由于Vaadin Tree不支持延迟加载,所以我想使用TreeTable。
TreeTable应该看起来像一个普通的树,没有标题和斑马行样式。
到目前为止,我得到的是:
TreeTable mainTree = new TreeTable();
mainTree.setSizeFull();
mainTree.setColumnHeaderMode(ColumnHeaderMode.HIDDEN);
mainTree.setColumnCollapsingAllowed(false);我还应该设置什么,如何摆脱斑马的图案?
发布于 2016-12-02 09:21:37
尽管在Vaadin文档中它说Tree的延迟加载是不支持,但我设法实现了下面的延迟加载 Hierarchical接口。
在一个本地结构中存储所有元素(在我的例子中是hierarchy中)是非常重要的,不要多次读取元素--这是不起作用的。我认为是因为Vaadin不使用equals()和hashCode()。
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.softmodeler.common.CommonPlugin;
import com.softmodeler.model.OutputNode;
import com.softmodeler.service.IViewService;
import com.vaadin.data.Container.Hierarchical;
import com.vaadin.data.Item;
import com.vaadin.data.Property;
import com.vaadin.data.util.BeanItem;
/**
* @author Flavio Donzé
* @version 1.0
*/
public class OutputNodeHierachical implements Hierarchical {
private static final long serialVersionUID = 8289589835030184018L;
/** the view service */
private IViewService service = CommonPlugin.getService(IViewService.class);
/** collection of all root nodes */
private List<OutputNode> rootNodes = null;
/** parent=>children mapping */
private Map<OutputNode, List<OutputNode>> hierarchy = new HashMap<>();
/**
* constructor
*
* @param rootNodes collection of all root nodes
*/
public OutputNodeHierachical(List<OutputNode> rootNodes) {
this.rootNodes = Collections.unmodifiableList(rootNodes);
addToHierarchy(rootNodes);
}
@Override
public Collection<?> getChildren(Object itemId) {
try {
List<OutputNode> children = hierarchy.get(itemId);
if (children == null) {
OutputNode node = (OutputNode) itemId;
children = service.getChildren(node.getNodeId(), false);
hierarchy.put(node, children);
// add children to hierarchy, their children will be added on click
addToHierarchy(children);
}
return children;
} catch (Exception e) {
VaadinUtil.handleException(e);
}
return null;
}
/**
* add each element to the hierarchy without their children hierarchy(child=>null)
*
* @param children elements to add
*/
private void addToHierarchy(List<OutputNode> children) {
for (OutputNode child : children) {
hierarchy.put(child, null);
}
}
@Override
public boolean areChildrenAllowed(Object itemId) {
return !((OutputNode) itemId).getChilds().isEmpty();
}
@Override
public boolean hasChildren(Object itemId) {
return !((OutputNode) itemId).getChilds().isEmpty();
}
@Override
public Object getParent(Object itemId) {
String parentId = ((OutputNode) itemId).getParentId();
for (OutputNode node : hierarchy.keySet()) {
if (node.getNodeId().equals(parentId)) {
return node;
}
}
return null;
}
@Override
public Collection<?> rootItemIds() {
return rootNodes;
}
@Override
public boolean isRoot(Object itemId) {
return rootNodes.contains(itemId);
}
@Override
public Item getItem(Object itemId) {
return new BeanItem<OutputNode>((OutputNode) itemId);
}
@Override
public boolean containsId(Object itemId) {
return hierarchy.containsKey(itemId);
}
@Override
public Collection<?> getItemIds() {
return hierarchy.keySet();
}
@Override
public int size() {
return hierarchy.size();
}
@Override
public boolean setParent(Object itemId, Object newParentId) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
@Override
public boolean setChildrenAllowed(Object itemId, boolean areChildrenAllowed) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
@Override
public Item addItem(Object itemId) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
@Override
public Object addItem() throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
@Override
public boolean removeItem(Object itemId) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
@Override
public boolean removeAllItems() throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
@Override
public Class<?> getType(Object propertyId) {
throw new UnsupportedOperationException();
}
@Override
public Collection<?> getContainerPropertyIds() {
throw new UnsupportedOperationException();
}
@Override
public Property<?> getContainerProperty(Object itemId, Object propertyId) {
throw new UnsupportedOperationException();
}
@Override
public boolean addContainerProperty(Object propertyId, Class<?> type, Object defaultValue) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
@Override
public boolean removeContainerProperty(Object propertyId) throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
}将容器添加到Tree中如下所示:
OutputNodeHierachical dataSource = new OutputNodeHierachical(rootNodes);
Tree mainTree = new Tree();
mainTree.setSizeFull();
mainTree.setContainerDataSource(dataSource);
mainTree.addItemClickListener(new ItemClickListener() {
private static final long serialVersionUID = -413371711541672605L;
@Override
public void itemClick(ItemClickEvent event) {
OutputNode node = (OutputNode) event.getItemId();
openObject(node.getObjectId());
}
});发布于 2016-12-01 20:36:27
考虑自己实现一个延迟加载机制,其中加载三个的根。然后添加一个ExpandListener,它在调用时加载子对象并将它们添加到节点。
@Override
protected void init(VaadinRequest request) {
final VerticalLayout layout = new VerticalLayout();
layout.setMargin(true);
setContent(layout);
final Tree t = new Tree();
t.addItem(new TreeNode(0));
t.addExpandListener(new ExpandListener() {
@Override
public void nodeExpand(ExpandEvent event) {
TreeNode node = (TreeNode) event.getItemId();
for (TreeNode child : node.getMyChildren()){
t.addItem(child);
t.setParent(child, node);
}
}
});
layout.addComponent(t);
}
}https://stackoverflow.com/questions/40891302
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