JTextField is a lightweight component that allows the editing
* of a single line of text.
* For information on and examples of using text fields,
* see
* How to Use Text Fields
* in The Java Tutorial.
*
*
* JTextField is intended to be source-compatible
* with java.awt.TextField where it is reasonable to do so. This
* component has capabilities not found in the java.awt.TextField
* class. The superclass should be consulted for additional capabilities.
*
* JTextField has a method to establish the string used as the
* command string for the action event that gets fired. The
* java.awt.TextField used the text of the field as the command
* string for the ActionEvent.
* JTextField will use the command
* string set with the setActionCommand method if not null,
* otherwise it will use the text of the field as a compatibility with
* java.awt.TextField.
*
* The method setEchoChar and getEchoChar
* are not provided directly to avoid a new implementation of a
* pluggable look-and-feel inadvertently exposing password characters.
* To provide password-like services a separate class JPasswordField
* extends JTextField to provide this service with an independently
* pluggable look-and-feel.
*
* The java.awt.TextField could be monitored for changes by adding
* a TextListener for TextEvent's.
* In the JTextComponent based
* components, changes are broadcasted from the model via a
* DocumentEvent to DocumentListeners.
* The DocumentEvent gives
* the location of the change and the kind of change if desired.
* The code fragment might look something like:
*
* DocumentListener myListener = ??;
* JTextField myArea = ??;
* myArea.getDocument().addDocumentListener(myListener);
*
* The horizontal alignment of JTextField can be set to be left
* justified, leading justified, centered, right justified or trailing justified.
* Right/trailing justification is useful if the required size
* of the field text is smaller than the size allocated to it.
* This is determined by the setHorizontalAlignment
* and getHorizontalAlignment methods. The default
* is to be leading justified.
*
* How the text field consumes VK_ENTER events depends * on whether the text field has any action listeners. * If so, then VK_ENTER results in the listeners * getting an ActionEvent, * and the VK_ENTER event is consumed. * This is compatible with how AWT text fields handle VK_ENTER events. * If the text field has no action listeners, then as of v 1.3 the VK_ENTER * event is not consumed. Instead, the bindings of ancestor components * are processed, which enables the default button feature of * JFC/Swing to work. *
* Customized fields can easily be created by extending the model and * changing the default model provided. For example, the following piece * of code will create a field that holds only upper case characters. It * will work even if text is pasted into from the clipboard or it is altered via * programmatic changes. *
public class UpperCaseField extends JTextField {
public UpperCaseField(int cols) {
super(cols);
}
protected Document createDefaultModel() {
return new UpperCaseDocument();
}
static class UpperCaseDocument extends PlainDocument {
public void insertString(int offs, String str, AttributeSet a)
throws BadLocationException {
if (str == null) {
return;
}
char[] upper = str.toCharArray();
for (int i = 0; i < upper.length; i++) {
upper[i] = Character.toUpperCase(upper[i]);
}
super.insertString(offs, new String(upper), a);
}
}
}
* * Warning: Swing is not thread safe. For more * information see Swing's Threading * Policy. *
* Warning:
* Serialized objects of this class will not be compatible with
* future Swing releases. The current serialization support is
* appropriate for short term storage or RMI between applications running
* the same version of Swing. As of 1.4, support for long term storage
* of all JavaBeansTM
* has been added to the java.beans package.
* Please see {@link java.beans.XMLEncoder}.
*
* @beaninfo
* attribute: isContainer false
* description: A component which allows for the editing of a single line of text.
*
* @author Timothy Prinzing
* @see #setActionCommand
* @see JPasswordField
* @see #addActionListener
*/
public class JTextField extends JTextComponent implements SwingConstants {
/**
* Constructs a new TextField. A default model is created,
* the initial string is null,
* and the number of columns is set to 0.
*/
public JTextField() {
this(null, null, 0);
}
/**
* Constructs a new TextField initialized with the
* specified text. A default model is created and the number of
* columns is 0.
*
* @param text the text to be displayed, or null
*/
public JTextField(String text) {
this(null, text, 0);
}
/**
* Constructs a new empty TextField with the specified
* number of columns.
* A default model is created and the initial string is set to
* null.
*
* @param columns the number of columns to use to calculate
* the preferred width; if columns is set to zero, the
* preferred width will be whatever naturally results from
* the component implementation
*/
public JTextField(int columns) {
this(null, null, columns);
}
/**
* Constructs a new TextField initialized with the
* specified text and columns. A default model is created.
