Support scrollIntoView alignment options (#3952)

Co-authored-by: Jonathan Kelley <jkelleyrtp@gmail.com>

packages/html/src/events/mounted.rs

@@ -34,7 +34,7 @@ pub trait RenderedElementBacking: std::any::Any {
     /// Scroll to make the element visible
     fn scroll_to(
         &self,
-        _behavior: ScrollBehavior,
+        _options: ScrollToOptions,
     ) -> Pin<Box<dyn Future<Output = MountedResult<()>>>> {
         Box::pin(async { Err(MountedError::NotSupported) })
     }
@@ -72,6 +72,46 @@ pub enum ScrollBehavior {
     Smooth,
 }
 
+/// The desired final position within the scrollable ancestor container for a given axis.
+#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[doc(alias = "ScrollIntoViewOptions")]
+pub enum ScrollLogicalPosition {
+    /// Aligns the element's start edge (top or left) with the start of the scrollable container,
+    /// making the element appear at the start of the visible area.
+    #[cfg_attr(feature = "serialize", serde(rename = "start"))]
+    Start,
+    /// Aligns the element at the center of the scrollable container,
+    /// positioning it in the middle of the visible area.
+    #[cfg_attr(feature = "serialize", serde(rename = "center"))]
+    Center,
+    /// Aligns the element's end edge (bottom or right) with the end of the scrollable container,
+    /// making the element appear at the end of the visible area
+    #[cfg_attr(feature = "serialize", serde(rename = "end"))]
+    End,
+    /// Scrolls the element to the nearest edge in the given axis.
+    /// This minimizes the scrolling distance.
+    #[cfg_attr(feature = "serialize", serde(rename = "nearest"))]
+    Nearest,
+}
+
+/// The way that scrolling should be performed
+#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[doc(alias = "ScrollIntoViewOptions")]
+pub struct ScrollToOptions {
+    pub behavior: ScrollBehavior,
+    pub vertical: ScrollLogicalPosition,
+    pub horizontal: ScrollLogicalPosition,
+}
+impl Default for ScrollToOptions {
+    fn default() -> Self {
+        Self {
+            behavior: ScrollBehavior::Smooth,
+            vertical: ScrollLogicalPosition::Start,
+            horizontal: ScrollLogicalPosition::Center,
+        }
+    }
+}
+
 /// An Element that has been rendered and allows reading and modifying information about it.
 ///
 /// Different platforms will have different implementations and different levels of support for this trait. Renderers that do not support specific features will return `None` for those queries.
@@ -125,7 +165,19 @@ impl MountedData {
         &self,
         behavior: ScrollBehavior,
     ) -> Pin<Box<dyn Future<Output = MountedResult<()>>>> {
-        self.inner.scroll_to(behavior)
+        self.inner.scroll_to(ScrollToOptions {
+            behavior,
+            ..ScrollToOptions::default()
+        })
+    }
+
+    /// Scroll to make the element visible
+    #[doc(alias = "scrollIntoView")]
+    pub fn scroll_to_with_options(
+        &self,
+        options: ScrollToOptions,
+    ) -> Pin<Box<dyn Future<Output = MountedResult<()>>>> {
+        self.inner.scroll_to(options)
     }
 
     /// Scroll to the given element offsets