Layouts

Layouts provides a simple, clean and readable way for arranging Swing components in containers. Layouts was built with JPanel in mind but works with any Container. Four of Swing's basic LayoutManagers are represented:

• Flow
• Box
• Border
• Grid

Using a fluent interface and varargs, we're able to create a container, set it's layout and add it's components in one line. Since Container extends Component, it's also possible to compose calls to Layouts to create complex structures.

How to use

Here is the most basic example:

Layouts.Flow.getJPanel(component1, component2, ..., componentN);

This line creates a new JPanel, sets it's layout to be a new FlowLayout and adds the components to the panel.

We can do the same basic thing with a Box:

Layouts.Box.getHorizontalJPanel(component1, component2, ..., componentN);
Layouts.Box.getVerticalJPanel(component1, component2, ..., componentN);

Border and Grid are a tiny bit more complex:

Layouts.Border.buildJPanel()
	.setNorth(northComponent)
	.setWest(westComponent).setCenter(centerComponent).setEast(eastComponent)
	.setSouth(southComponent).getContainer();

Layouts.Grid.buildJPanel().setRows(2).setColumns(3)
	.addRow(component1, component2, component3)
	.addRow(component4, component5, component6).getContainer();

Notice the use of the word build instead of get and the call to getContainer() at the end. This stems from the fact that just adding components to Border and Grid panels is not enough, we also need to specify where the component is added to. Although this is not entirely true in regards to GridLayout, it does offer better readability.

Builders

Building a panel (as opposed to just "getting" one) will return an appropriate builder. Every builder exposes all of the setters/modifiers relevant to it's layout. All of the builder's methods return this, allowing us to chain together calls. For example, the FlowLayoutBuilder exposes these methods:

Layouts.Flow.buildContainer(...)
	.setAlign(FlowLayout.Center)
	.setHorizontalGap(5)
	.setVerticalGap(5)
	.add(Components);

Containers

The buildContainer() and getContainer() methods allow us to use anything that <C extends Container> rather then just JPanels:

// we can setup a frame's content pane
JFrame frame = ...
Layouts.Border.buildContainer(frame.getContentPane()).setCenter(...);

// use our own implementation of JPanel
class XPanel extends JPanel {...}
Layouts.Box.getVerticalContainer(new XPanel(), component1, component2, ..., componentN)

// or any other component for that matter
Layouts.Grid.buildContainer(new JButton()).addRow(component1, component2, ..., componentN)

Composition

Since Container extends Component, we can combine all of the above to create one big mess:

Layouts.Border.buildContainer(frame.getContentPane()).setCenter(
	Layouts.Border.buildJPanel()
		.setNorth(Layouts.Flow.buildContainer(new XPanel())
			.setAlign(FlowLayout.Center)
			.setHorizontalGap(5)
			.setVerticalGap(5)
			.add(Layouts.Box.getHorizontalJPanel(component1, component2, ..., componentN)).getContainer())
		.setWest(eastComponent).setCenter(Layouts.Grid.buildJPanel().setRows(2).setColumns(3)
			.addRow(component1, component2, component3)
			.addRow(component4, component5, component6).getContainer()).setEast(westComponent)
		.setSouth(Layouts.Grid.buildContainer(new JButton())
			.addRow(component1, component2, ..., componentN)).getContainer());

Or something more sensible:

Layouts.Border.buildContainer(frame.getContentPane())
	.setCenter((Layouts.Border.buildJPanel()
		.setNorth(Layouts.Box.getVerticalJPanel(
			Layouts.Border.buildJPanel()
				.setNorth(label)
				.setCenter(Layouts.Flow.getJPanel(FlowLayout.LEFT, label1, value, label2, field)).getContainer(),
			Layouts.Border.buildJPanel()
				.setNorth(label3)
				.setCenter(Layouts.Flow.getJPanel(FlowLayout.LEFT, label4, stuff, label5, more)).getContainer()))
		.setCenter(Layouts.Border.buildJPanel()
			.setNorth(label6)
			.setCenter(scrollPane).getContainer())
		.setSouth(Layouts.Box.getVerticalJPanel(
			Layouts.Border.buildJPanel()
				.setNorth(label7)
				.setCenter(Layouts.Flow.getJPanel(FlowLayout.LEFT, label8, stuff1, label9, more1)).getContainer(),
			Layouts.Flow.getJPanel(FlowLayout.RIGHT, ok, exit))).getContainer()));

Which results in:

Download

As a maven dependency:

<dependency>
  <groupId>com.github.oryanmat</groupId>
  <artifactId>Layouts</artifactId>
  <version>2.0</version>
</dependency>