}
+
 UIEditorTabStripInteractionFrame UpdateUIEditorTabStripInteraction(
     UIEditorTabStripInteractionState& state,
     std::string& selectedTabId,

new_editor/src/Shell/UIEditorDockHostInteraction.cpp

@@ -192,6 +192,14 @@ bool IsPointInsideRect(
         point.y <= rect.y + rect.height;
 }
 
+void ClearAllTabStripTransientInteractions(
+    UIEditorDockHostInteractionState& state) {
+    for (UIEditorDockHostTabStripInteractionEntry& entry : state.tabStripInteractions) {
+        ClearUIEditorTabStripTransientInteraction(entry.state);
+    }
+    SyncDockHostTabStripVisualStates(state);
+}
+
 void ClearTabDockDragState(UIEditorDockHostInteractionState& state) {
     state.activeTabDragNodeId.clear();
     state.activeTabDragPanelId.clear();
@@ -510,9 +518,19 @@ UIEditorDockHostInteractionFrame UpdateUIEditorDockHostInteraction(
             state.hasPointerPosition = false;
         }
 
+        const UIEditorDockHostHitTarget pointerHitTarget =
+            state.hasPointerPosition
+                ? HitTestUIEditorDockHost(layout, state.pointerPosition)
+                : UIEditorDockHostHitTarget {};
+        const bool splitterOwnsPointerDown =
+            event.type == UIInputEventType::PointerButtonDown &&
+            event.pointerButton == ::XCEngine::UI::UIPointerButton::Left &&
+            pointerHitTarget.kind == UIEditorDockHostHitTargetKind::SplitterHandle;
+
         UIEditorDockHostInteractionResult eventResult = {};
         const DockHostTabStripEventResult tabStripResult =
-            ShouldDispatchTabStripEvent(event, state.splitterDragState.active)
+            !splitterOwnsPointerDown &&
+                ShouldDispatchTabStripEvent(event, state.splitterDragState.active)
                 ? ProcessTabStripEvent(state, layout, event, metrics)
                 : DockHostTabStripEventResult {};
         eventResult.requestPointerCapture = tabStripResult.requestPointerCapture;
@@ -541,6 +559,7 @@ UIEditorDockHostInteractionFrame UpdateUIEditorDockHostInteraction(
             if (state.splitterDragState.active) {
                 EndUISplitterDrag(state.splitterDragState);
                 state.dockHostState.activeSplitterNodeId.clear();
+                ClearAllTabStripTransientInteractions(state);
                 eventResult.consumed = true;
                 eventResult.releasePointerCapture = true;
             }
@@ -609,11 +628,11 @@ UIEditorDockHostInteractionFrame UpdateUIEditorDockHostInteraction(
                 break;
             }
 
-            if (state.dockHostState.hoveredTarget.kind ==
+            if (pointerHitTarget.kind ==
                 UIEditorDockHostHitTargetKind::SplitterHandle) {
                 const auto* splitter = FindUIEditorDockHostSplitterLayout(
                     layout,
-                    state.dockHostState.hoveredTarget.nodeId);
+                    pointerHitTarget.nodeId);
                 if (splitter != nullptr &&
                     BeginUISplitterDrag(
                         1u,
@@ -626,11 +645,12 @@ UIEditorDockHostInteractionFrame UpdateUIEditorDockHostInteraction(
                         splitter->metrics,
                         state.pointerPosition,
                         state.splitterDragState)) {
+                    ClearAllTabStripTransientInteractions(state);
                     state.dockHostState.activeSplitterNodeId = splitter->nodeId;
                     state.dockHostState.focused = true;
                     eventResult.consumed = true;
                     eventResult.requestPointerCapture = true;
-                    eventResult.hitTarget = state.dockHostState.hoveredTarget;
+                    eventResult.hitTarget = pointerHitTarget;
                     eventResult.activeSplitterNodeId = splitter->nodeId;
                 }
             } else {
@@ -643,7 +663,10 @@ UIEditorDockHostInteractionFrame UpdateUIEditorDockHostInteraction(
                         state.dockHostState.hoveredTarget.kind !=
                         UIEditorDockHostHitTargetKind::None;
                     eventResult.consumed = state.dockHostState.focused;
-                    eventResult.hitTarget = state.dockHostState.hoveredTarget;
+                    eventResult.hitTarget =
+                        pointerHitTarget.kind != UIEditorDockHostHitTargetKind::None
+                            ? pointerHitTarget
+                            : state.dockHostState.hoveredTarget;
                 }
             }
             break;
@@ -668,6 +691,7 @@ UIEditorDockHostInteractionFrame UpdateUIEditorDockHostInteraction(
                         UIEditorWorkspaceLayoutOperationStatus::Changed;
                 }
                 EndUISplitterDrag(state.splitterDragState);
+                ClearAllTabStripTransientInteractions(state);
                 eventResult.consumed = true;
                 eventResult.releasePointerCapture = true;
                 eventResult.activeSplitterNodeId = state.dockHostState.activeSplitterNodeId;

tests/UI/Editor/unit/test_ui_editor_dock_host_interaction.cpp

@@ -143,6 +143,18 @@ const UIEditorDockHostTabStackLayout* FindTabStackByNodeId(
     return nullptr;
 }
 
+const XCEngine::UI::Editor::Widgets::UIEditorDockHostSplitterLayout* FindSplitterByNodeId(
+    const UIEditorDockHostLayout& layout,
+    std::string_view nodeId) {
+    for (const auto& splitter : layout.splitters) {
+        if (splitter.nodeId == nodeId) {
+            return &splitter;
+        }
+    }
+
+    return nullptr;
+}
+
 } // namespace
 
