A JDialog is a top-level Swing container to host components and display a dialog.
Creating a dialog window is very simple: just create a new class that inherits from the JDialog class.
By default, a JDialog uses a BorderLayout as the layout manager.
To center the JDialog within a frame, assuming that myFrame exists
To position the JDialog in the center of screen
We can create a JDialog with an owner, which could be another JDialog, a JFrame, or a JWindow.
By specifying an owner for a JDialog, we are creating a parent-child relationship.
When the owner of a JDialog is closed, the JDialog is also closed. When the owner is minimized or maximized, the JDialog is also minimized or maximized.
A JDialog with an owner is always displayed on top of its owner.
We can specify an owner of a JDialog in its constructors.
When we create a JDialog using its no-args constructor, a hidden Frame is created as its owner.
We can create a JDialog with null as its owner, and in that case, it does not have an owner.
By default, a JDialog is resizable. To disable the resize, calling its setResizable(false) method.
Based on focus behavior of a JDialog, it can be categorized as
When a modal JDialog is displayed, it blocks other displayed windows in the application. To make a JDialog modal, we can use its setModal(true) method.
Some of the constructors of the JDialog allows us to set whether the JDialog should be modal or modeless.
A modeless JDialog does not block any other displayed windows in the application.
By default, a JDialog is modeless.
A JDialog can have one of the four types of modalities. They are defined by the four constants in java.awt.Dialog.ModalityType enum:
We can specify the modality type of a JDialog in its constructor or by using its setModalityType() method.