Java JFrame setFocusable (boolean focusable)
- Introduction. Sets the focusable state of this Component to the specified value. This value overrides the Component's default focusability.
- Syntax
- Example. JFrame ; import javax.swing. JList ; import javax.swing. JPanel ; import javax.swing. JScrollPane ; import javax.swing.
What is the use of setfocusable?
You can use setFocusable (boolean n), it´s mainly used to activate or deactivate the focus event (component of the graphical user interface that is selected to receive the input) of the view, both in the tactile / mouse mode, and in the keyboard (cursor) mode. Show activity on this post.
What happens when setfocusable is true in jpanel?
The JPanel component is focusable by default, so there will be no change when you set it to true. Also the setFocusable does not set the focus in itself. Show activity on this post.
What is the use of setrequestfocusenabled method?
The setRequestFocusEnabled method is recommended so that your program can be run by users employing assistive technologies. Requests that this component should get the focus. The component's window must be the current focused window.
What is the use of requestfocus in Java?
Correspondingly, what is requestFocus in Java? requestFocus() makes a request that the given Component gets set to a focused state. This method requires that the component is displayable, focusable, visible and have all it's ancestors be visible too. It is best to call requestFocusInWindow (), as that method is not platform dependent.
What does focusable mean in Java?
Focus means you have selected the particular GUI element. For example when you select a window that window gains focus, when you select another window the first window loses focus.... It's the same for JTextField, JTextArea, etc.
What is focus traversal?
A focus cycle (or focus traversal cycle) is a set of components that share a common ancestor in the containment hierarchy. The focus cycle root is the container that is the root for a particular focus traversal cycle.
What is paintComponent method in Java?
By now you know that the paintComponent method is where all of your painting code should be placed. It is true that this method will be invoked when it is time to paint, but painting actually begins higher up the class hierarchy, with the paint method (defined by java. awt.
How do I bring a JFrame to the front?
In order to get this, we have realized in the called method of the class which represents the frame of our application (extension of a JFrame ) following implementation: setVisible(true); toFront();
What is JLabel Java Swing?
JLabel is a class of java Swing . JLabel is used to display a short string or an image icon. JLabel can display text, image or both . JLabel is only a display of text or image and it cannot get focus . JLabel is inactive to input events such a mouse focus or keyboard focus.
How do you use JDialog?
The JDialog control represents a top level window with a border and a title used to take some form of input from the user. It inherits the Dialog class....Commonly used Constructors:ConstructorDescriptionJDialog()It is used to create a modeless dialog without a title and without a specified Frame owner.2 more rows
What is Graphics2D in swing?
Class Graphics2D This Graphics2D class extends the Graphics class to provide more sophisticated control over geometry, coordinate transformations, color management, and text layout. This is the fundamental class for rendering 2-dimensional shapes, text and images on the Java(tm) platform.
What is the difference between paint and paintComponent Java?
It looks like the paint() method actually draws the component, including the border and children. If you only want to customize the component's appearance excluding the border and children, you use paintComponent() .
What does JFrame repaint do?
repaint() will repaint itself and its children. JFrame. repaint() will repaint itself and its children. But since JFrame is the base, this will repaint every component within.
Which method is used to show the frame window?
A JFrame is like a Window with border, title, and buttons. We can implement most of the java swing applications using JFrame. By default, a JFrame can be displayed at the top-left position of a screen. We can display the center position of JFrame using the setLocationRelativeTo() method of Window class.
How do you use JLayeredPane?
Swing provides two layered pane classes. The first, JLayeredPane , is the class that root panes use and is the class used by the example in this section....Examples that Use Layered Panes.ExampleWhere DescribedNotesLayeredPaneDemoThis sectionIllustrates layers and intra-layer positions of a JLayeredPane .3 more rows
How do you make a JPanel on top of another JPanel?
So for what you want to do, you can do this: JPanel panel = new JPanel(); panel. setLayout(new GridLayout(2, 1)); //the first number is the number of rows, the second is the number of columns JPanel topPanel = new JPanel(); JPanel bottomPanel = new JPanel(); panel.
What is the focus subsystem?
The focus subsystem is designed to do the right thing as invisibly as possible. In most cases it behaves in a reasonable manner, and if it does not you can tweak its behavior in various ways. Some common scenarios might include:
What are the requirements for a component to gain focus?
For a component to gain the focus, it must satisfy three requirements: it must be visible, enabled, and focusable. An input map may also be given. For more information about input map, read How to Use Key Bindings.
What happens if the input verifier is not acceptable?
If the component's value is not acceptable, the input verifier can take appropriate action, such as refusing to yield the focus on the component or replacing the user's input with the last valid value and then allowing the focus to transfer to the next component.
What is input verifier?
You can use an input verifier as an alternative to a custom formatter, or when you have a component that is not a text field. An input verifier allows you to reject specific values, such as a properly formatted but invalid zip code, or values outside of a desired range, for example a body temperature higher than 110°F.
What is a focused window?
The focused window is the window that contains the focus owner. JWindow and focus: To use a JWindow component in your GUI, you should know that the JWindow component's owning frame must be visible in order for any components in the window to get the focus.
How to show changes in focus in a picture?
To visually show changes in the focus (by drawing a red border only when the component has the focus), Picture has a focus listener. To gain the focus when the user clicks on the picture, the component has a mouse listener. The listener's mouseClicked method requests for the focus to be transferred to the picture.
When does a component gain focus?
A component generally gains the focus when the user clicks it, or when the user tabs between components, or otherwise interacts with a component. A component can also be given the focus programmatically, such as when its containing frame or dialog-box is made visible.
