add(sizing): grow configuration

Currently the 'grid' and 'mixed' examples are not working yet.

examples/demo.zig

@@ -61,7 +61,9 @@ pub fn main() !void {
             .padding = .vertical(2),
             .direction = .vertical,
         },
-        .size = .{ .y = 90 },
+        .size = .{
+            .dim = .{ .y = 90 },
+        },
     }, .{});
     try box.append(try App.Container.init(allocator, .{
         .rectangle = .{ .fill = .light_green },
@@ -91,11 +93,15 @@ pub fn main() !void {
             .color = .light_blue,
             .sides = .all,
         },
-        .size = .{ .x = 100 },
+        .size = .{
+            .dim = .{ .x = 100 },
+        },
     }, .{}));
     try container.append(try App.Container.init(allocator, .{
         .rectangle = .{ .fill = .blue },
-        .size = .{ .x = 30 },
+        .size = .{
+            .dim = .{ .x = 30 },
+        },
     }, .{}));
     defer container.deinit(); // also de-initializes the children
 

examples/elements/scrollable.zig

@@ -98,15 +98,21 @@ pub fn main() !void {
     }, .{});
     try top_box.append(try App.Container.init(allocator, .{
         .rectangle = .{ .fill = .light_green },
-        .size = .{ .y = 30 },
+        .size = .{
+            .dim = .{ .y = 30 },
+        },
     }, .{}));
     try top_box.append(try App.Container.init(allocator, .{
         .rectangle = .{ .fill = .light_green },
-        .size = .{ .y = 5 },
+        .size = .{
+            .dim = .{ .y = 5 },
+        },
     }, element));
     try top_box.append(try App.Container.init(allocator, .{
         .rectangle = .{ .fill = .light_green },
-        .size = .{ .y = 2 },
+        .size = .{
+            .dim = .{ .y = 2 },
+        },
     }, .{}));
     defer top_box.deinit();
 
@@ -123,6 +129,9 @@ pub fn main() !void {
             .direction = .vertical,
             .padding = .vertical(1),
         },
+        .size = .{
+            .dim = .{ .y = 30 },
+        },
     }, .{});
     try bottom_box.append(try App.Container.init(allocator, .{
         .rectangle = .{ .fill = .grey },

examples/styles/palette.zig

@@ -64,7 +64,7 @@ pub fn main() !void {
         if (comptime field.value == 0) continue; // zterm.Color.default == 0 -> skip
         try box.append(try App.Container.init(allocator, .{ .rectangle = .{ .fill = @enumFromInt(field.value) } }, .{}));
     }
-    var scrollable: App.Scrollable = .init(box, .{ .x = 3 * std.meta.fields(zterm.Color).len }); // ensure enough columns to render all colors -> scrollable otherwise
+    var scrollable: App.Scrollable = .{ .container = box };
     try container.append(try App.Container.init(allocator, .{}, scrollable.element()));
 
     try app.start();

examples/styles/text.zig

@@ -114,10 +114,7 @@ pub fn main() !void {
     }, text_styles.element());
     defer box.deinit();
 
-    var scrollable: App.Scrollable = .init(box, .{
-        .x = std.meta.fields(zterm.Style.Emphasis).len * TextStyles.text.len,
-        .y = (std.meta.fields(zterm.Color).len - 1) * (std.meta.fields(zterm.Color).len - 2),
-    }); // ensure enough rows and/or columns to render all text styles -> scrollable otherwise
+    var scrollable: App.Scrollable = .{ .container = box };
     try container.append(try App.Container.init(allocator, .{}, scrollable.element()));
 
     try app.start();

src/container.zig

@@ -352,12 +352,15 @@ pub const Layout = packed struct {
             };
             const gap: u16 = (this.gap + 1) / 2;
 
