add(container/layout): sizing:fixed option

src/container.zig

@@ -30,6 +30,14 @@ pub const Border = struct {
         pub fn all() @This() {
             return .{ .top = true, .bottom = true, .left = true, .right = true };
         }
+
+        pub fn horizontal() @This() {
+            return .{ .left = true, .right = true };
+        }
+
+        pub fn vertical() @This() {
+            return .{ .top = true, .bottom = true };
+        }
     } = .{},
     /// Configure separator borders between child element to added to the layout
     separator: struct {
@@ -280,7 +288,45 @@ pub fn Container(comptime Event: type) type {
         pub fn handle(this: *@This(), event: Event) !void {
             switch (event) {
                 .init => log.debug(".init event", .{}),
-                .resize => |size| resize: {
+                .resize => |s| resize: {
+                    // sizing
+                    var size = s;
+                    const sizing = this.properties.layout.sizing;
+                    switch (sizing.width) {
+                        .fit => {
+                            // use as much space as necessary (but nothing more than necessary)
+                        },
+                        .grow => {
+                            // grow use as much space as available by the parent (i.e. the entire width)
+                            // NOTE: this is pretty much the current implementation
+                        },
+                        .fixed => |fix| {
+                            std.debug.assert(fix <= size.cols);
+                            size.cols = fix;
+                        },
+                        .percent => |percent| {
+                            // use a percentage unit calculated from the available space
+                            size.cols = @divTrunc(size.cols * percent, 100);
+                        },
+                    }
+                    switch (sizing.height) {
+                        .fit => {
+                            // use as much space as necessary (but nothing more than necessary)
+                        },
+                        .grow => {
+                            // grow use as much space as available by the parent (i.e. the entire width)
+                            // NOTE: this is pretty much the current implementation
+                        },
+                        .fixed => |fix| {
+                            std.debug.assert(fix <= size.rows);
+                            size.rows = fix;
+                        },
+                        .percent => |percent| {
+                            // use a percentage unit calculated from the available space
+                            size.rows = @divTrunc(size.rows * percent, 100);
+                        },
+                    }
+
                     log.debug("Event .resize: {{ .anchor = {{ .col = {d}, .row = {d} }}, .cols = {d}, .rows = {d} }}", .{
                         size.anchor.col,
                         size.anchor.row,