package org.clothocore.util.panels;
import java.awt.*;
import javax.swing.*;
/**
* A simpler alternative to a JPanel with a CardLayout. The AWT CardLayout
* layout manager can be inconvenient to use because the special "stack of
* cards" operations it supports require a cast to use. For example to show
* the card named "myCard" given a JPanel with a CardLayout one would write:
* <pre>
* ((CardLayout)(myJPanel.getLayout())).show(myJPanel, "myCard");
* </pre>
* This doesn't work well with Swing - all of the CardLayout display operations,
* like <code>show</code> call validate directly. Swing supports automatic
* validation (see JComponent.revalidate()); this direct call to validate is
* inefficient.
* <p>
* The CardPane JPanel subclass is intended to support a layout with a modest number
* of cards, on the order of 100 or less. A cards name is it's component
* name, as in java.awt.Component.getName(), which is set when the component
* is added to the CardPanel:
* <pre>
* myCardPanel.add(myChild, "MyChildName");
* myChild.getName() <i>=> "MyChildName"</i>
* </pre>
* As with CardLayout, the first child added to a CardPanel is made visible
* and there's only one child visible at a time. The <code>showCard</code>
* method accepts either a childs name or the child itself:
* <pre>
* myCardPanel.show("MyChildName");
* myCardPanel.show(myChild);
* </pre>
* <p>
* The CardPanel class doesn't support the vgap/hgap CardLayout properties since
* one can add a Border, see JComponent.setBorder().
*/
public class CardPanel extends JPanel
{
private static class Layout implements LayoutManager
{
/**
* Set the childs name (if non-null) and and make it visible
* iff it's the only CardPanel child.
* @see java.awt.Component#setName
*/
@Override
public void addLayoutComponent(String name, Component child) {
if (name != null) {
child.setName(name);
}
child.setVisible(child.getParent().getComponentCount() == 1);
}
/**
* If this child was visible, then make the first remaining
* child visible.
*/
@Override
public void removeLayoutComponent(Component child) {
if (child.isVisible()) {
Container parent = child.getParent();
if (parent.getComponentCount() > 0) {
parent.getComponent(0).setVisible(true);
}
}
}
/**
* @return the maximum preferred width/height + the parents insets
*/
@Override
public Dimension preferredLayoutSize(Container parent) {
int nChildren = parent.getComponentCount();
Insets insets = parent.getInsets();
int width = insets.left + insets.right;
int height = insets.top + insets.bottom;
for (int i = 0; i < nChildren; i++) {
Dimension d = parent.getComponent(i).getPreferredSize();
if (d.width > width) {
width = d.width;
}
if (d.height > height) {
height = d.height;
}
}
return new Dimension(width, height);
}
/**
* @return the maximum minimum width/height + the parents insets
*/
@Override
public Dimension minimumLayoutSize(Container parent) {
int nChildren = parent.getComponentCount();
Insets insets = parent.getInsets();
int width = insets.left + insets.right;
int height = insets.top + insets.bottom;
for (int i = 0; i < nChildren; i++) {
Dimension d = parent.getComponent(i).getMinimumSize();
if (d.width > width) {
width = d.width;
}
if (d.height > height) {
height = d.height;
}
}
return new Dimension(width, height);
}
@Override
public void layoutContainer(Container parent) {
int nChildren = parent.getComponentCount();
Insets insets = parent.getInsets();
for (int i = 0; i < nChildren; i++) {
Component child = parent.getComponent(i);
if (child.isVisible()) {
Rectangle r = parent.getBounds();
int width = r.width - insets.left + insets.right;
int height = r.height - insets.top + insets.bottom;
child.setBounds(insets.left, insets.top, width, height);
break;
}
}
}
}
/**
* Creates a CardPanel. Children, called "cards" in this API, should be added
* with add(). The first child we be made visible, subsequent children will
* be hidden. To show a card, use one of the show*Card methods.
*/
public CardPanel() {
super(new Layout());
}
/**
* Return the index of the first (and one would hope - only)
* visible child. If a visible child can't be found,
* perhaps the caller has inexlicably hidden all of the
* children, then return -1.
*/
private int getVisibleChildIndex() {
int nChildren = getComponentCount();
for (int i = 0; i < nChildren; i++) {
Component child = getComponent(i);
if (child.isVisible()) {
return i;
}
}
return -1;
}
/**
* Hide the currently visible child "card" and show the
* specified card. If the specified card isn't a child
* of the CardPanel then we add it here.
*/
public void showCard(Component card) {
if (card.getParent() != this) {
add(card);
}
int index = getVisibleChildIndex();
if (index != -1) {
getComponent(index).setVisible(false);
}
card.setVisible(true);
revalidate();
repaint();
}
/**
* Show the card with the specified name.
* @see java.awt.Component#getName
*/
public void showCard(String name) {
int nChildren = getComponentCount();
for (int i = 0; i < nChildren; i++) {
Component child = getComponent(i);
if (child.getName().equals(name)) {
showCard(child);
break;
}
}
}
/**
* Show the card that was added to this CardPanel after the currently
* visible card. If the currently visible card was added last, then
* show the first card.
*/
public void showNextCard() {
if (getComponentCount() <= 0) {
return;
}
int index = getVisibleChildIndex();
if (index == -1) {
showCard(getComponent(0));
}
else if (index == (getComponentCount() - 1)) {
showCard(getComponent(0));
}
else {
showCard(getComponent(index + 1));
}
}
/**
* Show the card that was added to this CardPanel before the currently
* visible card. If the currently visible card was added first, then
* show the last card.
*/
public void showPreviousCard() {
if (getComponentCount() <= 0) {
return;
}
int index = getVisibleChildIndex();
if (index == -1) {
showCard(getComponent(0));
}
else if (index == 0) {
showCard(getComponent(getComponentCount() - 1));
}
else {
showCard(getComponent(index -1));
}
}
/**
* Show the first card that was added to this CardPanel.
*/
public void showFirstCard() {
if (getComponentCount() <= 0) {
return;
}
showCard(getComponent(0));
}
/**
* Show the last card that was added to this CardPanel.
*/
public void showLastCard() {
if (getComponentCount() <= 0) {
return;
}
showCard(getComponent(getComponentCount() - 1));
}
}