*
* @param text the text to be displayed, or null
* @param columns the number of columns to use to calculate
* the preferred width; if columns is set to zero, the
* preferred width will be whatever naturally results from
* the component implementation
*/
public JTextField(String text, int columns) {
this(null, text, columns);
}
/**
* Constructs a new JTextField that uses the given text
* storage model and the given number of columns.
* This is the constructor through which the other constructors feed.
* If the document is null, a default model is created.
*
* @param doc the text storage to use; if this is null,
* a default will be provided by calling the
* createDefaultModel method
* @param text the initial string to display, or null
* @param columns the number of columns to use to calculate
* the preferred width >= 0; if columns
* is set to zero, the preferred width will be whatever
* naturally results from the component implementation
* @exception IllegalArgumentException if columns < 0
*/
public JTextField(Document doc, String text, int columns) {
if (columns < 0) {
throw new IllegalArgumentException("columns less than zero.");
}
visibility = new DefaultBoundedRangeModel();
visibility.addChangeListener(new ScrollRepainter());
this.columns = columns;
if (doc == null) {
doc = createDefaultModel();
}
setDocument(doc);
if (text != null) {
setText(text);
}
}
/**
* Gets the class ID for a UI.
*
* @return the string "TextFieldUI"
* @see JComponent#getUIClassID
* @see UIDefaults#getUI
*/
public String getUIClassID() {
return uiClassID;
}
/**
* Associates the editor with a text document.
* The currently registered factory is used to build a view for
* the document, which gets displayed by the editor after revalidation.
* A PropertyChange event ("document") is propagated to each listener.
*
* @param doc the document to display/edit
* @see #getDocument
* @beaninfo
* description: the text document model
* bound: true
* expert: true
*/
public void setDocument(Document doc) {
if (doc != null) {
doc.putProperty("filterNewlines", Boolean.TRUE);
}
super.setDocument(doc);
}
/**
* Calls to revalidate that come from within the
* textfield itself will
* be handled by validating the textfield, unless the textfield
* is contained within a JViewport,
* in which case this returns false.
*
* @return if the parent of this textfield is a JViewPort
* return false, otherwise return true
*
* @see JComponent#revalidate
* @see JComponent#isValidateRoot
*/
public boolean isValidateRoot() {
return SwingUtilities.getParentViewport(this) == null;
}
/**
* Returns the horizontal alignment of the text.
* Valid keys are:
*
JTextField.LEFT
* JTextField.CENTER
* JTextField.RIGHT
* JTextField.LEADING
* JTextField.TRAILING
* JTextField.LEFT
* JTextField.CENTER
* JTextField.RIGHT
* JTextField.LEADING
* JTextField.TRAILING
* invalidate and repaint are called when the
* alignment is set,
* and a PropertyChange event ("horizontalAlignment") is fired.
*
* @param alignment the alignment
* @exception IllegalArgumentException if alignment
* is not a valid key
* @beaninfo
* preferred: true
* bound: true
* description: Set the field alignment to LEFT, CENTER, RIGHT,
* LEADING (the default) or TRAILING
* enum: LEFT JTextField.LEFT CENTER JTextField.CENTER RIGHT JTextField.RIGHT
* LEADING JTextField.LEADING TRAILING JTextField.TRAILING
*/
public void setHorizontalAlignment(int alignment) {
if (alignment == horizontalAlignment) return;
int oldValue = horizontalAlignment;
if ((alignment == LEFT) || (alignment == CENTER) ||
(alignment == RIGHT)|| (alignment == LEADING) ||
(alignment == TRAILING)) {
horizontalAlignment = alignment;
} else {
throw new IllegalArgumentException("horizontalAlignment");
}
firePropertyChange("horizontalAlignment", oldValue, horizontalAlignment);
invalidate();
repaint();
}
/**
* Creates the default implementation of the model
* to be used at construction if one isn't explicitly
* given. An instance of PlainDocument is returned.
*
* @return the default model implementation
*/
protected Document createDefaultModel() {
return new PlainDocument();
}
/**
* Returns the number of columns in this TextField.
*
* @return the number of columns >= 0
*/
public int getColumns() {
return columns;
}
/**
* Sets the number of columns in this TextField,
* and then invalidate the layout.
*
* @param columns the number of columns >= 0
* @exception IllegalArgumentException if columns
* is less than 0
* @beaninfo
* description: the number of columns preferred for display
*/
public void setColumns(int columns) {
int oldVal = this.columns;
if (columns < 0) {
throw new IllegalArgumentException("columns less than zero.");
}
if (columns != oldVal) {
this.columns = columns;
invalidate();
}
}
/**
* Returns the column width.
