下面列出了怎么用javax.swing.plaf.basic.BasicComboPopup的API类实例代码及写法，或者点击链接到github查看源代码。
/**
* Adjusts the width of the scrollpane used by the popup.
*/
protected void popupWider(BasicComboPopup popup) {
JList<?> list = popup.getList();
// Determine the maximimum width to use:
// a) determine the popup preferred width
// b) ensure width is not less than the scroll pane width
int popupWidth = list.getPreferredSize().width
+ 5 // make sure horizontal scrollbar doesn't appear
+ getScrollBarWidth(popup, scrollPane);
Dimension scrollPaneSize = scrollPane.getPreferredSize();
popupWidth = Math.max(popupWidth, scrollPaneSize.width);
// Adjust the width
scrollPaneSize.width = popupWidth;
scrollPane.setPreferredSize(scrollPaneSize);
scrollPane.setMaximumSize(scrollPaneSize);
}
private static Point getItemPointToClick(final int item) throws Exception {
final Point[] result = new Point[1];
SwingUtilities.invokeAndWait(new Runnable() {
@Override
public void run() {
BasicComboPopup popup = (BasicComboPopup)comboBoxUI.getComboPopup();
Point point = popup.getLocationOnScreen();
Dimension size = popup.getSize();
int step = size.height / items.length;
point.x += size.width / 2;
point.y += step / 2 + step * item;
result[0] = point;
}
});
return result[0];
}
private static Point getItemPointToClick(final int item) throws Exception {
final Point[] result = new Point[1];
SwingUtilities.invokeAndWait(new Runnable() {
@Override
public void run() {
BasicComboPopup popup = (BasicComboPopup)comboBoxUI.getComboPopup();
Point point = popup.getLocationOnScreen();
Dimension size = popup.getSize();
int step = size.height / items.length;
point.x += size.width / 2;
point.y += step / 2 + step * item;
result[0] = point;
}
});
return result[0];
}
@Override
protected ComboPopup createPopup() {
return new BasicComboPopup(comboBox) {
/**
*
*/
private static final long serialVersionUID = -4232501153552563408L;
@Override
protected JScrollPane createScroller() {
JScrollPane scroller = new JScrollPane(list, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,
JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
scroller.setVerticalScrollBar(new DarkScrollBar(JScrollBar.VERTICAL));
return scroller;
}
};
}
private static Point getItemPointToClick(final int item) throws Exception {
final Point[] result = new Point[1];
SwingUtilities.invokeAndWait(new Runnable() {
@Override
public void run() {
BasicComboPopup popup = (BasicComboPopup)comboBoxUI.getComboPopup();
Point point = popup.getLocationOnScreen();
Dimension size = popup.getSize();
int step = size.height / items.length;
point.x += size.width / 2;
point.y += step / 2 + step * item;
result[0] = point;
}
});
return result[0];
}
private static Point getItemPointToClick(final int item) throws Exception {
final Point[] result = new Point[1];
SwingUtilities.invokeAndWait(new Runnable() {
@Override
public void run() {
BasicComboPopup popup = (BasicComboPopup)comboBoxUI.getComboPopup();
Point point = popup.getLocationOnScreen();
Dimension size = popup.getSize();
int step = size.height / items.length;
point.x += size.width / 2;
point.y += step / 2 + step * item;
result[0] = point;
}
});
return result[0];
}
private static Point getItemPointToClick(final int item) throws Exception {
final Point[] result = new Point[1];
SwingUtilities.invokeAndWait(new Runnable() {
@Override
public void run() {
BasicComboPopup popup = (BasicComboPopup)comboBoxUI.getComboPopup();
Point point = popup.getLocationOnScreen();
Dimension size = popup.getSize();
int step = size.height / items.length;
point.x += size.width / 2;
point.y += step / 2 + step * item;
result[0] = point;
}
});
return result[0];
}
private static Point getItemPointToClick(final int item) throws Exception {
final Point[] result = new Point[1];
SwingUtilities.invokeAndWait(new Runnable() {
@Override
public void run() {
BasicComboPopup popup = (BasicComboPopup)comboBoxUI.getComboPopup();
Point point = popup.getLocationOnScreen();
Dimension size = popup.getSize();
int step = size.height / items.length;
