inform_view.rb

# -*- coding: utf-8 -*-
class InformView < UIView

  WIDTH = 280
  HEIGHT = 100

  # singleton
  def self.instance()
    # Dispatch.once を使うとinitメソッドのsuperで以下のwaningがでました。どぼちて？
    # > unknown: warning: passing a block to an Objective-C method - will be ignored
    # Dispatch.once { @instance ||= new }
    @instance = new if @instance.nil?
    @instance
  end

  def self.show(message, target:view, animated:animated)

    # singltonでインスタンスを作成
    @instance = InformView.instance

    # Superviewからいったんremoveした上でaddSubview
    @instance.removeFromSuperview()
    view.addSubview(@instance)

    # @instanceのインスタンス変数,インスタンスメソッドにアクセスするために instance_eval をコール
    @instance.instance_eval do
      @label.text = message
      @indicator.startAnimating()
      changeAlpaTo(1.0, animated:animated)
    end
  end

  def self.hide(animated)

    # instanceが解放されてたら何もしない
    return if @instance.nil?
    
    # @instanceのインスタンス変数にアクセスするために instance_eval をコール
    @instance.instance_eval do
      changeAlpaTo(0, animated:animated)
      @indicator.stopAnimating()
    end
  end

  # ブログ本筋には関係ないけど参考までに
  def changeAlpaTo(alpha, animated:animated)
    if animated
      context = UIGraphicsGetCurrentContext()
      UIView.beginAnimations(nil, context:context)
      UIView.setAnimationDuration(0.5)
      UIView.setAnimationDelegate(self)
      self.alpha = alpha
      UIView.commitAnimations()
    else
      self.alpha = alpha
    end
  end

  # ブログ本筋には関係ないけど参考までに
  def init()
    if super
      x = (App.window.frame.size.width - WIDTH) / 2
      y = (App.window.frame.size.height - HEIGHT) / 2 - 50
      self.frame = [[x, y], [WIDTH, HEIGHT]]
      self.backgroundColor = UIColor.colorWithWhite(0.0, alpha:0.5)
      self.alpha = 1.0
      self.layer.cornerRadius = 8.0
      self.layer.masksToBounds = true
      self.clipsToBounds = true

      @label = UILabel.new.tap do |l|
        l.frame = [[0, 60], [WIDTH, 30]]
        l.textColor = UIColor.whiteColor
        l.textAlignment = NSTextAlignmentCenter
        l.font = UIFont.boldSystemFontOfSize(18.0)
        l.alpha = 1.0
        l.backgroundColor = UIColor.clearColor
        self.addSubview(l)
      end

      @indicator = UIActivityIndicatorView.new.tap do |i|
        i.initWithActivityIndicatorStyle(UIActivityIndicatorViewStyleWhiteLarge)
        i.frame = [[0, 10], [WIDTH, 50]]
        i.activityIndicatorViewStyle = UIActivityIndicatorViewStyleWhite
        i.backgroundColor = UIColor.clearColor
        self.addSubview(i)
      end

      InformView.hide(false)
    end
    self
  end
end