hero-section-ui-stability

name	Hero Section UI Stability
description	Best practices for stable, flicker-free Hero cards in MainActivity and History.

Hero Section UI Stability

This skill documents the layout and animation standards to prevent flickering and layout jitters in high-impact Hero sections.

Layout Constraints

1. Width Management: Hero amount TextViews MUST use android:layout_width="match_parent" instead of wrap_content to prevent the card from recalculating its center or width during numeric transitions.
2. Line Control: Always set android:maxLines="1" and android:ellipsize="end" to guarantee vertical stability.
3. Auto-Scaling Typography: Use Material 3 auto-sizing to handle varying currency lengths and massive amounts:

   app:autoSizeTextType="uniform"
   app:autoSizeMinTextSize="24sp"
   app:autoSizeMaxTextSize="45sp"
   

Animation Stability

1. Decimal Preservation: During count-up animations, the logic MUST determine if the target value has decimals and maintain that decimal count throughout the animation. Flashing from 120 to 120.4 to 121 causes horizontal jittering and MUST be avoided.
2. Formatting Parity: Every frame of an animation must re-apply the 50% smaller symbol and standard spacing through SpannableStringBuilder to ensure a smooth, coherent transition.

Performance Checklist

• Is the TextView wider than the largest possible value?
• Does the text shrink to fit without wrapping?
• Are decimal places stable during animation?
• Is the currency symbol consistently smaller than the numbers?