【发布时间】：2014-03-03 14:21:24
【问题描述】：
使用这个example，我想创建带有节点的TreeView，我可以拖动这些节点来改变它们的位置。
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.TreeCell;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeItem.TreeModificationEvent;
import javafx.scene.control.TreeView;
import javafx.scene.input.ClipboardContent;
import javafx.scene.input.DataFormat;
import javafx.scene.input.DragEvent;
import javafx.scene.input.Dragboard;
import javafx.scene.input.MouseEvent;
import javafx.scene.input.TransferMode;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.util.Callback;
public class MainApp extends Application {
private EventHandler<TreeModificationEvent<DynamicTreeNodeModel>> branchExpandedEventHandler;
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
Application.launch(MainApp.class, args);
}
@Override
public void start(Stage primaryStage) {
primaryStage.setTitle("Example Dynamic Tree");
primaryStage.setResizable(true);
final VBox box = new VBox();
box.setFillWidth(false);
Scene scene = new Scene(box);
primaryStage.setScene(scene);
box.getChildren().add(this.getExampleTree());
primaryStage.show();
}
private TreeView<DynamicTreeNodeModel> getExampleTree() {
DynamicTreeNodeModel rootNode = new RandomDynamicTreeNodeModel(null, "Root Node");
TreeView<DynamicTreeNodeModel> treeView = new TreeView<DynamicTreeNodeModel>();
treeView.setCellFactory(new Callback<TreeView<DynamicTreeNodeModel>, TreeCell<DynamicTreeNodeModel>>() {
@Override
public TreeCell call(TreeView<DynamicTreeNodeModel> param) {
return new DnDCell(param);
}
});
treeView.setPrefSize(1000, 750);
TreeItem rootItem = new TreeItem(rootNode);
branchExpandedEventHandler = new EventHandler<TreeModificationEvent<DynamicTreeNodeModel>>() {
public void handle(TreeModificationEvent<DynamicTreeNodeModel> event) {
// System.out.println("handling event " + event);
TreeItem<DynamicTreeNodeModel> item = event.getTreeItem();
populateTreeItem(item);
}
};
rootItem.addEventHandler(TreeItem.branchExpandedEvent(), branchExpandedEventHandler);
treeView.setShowRoot(true);
treeView.setRoot(rootItem);
populateTreeItem(rootItem);
rootItem.setExpanded(true);
// treeView.setCellFactory(new LearningTreeCellFactory());
return treeView;
}
private void populateTreeItem(TreeItem<DynamicTreeNodeModel> item) {
DynamicTreeNodeModel node = item.getValue();
boolean isPopulated = node.isPopulated();
boolean areGrandChildrenPopulated = node.areChildenPopulated();
node.populateToDepth(2);
if (!isPopulated) {
for (DynamicTreeNodeModel childNode : node.getChildren()) {
TreeItem childItem = new TreeItem(childNode);
childItem.addEventHandler(TreeItem.branchExpandedEvent(), branchExpandedEventHandler);
item.getChildren().add(childItem);
}
}
if (!areGrandChildrenPopulated) {
int i = 0;
for (TreeItem childItem : item.getChildren()) {
// get cooresponding node in the model
DynamicTreeNodeModel childNode = node.getChildren().get(i);
i++;
for (DynamicTreeNodeModel grandChildNode : childNode.getChildren()) {
TreeItem grandChildItem = new TreeItem(grandChildNode);
grandChildItem.addEventHandler(TreeItem.branchExpandedEvent(), branchExpandedEventHandler);
childItem.getChildren().add(grandChildItem);
}
}
}
}
private static interface DynamicTreeNodeModel {
public String getName();
public void setName(String name);
public boolean isPopulated();
public boolean areChildenPopulated();
public List<DynamicTreeNodeModel> getChildren();
public void setChildren(List<DynamicTreeNodeModel> children);
public DynamicTreeNodeModel getParent();
public void setParent(DynamicTreeNodeModel parent);
public void populateToDepth(int depth);
@Override
public String toString();
}
private static class RandomDynamicTreeNodeModel implements DynamicTreeNodeModel {
private DynamicTreeNodeModel parent;
private String name;
private List<DynamicTreeNodeModel> children = null;
public RandomDynamicTreeNodeModel(DynamicTreeNodeModel parent, String name) {
this.parent = parent;
this.name = name;
}
@Override
public String getName() {
return name;
}
@Override
public void setName(String name) {
this.name = name;
}
@Override
public boolean isPopulated() {
if (children == null) {
return false;
}
return true;
}
@Override
public boolean areChildenPopulated() {
if (!this.isPopulated()) {
return false;
}
for (DynamicTreeNodeModel child : this.children) {
if (!child.isPopulated()) {
return false;
}
}
return true;
}
@Override
public List<DynamicTreeNodeModel> getChildren() {
return children;
}
@Override
public void setChildren(List<DynamicTreeNodeModel> children) {
this.children = children;
}
@Override
public DynamicTreeNodeModel getParent() {
return parent;
}
@Override
public void setParent(DynamicTreeNodeModel parent) {
this.parent = parent;
}
private static Random random = new Random();
@Override
public void populateToDepth(int depth) {
if (depth <= 0) {
return;
}
if (children == null) {
int num = random.nextInt(5);
System.out.println("got a random number " + num);
children = new ArrayList(num);
for (int i = 0; i < num; i++) {
children.add(new RandomDynamicTreeNodeModel(this, "child " + i));
}
}
int childDepth = depth - 1;
for (DynamicTreeNodeModel child : children) {
child.populateToDepth(childDepth);
}
}
@Override
public String toString() {
return this.name;
}
}
public class DnDCell extends TreeCell<DynamicTreeNodeModel> {
private TreeView<DynamicTreeNodeModel> parentTree;
public DnDCell(final TreeView<DynamicTreeNodeModel> parentTree) {
this.parentTree = parentTree;
// ON SOURCE NODE.
