Control Panel

Inspired by Nodebox, Ruby-Processing provides a way to control the instance variables of your sketch with a control panel. You can create sliders, buttons, menus and checkboxes that set instance variables on your sketch. Since ruby-processing-2.0 you need to explicitly set the panel visible from the processing sketch (see included examples). Start by loading in the @control_panel@ library, and then define your panel like so:

class PanelTest < Processing::App
  load_library "control_panel"

  def setup
    control_panel do |c|
      c.look_feel "Nimbus"  # since processing-2.1.4 set look and feel (optional, metal by default)
      c.slider :opacity
      c.slider(:app_width, 5..60, 20) { reset! }
      c.menu(:options, ['one', 'two', 'three'], 'two') {|m| load_menu_item(m) }
      c.checkbox :paused
      c.button :reset!
    end
  end

  # Rest of the code follows
end

This code will create a sketch with a control panel for adjusting the value of the @@opacity@, @@app_width@, @@options@, and @@paused@ instance variables. The button will call the @reset!@ method when clicked (a method defined by you in your sketch). The @app_width@ slider will range from 5 to 60 instead of (the default) 0 to 100. The instance variable will be initialized at 20 when the sketch is loaded. The @app_width@ and @options@ controls have had callbacks attached to them. The callbacks will run, passing in the value of the control, any time the control changes. It all looks like this:

!http://s3.amazonaws.com/jashkenas/images/control_panel.png!

(@control_panel@ replaces the previous @has_slider@ functionality)