如何在JavaFX中将焦点侦听器放在Treecell上?
我正在构建一个am应用程序,在这个应用程序中,我需要在显示数据的窗格旁边有一个树状视图。当有人在树状视图中选择一个项目时,应用程序必须确定他们选择了什么,并从数据库中查找正确的数据,然后以我选择的格式显示它。无论用户如何在树状视图中选择项目(鼠标单击、选项卡、箭头键等),只要当项目获得焦点时,就会触发一个方法向用户显示数据 我只通过以下方式实现了鼠标点击的完美效果:如何在JavaFX中将焦点侦听器放在Treecell上?,java,javafx,treeview,listener,cell,Java,Javafx,Treeview,Listener,Cell,我正在构建一个am应用程序,在这个应用程序中,我需要在显示数据的窗格旁边有一个树状视图。当有人在树状视图中选择一个项目时,应用程序必须确定他们选择了什么,并从数据库中查找正确的数据,然后以我选择的格式显示它。无论用户如何在树状视图中选择项目(鼠标单击、选项卡、箭头键等),只要当项目获得焦点时,就会触发一个方法向用户显示数据 我只通过以下方式实现了鼠标点击的完美效果: // Application thread method to build the tree map, used in t
// Application thread method to build the tree map, used in the generateTree
// method.
public void treeBuilder(TreeMap<ModelSites, ArrayList<ModelPlants>> map) {
TreeMap<ModelSites, ArrayList<ModelPlants>> treeMap = map;
final TreeItemProperties<String, String> rootTreeItem = new TreeItemProperties<String, String>("EMT", null);
TreeItemProperties<String, Integer> site = null;
TreeItemProperties<String, Integer> plant = null;
for (Map.Entry<ModelSites, ArrayList<ModelPlants>> entry : treeMap.entrySet()) {
site = new TreeItemProperties<String, Integer>(entry.getKey().getLongName(), entry.getKey().getPrimaryKey());
rootTreeItem.getChildren().add(site);
if (site.getValue().equalsIgnoreCase("test item")) {
site.setExpanded(true);
}
for (int i = 0; i < entry.getValue().size(); i++) {
plant = new TreeItemProperties<String, Integer>(entry.getValue().get(i).getSitePlantId() + " " + entry.getValue().get(i).getShortName(), entry.getValue().get(i).getPrimaryKey());
site.getChildren().add(plant);
}
}
//Cell Factory is used to effectively turn the tree items into nodes, which they are not natively.
//This is necessary to have actions linked to the tree items (eg. double click an item to open an edit window).
emtTree.setCellFactory(new Callback<TreeView<String>, TreeCell<String>>() {
@Override
public TreeCell<String> call(TreeView<String> param) {
FactoryTreeCell<String> cell = new FactoryTreeCell<String>();
cell.setOnMouseClicked(event -> {
if (!cell.isEmpty()) {
@SuppressWarnings("unchecked")
TreeItemProperties<String, Integer> treeItem = (TreeItemProperties<String, Integer>) cell.getTreeItem();
generateEquipmentPanes(treeItem.getPropertyValue());
}
});
return cell;
}
});
rootTreeItem.setExpanded(true);
emtTree.setRoot(rootTreeItem);
}
// Populate the main screen with all equipment items in the selected plant.
public void generateEquipmentPanes(int plantId) {
int plant = plantId;
Task<LinkedList<ModelEquipment>> task = new Task<LinkedList<ModelEquipment>>() {
@Override
public LinkedList<ModelEquipment> call() {
LinkedList<ModelEquipment> equipmentList = DAOEquipment.listEquipmentByPlant(plant);
return equipmentList;
}
};
// When list is built successfully, send the results back to the application
// thread to load the equipment panes in the GUI.
task.setOnSucceeded(e -> equipmentPaneBuilder(task.getValue()));
task.setOnFailed(e -> task.getException().printStackTrace());
task.setOnCancelled(null);
String methodName = new Object() {}.getClass().getEnclosingMethod().getName();
Thread thread = new Thread(task);
thread.setName(methodName);
//System.out.println("Thread ID: " + thread.getId() + ", Thread Name: " + thread.getName());
thread.setDaemon(true);
thread.start();
}
// Application thread method to build the equipment panes, used in the
// generateEquipmentPanes method.
public void equipmentPaneBuilder(LinkedList<ModelEquipment> list) {
LinkedList<ModelEquipment> equipmentList = list;
EquipmentPanels.getChildren().clear();
for (int i = 0; i < equipmentList.size(); i++) {
ModelEquipment item = equipmentList.get(i);
try {
PaneEquipment equipmentPane = new PaneEquipment();
equipmentPane.updateFields(item.getTechId(), item.getShortName(), item.getLongDesc()); equipmentPane.setId("equipPane" + i);
EquipmentPanels.getChildren().add(equipmentPane);
} catch (Exception e) {
e.printStackTrace();
}
}
}
我注意到的另一件事是,还有其他实现回调的方法,这可能对侦听器更有效,但我不知道如何实现
我已经在这个问题上纠缠了很久,所以有一个突破是很好的。您不应该使用树单元来检查所选的值。您的ChangeListener已直接接收新值:
emtTree.getSelectionModel().selectedItemProperty().addListener(
(observable, oldSelection, newSelection) -> {
if (newSelection != null) {
TreeItemProperties<String, Integer> treeItem = newSelection;
generateEquipmentPanes(treeItem.getPropertyValue());
}
});
请…也许我误解了什么,但是如果你的目标只是观察选择了哪个项目,那么为什么不使用?谢谢,这让我又开始了。这段代码为newSelection提供了一个类型不匹配,因此我必须将其转换为匹配treeItem,作为一个解决方法TreeItemProperties treeItem=TreeItemProperties newSelection;。到目前为止,它似乎工作正常,我将用它进行更多的实验,以确保它在每个树级别上给出正确的结果。
cell.focusedProperty().addListener(new ChangeListener<Boolean>() {
@Override
public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
if (!cell.isEmpty()) {
@SuppressWarnings("unchecked")
TreeItemProperties<String, Integer> treeItem = (TreeItemProperties<String, Integer>) cell.getTreeItem();
generateEquipmentPanes(treeItem.getPropertyValue());
}
}
});
import javafx.scene.control.TreeCell;
public class FactoryTreeCell<T> extends TreeCell<T> {
public FactoryTreeCell() {
}
/*
* The update item method simply displays the cells in place of the tree items (which disappear when setCellFactory is set.
* This can be used for many more things (such as customising appearance) not implemented here.
*/
@Override
protected void updateItem(T item, boolean empty) {
super.updateItem(item, empty);
if (empty || item == null) {
setText(null);
setGraphic(null); //Note that a graphic can be many things, not just an image. Refer openJFX website for more details.
} else {
setText(item.toString());
}
}
}
emtTree.getSelectionModel().selectedItemProperty().addListener(
(observable, oldSelection, newSelection) -> {
if (newSelection != null) {
TreeItemProperties<String, Integer> treeItem = newSelection;
generateEquipmentPanes(treeItem.getPropertyValue());
}
});