setOnDragDetected(new EventHandler<MouseEvent>() {
@Override
public void handle(MouseEvent event) {
System.out.println("Drag detected on " + item);
if (item == null) {
return;
}
Dragboard dragBoard = startDragAndDrop(TransferMode.MOVE);
ClipboardContent content = new ClipboardContent();
content.put(DataFormat.PLAIN_TEXT, item.toString());
dragBoard.setContent(content);
event.consume();
}
});
setOnDragDone(new EventHandler<DragEvent>() {
@Override
public void handle(DragEvent dragEvent) {
System.out.println("Drag done on " + item);
dragEvent.consume();
}
});
// ON TARGET NODE.
// setOnDragEntered(new EventHandler<DragEvent>() {
// @Override
// public void handle(DragEvent dragEvent) {
// System.out.println("Drag entered on " + item);
// dragEvent.consume();
// }
// });
setOnDragOver(new EventHandler<DragEvent>() {
@Override
public void handle(DragEvent dragEvent) {
System.out.println("Drag over on " + item);
if (dragEvent.getDragboard().hasString()) {
int valueToMove = Integer.parseInt(dragEvent.getDragboard().getString());
if (valueToMove != item) {
// We accept the transfer!!!!!
dragEvent.acceptTransferModes(TransferMode.MOVE);
}
}
dragEvent.consume();
}
});
// setOnDragExited(new EventHandler<DragEvent>() {
// @Override
// public void handle(DragEvent dragEvent) {
// System.out.println("Drag exited on " + item);
// dragEvent.consume();
// }
// });
setOnDragDropped(new EventHandler<DragEvent>() {
@Override
public void handle(DragEvent dragEvent) {
System.out.println("Drag dropped on " + item);
int valueToMove = Integer.parseInt(dragEvent.getDragboard().getString());
TreeItem<DynamicTreeNodeModel> itemToMove = search(parentTree.getRoot(), valueToMove);
TreeItem<DynamicTreeNodeModel> newParent = search(parentTree.getRoot(), item);
// Remove from former parent.
itemToMove.getParent().getChildren().remove(itemToMove);
// Add to new parent.
newParent.getChildren().add(itemToMove);
newParent.setExpanded(true);
dragEvent.consume();
}
});
}
private TreeItem<DynamicTreeNodeModel> search(final TreeItem<DynamicTreeNodeModel> currentNode, final int valueToSearch) {
TreeItem<DynamicTreeNodeModel> result = null;
if (currentNode.getValue() == valueToSearch) {
result = currentNode;
} else if (!currentNode.isLeaf()) {
for (TreeItem<DynamicTreeNodeModel> child : currentNode.getChildren()) {
result = search(child, valueToSearch);
if (result != null) {
break;
}
}
}
return result;
}
private DynamicTreeNodeModel item;
@Override
protected void updateItem(DynamicTreeNodeModel item, boolean empty) {
super.updateItem(item, empty);
this.item = item;
String text = (item == null) ? null : item.toString();
setText(text);
}
}
}
我尝试实现该示例，但在这里遇到了问题：
@Controller
public class FileUploadController {
if (valueToMove != item) {
// We accept the transfer!!!!!
dragEvent.acceptTransferModes(TransferMode.MOVE);
}
...............
if (currentNode.getValue() == valueToSearch) {
我收到incomparable types: DynamicTreeNodeModel and int
你能帮我解决这个问题吗？
【问题讨论】：
-
我没有时间修复整个代码，只是为了帮助您朝着正确的方向前进。在示例中，用户拥有
TreeItem<Integer>，而您拥有TreeView<DynamicTreeNodeModel>。所以要么比较names，或者如果有可能重复的名字，把id放在你的DynamicTreeNodeModel里面然后比较它们！ -
我也试过了，但没有成功。
标签： java javafx javafx-2 javafx-8