README.md

📝 Task: Create a virtualized chat list with element recycling

Context:

You are developing an in-game chat UI that can hold up to 10,000 messages. Creating 10,000 UI objects directly would cause severe performance issues. You need to implement a dynamic list with virtualization and element recycling.

Requirements:

1. Create a ScrollView (vertical) with Viewport, Content, and a vertical Scrollbar.

2. Implement a script VirtualChatList.cs that:

   • Stores a list of messages (e.g., List<string>)
   • Creates a pool of 10 UI elements (e.g., a ChatMessagePrefab with a TextMeshProUGUI component)
   • During scrolling, calculates which message indices should be visible
   • Reuses elements: takes an element from the pool that went off-screen and fills it with new text
   • Subscribes to the ScrollRect's OnValueChanged event

3. Add test data generation:

   • A button "Add 1000 messages" — adds 1000 messages to the data list and refreshes the display

4. Performance indicator (optional):

   • Display the number of physical objects (should remain ~10) vs the total data count (grows)

Expected result:

• Scrolling through 10,000 messages is smooth (60+ FPS)
• Hierarchy always contains only 10–12 objects (not 10,000)
• New messages appear without delays

Hints:

• Use RectTransform.anchoredPosition to position elements
• Each element has a fixed height (e.g., 80 pixels)
• Call a Refresh() method when the list size changes or during scrolling
• For the buffer, often use visibleCount + 2 elements

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