停止ListView所选项目的更改，直到按下按钮 [英] Stop ListView selected item from changing until button pressed
本文介绍了停止ListView所选项目的更改，直到按下按钮的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
所以我在我想要创建的应用程序中遇到问题。我创建了一个示例应用程序来演示此问题。在应用程序中，我试图停止 TableView 中的所选项目，如果未在 TextField 。在我的实现中，我得到一个 StackOverFlow 错误。我理解为什么我收到错误。我基本上创建了一个无限循环，但我想不出另一种方法来解决这个问题。
So I am having a problem in an app I am trying to create. I have created a sample app to demonstrate the problem. In the app, I am trying to stop the selected item in the TableView from changing if enter is not pressed on a TextField. In my implementation, I am getting a StackOverFlow error. I understand why I am getting the error. I am basically creating an infinite loop, but I can't think of another way to approach this problem.
如果删除这行代码：
if(!validateTextFields())
{
tvPerson.getSelectionModel().select(oldPerson);
return;
}
如果选择表格行然后编辑 TextField 中的文本，然后按 TextField 上的Enter键。但是，如果您选择一个表行，编辑 TextField 并且不按Enter键，则用户可以选择一个新表行而不更新他/她正在尝试的表行编辑。所以我的问题是，如果他/她没有确认 TextField ，如何阻止用户更改 selectedItem 按Enter键进行编辑。
The app works like it's designed if you select a table row and then edit the text in the TextField and press enter on the TextField. Though, if you select a table row, edit the TextField and don't press enter, the user can select a new table row without updating the table row he/she was trying to edit. So my questions, how do I stop the user from changing the selectedItem if he/she hasn't confirmed the TextField edit by pressing enter.
控制器
Controller
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.ResourceBundle;
import javafx.collections.FXCollections;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.control.cell.PropertyValueFactory;
/**
*
* @author Sedrick
*/
public class FXMLDocumentController implements Initializable {
@FXML TextField tfFirstName, tfLastName;
@FXML TableView<Person> tvPerson;
@FXML TableColumn<Person, String> tcFirstName, tcLastName;
final String firstNames = "Darryl \n" +
"Enriqueta \n" +
"Katherine \n" +
"Harley \n" +
"Arlean \n" +
"Jacquelynn \n" +
"Yuko \n" +
"Dion \n" +
"Vivan \n" +
"Carly \n" +
"Eldon \n" +
"Joe \n" +
"Klara \n" +
"Shona \n" +
"Delores \n" +
"Sabra \n" +
"Vi \n" +
"Gearldine \n" +
"Laine \n" +
"Lila ";
final String lastNames = "Ollie \n" +
"Donnette \n" +
"Audra \n" +
"Angelica \n" +
"Janna \n" +
"Lekisha \n" +
"Michael \n" +
"Tomi \n" +
"Cheryl \n" +
"Roni \n" +
"Aurelio \n" +
"Mayola \n" +
"Kelsie \n" +
"Britteny \n" +
"Dannielle \n" +
"Kym \n" +
"Scotty \n" +
"Deloris \n" +
"Lavenia \n" +
"Sun \n";
@Override
public void initialize(URL url, ResourceBundle rb) {
// TODO
tcFirstName.setCellValueFactory(new PropertyValueFactory("firstName"));
tcLastName.setCellValueFactory(new PropertyValueFactory("lastName"));
tvPerson.setItems(FXCollections.observableArrayList(getPersons()));
tvPerson.getSelectionModel().selectedItemProperty().addListener((obs, oldPerson, newPerson)->{
if(!validateTextFields())
{
tvPerson.getSelectionModel().select(oldPerson);
return;
}
if(newPerson != null)
{
tfFirstName.setText(newPerson.getFirstName());
tfLastName.setText(newPerson.getLastName());
}
});
tfFirstName.setOnKeyReleased(keyEvent ->{
Person tempPerson = tvPerson.getSelectionModel().getSelectedItem();
if(!tfFirstName.getText().trim().equals(tempPerson.getFirstName().trim()))
{
tfFirstName.setStyle("-fx-control-inner-background: red;");
}
});
tfFirstName.setOnAction(actionEvent ->{
Person tempPerson = tvPerson.getSelectionModel().getSelectedItem();
tempPerson.setFirstName(tfFirstName.getText().trim());
tfFirstName.setStyle(null);
});
tfLastName.setOnKeyReleased(keyEvent ->{
Person tempPerson = tvPerson.getSelectionModel().getSelectedItem();
if(tfLastName.getText().trim().equals(tempPerson.getLastName().trim()))
{
tfLastName.setStyle("-fx-control-inner-background: red;");
