The resulting window is shown in the following diagram. Layout manager for a JFrame but inserting it does no harm and may serveĪs a useful reminder to readers of the program. The statement is not actually needed because BorderLayout is the default In the program, the layout style of the frame is set by the statement JFrame frame = new JFrame("Border Layout") įrame.add( new JButton("Center"),BorderLayout.CENTER) įrame.add( new JButton("West"),BorderLayout.WEST) įrame.add( new JButton("East"),BorderLayout.EAST) įrame.add( new JButton("North"),BorderLayout.NORTH) įrame.add( new JButton("South"),BorderLayout.SOUTH) This program creates five buttons and places one in each of the five regions It is still tempting to use the convenience of the shorter to type literals) Its usually better to find the error when you are compiling rather than running a program. If you use the literals you won't find out until the program tries to run. The advantage of the named constants is that the compiler will flag an error is you type it incorrectly.
So many programmers use those literals instead of the named constants. (Note: BorderLayout.NORTH = "North", BorderLayout.SOUTH = "South" and so on. Remaining right and left sides, and CENTER takes whatever is left in the Occupy the entire top and bottom of the area, EAST and WEST occupy the Parameters: the component to be added and its position. To add aĬomponent, we use a version of the overloaded method add that has two SOUTH, EAST, WEST, and CENTER in the BorderLayout class. Here, the panel is divided into five regions identified by the constants NORTH, The second layout manager that we will examine is BorderLayout. If we resize the window to make it narrower, the positions of the buttonsĪre changed automatically, as shown here. The order in which they appear in the window. The order in which we added the buttons determines Here the buttons are arranged in a single row, centred at the A FlowLayout manager uses this information to size and position That we create has a “preferred” size - enough space for the label plusĪ border. The output of the program is shown in the next illustration. JFrame frame = new JFrame("Flow Layout") įtDefaultCloseOperation(JFrame.EXIT_ON_CLOSE) This program uses a FlowLayout manager to create and arrange five buttons in a window We will, therefore, abbreviate the codeįor creating and adding a button to something like In this section, because we are not doing anything with our buttons, we JButton helpButton = new JButton("Help") With the label "Help" to the JFrame object called frame, we could first Once we have a manager for a JFrame we can add components using the To constructĪ FlowLayout in a JFrame object called frame, we could write Row centred between the left and right sides of the container. With FlowLayout, componentsĪre arranged rather like words are arranged by a word processor using aĬentred alignment - from left to right, and from top to bottom, with each The objects of Java's simplest layout manager are constructed from theĬlass FlowLayout in the package java.awt. Will only be creating and arranging buttons. Than one class of button our buttons are going to be objects constructedįrom the JButton class in the package javax.swing. Of the screen that can be "pressed" by clicking on a mouse. An object that is simple to create and display is a button, a region Here, however, we will examine only three.īefore we start to examine layout managers, we need something toĪrrange. Number of different layout managers and even allows you to create your Of these components can be controlled by a layout manager. If a container has more than one component, the position and size of each 13.3 Layout Managers 13.3 Layout Managers
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