Thursday April 17, 2008
Thursday April 17, 2008
org.openide.filesystems.FileChangeListener
How to listen to changes to a file, via the related NetBeans FileObject, and change the DataNode's display name, tooltip, and icon as a result:
public class DemoDataNode extends DataNode implements FileChangeListener {
//The objects we are dealing with:
private static final String ICON1 = "/org/netbeans/demofiletype/demo-1.png";
private static final String ICON2 = "/org/netbeans/demofiletype/demo-2.png";
DemoDataObject obj;
Date date;
String displayName;
String tooltip;
Image icon;
int count = 0;
//Constructor:
public DemoDataNode(DemoDataObject obj) {
super(obj, Children.LEAF);
this.obj = obj;
date = new Date();
}
//Constructor for receiving the lookup:
DemoDataNode(DemoDataObject obj, Lookup lookup) {
super(obj, Children.LEAF, lookup);
//Add file change listener to the FileObject:
obj.getPrimaryFile().addFileChangeListener(this);
//Set default icon:
setIconBaseWithExtension(ICON1);
//Set default tooltip:
setShortDescription("Hello world!");
}
@Override
public String getDisplayName() {
if (null != displayName) {
return displayName;
}
return super.getDisplayName();
}
@Override
public String getShortDescription() {
if (null != tooltip) {
return tooltip;
}
return super.getShortDescription();
}
@Override
public Image getIcon(int arg0) {
if (null != icon) {
return icon;
}
return super.getIcon(arg0);
}
//When the file changes...
@Override
public void fileChanged(FileEvent arg0) {
//Increment the count:
count = count + 1;
//Depending on the modulus, switch the icon:
if (count % 2 == 1) {
icon = Utilities.loadImage(ICON1);
} else {
icon = Utilities.loadImage(ICON2);
}
//Get the milliseconds and format it:
long mills = System.currentTimeMillis();
DateFormat dateFormatter = DateFormat.getDateTimeInstance(
DateFormat.LONG,
DateFormat.LONG);
String formatted = dateFormatter.format(mills);
//Save the current display name:
String oldDisplayName = displayName;
//Save the current tooltip:
String oldShortDescription = tooltip;
//Set the new display name:
displayName = "Change " + count + " (" + formatted + ")";
//Set the new tooltip:
tooltip = formatted;
//Fire change events on the node,
//which will immediately refresh it with the new values:
fireDisplayNameChange(oldDisplayName, displayName);
fireShortDescriptionChange(oldShortDescription, tooltip);
fireIconChange();
}
@Override
public void fileFolderCreated(FileEvent arg0) {}
@Override
public void fileDataCreated(FileEvent arg0) {}
@Override
public void fileDeleted(FileEvent arg0) {}
@Override
public void fileRenamed(FileRenameEvent arg0) {}
@Override
public void fileAttributeChanged(FileAttributeEvent arg0) {}
}
When you change a document associated with the DataNode and DataObject referred to here, and you then save the document, the display name, tooltip, and icon will change.
Apr 17 2008, 12:14:38 AM PDT Permalink
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