JCardPane
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Version vom 9. März 2018, 18:58 Uhr von L-ectron-X (Diskussion | Beiträge)
/*
* JCardPane.java
* wraps a JTabbedPane, hiding the tabs.
* The main method shows an example.
*/
import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import java.util.*;
import java.util.logging.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.plaf.*;
import javax.swing.plaf.basic.*;
public class JCardPane extends JComponent {
private JTabbedPane pane;
private CardAction nextAction;
private CardAction previousAction;
private TabFocusHandler tabFocusHandler;
private TabbedPaneUI uiNoTabs = new BasicTabbedPaneUI() {
@Override
protected int calculateTabAreaHeight(int tabPlacement,
int horizRunCount, int maxTabHeight) {
return 0;
}
@Override
protected Insets getContentBorderInsets(int tabPlacement) {
return new Insets(0, 0, 0, 0);
}
@Override
protected MouseListener createMouseListener() {
return null;
}
@Override
protected void installKeyboardActions() {
}
@Override
protected int calculateTabWidth(int tabPlacement, int tabIndex, FontMetrics metrics) {
return 0;
}
};
/**
* Creates an empty cardpane
*/
public JCardPane() {
pane = new JTabbedPane();
tabFocusHandler = new TabFocusHandler(pane);
hideTabs();
pane.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(final ChangeEvent e) {
if (nextAction != null) {
nextAction.setEnabled(hasNext());
}
if (previousAction != null) {
previousAction.setEnabled(hasPrevious());
}
}
});
setLayout(new BorderLayout());
super.add(pane);
}
/**
* Flips to the first card of the cardpane.
* @return 0 if this cardpane has a card
* or -1 if this cardpane has no card
*/
public int first() {
return show(0);
}
/**
* Flips to the last card of the cardpane.
* @return 0 if this cardpane has a card
* or -1 if this cardpane has no card
*/
public int last() {
return show(-1);
}
/**
* Flips to the next card of the cardpane.
* If the currently visible card is the last one,
* this method flips to the first card of the cardpane.
* @return the index of the card
* or -1 if this cardpane has no card
*/
public int next() {
return show(pane.getSelectedIndex() + 1);
}
/**
* Flips to the previous card of the cardpane.
* If the currently visible card is the first one,
* this method flips to the last card of the cardpane.
* @return the index of the card
* or -1 if this cardpane has no card
*/
public int previous() {
return show(pane.getSelectedIndex() - 1);
}
/**
* Flips to the card at the specified index.
* If the index is positive but does not exist,
* this method flips to the first card of the cardpane.
* If the index is negative,
* this method flips to the last card of the cardpane.
* @return the index of the card
* or -1 if this cardpane has no card
*/
public int show(final int index) {
if (pane.getTabCount() == 0) {
return -1;
}
if (index >= pane.getTabCount()) {
pane.setSelectedIndex(0);
return 0;
}
if (index < 0) {
pane.setSelectedIndex(pane.getTabCount() - 1);
return pane.getTabCount() - 1;
}
pane.setSelectedIndex(index);
return index;
}
/**
* Flips to the card with the specified name.
* If the name does not exist, nothing happens.
* @return the index of the card
* or -1 if the name does not exist
*/
public int show(final String name) {
int index = pane.indexOfTab(name);
if (index >= 0) {
pane.setSelectedIndex(index);
}
return index;
}
/**
* Flips to the specified card.
* If the card does not exist in the cardpane, it is added to it.
* @return the index of the specified card
*/
public int show(final JComponent card) {
int index = pane.indexOfComponent(card);
if (index < 0) {
index = pane.getTabCount();
pane.addTab(card.getName(), card);
}
pane.setSelectedIndex(index);
return index;
}
/**
* Flips to the specified card.
* If the card does not exist in the cardpane, it is added to it.
* @return the index of the specified card
*/
public int add(final JComponent card) {
return show(card);
}
/**
* Inserts the specified card at the sepcified index and
* flips to the specified card.
*/
public void insertAt(JComponent card, int index){
pane.insertTab(null, null, card, null, index);
pane.setSelectedIndex(index);
}
/**
* @return true if there is a card after the visible one
*/
public boolean hasNext() {
return pane.getSelectedIndex() < pane.getComponentCount() - 1;
}
/**
* @return true if there is a card before the visible one
*/
public boolean hasPrevious() {
return pane.getSelectedIndex() > 0;
}
/**
* @return the visible card
*/
public Component getCurrent() {
return pane.getSelectedComponent();
}
/**
* Adds a <code>ChangeListener</code> to this cardpane.
*/
public void addChangeListener(final ChangeListener l) {
pane.addChangeListener(l);
}
/**
* Removes a <code>ChangeListener</code> from this cardpane.
