new windows types

lib/bbs/windows/master_detail.rb

@@ -0,0 +1,128 @@
+# frozen_string_literal: true
+
+require_relative '../window'
+require_relative '../widgets'
+require_relative 'button_bar'
+
+module BBS
+  module Windows
+    # A two-pane browser: left ListBox of items, right ScrollView of details.
+    # Selecting an item in the list reloads the detail pane.
+    #
+    #   BBS::Windows::MasterDetail.open(app,
+    #     title: ' Game Catalog ',
+    #     items: services[:games].all,
+    #     item_label: ->(g) { g.title },
+    #     list_width: 30,
+    #     render_detail: ->(game, width) { GameCard.lines(game, width) },
+    #     actions: [
+    #       { label: '&New', on_click: ->(win) { ... } }
+    #     ],
+    #     bottom_meta: ->(item) { "...optional 1-line meta..." }
+    #   )
+    #
+    # `render_detail` is called with `(item, width)` whenever the selection
+    # changes and on first paint. It must return an Array of strings (each one
+    # is one rendered line; ANSI is supported). Returning nil shows nothing.
+    #
+    # `bottom_meta` is optional; if given, it's a `->(item) { text }` lambda
+    # for a single info line below the detail pane.
+    #
+    # `actions:` are extra buttons (right-aligned by default). A `Close` button
+    # is always appended on the right unless the caller suppresses it via
+    # `close_button: false`.
+    class MasterDetail < Window
+      def self.open(app, **kw)
+        new(app: app, **kw).tap(&:attach)
+      end
+
+      attr_reader :list_widget, :detail_view, :meta_label
+
+      def initialize(app:, title:, items:, item_label:, render_detail:,
+                     list_width: nil, bottom_meta: nil, actions: nil,
+                     close_button: true, close_label: '&Close',
+                     empty_message: '  (empty)',
+                     width: nil, height: nil)
+        super(title: title, modal: true)
+        self.theme = app.theme
+        @app           = app
+        @items         = items
+        @item_label    = item_label
+        @render_detail = render_detail
+        @bottom_meta   = bottom_meta
+        @actions       = (actions || []).dup
+        @actions << { label: close_label, cancel: true } if close_button
+        @list_width    = list_width
+        @empty_message = empty_message
+        @width         = width
+        @height        = height
+        build
+      end
+
+      def attach
+        @app.open_window(self)
+        reset_focus
+        focus_manager.focus(@list_widget) if @list_widget
+        reload_detail
+        self
+      end
+
+      def reload_detail
+        item = @list_widget&.selected_item
+        if item.nil?
+          @detail_view.lines  = [@empty_message]
+          @detail_view.scroll = 0
+          @meta_label.text    = '' if @meta_label
+        else
+          lines = @render_detail.call(item, @detail_view.bounds.width - 1)
+          @detail_view.lines  = Array(lines)
+          @detail_view.scroll = 0
+          @meta_label.text    = @bottom_meta.call(item) if @meta_label && @bottom_meta
+        end
+      end
+
+      private
+
+      def build
+        w = @width  || @app.cols - 4
+        h = @height || @app.rows - 6
+        x = (@app.cols - w) / 2 + 1
+        y = (@app.rows - h) / 2 + 1
+        layout(x, y, w, h)
+
+        has_buttons = !@actions.empty?
+        has_meta    = !@bottom_meta.nil?
+        panel_h     = h - 4 - (has_meta ? 1 : 0) - (has_buttons ? 1 : 0)
+        panel_h     = [panel_h, 3].max
+
+        list_w = @list_width || [(w / 3).clamp(20, 40), w - 10].min
+        list_x = bounds.x + 2
+        list_y = bounds.y + 2
+
+        @list_widget = BBS::Widgets::ListBox.new(
+          items: @items,
+          label: ->(item) { "  #{@item_label.call(item)}".ljust(list_w) }
+        )
+        @list_widget.layout(list_x, list_y, list_w, panel_h)
+        add(@list_widget)
+
+        detail_x = list_x + list_w + 2
+        detail_w = bounds.width - list_w - 5
+        @detail_view = BBS::Widgets::ScrollView.new(lines: [])
+        @detail_view.layout(detail_x, list_y, detail_w, panel_h)
+        add(@detail_view)
+
+        if has_meta
+          meta_y = bounds.y + h - (has_buttons ? 3 : 2)
+          @meta_label = BBS::Widgets::Label.new(text: '', style_key: :input_label)
+          @meta_label.layout(bounds.x + 2, meta_y, bounds.width - 4, 1)
+          add(@meta_label)
+        end
+
+        @list_widget.on_select = ->(_, _) { reload_detail }
+
+        ButtonBar.attach(self, @app, @actions)
+      end
+    end
+  end
+end