Text components are available for simple text and for enhanced text and editing panes. VisualAge provides text beans from the com.sun.java.swing, com.sun.java.swing.text, and java.awt package.
You can add a text bean to enable text input or provide a label.
Bean | Description |
---|---|
JLabel (Swing) or Label (AWT) | A label, usually to identify another component |
JPasswordField (Swing) | A text field for sensitive data |
JTextArea (Swing) or TextArea (AWT) | A multiline text area |
JTextField (Swing) or TextField (AWT) | A single-line text field |
Adding a label graphic
You can add a graphic to a JLabel bean. Select a graphic file for the icon property in the label's property sheet. Use the horizontalTextPosition property to specify a LEFT, CENTER, or RIGHT position of text relative to the graphic. The default choice is RIGHT. Set the iconTextGap property to specify the space between the icon and label text.
Defining keyboard access to an input field
For Swing text input components, you can define keyboard shortcuts to place the focus in the input field or area.
Aligning text
Select an alignment choice for the horizontalAlignment or alignment property in the text component's property sheet. The alignment options are LEFT, CENTER, and RIGHT.
Selecting initial text
To select the initial text, set the selectionStart and selectionEnd properties in the text component's property sheet. These values are offsets from the beginning of the text, which is at offset 0. To select all text without determining the initial text length, specify selection from offset 0 to an offset that you consider to be larger than the initial text length.
Defining a minimum size for layout managers
Some layout managers use a minimum size for placement of components. To specify a minimum width for a text area, enter the width, in characters, for the columns property in the text component's property sheet. To specify a minimum height for a text area, enter the number of rows for the rows property.
Hiding input text
To hide input text, either use a JPasswordField bean or, from the text component's property sheet, specify an echo character for the echoChar property.
Preventing text modification in a text area
To prevent any input in a text area, set the editable property to False in the text component's property sheet.
Making a text area scrollable
An AWT TextArea implements scrolling, duplicating the capability of a ScrollPane. A JTextArea does not implement scrolling itself, but can become scrollable by placing it in a JScrollPane and using its scrolling capability.
Defining tool tip text for a text component
For Swing components, you can specify tool tip text, also known as fly-over text or hover help. Enter text for the toolTipText property in the component's property sheet.
Defining initial availability
By default, the component is enabled for user interaction. To initially disable the component, set the enabled property to False in the component's property sheet.
Synchronizing text
If you need to synchronize user input between two text components, do the following:
If you need to synchronize text that you set by connection from another source, make connections to both text components.
Disabling a text component
To disable a text component when an event occurs, connect the event to the component's enabled property and set the connection parameter value to False.
Enabling a text component
To enable a text component when an event occurs, connect the event to the component's enabled property and set the connection parameter value to True.
For examples, see the LayoutManagers class in the com.ibm.ivj.examples.vc.swing.layoutmanagers and com.ibm.ivj.examples.vc.layoutmanagers packages and the Amortization class in the com.ibm.ivj.examples.vc.swing.mortgageamortizer and com.ibm.ivj.examples.vc.mortgageamortizer packages. These examples are shipped in the IBM Java Examples project.
Visual bean basics
Using VisualAge beans in visual composition
Adding the IBM Java Examples project
Text beans
LayoutManagers sample
MortgageAmortizor sample