Get effective screen size from Java

GraphicsEnvironment has a method which returns the maximum available size, accounting all taskbars etc. no matter where they are aligned: GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds() Note: On multi-monitor systems, getMaximumWindowBounds() returns the bounds of the entire display area. To get the usable bounds of a single display, use GraphicsConfiguration.getBounds() and Toolkit.getScreenInsets() as shown in other answers.

JComponents disappearing after calling mouseClicked()

Consider using a JList for the right panel to take advantage of the flexible layout options and selection handling, as shown here and below. import java.awt.Component; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.GridLayout; import java.awt.RenderingHints; import java.awt.image.BufferedImage; import javax.swing.BorderFactory; import javax.swing.DefaultListCellRenderer; import javax.swing.DefaultListModel; import javax.swing.Icon; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JList; import … Read more

Using addMouseListener() and paintComponent() for JPanel

This is not an immediate answer to your question, but knowing (or at least suspecting) what it is that you wish to offer (a simple paint program), I suggest starting with this approach based around a BufferedImage as the painting surface.. import java.awt.*; import java.awt.RenderingHints.Key; import java.awt.event.*; import java.awt.image.BufferedImage; import; import; import java.util.HashMap; … Read more

KeyListener vs. Key Bindings

KeyListener is a much lower level API which requires the component that it is registered to be focused AND have keyboard focus. This can cause issues when you have other components within your game that may grab keyboard focus, for example. KeyListener is generally more difficult to maintain and extend or change, as typically, all … Read more