*/
public void removeChangeListener(final ChangeListener l) {
pane.removeChangeListener(l);
}
/**
* gets the action to be used for a "Next" button
*/
public Action getNextAction(final String name) {
if (nextAction == null) {
nextAction = new CardAction(name, true);
nextAction.putValue(Action.MNEMONIC_KEY, (int) name.charAt(0));
nextAction.setEnabled(hasNext());
}
return nextAction;
}
/**
* gets the action to be used for a "Previous" button
*/
public Action getPreviousAction(final String name) {
if (previousAction == null) {
previousAction = new CardAction(name, false);
previousAction.putValue(Action.MNEMONIC_KEY, (int) name.charAt(0));
previousAction.setEnabled(hasPrevious());
}
return previousAction;
}
/**
*
* retain: if true, the component focused within a card will remain focused
* each time it becomes visible, otherwise the first component of each card is focused
*/
public void retainFocus(final boolean retain) {
int focusPolicy = TabFocusHandler.RESET_FOCUS;
if (retain) {
focusPolicy = TabFocusHandler.RETAIN_FOCUS;
}
tabFocusHandler.uninstall();
tabFocusHandler = new TabFocusHandler(pane, focusPolicy);
}
private void hideTabs() {
pane.setUI(uiNoTabs);
}
private class CardAction extends AbstractAction {
private boolean isNext;
CardAction(final String text, final boolean isNext) {
super(text);
this.isNext = isNext;
putValue(Action.SHORT_DESCRIPTION, getValue(Action.NAME));
}
@Override
public void actionPerformed(final ActionEvent e) {
if (isNext) {
next();
} else {
previous();
}
}
}
/**
* Manage the focus when a new tab is selected. You can select a focus policy:
* a) Reset Focus - focus is reset to the first focusable component on the tab
* b) Retain Focus - focus returns to the last component with focus on the tab
*
* In addition you add tabs that you want to exclude from the focus policy,
* in which case the other policy will be in effect.
*/
private class TabFocusHandler {
public final static int RESET_FOCUS = 0;
public final static int RETAIN_FOCUS = 1;
private HashMap<Component, Component> tabFocus = new HashMap<Component, Component>(16);
private HashSet<Component> exceptions;
private JTabbedPane tabbedPane;
private int focusPolicy;
private final KeyboardFocusManager focusManager;
private final ChangeListener changeListener;
private final PropertyChangeListener propertyChangeListener;
/**
* Create with the default Retain Focus policy
*/
TabFocusHandler(final JTabbedPane tabbedPane) {
this(tabbedPane, RETAIN_FOCUS);
}
/**
* Create using the specified focus policy
*/
TabFocusHandler(final JTabbedPane tabbedPane, final int focusPolicy) {
if (focusPolicy != RESET_FOCUS && focusPolicy != RETAIN_FOCUS) {
throw new IllegalArgumentException("Invalid focus policy");
}
this.tabbedPane = tabbedPane;
this.focusPolicy = focusPolicy;
// Add listeners to manage a tab change
changeListener = new TabChangeListener();
propertyChangeListener = new TabPropertyChangeListener();
tabbedPane.addChangeListener(changeListener);
focusManager = KeyboardFocusManager.getCurrentKeyboardFocusManager();
focusManager.addPropertyChangeListener("permanentFocusOwner", propertyChangeListener);
}
public void uninstall() {
tabbedPane.removeChangeListener(changeListener);
focusManager.removePropertyChangeListener(propertyChangeListener);
}
/**
* Specify a tab with an exception to the focus policy rule
*/
public void addException(final int index) {
if (exceptions == null) {
exceptions = new HashSet<Component>(16);
}
Component key = tabbedPane.getComponentAt(index);
exceptions.add(key);
}
private class TabPropertyChangeListener implements PropertyChangeListener {
TabPropertyChangeListener() {
}
/**
* Track focus changes and update the current focus component
* for the current tab
*/
@Override
public void propertyChange(final PropertyChangeEvent e) {
// No need to track focus change
if (exceptions == null && focusPolicy == RESET_FOCUS) {
return;
}
Component key = tabbedPane.getComponentAt(tabbedPane.getSelectedIndex());
if (exceptions != null) {
if (focusPolicy == RESET_FOCUS && !exceptions.contains(key)) {
return;
}
if (focusPolicy == RETAIN_FOCUS && exceptions.contains(key)) {
return;
}
}
Component value = (Component) e.getNewValue();
if (value != null && SwingUtilities.isDescendingFrom(value, key)) {
tabFocus.put(key, value);
}
}
}
private class TabChangeListener implements ChangeListener {
TabChangeListener() {
}
/**
* Tab has changed. Focus on saved component for the given tab.
* When there is no saved component, focus on the first component.
*/
@Override
public void stateChanged(final ChangeEvent e) {
Component key = tabbedPane.getComponentAt(tabbedPane.getSelectedIndex());
if (key == null) {
return;
}
Component value = tabFocus.get(key);
// First time selecting this tab or focus policy is RESET_FOCUS
if (value == null) {
key.transferFocus();
tabFocus.put(key, value);
} else // Use the saved component for focusing
{
value.requestFocusInWindow();
}
}
}
}
//for testing only:
public static void main(final String... args) {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
Logger.getLogger(JCardPane.class.getName()).log(Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
Logger.getLogger(JCardPane.class.getName()).log(Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
Logger.getLogger(JCardPane.class.getName()).log(Level.SEVERE, null, ex);
} catch (UnsupportedLookAndFeelException ex) {
Logger.getLogger(JCardPane.class.getName()).log(Level.SEVERE, null, ex);
}
Runnable gui = new Runnable() {
@Override
public void run() {
final JFrame f = new JFrame("JCardPane Demo");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(400, 150);
f.setLocationRelativeTo(null);
final JCardPane cardPane = new JCardPane();
f.add(cardPane, BorderLayout.CENTER);
class Card extends JPanel {
Card(final String name) {
JTextField tf = new JTextField(20);
tf.setText(name);
add(tf);
tf = new JTextField(20);
tf.setText(name);
add(tf);
setName(name);
}
}
for (int i = 0; i < 5; i++) {
cardPane.show(new Card(String.valueOf(i + 1)));
}
cardPane.first();
JPanel control = new JPanel();
control.add(new JButton(cardPane.getPreviousAction("Previous")));
control.add(new JButton(cardPane.getNextAction("Next")));
f.add(control, BorderLayout.SOUTH);
f.setVisible(true);
}
};
//GUI must start on EventDispatchThread:
SwingUtilities.invokeLater(gui);
}
}