 TEST(UIEditorDockHostInteractionTest, SplitterDragUpdatesWorkspaceSplitRatio) {
@@ -216,6 +228,87 @@ TEST(UIEditorDockHostInteractionTest, FocusLostWhileDraggingSplitterRequestsPoin
     EXPECT_TRUE(state.dockHostState.activeSplitterNodeId.empty());
 }
 
+TEST(UIEditorDockHostInteractionTest, SplitterGestureDoesNotLeaveGhostTabDragWhenHitZoneOverlapsTabHeader) {
+    auto controller =
+        BuildDefaultUIEditorWorkspaceController(BuildPanelRegistry(), BuildWorkspace());
+    UIEditorDockHostInteractionState state = {};
+
+    auto frame = UpdateUIEditorDockHostInteraction(
+        state,
+        controller,
+        UIRect(0.0f, 0.0f, 800.0f, 600.0f),
+        {});
+    const auto* consoleStack = FindTabStackByNodeId(frame.layout, "console-node");
+    const auto* rightSplitter = FindSplitterByNodeId(frame.layout, "right-split");
+    ASSERT_NE(consoleStack, nullptr);
+    ASSERT_NE(rightSplitter, nullptr);
+
+    const UIRect overlapRect(
+        (std::max)(consoleStack->tabStripLayout.headerRect.x, rightSplitter->handleHitRect.x),
+        (std::max)(consoleStack->tabStripLayout.headerRect.y, rightSplitter->handleHitRect.y),
+        (std::min)(
+            consoleStack->tabStripLayout.headerRect.x + consoleStack->tabStripLayout.headerRect.width,
+            rightSplitter->handleHitRect.x + rightSplitter->handleHitRect.width) -
+            (std::max)(consoleStack->tabStripLayout.headerRect.x, rightSplitter->handleHitRect.x),
+        (std::min)(
+            consoleStack->tabStripLayout.headerRect.y + consoleStack->tabStripLayout.headerRect.height,
+            rightSplitter->handleHitRect.y + rightSplitter->handleHitRect.height) -
+            (std::max)(consoleStack->tabStripLayout.headerRect.y, rightSplitter->handleHitRect.y));
+    ASSERT_GT(overlapRect.width, 0.0f);
+    ASSERT_GT(overlapRect.height, 0.0f);
+    const UIPoint overlapPoint = RectCenter(overlapRect);
+    const UIPoint splitterDragPoint(overlapPoint.x, overlapPoint.y + 24.0f);
+    const UIPoint probeMovePoint(
+        consoleStack->tabStripLayout.headerRect.x + 8.0f,
+        consoleStack->tabStripLayout.headerRect.y + consoleStack->tabStripLayout.headerRect.height * 0.5f);
+
+    frame = UpdateUIEditorDockHostInteraction(
+        state,
+        controller,
+        UIRect(0.0f, 0.0f, 800.0f, 600.0f),
+        { MakePointerMove(overlapPoint.x, overlapPoint.y) });
+
+    frame = UpdateUIEditorDockHostInteraction(
+        state,
+        controller,
+        UIRect(0.0f, 0.0f, 800.0f, 600.0f),
+        { MakePointerDown(overlapPoint.x, overlapPoint.y) });
+    EXPECT_TRUE(frame.result.consumed);
+    EXPECT_TRUE(frame.result.requestPointerCapture);
+    EXPECT_EQ(frame.result.activeSplitterNodeId, "right-split");
+
+    frame = UpdateUIEditorDockHostInteraction(
+        state,
+        controller,
+        UIRect(0.0f, 0.0f, 800.0f, 600.0f),
+        { MakePointerMove(splitterDragPoint.x, splitterDragPoint.y) });
+    EXPECT_TRUE(frame.result.consumed);
+    EXPECT_TRUE(frame.result.layoutChanged);
+
+    frame = UpdateUIEditorDockHostInteraction(
+        state,
+        controller,
+        UIRect(0.0f, 0.0f, 800.0f, 600.0f),
+        { MakePointerUp(splitterDragPoint.x, splitterDragPoint.y) });
+    EXPECT_TRUE(frame.result.releasePointerCapture);
+    EXPECT_TRUE(state.dockHostState.activeSplitterNodeId.empty());
+    EXPECT_TRUE(state.activeTabDragNodeId.empty());
+    EXPECT_TRUE(state.activeTabDragPanelId.empty());
+    EXPECT_FALSE(state.dockHostState.dropPreview.visible);
+
+    frame = UpdateUIEditorDockHostInteraction(
+        state,
+        controller,
+        UIRect(0.0f, 0.0f, 800.0f, 600.0f),
+        { MakePointerMove(probeMovePoint.x, probeMovePoint.y) });
+    EXPECT_FALSE(frame.result.requestPointerCapture);
+    EXPECT_FALSE(frame.result.releasePointerCapture);
+    EXPECT_FALSE(frame.result.layoutChanged);
+    EXPECT_TRUE(state.activeTabDragNodeId.empty());
+    EXPECT_TRUE(state.activeTabDragPanelId.empty());
+    EXPECT_FALSE(state.dockHostState.dropPreview.visible);
+}
+
 TEST(UIEditorDockHostInteractionTest, ClickingTabActivatesTargetPanel) {
     auto controller =
         BuildDefaultUIEditorWorkspaceController(BuildPanelRegistry(), BuildWorkspace());