ruby/ext/tk/sample/demos-en/anilabel.rb

#
# animated label widget demo (called by 'widget')
#
# based on Tcl/Tk8.5a2 widget demos

if defined?($anilabel_demo) && $anilabel_demo
  $anilabel_demo.destroy
  $anilabel_demo = nil
end

# demo toplevel widget
$anilabel_demo = TkToplevel.new {|w|
  title("Animated Label Demonstration")
  iconname("anilabel")
  positionWindow(w)
}

base_frame = TkFrame.new($anilabel_demo).pack(:fill=>:both, :expand=>true)

# label
msg = TkLabel.new(base_frame) {
  font $font
  wraplength '4i'
  justify 'left'
  text "Four animated labels are displayed below; each of the labels on the left is animated by making the text message inside it appear to scroll, and the label on the right is animated by animating the image that it displays."
}
msg.pack('side'=>'top')

# frame
TkFrame.new(base_frame) {|frame|
  TkButton.new(frame) {
    text 'Dismiss'
    command proc{
      tmppath = $anilabel_demo
      $anilabel_demo = nil
      tmppath.destroy
    }
  }.pack('side'=>'left', 'expand'=>'yes')

  TkButton.new(frame) {
    text 'See Code'
    command proc{showCode 'anilabel'}
  }.pack('side'=>'left', 'expand'=>'yes')

}.pack('side'=>'bottom', 'fill'=>'x', 'pady'=>'2m')

# create frame for label demo
f_left = TkLabelFrame.new(base_frame,  :text=>'Scrolling Texts')
f_right = TkLabelFrame.new(base_frame, :text=>'GIF Image')
Tk.pack(f_left, f_right, 'side'=>'left', 'expand'=>'yes', 'fill'=>'both',
        'padx'=>10, 'pady'=>10)

# animated label
class AnimatedTextLabel < TkLabel
  def initialize(*args)
    super(*args)
    @timer = TkTimer.new{ _animation_callback }
    @timer.loop_exec = -1
    # bind('Destroy'){ @timer.stop }
    @btag = TkBindTag.new('Destroy'){ @timer.stop }
    self.bindtags_unshift(@btag)
  end

  def _animation_callback()
    txt = self.text
    self.text = (txt[1..-1] << txt[0])
  end
  private :_animation_callback

  def start(interval)
    @timer.set_interval(interval)
    @timer.start
  end

  def stop
    @timer.stop
  end
end

# animated image
class AnimatedImageLabel < AnimatedTextLabel
  def initialize(*args)
    super(*args)
    @destroy_image = false
    @btag.bind_append('Destroy'){
      if @destroy_image
        begin
          self.image.delete
        rescue
        end
      end
    }
  end
  attr_accessor :destroy_image

  def _animation_callback()
    img = self.image

    fmt = img.format
    if fmt.kind_of?(Array)
      if fmt[1].kind_of?(Hash)
        # fmt == ['GIF', {'index'=>idx}]
        idx = fmt[1]['index']
      else
        # fmt == ['GIF', '-index', idx]  :: Ruby1.8.2 returns this.
        idx = fmt[2]
      end
    elsif fmt.kind_of?(String) && fmt =~ /GIF -index (\d+)/
      idx = $1.to_i
    else
      idx = -1
    end

    begin
      img.format("GIF -index #{idx + 1}")
    rescue => e
      img.format("GIF -index 0")
    end
  end
  private :_animation_callback
end

# create labels
l1 = AnimatedTextLabel.new(f_left, :borderwidth=>4, :relief=>:ridge,
                           :font=>{:family=>'Courier', :size=>10})
l2 = AnimatedTextLabel.new(f_left, :borderwidth=>4, :relief=>:groove,
                           :font=>{:family=>'Courier', :size=>10})
l3 = AnimatedTextLabel.new(f_left, :borderwidth=>4, :relief=>:flat,
                           :font=>{:family=>'Courier', :size=>10}, :width=>18)
Tk.pack(l1, l2, l3,
        :side=>:top, :expand=>true, :anchor=>:w, :padx=>10, :pady=>10)

limg = AnimatedImageLabel.new(f_right, :borderwidth=>0)
limg.pack(:side=>:top, :expand=>true, :padx=>10, :pady=>10)

