Add multidirectional scrolling capabilities to the existing Scrollable.

native/src/widget/column.rs

@@ -10,8 +10,6 @@ use crate::{
     Shell, Widget,
 };
 
-use std::u32;
-
 /// A container that distributes its contents vertically.
 #[allow(missing_debug_implementations)]
 pub struct Column<'a, Message, Renderer> {

native/src/widget/operation/scrollable.rs

@@ -1,27 +1,22 @@
 //! Operate on widgets that can be scrolled.
 use crate::widget::{Id, Operation};
+use iced_core::Vector;
 
 /// The internal state of a widget that can be scrolled.
 pub trait Scrollable {
     /// Snaps the scroll of the widget to the given `percentage`.
-    fn snap_to(&mut self, percentage: f32);
+    fn snap_to(&mut self, percentage: Vector<f32>);
 }
 
 /// Produces an [`Operation`] that snaps the widget with the given [`Id`] to
 /// the provided `percentage`.
-pub fn snap_to<T>(target: Id, percentage: f32) -> impl Operation<T> {
+pub fn snap_to<T>(target: Id, percentage: Vector<f32>) -> impl Operation<T> {
     struct SnapTo {
         target: Id,
-        percentage: f32,
+        percentage: Vector<f32>,
     }
 
     impl<T> Operation<T> for SnapTo {
-        fn scrollable(&mut self, state: &mut dyn Scrollable, id: Option<&Id>) {
-            if Some(&self.target) == id {
-                state.snap_to(self.percentage);
-            }
-        }
-
         fn container(
             &mut self,
             _id: Option<&Id>,
@@ -29,6 +24,12 @@ pub fn snap_to<T>(target: Id, percentage: f32) -> impl Operation<T> {
         ) {
             operate_on_children(self)
         }
+
+        fn scrollable(&mut self, state: &mut dyn Scrollable, id: Option<&Id>) {
+            if Some(&self.target) == id {
+                state.snap_to(self.percentage);
+            }
+        }
     }
 
     SnapTo { target, percentage }