* The meaning of what a column is can be considered a fairly weak
* notion for some fonts. This method is used to define the width
* of a column. By default this is defined to be the width of the
* character m for the font used. This method can be
* redefined to be some alternative amount
*
* @return the column width >= 1
*/
protected int getColumnWidth() {
if (columnWidth == 0) {
FontMetrics metrics = getFontMetrics(getFont());
columnWidth = metrics.charWidth('m');
}
return columnWidth;
}
/**
* Returns the preferred size Dimensions needed for this
* TextField. If a non-zero number of columns has been
* set, the width is set to the columns multiplied by
* the column width.
*
* @return the dimension of this textfield
*/
public Dimension getPreferredSize() {
Dimension size = super.getPreferredSize();
if (columns != 0) {
Insets insets = getInsets();
size.width = columns * getColumnWidth() +
insets.left + insets.right;
}
return size;
}
/**
* Sets the current font. This removes cached row height and column
* width so the new font will be reflected.
* revalidate is called after setting the font.
*
* @param f the new font
*/
public void setFont(Font f) {
super.setFont(f);
columnWidth = 0;
}
/**
* Adds the specified action listener to receive
* action events from this textfield.
*
* @param l the action listener to be added
*/
public synchronized void addActionListener(ActionListener l) {
listenerList.add(ActionListener.class, l);
}
/**
* Removes the specified action listener so that it no longer
* receives action events from this textfield.
*
* @param l the action listener to be removed
*/
public synchronized void removeActionListener(ActionListener l) {
if ((l != null) && (getAction() == l)) {
setAction(null);
} else {
listenerList.remove(ActionListener.class, l);
}
}
/**
* Returns an array of all the ActionListeners added
* to this JTextField with addActionListener().
*
* @return all of the ActionListeners added or an empty
* array if no listeners have been added
* @since 1.4
*/
public synchronized ActionListener[] getActionListeners() {
return listenerList.getListeners(ActionListener.class);
}
/**
* Notifies all listeners that have registered interest for
* notification on this event type. The event instance
* is lazily created.
* The listener list is processed in last to
* first order.
* @see EventListenerList
*/
protected void fireActionPerformed() {
// Guaranteed to return a non-null array
Object[] listeners = listenerList.getListenerList();
int modifiers = 0;
AWTEvent currentEvent = EventQueue.getCurrentEvent();
if (currentEvent instanceof InputEvent) {
modifiers = ((InputEvent)currentEvent).getModifiers();
} else if (currentEvent instanceof ActionEvent) {
modifiers = ((ActionEvent)currentEvent).getModifiers();
}
ActionEvent e =
new ActionEvent(this, ActionEvent.ACTION_PERFORMED,
(command != null) ? command : getText(),
EventQueue.getMostRecentEventTime(), modifiers);
// Process the listeners last to first, notifying
// those that are interested in this event
for (int i = listeners.length-2; i>=0; i-=2) {
if (listeners[i]==ActionListener.class) {
((ActionListener)listeners[i+1]).actionPerformed(e);
}
}
}
/**
* Sets the command string used for action events.
*
* @param command the command string
*/
public void setActionCommand(String command) {
this.command = command;
}
private Action action;
private PropertyChangeListener actionPropertyChangeListener;
/**
* Sets the Action for the ActionEvent source.
* The new Action replaces
* any previously set Action but does not affect
* ActionListeners independently
* added with addActionListener.
* If the Action is already a registered
* ActionListener
* for the ActionEvent source, it is not re-registered.
*
* Setting the Action results in immediately changing
* all the properties described in
* Swing Components Supporting Action.
* Subsequently, the textfield's properties are automatically updated
* as the Action's properties change.
*
* This method uses three other methods to set
* and help track the Action's property values.
* It uses the configurePropertiesFromAction method
* to immediately change the textfield's properties.
* To track changes in the Action's property values,
* this method registers the PropertyChangeListener
* returned by createActionPropertyChangeListener. The
* default {@code PropertyChangeListener} invokes the
* {@code actionPropertyChanged} method when a property in the
* {@code Action} changes.