# base64-encoded animated GIF file
tclPowerdData = <<EOD
    R0lGODlhKgBAAPQAAP//////zP//AP/MzP/Mmf/MAP+Zmf+ZZv+ZAMz//8zM
    zMyZmcyZZsxmZsxmAMwzAJnMzJmZzJmZmZlmmZlmZplmM5kzM2aZzGZmzGZm
    mWZmZmYzZmYzMzNmzDMzZgAzmSH+IE1hZGUgd2l0aCBHSU1QIGJ5IExARGVt
    YWlsbHkuY29tACH5BAVkAAEALAAAAAAqAEAAAAX+YCCOZEkyTKM2jOm66yPP
    dF03bx7YcuHIDkGBR7SZeIyhTID4FZ+4Es8nQyCe2EeUNJ0peY2s9mi7PhAM
    ngEAMGRbUpvzSxskLh1J+Hkg134OdDIDEB+GHxtYMEQMTjMGEYeGFoomezaC
    DZGSHFmLXTQKkh8eNQVpZ2afmDQGHaOYSoEyhhcklzVmMpuHnaZmDqiGJbg0
    qFqvh6UNAwB7VA+OwydEjgujkgrPNhbTI8dFvNgEYcHcHx0lB1kX2IYeA2G6
    NN0YfkXJ2BsAMuAzHB9cZMk3qoEbRzUACsRCUBK5JxsC3iMiKd8GN088SIyT
    0RAFSROyeEg38caDiB/+JEgqxsODrZJ1BkT0oHKSmI0ceQxo94HDpg0qsuDk
    UmRAMgu8OgwQ+uIJgUMVeGXA+IQkzEeHGvD8cIGlDXsLiRjQ+EHroQhea7xY
    8IQBSgYYDi1IS+OFBCgaDMGVS3fGi5BPJpBaENdQ0EomKGD56IHwO39EXiSC
    Ysgxor5+Xfgq0qByYUpiXmwuoredB2aYH4gWWda0B7SeNENpEJHC1ghi+pS4
    AJpIAwWvKPBi+8YEht5EriEqpFfMlhEdkBNpx0HUhwypx5T4IB1MBg/Ws2sn
    wV3MSQOkzI8fUd48Aw3dOZto71x85hHtHijYv18Gf/3GqCdDCXHNoICBobSo
    IqBqJLyCoH8JPrLgdh88CKCFD0CGmAiGYPgffwceZh6FC2ohIIklnkhehTNY
    4CIHHGzgwYw01ujBBhvAqKOLLq5AAk9kuSPkkKO40NB+h1gnypJIIvkBf09a
    N5QIRz5p5ZJXJpmlIVhOGQA2TmIJZZhKKmmll2BqyWSXWUrZpQtpatlmk1c2
    KaWRHeTZEJF8SqLDn/hhsOeQgBbqAh6DGqronxeARUIIACH5BAUeAAAALAUA
    LgAFAAUAAAUM4CeKz/OV5YmqaRkCACH5BAUeAAEALAUALgAKAAUAAAUUICCK
    z/OdJVCaa7p+7aOWcDvTZwgAIfkEBR4AAQAsCwAuAAkABQAABRPgA4zP95zA
    eZqoWqqpyqLkZ38hACH5BAUKAAEALAcALgANAA4AAAU7ICA+jwiUJEqeKau+
    r+vGaTmac63v/GP9HM7GQyx+jsgkkoRUHJ3Qx0cK/VQVTKtWwbVKn9suNunc
    WkMAIfkEBQoAAAAsBwA3AAcABQAABRGgIHzk842j+Yjlt5KuO8JmCAAh+QQF
    CgAAACwLADcABwAFAAAFEeAnfN9TjqP5oOWziq05lmUIACH5BAUKAAAALA8A
    NwAHAAUAAAUPoPCJTymS3yiQj4qOcPmEACH5BAUKAAAALBMANwAHAAUAAAUR
    oCB+z/MJX2o+I2miKimiawgAIfkEBQoAAAAsFwA3AAcABQAABRGgIHzfY47j
    Q4qk+aHl+pZmCAAh+QQFCgAAACwbADcABwAFAAAFEaAgfs/zCV9qPiNJouo7
    ll8IACH5BAUKAAAALB8ANwADAAUAAAUIoCB8o0iWZggAOw==
EOD

l1.text('* Slow Animation *').start(300)
l2.text('* Fast Animation *').start(80)
l3.text('This is a longer scrolling text in a widget that will not show the whole message at once. ').start(150)

limg.destroy_image = true
limg.image(TkPhotoImage.new(:format=>'GIF', :data=>tclPowerdData)).start(100)