SwingBuilder Series: Layouts - CardLayout

CardLayout is a nice layout to do things like simple step-by-step wizards. Here I've added 3 different panels to a CardLayout, and thanks to two buttons "previous" and "next" I'm going to be able to show them like if I were going through a wizard form.

import static org.fife.ui.rsyntaxtextarea.SyntaxConstants.*
import static java.awt.BorderLayout.*
import static javax.swing.JSplitPane.*
import static javax.swing.JLabel.*
import java.awt.Color
import java.awt.Dimension
import groovy.beans.*

@Bindableclass Step{
 def current = 0 
}

def step = new Step()
def panelColors = ['RED','YELLOW','BLUE']

panel{
 borderLayout() panel(id:'cards',constraints:CENTER){
  cardLayout()
  panelColors.each{color->
   label(
    text:color,
    horizontalAlignment: CENTER_ALIGNMENT,
    opaque:true,
    background: Color."${color}" ,
    constraints: color
   )    }
 }
 hbox(constraints:SOUTH){
  button(
   id:'previous',
   text:'Previous',     
   enabled:bind{step.current > 0},
   actionPerformed:{
    step.current--
    cards?.layout?.show(cards,colors[step.current])
   }
  )    
  button(
     id:'next',
     text:'Next',
     enabled:bind{step.current < 2},    
     actionPerformed:{    
        step.current++     
        cards?.layout?.show(cards,colors[step.current])    
      }   
   )      
  }  
} 

It's a pretty simple example that looks like this in SwingPad:

Most important to pay attention to are:

• The name of the constraint of each panel added to CardLayout. That name will be used to show the given panel

 panelColors.each{color->
   label(
    text:color,
    horizontalAlignment: CENTER_ALIGNMENT,
    opaque:true,
    background: Color."${color}" ,
    constraints: color
   )   
  }

• Once we recover the name of the panel we want to show up, we should invoke the CardLayout's show(id) method.

actionPerformed:{
      step.current--
      cards?.layout?.show(cards,colors[step.current])
}

Here I've used the bind() node to enabling buttons depending on the position of the wizard's current step.