refactor(new_editor): continue architecture closeout

new_editor/src/Collections/UIEditorTabStrip.cpp

@@ -196,41 +196,6 @@ void AppendSelectedTabBottomBorderMask(
         0.0f);
 }
 
-UIEditorTabStripInsertionPreview BuildInsertionPreview(
-    const UIEditorTabStripLayout& layout,
-    const UIEditorTabStripState& state,
-    const UIEditorTabStripMetrics& metrics) {
-    UIEditorTabStripInsertionPreview preview = {};
-    if (!state.reorder.dragging ||
-        state.reorder.previewInsertionIndex == UIEditorTabStripInvalidIndex ||
-        layout.tabHeaderRects.empty() ||
-        state.reorder.previewInsertionIndex > layout.tabHeaderRects.size() ||
-        layout.headerRect.height <= 0.0f) {
-        return preview;
-    }
-
-    float indicatorX = layout.tabHeaderRects.front().x;
-    if (state.reorder.previewInsertionIndex >= layout.tabHeaderRects.size()) {
-        const UIRect& lastRect = layout.tabHeaderRects.back();
-        indicatorX = lastRect.x + lastRect.width;
-    } else {
-        indicatorX = layout.tabHeaderRects[state.reorder.previewInsertionIndex].x;
-    }
-
-    const float thickness = (std::max)(ClampNonNegative(metrics.reorderPreviewThickness), 1.0f);
-    const float insetY = ClampNonNegative(metrics.reorderPreviewInsetY);
-    const float indicatorHeight = (std::max)(layout.headerRect.height - insetY * 2.0f, thickness);
-
-    preview.visible = true;
-    preview.insertionIndex = state.reorder.previewInsertionIndex;
-    preview.indicatorRect = UIRect(
-        indicatorX - thickness * 0.5f,
-        layout.headerRect.y + insetY,
-        thickness,
-        indicatorHeight);
-    return preview;
-}
-
 } // namespace
 
 float ResolveUIEditorTabStripDesiredHeaderLabelWidth(
@@ -287,9 +252,6 @@ UIEditorTabStripLayout BuildUIEditorTabStripLayout(
     layout.headerRect = arranged.headerRect;
     layout.contentRect = arranged.contentRect;
     layout.tabHeaderRects = arranged.tabHeaderRects;
-    layout.closeButtonRects.resize(items.size());
-    layout.showCloseButtons.resize(items.size(), false);
-    layout.insertionPreview = BuildInsertionPreview(layout, state, metrics);
     return layout;
 }
 
@@ -361,12 +323,6 @@ void AppendUIEditorTabStripBackground(
         }
     }
 
-    if (layout.insertionPreview.visible) {
-        drawList.AddFilledRect(
-            layout.insertionPreview.indicatorRect,
-            palette.reorderPreviewColor,
-            0.0f);
-    }
 }
 
 void AppendUIEditorTabStripForeground(