1. Panels & Layout Managers28
Panels & Layout Managers

2. Previously
Coursework Support

3. Overview Panels & Layout Manager Positioning Elements
Some of the Layout Managers
Using Layout Managers
Layout Manager Sample

4. Positioning Elements
Layout Managers determines the size and position of the components within a container
Layout manager has the final say on the size and position of the components within the container
A layout manager is an object that implements the LayoutManager interface
Common containers of interest are JPanel and Content Panes

5. Some of the Layout Managers
BorderLayout
Places components in up to five areas: top, bottom, left, right, and centre
BoxLayout
Places components in a single row or column
CardLayout
Used to display just one element from a list of components at a time
add(Component, int)
add(Component)
add(Component, String)

6. Some of the Layout Managers
FlowLayout
Places components in a single row, starting a new row if its container is not sufficiently wide. It is the default Layout Manager for JPanel
GridBagLayout
Places components within a grid of cells, allowing components to span more than one cell
GridLayout
Places components in a grid of cells where each cell is exactly the same size and each component takes all the available space within its cell
add(Component)
add(Component, GridBagConstraints)
add(Component)

7. Some of the Layout Managers
GroupLayout with the horizontal and vertical layouts separately
SpringLayout allows to specify relationships between the edges of components under its control
GroupLayout and SpringLayout were developed for use by GUI builder tools

8. Using Layout Managers Methods to use Create Layout Manager
Set the Layout Manager in the Container
setLayout()
Add Components into the Container
add(…)

9. Lets code with a BorderLayout!
Layout Manager Sample
Lets code with a BorderLayout!

10. Layout Manager Sample
JPanel mainView = new JPanel(new BorderLayout());
JButton jb1 = new JButton("Button 1 (PAGE_START)");
JButton jb2 = new JButton("Button 2 (CENTER)");
JButton jb3 = new JButton("Button 3 (LINE_START)");
JButton jb4 = new JButton("Button 4 (PAGE_END)");
JButton jb5 = new JButton("5 (LINE_START)");
setContentPane(mainView);
mainView.add(jb1, BorderLayout.PAGE_START);
mainView.add(jb2, BorderLayout.CENTER);
mainView.add(jb3, BorderLayout.LINE_START);
mainView.add(jb4, BorderLayout.PAGE_END);
mainView.add(jb5, BorderLayout.LINE_END);

11. References A Visual Guide to Layout Managers Using Layout Managers
Using Layout Managers