point.x += size.width / 2;
point.y += step / 2 + step * item;
result[0] = point;
}
});
return result[0];
}
private static Point getItemPointToClick(final int item) throws Exception {
final Point[] result = new Point[1];
SwingUtilities.invokeAndWait(new Runnable() {
@Override
public void run() {
BasicComboPopup popup = (BasicComboPopup)comboBoxUI.getComboPopup();
Point point = popup.getLocationOnScreen();
Dimension size = popup.getSize();
int step = size.height / items.length;
point.x += size.width / 2;
point.y += step / 2 + step * item;
result[0] = point;
}
});
return result[0];
}
private static Point getItemPointToClick(final int item) throws Exception {
final Point[] result = new Point[1];
SwingUtilities.invokeAndWait(new Runnable() {
@Override
public void run() {
BasicComboPopup popup = (BasicComboPopup)comboBoxUI.getComboPopup();
Point point = popup.getLocationOnScreen();
Dimension size = popup.getSize();
int step = size.height / items.length;
point.x += size.width / 2;
point.y += step / 2 + step * item;
result[0] = point;
}
});
return result[0];
}
private static Point getItemPointToClick(final int item) throws Exception {
final Point[] result = new Point[1];
SwingUtilities.invokeAndWait(new Runnable() {
@Override
public void run() {
BasicComboPopup popup = (BasicComboPopup)comboBoxUI.getComboPopup();
Point point = popup.getLocationOnScreen();
Dimension size = popup.getSize();
int step = size.height / items.length;
point.x += size.width / 2;
point.y += step / 2 + step * item;
result[0] = point;
}
});
return result[0];
}
public MaterialComboBox() {
setModel(new DefaultComboBoxModel<T>());
setRenderer(new FieldRenderer<T>(this));
setUI(new BasicComboBoxUI() {
@Override
protected ComboPopup createPopup() {
BasicComboPopup popup = new Popup(comboBox);
popup.getAccessibleContext().setAccessibleParent(comboBox);
return popup;
}
@Override
protected JButton createArrowButton() {
JButton button = new javax.swing.plaf.basic.BasicArrowButton(
javax.swing.plaf.basic.BasicArrowButton.SOUTH,
MaterialColor.TRANSPARENT,
MaterialColor.TRANSPARENT,
MaterialColor.TRANSPARENT,
MaterialColor.TRANSPARENT);
button.setName("ComboBox.arrowButton");
return button;
}
});
setOpaque(false);
setBackground(MaterialColor.TRANSPARENT);
}
/**
* Creates a grayed out version of the loading gif that can be used in a combobox through an image observer
*
* @since 9.2.0
*/
private static ImageIcon makeLoadingIcon(JComboBox comboBox) {
ImageIcon icon = new ImageIcon(LOADING_ICON);
icon.setImageObserver((img, infoflags, x, y, w, h) -> {
boolean isFrameOrAll = (infoflags & (ImageObserver.FRAMEBITS | ImageObserver.ALLBITS)) != 0;
if (!comboBox.isShowing() || !isFrameOrAll) {
return !isFrameOrAll;
}
if (comboBox.getSelectedIndex() == 0) {
comboBox.repaint();
}
BasicComboPopup p = (BasicComboPopup) comboBox.getAccessibleContext().getAccessibleChild(0);
JList list = p.getList();
if (list.isShowing()) {
list.repaint();
}
return true;
});
return icon;
}
private static Point getItemPointToClick(final int item) throws Exception {
final Point[] result = new Point[1];
SwingUtilities.invokeAndWait(new Runnable() {
@Override
public void run() {
BasicComboPopup popup = (BasicComboPopup)comboBoxUI.getComboPopup();
Point point = popup.getLocationOnScreen();
Dimension size = popup.getSize();
int step = size.height / items.length;
point.x += size.width / 2;
point.y += step / 2 + step * item;
result[0] = point;
}
});
return result[0];
}
private static Point getItemPointToClick(final int item) throws Exception {
final Point[] result = new Point[1];
SwingUtilities.invokeAndWait(new Runnable() {
@Override
public void run() {
BasicComboPopup popup = (BasicComboPopup)comboBoxUI.getComboPopup();
Point point = popup.getLocationOnScreen();
Dimension size = popup.getSize();
int step = size.height / items.length;
point.x += size.width / 2;
point.y += step / 2 + step * item;
result[0] = point;
}
});
return result[0];
}
/**
* Alter the bounds of the popup just before it is made visible.