*
* @param a the Action for the JTextField,
* or null
* @since 1.3
* @see Action
* @see #getAction
* @see #configurePropertiesFromAction
* @see #createActionPropertyChangeListener
* @see #actionPropertyChanged
* @beaninfo
* bound: true
* attribute: visualUpdate true
* description: the Action instance connected with this ActionEvent source
*/
public void setAction(Action a) {
Action oldValue = getAction();
if (action==null || !action.equals(a)) {
action = a;
if (oldValue!=null) {
removeActionListener(oldValue);
oldValue.removePropertyChangeListener(actionPropertyChangeListener);
actionPropertyChangeListener = null;
}
configurePropertiesFromAction(action);
if (action!=null) {
// Don't add if it is already a listener
if (!isListener(ActionListener.class, action)) {
addActionListener(action);
}
// Reverse linkage:
actionPropertyChangeListener = createActionPropertyChangeListener(action);
action.addPropertyChangeListener(actionPropertyChangeListener);
}
firePropertyChange("action", oldValue, action);
}
}
private boolean isListener(Class c, ActionListener a) {
boolean isListener = false;
Object[] listeners = listenerList.getListenerList();
for (int i = listeners.length-2; i>=0; i-=2) {
if (listeners[i]==c && listeners[i+1]==a) {
isListener=true;
}
}
return isListener;
}
/**
* Returns the currently set Action for this
* ActionEvent source, or null
* if no Action is set.
*
* @return the Action for this ActionEvent source,
* or null
* @since 1.3
* @see Action
* @see #setAction
*/
public Action getAction() {
return action;
}
/**
* Sets the properties on this textfield to match those in the specified
* Action. Refer to
* Swing Components Supporting Action for more
* details as to which properties this sets.
*
* @param a the Action from which to get the properties,
* or null
* @since 1.3
* @see Action
* @see #setAction
*/
protected void configurePropertiesFromAction(Action a) {
AbstractAction.setEnabledFromAction(this, a);
AbstractAction.setToolTipTextFromAction(this, a);
setActionCommandFromAction(a);
}
/**
* Updates the textfield's state in response to property changes in
* associated action. This method is invoked from the
* {@code PropertyChangeListener} returned from
* {@code createActionPropertyChangeListener}. Subclasses do not normally
* need to invoke this. Subclasses that support additional {@code Action}
* properties should override this and
* {@code configurePropertiesFromAction}.
*
* Refer to the table at
* Swing Components Supporting Action for a list of
* the properties this method sets.
*
* @param action the Action associated with this textfield
* @param propertyName the name of the property that changed
* @since 1.6
* @see Action
* @see #configurePropertiesFromAction
*/
protected void actionPropertyChanged(Action action, String propertyName) {
if (propertyName == Action.ACTION_COMMAND_KEY) {
setActionCommandFromAction(action);
} else if (propertyName == "enabled") {
AbstractAction.setEnabledFromAction(this, action);
} else if (propertyName == Action.SHORT_DESCRIPTION) {
AbstractAction.setToolTipTextFromAction(this, action);
}
}
private void setActionCommandFromAction(Action action) {
setActionCommand((action == null) ? null :
(String)action.getValue(Action.ACTION_COMMAND_KEY));
}
/**
* Creates and returns a PropertyChangeListener that is
* responsible for listening for changes from the specified
* Action and updating the appropriate properties.
*
* Warning: If you subclass this do not create an anonymous
* inner class. If you do the lifetime of the textfield will be tied to
* that of the
* The fields look-and-feel implementation manages
* the values of the minimum, maximum, and extent
* properties on the
* Warning:
* Serialized objects of this class will not be compatible with
* future Swing releases. The current serialization support is
* appropriate for short term storage or RMI between applications running
* the same version of Swing. As of 1.4, support for long term storage
* of all JavaBeansTM
* has been added to the Action.
*
* @param a the textfield's action
* @since 1.3
* @see Action
* @see #setAction
*/
protected PropertyChangeListener createActionPropertyChangeListener(Action a) {
return new TextFieldActionPropertyChangeListener(this, a);
}
private static class TextFieldActionPropertyChangeListener extends
ActionPropertyChangeListenerActionListener objects.
* This is normally called by the controller registered with
* textfield.
*/
public void postActionEvent() {
fireActionPerformed();
}
// --- Scrolling support -----------------------------------
/**
* Gets the visibility of the text field. This can
* be adjusted to change the location of the visible
* area if the size of the field is greater than
* the area that was allocated to the field.
*
* BoundedRangeModel.
*
* @return the visibility
* @see BoundedRangeModel
*/
public BoundedRangeModel getHorizontalVisibility() {
return visibility;
}
/**
* Gets the scroll offset, in pixels.
*
* @return the offset >= 0
*/
public int getScrollOffset() {
return visibility.getValue();
}
/**
* Sets the scroll offset, in pixels.
*
* @param scrollOffset the offset >= 0
*/
public void setScrollOffset(int scrollOffset) {
visibility.setValue(scrollOffset);
}
/**
* Scrolls the field left or right.