+            log.debug("origin: {any}, size: {any}", .{ origin, size });
             for (0..children.len - 1) |idx| {
                 const child = children[idx];
                 const anchor = switch (this.direction) {
-                    .horizontal => ((@as(usize, child.origin.y) -| @as(usize, origin.y)) * @as(usize, size.x)) + @as(usize, child.origin.x) + @as(usize, child.size.x) + gap -| @as(usize, origin.x),
-                    .vertical => ((@as(usize, child.origin.y) + @as(usize, child.size.y) + gap -| @as(usize, origin.y)) * @as(usize, size.x)) + @as(usize, child.origin.x) -| @as(usize, origin.x),
+                    .horizontal => (@as(usize, child.origin.y) * @as(usize, size.x)) + @as(usize, child.origin.x) + @as(usize, child.size.x) + gap,
+                    .vertical => ((@as(usize, child.origin.y) + @as(usize, child.size.y) + gap) * @as(usize, size.x)) + @as(usize, child.origin.x),
                 };
+                log.debug("child.origin: {any}, child.size: {any}", .{ child.origin, child.size });
+                log.debug("anchor: {d}", .{anchor});
 
                 switch (this.direction) {
                     .horizontal => for (0..child.size.y) |row| {
@@ -553,6 +556,17 @@ pub const Layout = packed struct {
     }
 };
 
+/// Sizing options which should be used by the `Container`
+pub const Size = packed struct {
+    dim: Point = .{},
+    grow: enum(u2) {
+        both,
+        fixed,
+        vertical,
+        horizontal,
+    } = .both,
+};
+
 pub fn Container(comptime Event: type) type {
     if (!isTaggedUnion(Event)) @compileError("Provided user event `Event` for `Container(comptime Event: type)`");
 
@@ -572,10 +586,7 @@ pub fn Container(comptime Event: type) type {
             border: Border = .{},
             rectangle: Rectangle = .{},
             layout: Layout = .{},
-            /// size which should be used by the `Container`
-            size: Point = .{},
-            /// should size grow to the available space?
-            grow: bool = true,
+            size: Size = .{},
         };
 
         pub fn init(
@@ -609,7 +620,7 @@ pub fn Container(comptime Event: type) type {
             this.origin = origin;
             this.element.reposition(origin);
 
-            var offset: Point = Point.add(origin, .{
+            var offset = origin.add(.{
                 .x = layout.padding.left,
                 .y = layout.padding.top,
             });
@@ -633,7 +644,8 @@ pub fn Container(comptime Event: type) type {
             }
         }
 
-        pub fn fit_resize(this: *@This()) Point {
+        /// Resize all fit sized `Containers` to the necessary size required by its child elements.
+        fn fit_resize(this: *@This()) Point {
             // NOTE this is supposed to be a simple and easy to understand algorithm, there are currently no optimizations done
             const layout = this.properties.layout;
             var size: Point = switch (layout.direction) {
@@ -647,8 +659,10 @@ pub fn Container(comptime Event: type) type {
             };
 
             const sides = this.properties.border.sides;
-            if (sides.right) size.x -|= 1;
-            if (sides.bottom) size.y -|= 1;
+            if (sides.left) size.x += 1;
+            if (sides.right) size.x += 1;
+            if (sides.top) size.y += 1;
+            if (sides.bottom) size.y += 1;
 
             if (layout.separator.enabled) switch (layout.direction) {
                 .horizontal => size.x += @as(u16, @truncate(this.elements.items.len -| 1)),
@@ -670,44 +684,55 @@ pub fn Container(comptime Event: type) type {
             }
 
             // assign currently calculated size
-            this.size = Point.max(size, this.properties.size);
+            this.size = switch (this.properties.size.grow) {
+                .both => Point.max(size, this.properties.size.dim),
+                .fixed => this.properties.size.dim,
+                .horizontal => .{
+                    .x = @max(size.x, this.properties.size.dim.x),
+                    .y = size.y,
+                },
+                .vertical => .{
+                    .x = size.x,
+                    .y = @max(size.y, this.properties.size.dim.y),
+                },
+            };
             return this.size;
         }
 