*/
@Override
public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
@SuppressWarnings("unchecked")
JComboBox<E> comboBox = (JComboBox<E>) e.getSource();
if (comboBox.getItemCount() == 0) return;
final Object child = comboBox.getAccessibleContext().getAccessibleChild(0);
if (child instanceof BasicComboPopup) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
customizePopup((BasicComboPopup) child);
}
});
}
}
private void customizePopup(BasicComboPopup popup) {
scrollPane = getScrollPane(popup);
if (popupWider)
popupWider(popup);
checkHorizontalScrollBar(popup);
// For some reason in JDK7 the popup will not display at its preferred
// width unless its location has been changed from its default
// (ie. for normal "pop down" shift the popup and reset)
Component comboBox = popup.getInvoker();
Point location = comboBox.getLocationOnScreen();
if (popupAbove) {
int height = popup.getPreferredSize().height;
popup.setLocation(location.x, location.y - height);
} else {
//int height = comboBox.getPreferredSize().height;
//popup.setLocation(location.x, location.y + height - 1);
//popup.setLocation(location.x, location.y + height);
//TODO should not be hardcoded
popup.setLocation(location.x + 5, location.y + 35);
}
}
private void popupWider(BasicComboPopup popup) {
@SuppressWarnings("unchecked")
JList<E> list = (JList<E>) popup.getList();
// Determine the maximimum width to use:
// a) determine the popup preferred width
// b) limit width to the maximum if specified
// c) ensure width is not less than the scroll pane width
int popupWidth = list.getPreferredSize().width
+ 5 // make sure horizontal scrollbar doesn't appear
+ getScrollBarWidth(popup, scrollPane);
if (maximumWidth != -1) {
popupWidth = Math.min(popupWidth, maximumWidth);
}
Dimension scrollPaneSize = scrollPane.getPreferredSize();
popupWidth = Math.max(popupWidth, scrollPaneSize.width);
// Adjust the width
scrollPaneSize.width = popupWidth;
scrollPane.setPreferredSize(scrollPaneSize);
scrollPane.setMaximumSize(scrollPaneSize);
}
/**
* Alter the bounds of the popup just before it is made visible.
*
* @param e The event.
*/
@Override
public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
JComboBox<?> comboBox = (JComboBox) e.getSource();
if (comboBox.getItemCount() == 0) {
return;
}
final Object child = comboBox.getAccessibleContext().getAccessibleChild(0);
if (child instanceof BasicComboPopup) {
SwingUtilities.invokeLater(() -> customizePopup((BasicComboPopup) child));
}
}
protected void customizePopup(BasicComboPopup popup) {
scrollPane = getScrollPane(popup);
popupWider(popup);
// For some reason in JDK7 the popup will not display at its preferred
// width unless its location has been changed from its default
// (ie. for normal "pop down" shift the popup and reset)
Component comboBox = popup.getInvoker();
Point location = comboBox.getLocationOnScreen();
int height = comboBox.getSize().height;
popup.setLocation(location.x, location.y + height - 1);
popup.setLocation(location.x, location.y + height);
}
/**
* Returns the scroll pane used by the popup so its bounds can be adjusted.
*/
protected JScrollPane getScrollPane(BasicComboPopup popup) {
JList<?> list = popup.getList();
Container c = SwingUtilities.getAncestorOfClass(JScrollPane.class, list);
return (JScrollPane) c;
}
protected int getScrollBarWidth(BasicComboPopup popup, JScrollPane scrollPane) {
// I can't find any property on the scrollBar to determine if it will be
// displayed or not so use brute force to determine this.
JComboBox<?> comboBox = (JComboBox) popup.getInvoker();
if (comboBox.getItemCount() > comboBox.getMaximumRowCount()) {
return scrollPane.getVerticalScrollBar().getPreferredSize().width;
}
else {
return 0;
}
}
private void fireActiveDescendant() {
if (JPopupMenu.this instanceof BasicComboPopup) {
// get the popup list
JList<?> popupList = ((BasicComboPopup)JPopupMenu.this).getList();
if (popupList == null) {
return;
}
// get the first selected item
AccessibleContext ac = popupList.getAccessibleContext();
AccessibleSelection selection = ac.getAccessibleSelection();
if (selection == null) {
return;
}
Accessible a = selection.getAccessibleSelection(0);
if (a == null) {
return;
}
AccessibleContext selectedItem = a.getAccessibleContext();
// fire the event with the popup invoker as the source.
if (selectedItem != null && invoker != null) {
AccessibleContext invokerContext = invoker.getAccessibleContext();
if (invokerContext != null) {
// Check invokerContext because Component.getAccessibleContext
// returns null. Classes that extend Component are responsible
// for returning a non-null AccessibleContext.
