JInternalFrame objects and add them to the
* JDesktopPane. JDesktopPane extends
* JLayeredPane to manage the potentially overlapping internal
* frames. It also maintains a reference to an instance of
* DesktopManager that is set by the UI
* class for the current look and feel (L&F). Note that JDesktopPane
* does not support borders.
*
* This class is normally used as the parent of JInternalFrames
* to provide a pluggable DesktopManager object to the
* JInternalFrames. The installUI of the
* L&F specific implementation is responsible for setting the
* desktopManager variable appropriately.
* When the parent of a JInternalFrame is a JDesktopPane,
* it should delegate most of its behavior to the desktopManager
* (closing, resizing, etc).
*
* For further documentation and examples see * How to Use Internal Frames, * a section in The Java Tutorial. *
* 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}.
*
* @see JInternalFrame
* @see JInternalFrame.JDesktopIcon
* @see DesktopManager
*
* @version 1.51 12/19/03
* @author David Kloba
*/
public class JDesktopPane extends JLayeredPane implements Accessible
{
/**
* @see #getUIClassID
* @see #readObject
*/
private static final String uiClassID = "DesktopPaneUI";
transient DesktopManager desktopManager;
private transient JInternalFrame selectedFrame = null;
/**
* Indicates that the entire contents of the item being dragged
* should appear inside the desktop pane.
*
* @see #OUTLINE_DRAG_MODE
* @see #setDragMode
*/
public static final int LIVE_DRAG_MODE = 0;
/**
* Indicates that an outline only of the item being dragged
* should appear inside the desktop pane.
*
* @see #LIVE_DRAG_MODE
* @see #setDragMode
*/
public static final int OUTLINE_DRAG_MODE = 1;
private int dragMode = LIVE_DRAG_MODE;
private boolean dragModeSet = false;
/**
* Creates a new JDesktopPane.
*/
public JDesktopPane() {
setFocusCycleRoot(true);
setFocusTraversalPolicy(new LayoutFocusTraversalPolicy() {
public Component getDefaultComponent(Container c) {
JInternalFrame jifArray[] = getAllFrames();
Component comp = null;
for (int i = 0; i < jifArray.length; i++) {
comp = jifArray[i].getFocusTraversalPolicy().getDefaultComponent(jifArray[i]);
if (comp != null) {
break;
}
}
return comp;
}
});
updateUI();
}
/**
* Returns the L&F object that renders this component.
*
* @return the DesktopPaneUI object that
* renders this component
*/
public DesktopPaneUI getUI() {
return (DesktopPaneUI)ui;
}
/**
* Sets the L&F object that renders this component.
*
* @param ui the DesktopPaneUI L&F object
* @see UIDefaults#getUI
* @beaninfo
* bound: true
* hidden: true
* attribute: visualUpdate true
* description: The UI object that implements the Component's LookAndFeel.
*/
public void setUI(DesktopPaneUI ui) {
super.setUI(ui);
}
/**
* Sets the "dragging style" used by the desktop pane.
* You may want to change to one mode or another for
* performance or aesthetic reasons.
*
* @param dragMode the style of drag to use for items in the Desktop
*
* @see #LIVE_DRAG_MODE
* @see #OUTLINE_DRAG_MODE
*
* @beaninfo
* bound: true
* description: Dragging style for internal frame children.
* enum: LIVE_DRAG_MODE JDesktopPane.LIVE_DRAG_MODE
* OUTLINE_DRAG_MODE JDesktopPane.OUTLINE_DRAG_MODE
*/
public void setDragMode(int dragMode) {
int oldDragMode = this.dragMode;
this.dragMode = dragMode;
firePropertyChange("dragMode", oldDragMode, this.dragMode);
dragModeSet = true;
}
/**
* Gets the current "dragging style" used by the desktop pane.
* @return either Live_DRAG_MODE or
* OUTLINE_DRAG_MODE
* @see #setDragMode
*/
public int getDragMode() {
return dragMode;
}
/**
* Returns the DesktopManger that handles
* desktop-specific UI actions.
*/
public DesktopManager getDesktopManager() {
return desktopManager;
}
/**
* Sets the DesktopManger that will handle
* desktop-specific UI actions.
*
* @param d the DesktopManager to use
*
* @beaninfo
* bound: true
* description: Desktop manager to handle the internal frames in the
* desktop pane.
*/
public void setDesktopManager(DesktopManager d) {
DesktopManager oldValue = desktopManager;
desktopManager = d;
firePropertyChange("desktopManager", oldValue, desktopManager);
}
/**
* Notification from the UIManager that the L&F has changed.