}
});
tfLastName.setOnAction(actionEvent ->{
Person tempPerson = tvPerson.getSelectionModel().getSelectedItem();
tempPerson.setLastName(tfLastName.getText().trim());
tfLastName.setStyle(null);
});
}
private boolean validateTextFields()
{
if(!tfFirstName.getStyle().isEmpty()){return false;}
if(!tfLastName.getStyle().isEmpty()){return false;}
return true;
}
List<Person> getPersons()
{
List<Person> tempPerson = new ArrayList();
List<String> tempFirstName = Arrays.asList(firstNames.split("\n"));
List<String> tempLastName = Arrays.asList(lastNames.split("\n"));
for(int i = 0; i < tempFirstName.size(); i++)
{
tempPerson.add(new Person(tempFirstName.get(i).trim(), tempLastName.get(i).trim()));
}
return tempPerson;
}
}
FXML
FXML
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.TableColumn?>
<?import javafx.scene.control.TableView?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.VBox?>
<AnchorPane id="AnchorPane" prefHeight="575.0" prefWidth="836.0" xmlns="http://javafx.com/javafx/8.0.60" xmlns:fx="http://javafx.com/fxml/1" fx:controller="javafxapplication17.FXMLDocumentController">
<children>
<VBox layoutX="7.0" prefHeight="200.0" prefWidth="100.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<children>
<VBox prefHeight="200.0" prefWidth="100.0" spacing="5.0" VBox.vgrow="ALWAYS">
<children>
<HBox spacing="5.0">
<children>
<Label prefHeight="31.0" prefWidth="72.0" text="First Name" />
<TextField fx:id="tfFirstName" />
</children>
</HBox>
<HBox spacing="5.0">
<children>
<Label prefHeight="31.0" prefWidth="72.0" text="Last Name" />
<TextField fx:id="tfLastName" />
</children>
</HBox>
</children>
<padding>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</padding>
</VBox>
<TableView fx:id="tvPerson" prefHeight="200.0" prefWidth="200.0">
<columns>
<TableColumn fx:id="tcFirstName" prefWidth="108.0" text="First Name" />
<TableColumn fx:id="tcLastName" prefWidth="110.0" text="Last Name" />
</columns>
<VBox.margin>
<Insets />
</VBox.margin>
<padding>
<Insets bottom="5.0" left="5.0" right="5.0" top="5.0" />
</padding>
</TableView>
</children>
</VBox>
</children>
</AnchorPane>
Person Class
Person Class
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
/**
*
* @author Sedrick
*/
public class Person {
StringProperty firstName = new SimpleStringProperty();
StringProperty lastName = new SimpleStringProperty();
public Person(String firstName, String lastName)
{
this.firstName.set(firstName);
this.lastName.set(lastName);
}
public StringProperty firstNameProperty()
{
return firstName;
}
public String getFirstName()
{
return firstName.get();
}
public void setFirstName(String firstName)
{
this.firstName.set(firstName);
}
public StringProperty lastNameProperty()
{
return lastName;
}
public String getLastName()
{
return lastName.get();
}
public void setLastName(String firstName)
{
this.lastName.set(firstName);
}
}
异常
Exception
Exception in thread "JavaFX Application Thread" java.lang.StackOverflowError
at javafx.collections.ListChangeBuilder.findSubChange(ListChangeBuilder.java:62)
at javafx.collections.ListChangeBuilder.insertAdd(ListChangeBuilder.java:127)
at javafx.collections.ListChangeBuilder.nextAdd(ListChangeBuilder.java:254)
at javafx.collections.ObservableListBase.nextAdd(ObservableListBase.java:179)
at javafx.collections.transformation.SortedList.setAllToMapping(SortedList.java:354)
at javafx.collections.transformation.SortedList.addRemove(SortedList.java:397)
at javafx.collections.transformation.SortedList.sourceChanged(SortedList.java:108)
at javafx.collections.transformation.TransformationList.lambda$getListener$23(TransformationList.java:106)
at javafx.collections.WeakListChangeListener.onChanged(WeakListChangeListener.java:88)
at com.sun.javafx.collections.ListListenerHelper$SingleChange.fireValueChangedEvent(ListListenerHelper.java:164)
