add: signal handling WINCH, user input thread with waiting blocking

src/layout/Pane.zig

@@ -1,26 +1,27 @@
 const std = @import("std");
-const lib_event = @import("../event.zig");
-const widget = @import("../widget.zig");
+const isTaggedUnion = @import("../event.zig").isTaggedUnion;
+const Error = @import("../event.zig").Error;
 
 pub fn Layout(comptime Event: type) type {
-    if (!lib_event.isTaggedUnion(Event)) {
+    if (!isTaggedUnion(Event)) {
         @compileError("Provided user event `Event` for `Layout(comptime Event: type)` is not of type `union(enum)`.");
     }
+    const Widget = @import("../widget.zig").Widget(Event);
     return struct {
-        w: widget.Widget(Event) = undefined,
+        widget: Widget = undefined,
         events: std.ArrayList(Event) = undefined,
         c: std.ArrayList(u8) = undefined,
 
-        pub fn init(allocator: std.mem.Allocator, w: widget.Widget(Event)) @This() {
+        pub fn init(allocator: std.mem.Allocator, widget: Widget) @This() {
             return .{
-                .w = w,
+                .widget = widget,
                 .events = std.ArrayList(Event).init(allocator),
                 .c = std.ArrayList(u8).init(allocator),
             };
         }
 
         pub fn deinit(this: *@This()) void {
-            this.w.deinit();
+            this.widget.deinit();
             this.events.deinit();
             this.c.deinit();
             this.* = undefined;
@@ -28,14 +29,14 @@ pub fn Layout(comptime Event: type) type {
 
         pub fn handle(this: *@This(), event: Event) !*std.ArrayList(Event) {
             this.events.clearRetainingCapacity();
-            if (this.w.handle(event)) |e| {
+            if (this.widget.handle(event)) |e| {
                 try this.events.append(e);
             }
             return &this.events;
         }
 
         pub fn content(this: *@This()) !*std.ArrayList(u8) {
-            const widget_content = try this.w.content();
+            const widget_content = try this.widget.content();
             this.c.clearRetainingCapacity();
             try this.c.appendSlice(widget_content.items);
             return &this.c;