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java - 拖动 TreeView 的节点

转载 作者:行者123 更新时间:2023-12-02 02:42:09 27 4
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使用这个 example我想创建带有节点的 TreeView,我可以拖动这些节点以更改它们的位置。

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);
}
}
}

我试图实现这个例子,但我在这里遇到了一个问题:

@Controller
public class FileUploadController {

if (valueToMove != item) {
// We accept the transfer!!!!!
dragEvent.acceptTransferModes(TransferMode.MOVE);
}
...............
if (currentNode.getValue() == valueToSearch) {

我得到了无法比较的类型:DynamicTreeNodeModel 和 int

你能帮我解决这个问题吗?

最佳答案

请试试这个:

/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package test;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.logging.Level;
import java.util.logging.Logger;
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;
int size = node.getChildren().size();
for (TreeItem childItem : item.getChildren()) {
// get cooresponding node in the model
if (i < size) {
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));

children.add(new RandomDynamicTreeNodeModel(this, "child " + System.currentTimeMillis()));
try {
Thread.sleep(100);
} catch (InterruptedException ex) {
Logger.getLogger(MainApp.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
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()) {
String valueToMove = dragEvent.getDragboard().getString();
if (!valueToMove.matches(item.getName())) {
// 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);
String valueToMove = dragEvent.getDragboard().getString();
TreeItem<DynamicTreeNodeModel> itemToMove = search(parentTree.getRoot(), valueToMove);
TreeItem<DynamicTreeNodeModel> newParent = search(parentTree.getRoot(), item.getName());
// 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 String valueToSearch) {
TreeItem<DynamicTreeNodeModel> result = null;
if (currentNode.getValue().getName().matches(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);
}
}
}

在这里,我比较了名称(与 Ithachi 的意见相同)并做了一些调整(检查你的 populateTreeItem(..) 函数并修改它以满足你的需要 - 如果目前它没有)..

为了避免重名,我使用了 system.currentTimemillis 作为节点名称的一部分。

希望对你有帮助

关于java - 拖动 TreeView 的节点,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/22149137/

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