yasirkula · October 23, 2021 10:09 · Oct 23, 2021
diff --git a/ScrollViewFocusFunctions.cs b/ScrollViewFocusFunctions.cs
@@ -0,0 +1,70 @@
+using System.Collections;
+using UnityEngine;
+using UnityEngine.UI;
+
+public static class ScrollViewFocusFunctions
+{
+	public static Vector2 CalculateFocusedScrollPosition( this ScrollRect scrollView, Vector2 focusPoint )
+	{
+		Vector2 contentSize = scrollView.content.rect.size;
+		Vector2 viewportSize = ( (RectTransform) scrollView.content.parent ).rect.size;
+		Vector2 contentScale = scrollView.content.localScale;
+
+		contentSize.Scale( contentScale );
+		focusPoint.Scale( contentScale );
+
+		Vector2 scrollPosition = scrollView.normalizedPosition;
+		if( scrollView.horizontal && contentSize.x > viewportSize.x )
+			scrollPosition.x = Mathf.Clamp01( ( focusPoint.x - viewportSize.x * 0.5f ) / ( contentSize.x - viewportSize.x ) );
+		if( scrollView.vertical && contentSize.y > viewportSize.y )
+			scrollPosition.y = Mathf.Clamp01( ( focusPoint.y - viewportSize.y * 0.5f ) / ( contentSize.y - viewportSize.y ) );
+
+		return scrollPosition;
+	}
+
+	public static Vector2 CalculateFocusedScrollPosition( this ScrollRect scrollView, RectTransform item )
+	{
+		Vector2 itemCenterPoint = scrollView.content.InverseTransformPoint( item.transform.TransformPoint( item.rect.center ) );
+
+		Vector2 contentSizeOffset = scrollView.content.rect.size;
+		contentSizeOffset.Scale( scrollView.content.pivot );
+
+		return scrollView.CalculateFocusedScrollPosition( itemCenterPoint + contentSizeOffset );
+	}
+
+	public static void FocusAtPoint( this ScrollRect scrollView, Vector2 focusPoint )
+	{
+		scrollView.normalizedPosition = scrollView.CalculateFocusedScrollPosition( focusPoint );
+	}
+
+	public static void FocusOnItem( this ScrollRect scrollView, RectTransform item )
+	{
+		scrollView.normalizedPosition = scrollView.CalculateFocusedScrollPosition( item );
+	}
+
+	private static IEnumerator LerpToScrollPositionCoroutine( this ScrollRect scrollView, Vector2 targetNormalizedPos, float speed )
+	{
+		Vector2 initialNormalizedPos = scrollView.normalizedPosition;
+
+		float t = 0f;
+		while( t < 1f )
+		{
+			scrollView.normalizedPosition = Vector2.LerpUnclamped( initialNormalizedPos, targetNormalizedPos, 1f - ( 1f - t ) * ( 1f - t ) );
+
+			yield return null;
+			t += speed * Time.unscaledDeltaTime;
+		}
+
+		scrollView.normalizedPosition = targetNormalizedPos;
+	}
+
+	public static IEnumerator FocusAtPointCoroutine( this ScrollRect scrollView, Vector2 focusPoint, float speed )
+	{
+		yield return scrollView.LerpToScrollPositionCoroutine( scrollView.CalculateFocusedScrollPosition( focusPoint ), speed );
+	}
+
+	public static IEnumerator FocusOnItemCoroutine( this ScrollRect scrollView, RectTransform item, float speed )
+	{
+		yield return scrollView.LerpToScrollPositionCoroutine( scrollView.CalculateFocusedScrollPosition( item ), speed );
+	}
+}