mod: make Element's for rendering stateless

The elements derive their corresponding content to render from
the `Model` without any local state.

src/content.zig

@@ -1,12 +1,10 @@
 pub fn Content(App: type) type {
     return struct {
         allocator: Allocator,
-        document: *const App.Model.Document,
 
-        pub fn init(allocator: Allocator, document: *const App.Model.Document) @This() {
+        pub fn init(allocator: Allocator) @This() {
             return .{
                 .allocator = allocator,
-                .document = document,
             };
         }
 
@@ -21,27 +19,22 @@ pub fn Content(App: type) type {
             };
         }
 
-        fn minSize(ctx: *anyopaque, _: *const App.Model, size: zterm.Point) zterm.Point {
+        fn minSize(_: *anyopaque, model: *const App.Model, _: zterm.Point) zterm.Point {
-            const this: *const @This() = @ptrCast(@alignCast(ctx));
+            // NOTE currently the contents are assumed to fit into the viewport, excessive lines are cut off
-            _ = this;
+            // (there currently no horizontal scrolling)
-            //const text = this.document.content;
+            return .{ .y = @intCast(std.mem.count(u8, model.document.content, "\n") + 1) };
-            //var index: usize = 0;
-            const new_size: zterm.Point = .{ .x = size.x };
-
-            return new_size;
         }
 
         fn handle(ctx: *anyopaque, model: *App.Model, event: App.Event) !void {
+            // FIX this `Element` should not handle the de-/allocation of `Model` contents!
             const this: *@This() = @ptrCast(@alignCast(ctx));
             switch (event) {
-                .init => this.document = &model.document,
                 .about => {
                     model.page.deinit(this.allocator);
                     model.page = .about;
 
                     model.document.deinit(this.allocator);
                     model.document = .init(try std.fs.cwd().readFileAlloc(this.allocator, "./doc/about.md", std.math.maxInt(usize)));
-                    this.document = &model.document;
                 },
                 .blog => |path| {
                     model.page.deinit(this.allocator);
@@ -54,15 +47,12 @@ pub fn Content(App: type) type {
 
                     model.document = .init(try std.fs.cwd().readFileAlloc(this.allocator, if (path) |p| p else "./doc/blog.md", std.math.maxInt(usize)));
                     model.page = .{ .blog = path };
-
-                    this.document = &model.document;
                 },
                 else => {},
             }
         }
 
-        fn content(ctx: *anyopaque, model: *const App.Model, cells: []zterm.Cell, size: zterm.Point) !void {
+        fn content(_: *anyopaque, model: *const App.Model, cells: []zterm.Cell, size: zterm.Point) !void {
-            _ = ctx;
             assert(cells.len == @as(usize, size.x) * @as(usize, size.y));
 
             const text = model.document.content;
@@ -81,6 +71,10 @@ pub fn Content(App: type) type {
                         else => cp,
                     };
                 }
+                if (text[index - 1] != '\n') {
+                    // go to the end of the line
+                    while (index < text.len and text[index] != '\n') index +=1;
+                }
             }
         }
     };
@@ -97,9 +91,7 @@ pub fn Title(App: type) type {
             };
         }
 
-        fn content(ctx: *anyopaque, model: *const App.Model, cells: []zterm.Cell, size: zterm.Point) !void {
+        fn content(_: *anyopaque, model: *const App.Model, cells: []zterm.Cell, size: zterm.Point) !void {
-            const this: *const @This() = @ptrCast(@alignCast(ctx));
-            _ = this;
             assert(cells.len == @as(usize, size.x) * @as(usize, size.y));
 
             if (model.document.title) |text| {
@@ -117,10 +109,10 @@ pub fn Title(App: type) type {
 }
 
 pub fn InfoBanner(App: type) type {
-    return struct {
+    const left_text: []const u8 = "Build with zig";
-        left_text: []const u8 = "Build with zig",
+    const right_text: []const u8 = "Yves Biener (@yves-biener)";
-        right_text: []const u8 = "Yves Biener (@yves-biener)",
 
+    return struct {
         pub fn element(this: *@This()) App.Element {
             return .{
                 .ptr = this,
@@ -130,11 +122,10 @@ pub fn InfoBanner(App: type) type {
             };
         }
 
-        fn content(ctx: *anyopaque, model: *const App.Model, cells: []zterm.Cell, size: zterm.Point) !void {
+        fn content(_: *anyopaque, model: *const App.Model, cells: []zterm.Cell, size: zterm.Point) !void {
-            const this: *const @This() = @ptrCast(@alignCast(ctx));
             assert(cells.len == @as(usize, size.x) * @as(usize, size.y));
 
-            for (0.., this.left_text) |idx, cp| {
+            for (0.., left_text) |idx, cp| {
                 // NOTE do not write over the contents of this `Container`'s `Size`
                 if (idx == cells.len) break;
 
@@ -147,7 +138,7 @@ pub fn InfoBanner(App: type) type {
                 .about => {},
                 .blog => |path| if (path) |p| page: {
                     const start_idx = (size.x -| p.len) / 2;
-                    if (start_idx <= this.left_text.len) break :page;
+                    if (start_idx <= left_text.len) break :page;
 
                     for (start_idx.., p) |idx, cp| {
                         // NOTE do not write over the contents of this `Container`'s `Size`
@@ -159,10 +150,10 @@ pub fn InfoBanner(App: type) type {
                 },
             }
 
-            var start_idx = size.x -| this.right_text.len;
+            var start_idx = size.x -| right_text.len;
-            if (start_idx <= this.left_text.len) start_idx = this.left_text.len + 1;
+            if (start_idx <= left_text.len) start_idx = left_text.len + 1;
 
-            for (start_idx.., this.right_text) |idx, cp| {
+            for (start_idx.., right_text) |idx, cp| {
                 // NOTE do not write over the contents of this `Container`'s `Size`
                 if (idx == cells.len) break;
 
@@ -178,3 +169,4 @@ const std = @import("std");
 const Allocator = std.mem.Allocator;
 const assert = std.debug.assert;
 const zterm = @import("zterm");
+const Model = @import("model.zig");

src/main.zig

@@ -79,7 +79,7 @@ pub fn main() !void {
     }
     // main actual tui_website page content
     {
-        var content: Content = .init(allocator, &app.model.document);
+        var content: Content = .init(allocator);
         content_container = try .init(allocator, .{}, content.element());
 
         var scrollable: App.Scrollable = .init(content_container, .enabled(.green, false));
@@ -139,7 +139,7 @@ pub fn main() !void {
                 .key => |key| {
                     if (key.eql(.{ .cp = 'c', .mod = .{ .ctrl = true } }) or key.eql(.{ .cp = 'q' })) app.quit();
                     // test if the event handling is working correctly
-                    if (key.eql(.{ .cp = zterm.input.Space })) app.postEvent(.{ .blog = allocator.dupe(u8, "./doc/test.md") catch unreachable });
+                    if (key.eql(.{ .cp = zterm.input.Space })) app.postEvent(.{ .blog = try allocator.dupe(u8, "./doc/test.md") });
                 },
                 .about => log.info(ResourceRequestFormat, .{"./doc/about.md"}),
                 .blog => |path| log.info(ResourceRequestFormat, .{if (path) |p| p else "./doc/blog.md"}),