add/mod the following features

- split structure for better inclusions
- create PlainRenderer to render contents to the terminal
- simplify events
- clearify what structs are created on the heap and which are on the stack
- quit event is now emitted from the main event loop and not the input loop (see helper function `App.quit`)
- rename several variables and/or functions for easier understanding
- introduce `App.interrupt` to stop the input thread and start a new sub TUI which takes over the entire screen (i.e. 'hx', 'nvim', etc.)

src/main.zig

@@ -3,6 +3,8 @@ const terminal = @import("terminal.zig");
 const zlog = @import("zlog");
 
 const App = @import("app.zig").App(union(enum) {});
+const Renderer = @import("render.zig").PlainRenderer();
+const Key = @import("key.zig");
 
 pub const std_options = zlog.std_options;
 const log = std.log.scoped(.default);
@@ -20,7 +22,8 @@ pub fn main() !void {
     }
     const allocator = gpa.allocator();
 
-    var app = App.init();
+    var app: App = .{};
+    var renderer: Renderer = .{};
 
     var rawText = App.Widget.RawText.init(allocator);
     const widget = App.Widget.createFrom(&rawText);
@@ -40,29 +43,36 @@ pub fn main() !void {
 
         switch (event) {
             .quit => break,
-            .resize => |size| {
-                // NOTE: draw actions should not happen here (still here for testing)
-                // NOTE: clearing the screen and positioning the cursor is only necessary for full screen applications
-                // - in-line applications should use relative movements instead and should only clear lines (which they draw)
-                // - in-line applications should not enter the alt screen
-                try terminal.clearScreen();
-                try terminal.setCursorPositionHome();
-                log.debug("Size := [x: {d}, y: {d}]", .{ size.cols, size.rows });
-            },
             .key => |key| {
-                log.debug("received key: {any}", .{key});
                 // ctrl+c to quit
-                if (terminal.Key.matches(key, .{ .cp = 'c', .mod = .{ .ctrl = true } })) {
-                    app.quit.set();
+                if (Key.matches(key, .{ .cp = 'c', .mod = .{ .ctrl = true } })) {
+                    app.quit();
                 }
+                if (Key.matches(key, .{ .cp = 'n', .mod = .{ .ctrl = true } })) {
+                    try app.interrupt();
+                    defer app.start() catch @panic("could not start app event loop");
+                    var child = std.process.Child.init(&.{"hx"}, allocator);
+                    _ = child.spawnAndWait() catch |err| {
+                        app.postEvent(.{
+                            .err = .{
+                                .err = err,
+                                .msg = "Spawning Helix failed",
+                            },
+                        });
+                    };
+                }
+            },
+            .err => |err| {
+                log.err("Received {any} with message: {s}", .{ err.err, err.msg });
             },
             else => {},
         }
+        // NOTE: this currently re-renders the screen for every key-press -> which might be a bit of an overkill
         const events = try layout.handle(event);
         for (events.items) |e| {
             app.postEvent(e);
         }
-        log.debug("Layout result: {s}", .{(try layout.content()).items});
+        try renderer.render(try layout.content());
     }
     // TODO: I could use the ascii codes in vaxis
     // - see https://gist.github.com/ConnerWill/d4b6c776b509add763e17f9f113fd25b