invokerContext.firePropertyChange(
ACCESSIBLE_ACTIVE_DESCENDANT_PROPERTY,
null, selectedItem);
}
}
}
}
@Override
protected PropertyChangeListener createPropertyChangeListener() {
return new BasicComboPopup.PropertyChangeHandler() {
@Override
public void propertyChange( PropertyChangeEvent e ) {
super.propertyChange( e );
if( e.getPropertyName() == "renderer" )
list.setCellRenderer( new PopupListCellRenderer() );
}
};
}
private void fireActiveDescendant() {
if (JPopupMenu.this instanceof BasicComboPopup) {
// get the popup list
JList<?> popupList = ((BasicComboPopup)JPopupMenu.this).getList();
if (popupList == null) {
return;
}
// get the first selected item
AccessibleContext ac = popupList.getAccessibleContext();
AccessibleSelection selection = ac.getAccessibleSelection();
if (selection == null) {
return;
}
Accessible a = selection.getAccessibleSelection(0);
if (a == null) {
return;
}
AccessibleContext selectedItem = a.getAccessibleContext();
// fire the event with the popup invoker as the source.
if (selectedItem != null && invoker != null) {
AccessibleContext invokerContext = invoker.getAccessibleContext();
if (invokerContext != null) {
// Check invokerContext because Component.getAccessibleContext
// returns null. Classes that extend Component are responsible
// for returning a non-null AccessibleContext.
invokerContext.firePropertyChange(
ACCESSIBLE_ACTIVE_DESCENDANT_PROPERTY,
null, selectedItem);
}
}
}
}
public static BasicComboPopup getPopup() {
AccessibleContext c = cb.getAccessibleContext();
for(int i = 0; i < c.getAccessibleChildrenCount(); i ++) {
if (c.getAccessibleChild(i) instanceof BasicComboPopup) {
return (BasicComboPopup) c.getAccessibleChild(i);
}
}
throw new AssertionError("No BasicComboPopup found");
}
private void fireActiveDescendant() {
if (JPopupMenu.this instanceof BasicComboPopup) {
// get the popup list
JList<?> popupList = ((BasicComboPopup)JPopupMenu.this).getList();
if (popupList == null) {
return;
}
// get the first selected item
AccessibleContext ac = popupList.getAccessibleContext();
AccessibleSelection selection = ac.getAccessibleSelection();
if (selection == null) {
return;
}
Accessible a = selection.getAccessibleSelection(0);
if (a == null) {
return;
}
AccessibleContext selectedItem = a.getAccessibleContext();
// fire the event with the popup invoker as the source.
if (selectedItem != null && invoker != null) {
AccessibleContext invokerContext = invoker.getAccessibleContext();
if (invokerContext != null) {
// Check invokerContext because Component.getAccessibleContext
// returns null. Classes that extend Component are responsible
// for returning a non-null AccessibleContext.
invokerContext.firePropertyChange(
ACCESSIBLE_ACTIVE_DESCENDANT_PROPERTY,
null, selectedItem);
}
}
}
}
public static BasicComboPopup getPopup() {
AccessibleContext c = cb.getAccessibleContext();
for(int i = 0; i < c.getAccessibleChildrenCount(); i ++) {
if (c.getAccessibleChild(i) instanceof BasicComboPopup) {
return (BasicComboPopup) c.getAccessibleChild(i);
}
}
throw new AssertionError("No BasicComboPopup found");
}
private void fireActiveDescendant() {
if (JPopupMenu.this instanceof BasicComboPopup) {
// get the popup list
JList<?> popupList = ((BasicComboPopup)JPopupMenu.this).getList();
if (popupList == null) {
return;
}
// get the first selected item
AccessibleContext ac = popupList.getAccessibleContext();
AccessibleSelection selection = ac.getAccessibleSelection();
if (selection == null) {
return;
}
Accessible a = selection.getAccessibleSelection(0);
if (a == null) {
return;
}
AccessibleContext selectedItem = a.getAccessibleContext();
// fire the event with the popup invoker as the source.
if (selectedItem != null && invoker != null) {
AccessibleContext invokerContext = invoker.getAccessibleContext();
if (invokerContext != null) {
// Check invokerContext because Component.getAccessibleContext
// returns null. Classes that extend Component are responsible
// for returning a non-null AccessibleContext.
invokerContext.firePropertyChange(
ACCESSIBLE_ACTIVE_DESCENDANT_PROPERTY,
null, selectedItem);
}
}
}
}
public static BasicComboPopup getPopup() {
AccessibleContext c = cb.getAccessibleContext();
for(int i = 0; i < c.getAccessibleChildrenCount(); i ++) {
if (c.getAccessibleChild(i) instanceof BasicComboPopup) {
return (BasicComboPopup) c.getAccessibleChild(i);
}
}
throw new AssertionError("No BasicComboPopup found");
}