at com.sun.javafx.collections.ListListenerHelper.fireValueChangedEvent(ListListenerHelper.java:73)
at javafx.collections.ObservableListBase.fireChange(ObservableListBase.java:233)
at javafx.collections.ListChangeBuilder.commit(ListChangeBuilder.java:482)
at javafx.collections.ListChangeBuilder.endChange(ListChangeBuilder.java:541)
at javafx.collections.ObservableListBase.endChange(ObservableListBase.java:205)
at javafx.collections.ModifiableObservableListBase.add(ModifiableObservableListBase.java:155)
at java.util.AbstractList.add(AbstractList.java:108)
at com.sun.javafx.scene.control.SelectedCellsMap.add(SelectedCellsMap.java:118)
at javafx.scene.control.TableView$TableViewArrayListSelectionModel.select(TableView.java:2456)
at javafx.scene.control.TableView$TableViewArrayListSelectionModel.select(TableView.java:2427)
at javafx.scene.control.TableView$TableViewArrayListSelectionModel.select(TableView.java:2485)
at javafxapplication17.FXMLDocumentController.lambda$initialize$0(FXMLDocumentController.java:83)
at com.sun.javafx.binding.ExpressionHelper$SingleChange.fireValueChangedEvent(ExpressionHelper.java:182)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
at javafx.beans.property.ReadOnlyObjectPropertyBase.fireValueChangedEvent(ReadOnlyObjectPropertyBase.java:74)
at javafx.beans.property.ReadOnlyObjectWrapper.fireValueChangedEvent(ReadOnlyObjectWrapper.java:102)
at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112)
at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146)
at javafx.scene.control.SelectionModel.setSelectedItem(SelectionModel.java:102)
at javafx.scene.control.MultipleSelectionModelBase.lambda$new$34(MultipleSelectionModelBase.java:67)
at com.sun.javafx.binding.ExpressionHelper$SingleInvalidation.fireValueChangedEvent(ExpressionHelper.java:137)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
at javafx.beans.property.ReadOnlyIntegerPropertyBase.fireValueChangedEvent(ReadOnlyIntegerPropertyBase.java:72)
at javafx.beans.property.ReadOnlyIntegerWrapper.fireValueChangedEvent(ReadOnlyIntegerWrapper.java:102)
at javafx.beans.property.IntegerPropertyBase.markInvalid(IntegerPropertyBase.java:113)
at javafx.beans.property.IntegerPropertyBase.set(IntegerPropertyBase.java:147)
at javafx.scene.control.SelectionModel.setSelectedIndex(SelectionModel.java:68)
at javafx.scene.control.TableView$TableViewArrayListSelectionModel.updateSelectedIndex(TableView.java:2945)
at javafx.scene.control.TableView$TableViewArrayListSelectionModel.select(TableView.java:2458)
at javafx.scene.control.TableView$TableViewArrayListSelectionModel.select(TableView.java:2427)
at javafx.scene.control.TableView$TableViewArrayListSelectionModel.select(TableView.java:2485)
at javafxapplication17.FXMLDocumentController.lambda$initialize$0(FXMLDocumentController.java:83)
at com.sun.javafx.binding.ExpressionHelper$SingleChange.fireValueChangedEvent(ExpressionHelper.java:182)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
at javafx.beans.property.ReadOnlyObjectPropertyBase.fireValueChangedEvent(ReadOnlyObjectPropertyBase.java:74)
at javafx.beans.property.ReadOnlyObjectWrapper.fireValueChangedEvent(ReadOnlyObjectWrapper.java:102)
at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112)
at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146)
at javafx.scene.control.SelectionModel.setSelectedItem(SelectionModel.java:102)
at javafx.scene.control.MultipleSelectionModelBase.lambda$new$34(MultipleSelectionModelBase.java:67)
at com.sun.javafx.binding.ExpressionHelper$SingleInvalidation.fireValueChangedEvent(ExpressionHelper.java:137)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
异常很长，所以我发布了一个简短的版本。
The exception is really long so I on posted a short version.
