Java™ Application Development on Linux - Dator

16.7 Getting Down to Cases: Designing a GUI for BudgetPro353With a BorderLayout, if you put something in the NORTH section, it willappear across the top area of that container. If you resize the container (e.g.,drag the window edges), it will take extra space and use it for horizontal, butnot vertical, stretching. That is, the objects won’t get bigger than they need tovertically, though they will stretch wider. The same is true for SOUTH, but theobjects are at the bottom rather than top of the container. Putting somethingin EAST or WEST will move them to the left or right of the container. For thesetwo areas, though, space when resizing a window is added to the objects vertically,but not horizontally. Putting an object in EAST or WEST will let it gettaller, but not wider.The CENTER area, the default location if you use the add() method withno second parameter, will use extra space both vertically and horizontally.Adding more than one object into a region (e.g., NORTH) will result in onlythe last item added being displayed. For this reason, too, one often builds intermediatecontainers to hold several objects. Then the single container object isadded to one of BorderLayout’s regions.16.7.2.1 Simple JLabelsLet’s look at the simplest of the three pieces that we create for our GUI—thetop line of information indicating the status of the account. In lines 88–107we create this portion of the GUI.88 private Component89 createStatus()90 {91 JPanel retval = new JPanel(); // default: flow layout9293 upton.addActionListener(upAction);9495 nam = new JLabel("Account: Name");96 tot = new JLabel("Total: $");97 val = new JLabel("Remaining: $");9899 retval.add(upton);100 retval.add(nam);101 retval.add(tot);102 retval.add(val);103104 setStatus();105106 return retval;107 } // createStatus