NPE javafx.scene.control.behavior.ListViewBehavior.mousePressed

エリック・バラード：

私のポストを表示するために時間を割いていただきありがとうございます。

リストビュー（クリックペインではなく、タイトル）内TitledPaneをクリックするとただしNPEがスローされます - 私は、ListViewコントロールが素晴らしい作品ネストされたTitledPanesでListViewコントロールを実装しています。

意図した領域内でクリックすると、問題なくスムーズに動作します

ここでクリックすると、NPEがスローされます。

コード：

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class Example extends Application {

    @Override
    public void start(final Stage primaryStage) throws Exception {
        final ExpandableListView<Item> listView = new ExpandableListView<Item>();
        listView.setContentProvider(new ExpandableListView.ContentProvider<Item>() {
            @Override
            public String getTitleOf(final Item item) {
                return item.getTitle();
            }

            @Override
            public String getContentOf(final Item item) {
                return item.getContent();
            }
        });
        for (int i = 0; i < 100000; i++) {
            listView.getItems().add(new Item("title" + i, "content" + i));
        }

        final BorderPane group = new BorderPane();
        group.setCenter(listView);
        final Scene scene = new Scene(group);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    public static class Item {

        String title;
        String content;

        public Item(String title, String content) {
            this.title = title;
            this.content = content;
        }

        public String getTitle() {
            return title;
        }

        public String getContent() {
            return content;
        }
    }

    public static void main(String[] args) {
        launch(args);
    }
}



import java.util.HashSet;
import java.util.Set;

import javafx.collections.ObservableList;
import javafx.event.EventHandler;
import javafx.scene.control.ListCell;
import javafx.scene.control.ListView;
import javafx.scene.control.TitledPane;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.text.Text;
import javafx.util.Callback;

public class ExpandableListView<E> extends ListView<E> {

    private ContentProvider<E> contentProvider=new ContentProvider<E>(){@Override public String getTitleOf(final E item){return item.toString();}

    @Override public String getContentOf(final E item){return getTitleOf(item);}};

    private final Set<E> expandedItems = new HashSet<E>();

    public ExpandableListView() {
        setSelectionModel(null);
        setCellFactory(new Callback<ListView<E>, ListCell<E>>() {
            @Override
            public ListCell<E> call(final ListView<E> param) {
                final TitledPane titledPane = new TitledPane();
                final Text contentArea = new Text();

                titledPane.setAnimated(false);
                titledPane.setCollapsible(true);
                titledPane.setExpanded(false);

                final BorderPane contentAreaWrapper = new BorderPane();
                contentAreaWrapper.setLeft(contentArea);
                titledPane.setContent(contentAreaWrapper);

                titledPane.addEventHandler(MouseEvent.MOUSE_CLICKED, new EventHandler<MouseEvent>() {
                    @Override
                    public void handle(final MouseEvent event) {
                        final boolean expanded = titledPane.isExpanded();
                        final E item = (E) titledPane.getUserData();
                        if (item == null) {
                            return;
                        }
                        if (expanded) {
                            expandedItems.add(item);
                        } else {
                            expandedItems.remove(item);
                        }
                    }
                });
                return new ListCell<E>() {
                    @Override
                    protected void updateItem(final E item, final boolean empty) {
                        super.updateItem(item, empty);
                        if (empty) {
                            titledPane.setText("");
                            contentArea.setText("");
                            return;
                        }
                        final boolean expanded = isExpanded(item);
                        titledPane.setUserData(item);
                        titledPane.setExpanded(expanded);
                        titledPane.setText(contentProvider.getTitleOf(item));
                        contentArea.setText(contentProvider.getContentOf(item));
                        setGraphic(titledPane);
                    }
                };
            }
        });

    }

    public void setContentProvider(final ContentProvider<E> contentProvider) {
        this.contentProvider = contentProvider;
    }

    public void expand(E item) {
        expand(item, true);
    }

    public void collapse(E item) {
        expand(item, false);
    }

    private void expand(E item, boolean expand) {
        if (expand) {
            this.expandedItems.add(item);
        } else {
            this.expandedItems.remove(item);
        }

        ObservableList<E> o = getItems();
        setItems(null);
        setItems(o);
    }

    public boolean isExpanded(E item) {
        return this.expandedItems.contains(item);
    }

    public static interface ContentProvider<E> {

        String getTitleOf(E item);

        String getContentOf(E item);

    }
}

NAME：

java.lang.NullPointerException
at com.sun.javafx.scene.control.behavior.ListViewBehavior.mousePressed(ListViewBehavior.java:366)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:95)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:394)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$2(GlassViewEventHandler.java:432)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:410)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:431)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$3(WinApplication.java:177)
at java.lang.Thread.run(Unknown Source)

Przemek Krysztofiak：

NullPointerExceptionがラインによって引き起こされます。

setSelectionModel(null);

独自の、カスタムの提供なし選択モデルを。