ref(event): remove .resize and replace with recursize method calls

This also means that currently the dynamic resizing through the app's
detached thread is not working, as it cannot send size updates. The
examples have been overhauled to still implement intermediate mode
applications accordingly.

src/element.zig

@@ -13,10 +13,24 @@ pub fn Element(Event: type) type {
         vtable: *const VTable = &.{},
 
         pub const VTable = struct {
+            resize: ?*const fn (ctx: *anyopaque, size: Point) void = null,
+            reposition: ?*const fn (ctx: *anyopaque, origin: Point) void = null,
             handle: ?*const fn (ctx: *anyopaque, event: Event) anyerror!void = null,
             content: ?*const fn (ctx: *anyopaque, cells: []Cell, origin: Point, size: Point) anyerror!void = null,
         };
 
+        /// Resize the corresponding `Element` with the given *size*.
+        pub fn resize(this: @This(), size: Point) void {
+            if (this.vtable.resize) |resize_fn|
+                resize_fn(this.ptr, size);
+        }
+
+        /// Reposition the corresponding `Element` with the given *origin*.
+        pub fn reposition(this: @This(), origin: Point) void {
+            if (this.vtable.reposition) |reposition_fn|
+                reposition_fn(this.ptr, origin);
+        }
+
         /// Handle the received event. The event is one of the user provided
         /// events or a system event, with the exception of the `.size`
         /// `Event` as every `Container` already handles that event.
@@ -73,6 +87,8 @@ pub fn Scrollable(Event: type) type {
             return .{
                 .ptr = this,
                 .vtable = &.{
+                    .resize = resize,
+                    .reposition = reposition,
                     .handle = handle,
                     .content = content,
                 },
@@ -86,16 +102,23 @@ pub fn Scrollable(Event: type) type {
             };
         }
 
+        fn resize(ctx: *anyopaque, size: Point) void {
+            const this: *@This() = @ptrCast(@alignCast(ctx));
+            this.size = size;
+            // TODO scrollbar space - depending on configuration and only if necessary?
+            this.container_size = Point.max(size, this.min_size);
+            this.container_origin = size; // TODO the size should be a provided origin
+            this.container.resize(this.container_size);
+        }
+
+        fn reposition(ctx: *anyopaque, origin: Point) void {
+            const this: *@This() = @ptrCast(@alignCast(ctx));
+            this.container_origin = origin; // TODO the size should be a provided origin
+        }
+
         fn handle(ctx: *anyopaque, event: Event) !void {
             const this: *@This() = @ptrCast(@alignCast(ctx));
             switch (event) {
-                .size => |size| {
-                    this.size = size;
-                    // TODO scrollbar space - depending on configuration and only if necessary?
-                    this.container_size = size.max(this.min_size);
-                    this.container_origin = size; // TODO the size should be a provided origin
-                    try this.container.handle(.{ .size = this.container_size });
-                },
                 // TODO other means to scroll except with the mouse? (i.e. Ctrl-u/d, k/j, etc.?)
                 .mouse => |mouse| switch (mouse.button) {
                     Mouse.Button.wheel_up => if (this.container_size.y > this.size.y) {
@@ -224,7 +247,7 @@ test "scrollable vertical" {
     var renderer: testing.Renderer = .init(allocator, size);
     defer renderer.deinit();
 
-    try container.handle(.{ .size = size });
+    container.resize(size);
     try renderer.render(Container(event.SystemEvent), &container);
     try testing.expectEqualCells(.{}, renderer.size, @import("test/element/scrollable.vertical.top.zon"), renderer.screen);
 
@@ -298,7 +321,7 @@ test "scrollable horizontal" {
     var renderer: testing.Renderer = .init(allocator, size);
     defer renderer.deinit();
 
-    try container.handle(.{ .size = size });
+    container.resize(size);
     try renderer.render(Container(event.SystemEvent), &container);
     try testing.expectEqualCells(.{}, renderer.size, @import("test/element/scrollable.horizontal.left.zon"), renderer.screen);