         // growable implicitly requires the root `Container` to have a set a size property to the size of the available terminal screen
-        fn grow_resize(this: *@This()) void {
+        fn grow_resize(this: *@This(), max_size: Point) void {
             const layout = this.properties.layout;
             var remainder = switch (layout.direction) {
-                .horizontal => this.size.x -| (layout.padding.left + layout.padding.right),
-                .vertical => this.size.y -| (layout.padding.top + layout.padding.bottom),
+                .horizontal => max_size.x -| (layout.padding.left + layout.padding.right),
+                .vertical => max_size.y -| (layout.padding.top + layout.padding.bottom),
             };
             remainder -|= layout.gap * @as(u16, @truncate(this.elements.items.len -| 1));
 
             if (layout.separator.enabled) remainder -|= @as(u16, @truncate(this.elements.items.len -| 1));
 
             var available = switch (layout.direction) {
-                .horizontal => this.size.y -| (layout.padding.top + layout.padding.bottom),
-                .vertical => this.size.x -| (layout.padding.left + layout.padding.right),
+                .horizontal => max_size.y -| (layout.padding.top + layout.padding.bottom),
+                .vertical => max_size.x -| (layout.padding.left + layout.padding.right),
             };
 
             const sides = this.properties.border.sides;
             switch (layout.direction) {
                 .horizontal => {
-                    if (sides.bottom) {
+                    if (sides.top) {
                         available -|= 1;
                         remainder -|= 1;
                     }
-                    if (sides.top) {
+                    if (sides.bottom) {
                         available -|= 1;
                         remainder -|= 1;
                     }
                 },
                 .vertical => {
-                    if (sides.right) {
+                    if (sides.left) {
                         available -|= 1;
                         remainder -|= 1;
                     }
-                    if (sides.left) {
+                    if (sides.right) {
                         available -|= 1;
                         remainder -|= 1;
                     }
@@ -724,18 +749,23 @@ pub fn Container(comptime Event: type) type {
             var growable_children: usize = 0;
             var first_growable_child: *@This() = undefined;
             for (this.elements.items) |*child| {
-                if (child.properties.grow) {
+                if (child.properties.size.grow != .fixed) {
                     if (growable_children == 0) first_growable_child = child;
                     growable_children += 1;
 
                     switch (layout.direction) {
-                        .horizontal => child.size.y = available,
-                        .vertical => child.size.x = available,
+                        .horizontal => if (child.properties.size.grow != .vertical) {
+                            child.size.y = available;
+                        },
+                        .vertical => if (child.properties.size.grow != .horizontal) {
+                            child.size.x = available;
+                        },
                     }
                 }
             }
 
-            while (growable_children > 0 and remainder > 0) {
+            var count: usize = this.elements.items.len;
+            while (growable_children > 0 and remainder > 0 and count > 0) : (count -|= 1) {
                 var smallest_size = switch (layout.direction) {
                     .horizontal => first_growable_child.size.x,
                     .vertical => first_growable_child.size.y,
@@ -744,7 +774,7 @@ pub fn Container(comptime Event: type) type {
                 var size_to_correct = remainder;
 
                 for (this.elements.items) |child| {
-                    if (!child.properties.grow) continue;
+                    if (child.properties.size.grow == .fixed) continue;
 