推荐答案
基本上，正确的方法是自定义selectionModel，它具有要禁用的属性，并且在该状态下不执行任何操作。不幸的是，selectionModels不是为自定义类扩展/替换而设计的。此外，在表格控件中选择的共同祖先是MultipleSelectionModelBase，它既完全隐藏又极其错误。因此，制作自定义模型的机会是......不是很好。
Basically, the "correct" approach would be a custom selectionModel that has a property to be disabled and does nothing in that state. Unfortunately, selectionModels are not designed for being extended/replaced by custom classes. Plus the common ancestor for selection in tabular controls is MultipleSelectionModelBase which is both entirely hidden and extremely buggy. So the chances to make a custom model behave are ... not very good.
尽管如此，它可能（并且投资足够的能量和资源甚至可以可靠地工作;）：实现一个自定义的TableViewSelectionModel，它委托默认的实现TableViewBitSelectionModel（一个）它从TableView获取，保持与它同步并将自己安装到表中。
Nevertheless, it might be possible (and with investing enough enery and resources might even work reliably ;): implement a custom TableViewSelectionModel that delegates to the default implementation TableViewBitSelectionModel (the one it grabs from the TableView), keeps itself in synch with that and installs itself to the table.
类似于：
public static class VetoableSelection<T> extends TableViewSelectionModel<T> {
private boolean disabled;
private TableViewSelectionModel<T> delegate;
public VetoableSelection(TableView<T> table) {
super(table);
delegate = table.getSelectionModel();
table.setSelectionModel(this);
new VetoableFocusModel<>(table);
delegate.selectedIndexProperty().addListener(c -> indexInvalidated());
}
/**
* keep selectedIndex in sync
*/
private void indexInvalidated() {
setSelectedIndex(delegate.getSelectedIndex());
}
/**
* Does nothing if disabled.
*/
public void setDisabled(boolean disabled) {
this.disabled = disabled;
}
public boolean isDisabled() {
return disabled;
}
/**
* Override all state changing methods to delegate
* if not disabled, do nothing if disabled.
* Here: row selection.
*/
@Override
public void clearAndSelect(int row) {
if (isDisabled()) return;
delegate.clearAndSelect(row);
}
@Override
public void select(int row) {
if (isDisabled()) return;
delegate.select(row);
}
/**
* Here: methods with columns
*/
@Override
public void clearAndSelect(int row, TableColumn<T, ?> column) {
if (isDisabled()) return;
delegate.clearAndSelect(row, column);
}
@Override
public void select(int row, TableColumn<T, ?> column) {
if (isDisabled()) return;
delegate.select(row, column);
}
...
与您的粗略支票示例似乎正在工作，有点：如果未提交修改后的textFields，则不允许更改选择。有些问题没有显示处于选定状态的单元格以及动态添加/删除人员......可能还有很多其他情境。
A crude check with your example seems to be working, kind of: it does not allow the selection to change if the modified textFields are not committed. There are problems in not showing the cells in selected state and with dynamic add/remove persons and ... probably with a whole bunch of other contexts.
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