What is a containment hierarchy?
What is a containment hierarchy?
A containment hierarchy is a tree of components that has a top-level container as its root. We’ll show you one in a bit. Each GUI component can be contained only once.
Is JFrame a subclass of JComponent?
With the exception of top-level containers, all Swing components whose names begin with “J” descend from the JComponent class. For example, JPanel , JScrollPane , JButton , and JTable all inherit from JComponent . However, JFrame and JDialog don’t because they implement top-level containers.
Is JPanel a subclass of JFrame?
Windows can contain/display multiple panels, although in the simplest GUIs, we will associate just one panel with a window. When we discuss JFrames and JPanels, we will discuss just a very few of their many methods: they are highly subclassed (in a deep hierarchy) and therefore inherit many (many) interesting methods.
Which is the top level pane?
Glass pane: A glass pane is a top-level pane which covers all other panes. By default, it is a transparent instance of JPanel class. It is used to handle the mouse events affecting the entire container. Layered pane: A layered pane is an instance of JLayeredPane class.
What is JPanel used for?
JPanel, a part of the Java Swing package, is a container that can store a group of components. The main task of JPanel is to organize components, various layouts can be set in JPanel which provide better organization of components, however, it does not have a title bar.
Is JFrame awt or Swing?
Introduction. The class JFrame is an extended version of java. awt. Frame that adds support for the JFC/Swing component architecture.
Can a jpanel be organized on a JFrame?
By organizing related components within one single JPanel you can re-arrange the individual JPanels on the JFrame later .
Which is the parent class of JFrame in Java?
JFrame: JFrame is available in javax.swing package and is a container whose parent is java.awt.Frame class. JFrame generally servers as a window where important components like buttons, text fields and labels are added.
How does a containment hierarchy work in Java?
One containment hierarchy has a JFrame as its root, and each of the other two has a JDialog object as its root. A Swing-based applet has at least one containment hierarchy, exactly one of which is rooted by a JApplet object. For example, an applet that brings up a dialog has two containment hierarchies.
What’s the difference between jpanel and JComponent?
In JPanel, we can accommodate many operations inside a single panel. JPanel is a subclass of the JComponent, which is a child of the Container; therefore, JPanel is also considered a container. There are many methods used by JPanel, which it inherits from its parent classes.