                     const size = switch (layout.direction) {
                         .horizontal => child.size.x,
@@ -771,18 +801,28 @@ pub fn Container(comptime Event: type) type {
                         .horizontal => child.size.x,
                         .vertical => child.size.y,
                     };
-                    if (child.properties.grow and child_size == smallest_size) {
+                    if (child.properties.size.grow != .fixed and child_size == smallest_size) {
                         switch (layout.direction) {
-                            .horizontal => child.size.x += size_to_correct,
-                            .vertical => child.size.y += size_to_correct,
+                            .horizontal => if (child.properties.size.grow != .vertical) {
+                                child.size.x += size_to_correct;
+                            },
+                            .vertical => if (child.properties.size.grow != .horizontal) {
+                                child.size.y += size_to_correct;
+                            },
                         }
                         if (overflow > 0) {
                             switch (layout.direction) {
-                                .horizontal => child.size.x += 1,
-                                .vertical => child.size.y += 1,
-                            }
+                                .horizontal => if (child.properties.size.grow != .vertical) {
+                                    child.size.x += 1;
                                     overflow -|= 1;
                                     remainder -|= 1;
+                                },
+                                .vertical => if (child.properties.size.grow != .horizontal) {
+                                    child.size.y += 1;
+                                    overflow -|= 1;
+                                    remainder -|= 1;
+                                },
+                            }
                         }
                         remainder -|= size_to_correct;
                     }
@@ -790,16 +830,28 @@ pub fn Container(comptime Event: type) type {
             }
 
             this.element.resize(this.size);
-            for (this.elements.items) |*child| child.grow_resize();
+            for (this.elements.items) |*child| child.grow_resize(this.size);
         }
 
         pub fn resize(this: *@This(), origin: Point, size: Point) void {
             // NOTE assume that this function is only called for the root `Container`
-            this.size = size; // total screen size;
             const fit_size = this.fit_resize();
-            this.size = size; // total screen size
-            _ = fit_size;
-            this.grow_resize();
+            log.debug("fit_size: {any}; size: {any}", .{ fit_size, size });
+            // if (fit_size.y > size.y or fit_size.x > size.x) @panic("error: cannot render in available space");
+            switch (this.properties.size.grow) {
+                .both => this.size = Point.max(size, fit_size),
+                .fixed => {},
+                .horizontal => this.size = .{
+                    .x = @max(size.x, fit_size.x),
+                    .y = size.y,
+                },
+                .vertical => this.size = .{
+                    .x = size.x,
+                    .y = @max(size.y, fit_size.y),
+                },
+            }
+            log.debug("this.size: {any}", .{this.size});
+            this.grow_resize(this.size);
             this.reposition(origin);
         }
 
@@ -822,6 +874,7 @@ pub fn Container(comptime Event: type) type {
             @memset(cells, .{});
             errdefer this.allocator.free(cells);
 
+            log.debug("contents: this.size: {any}", .{this.size});
             this.properties.layout.contents(@This(), cells, this.origin, this.size, this.elements.items);
             this.properties.border.contents(cells, this.size);
             this.properties.rectangle.contents(cells, this.size);

src/element.zig

@@ -94,8 +94,8 @@ pub fn Scrollable(Event: type) type {
             this.size = size;
 
             // TODO scrollbar space - depending on configuration and only if necessary?
-            this.container_size = Point.max(size, this.container.fit_resize());
-            this.container.resize(.{}, this.container_size);
+            this.container.resize(.{}, this.size);
+            this.container_size = this.container.size;
         }
 
         fn handle(ctx: *anyopaque, event: Event) !void {
@@ -206,7 +206,9 @@ test "scrollable vertical" {
             .direction = .vertical,
             .padding = .all(1),
         },
-        .size = .{ .y = size.y + 15 },
+        .size = .{
+            .dim = .{ .y = size.y + 15 },
+        },
     }, .{});
     try box.append(try .init(allocator, .{
         .rectangle = .{ .fill = .grey },
@@ -281,7 +283,9 @@ test "scrollable horizontal" {
             .direction = .horizontal,
             .padding = .all(1),
         },
-        .size = .{ .x = size.x + 15 },
+        .size = .{
+            .dim = .{ .x = size.x + 15 },
+        },
     }, .{});
     try box.append(try .init(allocator, .{
         .rectangle = .{ .fill = .grey },