*
* @param r the region to scroll
*/
public void scrollRectToVisible(Rectangle r) {
// convert to coordinate system of the bounded range
Insets i = getInsets();
int x0 = r.x + visibility.getValue() - i.left;
int x1 = x0 + r.width;
if (x0 < visibility.getValue()) {
// Scroll to the left
visibility.setValue(x0);
} else if(x1 > visibility.getValue() + visibility.getExtent()) {
// Scroll to the right
visibility.setValue(x1 - visibility.getExtent());
}
}
/**
* Returns true if the receiver has an ActionListener
* installed.
*/
boolean hasActionListener() {
// Guaranteed to return a non-null array
Object[] listeners = listenerList.getListenerList();
// Process the listeners last to first, notifying
// those that are interested in this event
for (int i = listeners.length-2; i>=0; i-=2) {
if (listeners[i]==ActionListener.class) {
return true;
}
}
return false;
}
// --- variables -------------------------------------------
/**
* Name of the action to send notification that the
* contents of the field have been accepted. Typically
* this is bound to a carriage-return.
*/
public static final String notifyAction = "notify-field-accept";
private BoundedRangeModel visibility;
private int horizontalAlignment = LEADING;
private int columns;
private int columnWidth;
private String command;
private static final Action[] defaultActions = {
new NotifyAction()
};
/**
* @see #getUIClassID
* @see #readObject
*/
private static final String uiClassID = "TextFieldUI";
// --- Action implementations -----------------------------------
// Note that JFormattedTextField.CommitAction extends this
static class NotifyAction extends TextAction {
NotifyAction() {
super(notifyAction);
}
public void actionPerformed(ActionEvent e) {
JTextComponent target = getFocusedComponent();
if (target instanceof JTextField) {
JTextField field = (JTextField) target;
field.postActionEvent();
}
}
public boolean isEnabled() {
JTextComponent target = getFocusedComponent();
if (target instanceof JTextField) {
return ((JTextField)target).hasActionListener();
}
return false;
}
}
class ScrollRepainter implements ChangeListener, Serializable {
public void stateChanged(ChangeEvent e) {
repaint();
}
}
/**
* See readObject and writeObject in
* JComponent for more
* information about serialization in Swing.
*/
private void writeObject(ObjectOutputStream s) throws IOException {
s.defaultWriteObject();
if (getUIClassID().equals(uiClassID)) {
byte count = JComponent.getWriteObjCounter(this);
JComponent.setWriteObjCounter(this, --count);
if (count == 0 && ui != null) {
ui.installUI(this);
}
}
}
/**
* Returns a string representation of this JTextField.
* This method is intended to be used only for debugging purposes,
* and the content and format of the returned string may vary between
* implementations. The returned string may be empty but may not
* be null.
*
* @return a string representation of this JTextField
*/
protected String paramString() {
String horizontalAlignmentString;
if (horizontalAlignment == LEFT) {
horizontalAlignmentString = "LEFT";
} else if (horizontalAlignment == CENTER) {
horizontalAlignmentString = "CENTER";
} else if (horizontalAlignment == RIGHT) {
horizontalAlignmentString = "RIGHT";
} else if (horizontalAlignment == LEADING) {
horizontalAlignmentString = "LEADING";
} else if (horizontalAlignment == TRAILING) {
horizontalAlignmentString = "TRAILING";
} else horizontalAlignmentString = "";
String commandString = (command != null ?
command : "");
return super.paramString() +
",columns=" + columns +
",columnWidth=" + columnWidth +
",command=" + commandString +
",horizontalAlignment=" + horizontalAlignmentString;
}
/////////////////
// Accessibility support
////////////////
/**
* Gets the AccessibleContext associated with this
* JTextField. For JTextFields,
* the AccessibleContext takes the form of an
* AccessibleJTextField.
* A new AccessibleJTextField instance is created
* if necessary.
*
* @return an AccessibleJTextField that serves as the
* AccessibleContext of this JTextField
*/
public AccessibleContext getAccessibleContext() {
if (accessibleContext == null) {
accessibleContext = new AccessibleJTextField();
}
return accessibleContext;
}
/**
* This class implements accessibility support for the
* JTextField class. It provides an implementation of the
* Java Accessibility API appropriate to text field user-interface
* elements.
* java.beans package.
* Please see {@link java.beans.XMLEncoder}.
*/
protected class AccessibleJTextField extends AccessibleJTextComponent {
/**
* Gets the state set of this object.
*
* @return an instance of AccessibleStateSet describing the states
* of the object
* @see AccessibleState
*/
public AccessibleStateSet getAccessibleStateSet() {
AccessibleStateSet states = super.getAccessibleStateSet();
states.add(AccessibleState.SINGLE_LINE);
return states;
}
}
}