Sample of keyboard event handling on Chingu

gistfile1.rb

#coding:utf-8
require 'chingu'

class GameWindow < Chingu::Window
  # 1行の高さ(=フォントサイズ)
  LINE_HEIGHT =20
  # ウィンドウの高さ(行数)
  LINES_IN_WINDOW = 24
  # 標準フォントサイズ
  FONT_SIZE = 20

  def initialize
    super(640, LINE_HEIGHT * LINES_IN_WINDOW, false)
  end

  def setup
    self.caption = "ゲーム画面サンプル"

    # テキストの設定
    @title = Chingu::Text.create(:text=>"サンプルゲームタイトル", :x=>0, :y=>0, :size=>(FONT_SIZE * 1.5).to_i, :color => Gosu::Color::RED)
    @menu1_text = Chingu::Text.create(:text=>"1. ダンジョンに潜る", :x=>30, :y=> LINE_HEIGHT * 3, :size=>FONT_SIZE, :color => Gosu::Color::WHITE)
    @menu2_text = Chingu::Text.create(:text=>"2. 宿屋に泊まる", :x=>30, :y=> LINE_HEIGHT * 4, :size=>FONT_SIZE, :color => Gosu::Color::WHITE)
    @menu3_text = Chingu::Text.create(:text=>"3. 商店街に行く", :x=>30, :y=> LINE_HEIGHT * 5, :size=>FONT_SIZE, :color => Gosu::Color::WHITE)
    @menu4_text = Chingu::Text.create(:text=>"4. お城に行く", :x=>30, :y=> LINE_HEIGHT * 6, :size=>FONT_SIZE, :color => Gosu::Color::WHITE)
    @menu5_text = Chingu::Text.create(:text=>"5. 街はずれに行く", :x=>30, :y=> LINE_HEIGHT * 7, :size=>FONT_SIZE, :color => Gosu::Color::WHITE)

    # 選択中メニュー
    @menu_id = 1

    # キー入力イベントの定義
    self.input = {
      :escape => :close,
      :up => :menu_up,
      :down => :menu_down
    }
  end

  def update
  end

  def draw
    # タイトル描画
    @title.draw

    # 選択されてるメニューの設定
    @menu1_text.color = (@menu_id == 1) ? Gosu::Color::CYAN : Gosu::Color::WHITE
    @menu2_text.color = (@menu_id == 2) ? Gosu::Color::CYAN : Gosu::Color::WHITE
    @menu3_text.color = (@menu_id == 3) ? Gosu::Color::CYAN : Gosu::Color::WHITE
    @menu4_text.color = (@menu_id == 4) ? Gosu::Color::CYAN : Gosu::Color::WHITE
    @menu5_text.color = (@menu_id == 5) ? Gosu::Color::CYAN : Gosu::Color::WHITE

    # メニュー描画
    @menu1_text.draw
    @menu2_text.draw
    @menu3_text.draw
    @menu4_text.draw
    @menu5_text.draw

  end

  # メニューを上へ
  def menu_up
    menu_move(-1)
  end

  # メニューを下へ
  def menu_down
    menu_move(+1)
  end

  # メニュー移動
  def menu_move(direction)
    @menu_id += direction

    @menu_id = 1 if @menu_id < 1
    @menu_id = 5 if @menu_id > 5
  end
end

window = GameWindow.new
window.show