feat(scrollable): make Container scrollable through Element Scrollable

src/container.zig

@@ -225,9 +225,8 @@ pub const Layout = packed struct {
 };
 
 pub fn Container(comptime Event: type) type {
-    if (!isTaggedUnion(Event)) {
-        @compileError("Provided user event `Event` for `Container(comptime Event: type)`");
-    }
+    if (!isTaggedUnion(Event)) @compileError("Provided user event `Event` for `Container(comptime Event: type)`");
+
     const Element = @import("element.zig").Element(Event);
     return struct {
         allocator: std.mem.Allocator,
@@ -243,6 +242,7 @@ pub fn Container(comptime Event: type) type {
             border: Border = .{},
             rectangle: Rectangle = .{},
             layout: Layout = .{},
+            min_size: Size = .{},
         };
 
         pub fn init(
@@ -270,6 +270,24 @@ pub fn Container(comptime Event: type) type {
             try this.elements.append(element);
         }
 
+        pub fn minSize(this: @This()) Size {
+            var size: Size = .{};
+            const len: u16 = @truncate(this.elements.items.len);
+            if (len > 0) {
+                for (this.elements.items) |element| {
+                    size = size.merge(element.minSize());
+                }
+                switch (this.properties.layout.direction) {
+                    .horizontal => size.cols += this.properties.layout.gap * (len - 1),
+                    .vertical => size.rows += this.properties.layout.gap * (len - 1),
+                }
+            }
+            return .{
+                .cols = @max(size.cols, this.properties.min_size.cols),
+                .rows = @max(size.rows, this.properties.min_size.rows),
+            };
+        }
+
         pub fn handle(this: *@This(), event: Event) !void {
             switch (event) {
                 .resize => |size| resize: {