Sunday, September 25, 2011

Working With Swing Components: Java GUI

Working with the basic Swing Controls in Java GUI programming i.e using the simple data members(properties) and methods.

jLabel -
Used to display a short text.
Cannot insert a line break within the text in a label.
Can be used to display images.
Generally used describe text-fields

The table below reveals the methods that can be used to set the basic properties for a label

Method Description Example
setText To set a single line text that the label will display. jLabel1.setText("A String");
setIcon To display a image in a label. jLabel1.setIcon(new ImageIcon("D:\\books.jpeg"));
setEnabled The enabled state of component.True if enabled else false (Boolean) jLabel1.setEnabled(true);
setBackground To set a background colour for label. jLabel1.setBackground(new java.awt.Color (255, 255, 51 ));

jButton - 
A simple 'push' button used to perform some action or function.
All the properties of button are almost similar to the above mentioned properties for a label. Other useful properties are:-

Method Description Example
setMnemonic Lets you specify the shortcut key or the access key, that you can combine with Alt to invoke the button jButton1.setMnemonic('K');
setToolTipText Sets the text(tool tip) to be displayed when you rollover mouse over button jTextField1.setToolTipText("Click!");

jTextField -
Used as a input field from which we can obtain text
Only single line input allowed
Can be used to display text

The methods above for the label component can also be used for a text-field except the setIcon method.
The other useful methods for a textfield are described below

Method Description Example
getText To retrieve a single line text as a String. String a=jTextField1.getText();
setEditable Sets whether the user can edit the text in the textfield. jTextField1.setEditable(false);
setToolTipText Sets the text(tool tip) to be displayed on mouse over jTextField1.setToolTipText("Enter Name");

jTextArea -
Used as a input field for multi-line text. eg- address
Can be used to display multi-line text eg- displaying some codes
You can set desired number of rows.

Apart from the basic methods that you have read for the text-field, the useful methods for a Text Area are:-

Method Description Example
.append Adds the specified text to the end of the already existing text jTextArea1.append("End of text");
setLineWrap Sets whether lines are wrapped if they are too long to fit within the allocated width jTextArea1.setLineWrap(true);
setWrapStyleWord Sets whether lines can be wrapped at white space or at any character jTextArea1.setWrapStyleWord(true);

jRadioButton -
Used to get an option out of several mutually exclusive options eg- Gender(Male or Female)
They must be added to a button group so that a user cannot select more than one , otherwise they will act as check boxes
If, in a buttonGroup if a user selects a option then the other is automatically deselected.

Method Description Example
setText Sets the display text for the Radio Button jRadioButton1.setText("Male);
setEnabled To enable the component. True to enable else false (Boolean) jTextArea1.setLineWrap(true);
isSelected Returns the state of component.True if selected else false if (jRadioButton1.isSelected()) gender="Male";
setSelected To change the state of component. True to select else deselect jRadioButton1.setSelected(false);
Note: To clear(deselect) all radio buttons in a button group, use buttonGroup1.clearSelection();

jCheckBox -
Used to get one or more options out of several options which are not mutually exclusive eg- Hobbies(a user may select more than 1)
It is not necessary to put them in a button group, but it is recommended so that you can perform group actions like deselecting all.
Almost all the properties for Radio button are applicable here.

Below you can see a image depicting the basic use of the above mentioned simple swing controls.
Simple Java Swing Controls


Related Video Tutorial:

3 comments:

  1. can you make a tutorial for Combobox?

    ReplyDelete
  2. I am trying to develop an employee info storage app with Java, using derby DB, i am finding it to difficult store employee image to the database.

    and i am also finding it difficult to display image on the UI

    ReplyDelete
  3. please how to retrieve image/picture from database and display on java user interface

    ReplyDelete