feat(tabs): start work on a tabbar widget

src/tui/status/tabs.zig

@@ -0,0 +1,177 @@
+const std = @import("std");
+const tp = @import("thespian");
+
+const EventHandler = @import("EventHandler");
+const Plane = @import("renderer").Plane;
+const Buffer = @import("Buffer");
+
+const tui = @import("../tui.zig");
+const Widget = @import("../Widget.zig");
+const WidgetList = @import("../WidgetList.zig");
+const Button = @import("../Button.zig");
+
+const dirty_indicator = "";
+
+pub fn create(allocator: std.mem.Allocator, parent: Plane, event_handler: ?EventHandler) @import("widget.zig").CreateError!Widget {
+    const self = try allocator.create(TabBar);
+    self.* = try TabBar.init(allocator, parent, event_handler);
+    return Widget.to(self);
+}
+
+const TabBar = struct {
+    allocator: std.mem.Allocator,
+    plane: Plane,
+    widget_list: *WidgetList,
+    event_handler: ?EventHandler,
+    tab_buffers: []*Buffer = &[_]*Buffer{},
+
+    const Self = @This();
+
+    fn init(allocator: std.mem.Allocator, parent: Plane, event_handler: ?EventHandler) !Self {
+        var w = try WidgetList.createH(allocator, parent, "tabs", .dynamic);
+        w.ctx = w;
+        return .{
+            .allocator = allocator,
+            .plane = w.plane,
+            .widget_list = w,
+            .event_handler = event_handler,
+        };
+    }
+
+    pub fn deinit(self: *Self, allocator: std.mem.Allocator) void {
+        self.allocator.free(self.tab_buffers);
+        self.widget_list.deinit(allocator);
+        allocator.destroy(self);
+    }
+
+    pub fn layout(self: *Self) Widget.Layout {
+        return self.widget_list.layout;
+    }
+
+    pub fn update(self: *Self) void {
+        self.update_tabs() catch {};
+        self.widget_list.resize(Widget.Box.from(self.plane));
+        self.widget_list.update();
+    }
+
+    pub fn render(self: *Self, theme: *const Widget.Theme) bool {
+        return self.widget_list.render(theme);
+    }
+
+    pub fn receive(self: *Self, from_: tp.pid_ref, m: tp.message) error{Exit}!bool {
+        return self.widget_list.receive(from_, m);
+    }
+
+    pub fn handle_resize(self: *Self, pos: Widget.Box) void {
+        self.widget_list.handle_resize(pos);
+        self.plane = self.widget_list.plane;
+    }
+
+    pub fn get(self: *Self, name: []const u8) ?*Widget {
+        return self.widget_list.get(name);
+    }
+
+    pub fn walk(self: *Self, ctx: *anyopaque, f: Widget.WalkFn, self_w: *Widget) bool {
+        return self.widget_list.walk(ctx, f, self_w);
+    }
+
+    pub fn hover(self: *Self) bool {
+        return self.widget_list.hover();
+    }
+
+    fn update_tabs(self: *Self) !void {
+        self.widget_list.remove_all();
+        try self.update_tab_buffers();
+        var first = true;
+        for (self.tab_buffers) |buffer| {
+            if (first) {
+                first = false;
+            } else {
+                try self.widget_list.add(try self.make_spacer(1));
+            }
+            // const hint = if (buffer.is_dirty()) dirty_indicator else "";
+            try self.widget_list.add(try Tab.create(self, buffer.file_path, self.event_handler));
+        }
+    }
+
+    fn update_tab_buffers(self: *Self) !void {
+        const buffer_manager = tui.get_buffer_manager() orelse @panic("tabs no buffer manager");
+        const buffers = try buffer_manager.list_most_recently_used(self.allocator);
+        defer self.allocator.free(buffers);
+        const exiting_buffers = self.tab_buffers;
+        defer self.allocator.free(exiting_buffers);
+        var result: std.ArrayListUnmanaged(*Buffer) = .{};
+        errdefer result.deinit(self.allocator);
+
+        // add existing tabs in original order if they still exist
+        outer: for (exiting_buffers) |exiting_buffer|
+            for (buffers) |buffer| if (exiting_buffer == buffer) {
+                if (!buffer.hidden)
+                    (try result.addOne(self.allocator)).* = buffer;
+                continue :outer;
+            };
+
+        // add new tabs
+        outer: for (buffers) |buffer| {
+            for (result.items) |result_buffer| if (result_buffer == buffer)
+                continue :outer;
+            if (!buffer.hidden)
+                (try result.addOne(self.allocator)).* = buffer;
+        }
+
+        self.tab_buffers = try result.toOwnedSlice(self.allocator);
+    }
+
+    fn make_spacer(self: @This(), comptime size: usize) !Widget {
+        return @import("blank.zig").Create(.{ .static = size })(self.allocator, self.widget_list.plane, null);
+    }
+};
+
+const Tab = struct {
+    tabs: *TabBar,
+    file_path: []const u8,
+
+    fn create(
+        tabs: *TabBar,
+        file_path: []const u8,
+        event_handler: ?EventHandler,
+    ) !Widget {
+        return Button.create_widget(Tab, tabs.allocator, tabs.widget_list.plane, .{
+            .ctx = .{ .tabs = tabs, .file_path = file_path },
+            .label = name_from_buffer_file_path(file_path),
+            .on_click = Tab.on_click,
+            .on_layout = Tab.layout,
+            .on_render = Tab.render,
+            // .on_receive = receive,
+            .on_event = event_handler,
+        });
+    }
+    fn on_click(self: *@This(), _: *Button.State(@This())) void {
+        tp.self_pid().send(.{ "cmd", "navigate", .{ .file = self.file_path } }) catch {};
+    }
+
+    fn render(_: *@This(), btn: *Button.State(@This()), theme: *const Widget.Theme) bool {
+        btn.plane.set_base_style(theme.editor);
+        btn.plane.erase();
+        btn.plane.home();
+        btn.plane.set_style(if (btn.active) theme.editor_cursor else if (btn.hover) theme.statusbar_hover else theme.statusbar);
+        btn.plane.fill(" ");
+        btn.plane.home();
+        btn.plane.set_style(if (btn.active) theme.editor_cursor else if (btn.hover) theme.statusbar_hover else theme.statusbar);
+        _ = btn.plane.putstr(" ") catch {};
+        _ = btn.plane.putstr(btn.opts.label) catch {};
+        _ = btn.plane.putstr(" ") catch {};
+        return false;
+    }
+
+    fn layout(_: *@This(), btn: *Button.State(@This())) Widget.Layout {
+        const len = btn.plane.egc_chunk_width(btn.opts.label, 0, 1);
+        return .{ .static = len + 2 };
+    }
+
+    fn name_from_buffer_file_path(file_path: []const u8) []const u8 {
+        const basename_begin = std.mem.lastIndexOfScalar(u8, file_path, std.fs.path.sep);
+        const basename = if (basename_begin) |begin| file_path[begin + 1 ..] else file_path;
+        return basename;
+    }
+};

src/tui/status/widget.zig

@@ -18,6 +18,7 @@ const widgets = std.static_string_map.StaticStringMap(CreateFunction).initCompti
     .{ "spacer", @import("blank.zig").Create(.{ .static = 1 }) },
     .{ "clock", @import("clock.zig").create },
     .{ "keybind", @import("keybindstate.zig").create },
+    .{ "tabs", @import("tabs.zig").create },
 });
 pub const CreateError = error{ OutOfMemory, Exit };
 pub const CreateFunction = *const fn (allocator: std.mem.Allocator, parent: Plane, event_handler: ?EventHandler) CreateError!Widget;