fix(widget): respect size for RawText and Spacer Widgets

src/layout/VStack.zig

@@ -142,25 +142,12 @@ pub fn Layout(comptime Event: type, comptime Renderer: type) type {
 
         pub fn render(this: *@This(), renderer: Renderer) !void {
             // FIX: renderer should clear only what is going to change! (i.e. the 'active' widget / layout)
-            try renderer.clear(this.anchor, this.size);
-            var overflow = this.size.rows % this.elements.items.len;
-            for (this.elements.items, 0..) |*element, i| {
-                const row_mul: u16 = @truncate(i);
-                var row = row_mul * this.element_rows + 1;
-                if (i > 0 and overflow > 0) {
-                    overflow -|= 1;
-                    row += 1;
-                }
-                // TODO: that's the anchor of each component (only necessary for each widget rendering)
-                const pos: terminal.Position = .{ .col = 1, .row = row };
-                // TODO: do this using the renderer
-                try terminal.setCursorPosition(pos);
+            for (this.elements.items) |*element| {
                 switch (element.*) {
                     .layout => |*layout| {
                         try layout.render(renderer);
                     },
                     .widget => |*widget| {
-                        // TODO: clear per widget if necesary (i.e. can I query that?)
                         try widget.render(renderer);
                     },
                 }

src/render.zig

@@ -43,9 +43,9 @@ pub fn Buffered(comptime fullscreen: bool) type {
 
 pub fn Plain(comptime _: bool) type {
     return struct {
-        pub fn clear(this: @This(), anchor: Position, size: Size) !void {
+        pub fn clear(this: @This(), size: Size) !void {
             _ = this;
-            _ = size;
+            const anchor = size.anchor;
             // NOTE: clear entire screen for the first content (derived from the anchor being at the very left-top)
             if (anchor.col == 1 and anchor.row == 1) {
                 try terminal.clearScreen();

src/widget/RawText.zig

@@ -76,16 +76,16 @@ pub fn Widget(comptime Event: type, comptime Renderer: type) type {
         }
 
         pub fn render(this: *@This(), renderer: Renderer) !void {
+            try renderer.clear(this.size);
             try terminal.setCursorPosition(this.size.anchor);
             // TODO: render `this.contents`
-            _ = renderer;
             if (this.size.rows >= this.line_index.items.len) {
                 _ = try terminal.write(this.contents.items);
             } else {
                 // more rows than we can display
                 const i = this.line_index.items[this.line];
-                const e = this.size.rows + this.line + 1;
-                if (e >= this.line_index.items.len) {
+                const e = this.size.rows + this.line;
+                if (e > this.line_index.items.len) {
                     _ = try terminal.write(this.contents.items[i..]);
                 }
                 // last line should not end with the last character (likely a newline character)

src/widget/Spacer.zig

@@ -11,6 +11,8 @@ pub fn Widget(comptime Event: type, comptime Renderer: type) type {
         @compileError("Provided user event `Event` for `Layout(comptime Event: type)` is not of type `union(enum)`.");
     }
     return struct {
+        size: terminal.Size = undefined,
+
         pub fn init() @This() {
             return .{};
         }
@@ -20,15 +22,17 @@ pub fn Widget(comptime Event: type, comptime Renderer: type) type {
         }
 
         pub fn handle(this: *@This(), event: Event) ?Event {
-            _ = this;
-            _ = event;
+            switch (event) {
+                .resize => |size| {
+                    this.size = size;
+                },
+                else => {},
+            }
             return null;
         }
 
         pub fn render(this: *@This(), renderer: Renderer) !void {
-            // FIX: this should rather clear the `terminal.Size` provided through the event system using the _renderer_.
-            _ = this;
-            _ = renderer;
+            try renderer.clear(this.size);
         }
     };
 }