/**
* Loads all of the children to initialize the view. This is called by the {@link #setParent}
* method. Subclasses can reimplement this to initialize their child views in a different manner.
* The default implementation creates a child view for each child element.
*
* @param f the view factory
* @see #setParent
*/
protected void loadChildren(ViewFactory f) {
if (f == null) {
// No factory. This most likely indicates the parent view
// has changed out from under us, bail!
return;
}
Element e = getElement();
int n = e.getElementCount();
if (n > 0) {
View[] added = new View[n];
for (int i = 0; i < n; i++) {
added[i] = f.create(e.getElement(i));
}
replace(0, 0, added);
}
}
/**
* Updates the child views in response to receiving notification that the model changed, and there
* is change record for the element this view is responsible for. This is implemented to assume
* the child views are directly responsible for the child elements of the element this view
* represents. The <code>ViewFactory</code> is used to create child views for each element
* specified as added in the <code>ElementChange</code>, starting at the index specified in the
* given <code>ElementChange</code>. The number of child views representing the removed elements
* specified are removed.
*
* @param ec the change information for the element this view is responsible for. This should not
* be <code>null</code> if this method gets called
* @param e the change information from the associated document
* @param f the factory to use to build child views
* @return whether or not the child views represent the child elements of the element this view is
* responsible for. Some views create children that represent a portion of the element they
* are responsible for, and should return false. This information is used to determine if
* views in the range of the added elements should be forwarded to or not
* @see #insertUpdate
* @see #removeUpdate
* @see #changedUpdate
* @since 1.3
*/
protected boolean updateChildren(DocumentEvent.ElementChange ec, DocumentEvent e, ViewFactory f) {
Element[] removedElems = ec.getChildrenRemoved();
Element[] addedElems = ec.getChildrenAdded();
View[] added = null;
if (addedElems != null) {
added = new View[addedElems.length];
for (int i = 0; i < addedElems.length; i++) {
added[i] = f.create(addedElems[i]);
}
}
int nremoved = 0;
int index = ec.getIndex();
if (removedElems != null) {
nremoved = removedElems.length;
}
replace(index, nremoved, added);
return true;
}