add(examples/layout): mixed content with different layout options

examples/layouts/mixed.zig

@@ -0,0 +1,113 @@
+const std = @import("std");
+const zterm = @import("zterm");
+
+const App = zterm.App(union(enum) {});
+
+const log = std.log.scoped(.default);
+
+const QuitText = struct {
+    const text = "Press ctrl+c to quit.";
+
+    pub fn element(this: *@This()) App.Element {
+        return .{
+            .ptr = this,
+            // no handle function required
+            .vtable = &.{ .content = content },
+        };
+    }
+
+    fn content(ctx: *anyopaque, cells: []zterm.Cell, size: zterm.Size) !void {
+        _ = ctx;
+        std.debug.assert(cells.len == @as(usize, size.cols) * @as(usize, size.rows));
+
+        const row: u16 = 2;
+        const col: u16 = size.cols / 2 -| (@as(u16, @truncate(text.len)) / 2);
+        const anchor = (row * size.cols) + col;
+
+        for (text, 0..) |cp, idx| {
+            cells[anchor + idx].style.fg = .white;
+            cells[anchor + idx].style.bg = .black;
+            cells[anchor + idx].cp = cp;
+
+            // NOTE: do not write over the contents of this `Container`'s `Size`
+            if (anchor + idx == cells.len - 1) break;
+        }
+    }
+};
+
+pub fn main() !void {
+    errdefer |err| log.err("Application Error: {any}", .{err});
+
+    var gpa: std.heap.GeneralPurposeAllocator(.{}) = .init;
+    defer if (gpa.deinit() == .leak) {
+        log.err("memory leak", .{});
+    };
+    const allocator = gpa.allocator();
+
+    var app: App = .init;
+    var renderer = zterm.Renderer.Buffered.init(allocator);
+    defer renderer.deinit();
+
+    var quit_text: QuitText = .{};
+    const element = quit_text.element();
+
+    var container = try App.Container.init(allocator, .{
+        .layout = .{
+            .gap = 2,
+            .padding = .{ .top = 5, .bottom = 3, .left = 3, .right = 3 },
+            .direction = .horizontal,
+        },
+    }, element);
+    for (0..3) |i| {
+        var column = try App.Container.init(allocator, .{
+            .border = .{ .separator = .{ .enabled = true } },
+            .layout = .{
+                .direction = if (i > 0) .vertical else .horizontal,
+            },
+        }, .{});
+        if (i != 1) {
+            try column.append(try App.Container.init(allocator, .{
+                .rectangle = .{ .fill = .green },
+            }, .{}));
+            try column.append(try App.Container.init(allocator, .{
+                .rectangle = .{ .fill = .yellow },
+            }, .{}));
+        } else {
+            try column.append(try App.Container.init(allocator, .{}, .{}));
+        }
+        try column.append(try App.Container.init(allocator, .{
+            .rectangle = .{ .fill = .blue },
+        }, .{}));
+        try container.append(column);
+    }
+    defer container.deinit(); // also de-initializes the children
+
+    try app.start();
+    defer app.stop() catch |err| log.err("Failed to stop application: {any}", .{err});
+
+    // event loop
+    while (true) {
+        const event = app.nextEvent();
+        log.debug("received event: {s}", .{@tagName(event)});
+
+        switch (event) {
+            .init => continue,
+            .quit => break,
+            .resize => |size| try renderer.resize(size),
+            .key => |key| if (key.eql(.{ .cp = 'c', .mod = .{ .ctrl = true } })) app.quit(),
+            // NOTE: errors could be displayed in another container in case one was received, etc. to provide the user with feedback
+            .err => |err| log.err("Received {s} with message: {s}", .{ @errorName(err.err), err.msg }),
+            else => {},
+        }
+
+        // NOTE: returned errors should be propagated back to the application
+        container.handle(event) catch |err| app.postEvent(.{
+            .err = .{
+                .err = err,
+                .msg = "Container Event handling failed",
+            },
+        });
+        try renderer.render(@TypeOf(container), &container);
+        try renderer.flush();
+    }
+}