* Replaces the current UI object with the latest version from the
* UIManager.
*
* @see JComponent#updateUI
*/
public void updateUI() {
setUI((DesktopPaneUI)UIManager.getUI(this));
}
/**
* Returns the name of the L&F class that renders this component.
*
* @return the string "DesktopPaneUI"
* @see JComponent#getUIClassID
* @see UIDefaults#getUI
*/
public String getUIClassID() {
return uiClassID;
}
/**
* Returns all JInternalFrames currently displayed in the
* desktop. Returns iconified frames as well as expanded frames.
*
* @return an array of JInternalFrame objects
*/
public JInternalFrame[] getAllFrames() {
int i, count;
JInternalFrame[] results;
Vector vResults = new Vector(10);
Object next, tmp;
count = getComponentCount();
for(i = 0; i < count; i++) {
next = getComponent(i);
if(next instanceof JInternalFrame)
vResults.addElement(next);
else if(next instanceof JInternalFrame.JDesktopIcon) {
tmp = ((JInternalFrame.JDesktopIcon)next).getInternalFrame();
if(tmp != null)
vResults.addElement(tmp);
}
}
results = new JInternalFrame[vResults.size()];
vResults.copyInto(results);
return results;
}
/** Returns the currently active JInternalFrame
* in this JDesktopPane, or null
* if no JInternalFrame is currently active.
*
* @return the currently active JInternalFrame or
* null
* @since 1.3
*/
public JInternalFrame getSelectedFrame() {
return selectedFrame;
}
/** Sets the currently active JInternalFrame
* in this JDesktopPane.
*
* @param f the internal frame that's currently selected
* @since 1.3
*/
public void setSelectedFrame(JInternalFrame f) {
selectedFrame = f;
}
/**
* Returns all JInternalFrames currently displayed in the
* specified layer of the desktop. Returns iconified frames as well
* expanded frames.
*
* @param layer an int specifying the desktop layer
* @return an array of JInternalFrame objects
* @see JLayeredPane
*/
public JInternalFrame[] getAllFramesInLayer(int layer) {
int i, count;
JInternalFrame[] results;
Vector vResults = new Vector(10);
Object next, tmp;
count = getComponentCount();
for(i = 0; i < count; i++) {
next = getComponent(i);
if(next instanceof JInternalFrame) {
if(((JInternalFrame)next).getLayer() == layer)
vResults.addElement(next);
} else if(next instanceof JInternalFrame.JDesktopIcon) {
tmp = ((JInternalFrame.JDesktopIcon)next).getInternalFrame();
if(tmp != null && ((JInternalFrame)tmp).getLayer() == layer)
vResults.addElement(tmp);
}
}
results = new JInternalFrame[vResults.size()];
vResults.copyInto(results);
return results;
}
/**
* Returns true to indicate that this component paints every pixel
* in its range. (In other words, it does not have a transparent
* background or foreground.)
*
* @return true
* @see JComponent#isOpaque
*/
public boolean isOpaque() {
return true;
}
/**
* 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);
}
}
}
void setUIProperty(String propertyName, Object value) {
if (propertyName == "dragMode") {
if (!dragModeSet) {
setDragMode(((Integer)value).intValue());
dragModeSet = false;
}
} else {
super.setUIProperty(propertyName, value);
}
}
/**
* Returns a string representation of this JDesktopPane.
* 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 JDesktopPane
*/
protected String paramString() {
String desktopManagerString = (desktopManager != null ?
desktopManager.toString() : "");
return super.paramString() +
",desktopManager=" + desktopManagerString;
}
/////////////////
// Accessibility support
////////////////
/**
* Gets the AccessibleContext associated with this
* JDesktopPane. For desktop panes, the
* AccessibleContext takes the form of an
* AccessibleJDesktopPane.
* A new AccessibleJDesktopPane instance is created if necessary.
*
* @return an AccessibleJDesktopPane that serves as the
* AccessibleContext of this JDesktopPane
*/
public AccessibleContext getAccessibleContext() {
if (accessibleContext == null) {
accessibleContext = new AccessibleJDesktopPane();
}
return accessibleContext;
}
/**
* This class implements accessibility support for the
* JDesktopPane class. It provides an implementation of the
* Java Accessibility API appropriate to desktop pane user-interface
* elements.
*
* 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}.
*/
protected class AccessibleJDesktopPane extends AccessibleJComponent {
/**
* Get the role of this object.
*
* @return an instance of AccessibleRole describing the role of the
* object
* @see AccessibleRole
*/
public AccessibleRole getAccessibleRole() {
return AccessibleRole.DESKTOP_PANE;
}
}
}