mod(container): make reposition public and split from resize

src/element.zig

@@ -83,6 +83,7 @@ pub fn Scrollable(Event: type) type {
                 .ptr = this,
                 .vtable = &.{
                     .resize = resize,
+                    .reposition = reposition,
                     .handle = handle,
                     .content = content,
                 },
@@ -94,10 +95,15 @@ pub fn Scrollable(Event: type) type {
             this.size = size;
 
             // TODO scrollbar space - depending on configuration and only if necessary?
-            this.container.resize(.{}, this.size);
+            this.container.resize(this.size);
             this.container_size = this.container.size;
         }
 
+        fn reposition(ctx: *anyopaque, _: Point) void {
+            const this: *@This() = @ptrCast(@alignCast(ctx));
+            this.container.reposition(.{});
+        }
+
         fn handle(ctx: *anyopaque, event: Event) !void {
             const this: *@This() = @ptrCast(@alignCast(ctx));
             switch (event) {
@@ -229,7 +235,8 @@ test "scrollable vertical" {
     var renderer: testing.Renderer = .init(allocator, size);
     defer renderer.deinit();
 
-    container.resize(.{}, size);
+    container.resize(size);
+    container.reposition(.{});
     try renderer.render(Container(event.SystemEvent), &container);
     try testing.expectEqualCells(.{}, renderer.size, @import("test/element/scrollable.vertical.top.zon"), renderer.screen);
 
@@ -306,7 +313,8 @@ test "scrollable horizontal" {
     var renderer: testing.Renderer = .init(allocator, size);
     defer renderer.deinit();
 
-    container.resize(.{}, size);
+    container.resize(size);
+    container.reposition(.{});
     try renderer.render(Container(event.SystemEvent), &container);
     try testing.expectEqualCells(.{}, renderer.size, @import("test/element/scrollable.horizontal.left.zon"), renderer.screen);