mod(tui): create own terminal interface framework

src/main.zig

@@ -1,18 +1,15 @@
 const std = @import("std");
-
+const terminal = @import("terminal.zig");
 const zlog = @import("zlog");
 
-const terminal = @import("terminal.zig");
-
-const UserEvent = union(enum) {};
-
-const Widget = @import("widget.zig").Widget(UserEvent);
-const Layout = @import("layout.zig").Layout(UserEvent);
+const App = @import("app.zig").App(union(enum) {});
 
 pub const std_options = zlog.std_options;
 const log = std.log.scoped(.main);
 
 pub fn main() !void {
+    errdefer |err| log.err("Application Error: {any}", .{err});
+
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
     defer {
         const deinit_status = gpa.deinit();
@@ -23,18 +20,46 @@ pub fn main() !void {
     }
     const allocator = gpa.allocator();
 
-    const size = terminal.getTerminalSize();
+    var app = App.init();
 
-    log.debug("Size := [x: {d}, y: {d}]", .{ size.cols, size.rows });
-    var rawText = Widget.RawText.init(allocator);
-    const widget = Widget.createFrom(&rawText);
-    var layout = Layout.Pane.init(allocator, widget);
+    var rawText = App.Widget.RawText.init(allocator);
+    const widget = App.Widget.createFrom(&rawText);
+    var layout = App.Layout.Pane.init(allocator, widget);
     defer layout.deinit();
 
-    // single 'draw' loop
-    _ = layout.handle(.none);
-    log.debug("Layout result: {s}", .{layout.content().items});
+    try app.start();
+    defer app.stop() catch unreachable;
 
+    // NOTE: necessary for fullscreen tui applications
+    try terminal.enterAltScreen();
+    defer terminal.existAltScreen() catch unreachable;
+
+    // App.Event loop
+    while (true) {
+        const event = app.nextEvent();
+
+        switch (event) {
+            .none => continue,
+            .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 });
+            },
+            else => {},
+        }
+        const events = try layout.handle(event);
+        for (events.items) |e| {
+            app.postEvent(e);
+        }
+        log.debug("Layout result: {s}", .{(try layout.content()).items});
+    }
+    // TODO: I could use the ascii codes in vaxis
+    // - see https://gist.github.com/ConnerWill/d4b6c776b509add763e17f9f113fd25b
     // how would I draw?
     // use array for screen contents? <-> support partial re-draws
     // support widget type drawing similar to the already existing widgets
@@ -43,3 +68,7 @@ pub fn main() !void {
     // - contents of corresponding locations
     // resize event
 }
+
+test {
+    _ = @import("queue.zig");
+}