org.zkoss.zk.ui.ext.render
Interface Cropper

All Known Implementing Classes:

Listbox.ExtraCtrl, Rows.ExtraCtrl, Treechildren.ExtraCtrl

public interface Cropper

Implemented by the object returned by ComponentCtrl.getExtraCtrl() if not all of the children of a component are available at the client. In other word, the component support 'cropping'. Example: only children of the active page of ZUL's grid are available at the client, if it is in the paging mold.

ZK Update Engine detects this interface and then ignores any update to components that don't have counterpart at the client.

Author:

tomyeh

Method Summary

java.util.Set	getAvailableAtClient() Returns a set of child components that are available at the client, or null if ALL available.
boolean	isCropper() Returns whether it is a cropper, i.e., cropping is applied.

Method Detail

isCropper

boolean isCropper()

Returns whether it is a cropper, i.e., cropping is applied.

Note: this method is called when an child is detached, so you have to count one more for the total number of children. Example <= must be used, not <:
getChildCount() <= getPageSize()

The result of returning false is the same as not declaring with Cropper.

getAvailableAtClient

java.util.Set getAvailableAtClient()

Returns a set of child components that are available at the client, or null if ALL available. The child components in the returned set must be in the same order of Component.getChildren(). In order words, you must use LinkedHashSet or similar to ensure the order in the returned set.

Note: for better performance, it is better to return null if all children are available at the client.