11.15. JPanel Subclass for Drawing with the Mouse

Section 11.13 showed how to track mouse events in a JPanel. In this section, we use a JPanel as a dedicated drawing area in which the user can draw by dragging the mouse. In addition, this section demonstrates an event listener that extends an adapter class.

Method paintComponent

Lightweight Swing components that extend class JComponent (such as JPanel) contain method paintComponent, which is called when a lightweight Swing component is displayed. By overriding this method, you can specify how to draw shapes using Java’s graphics capabilities. When customizing a JPanel for use as a dedicated drawing area, the subclass should override method paintComponent and call the superclass version of ...

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