Question

我是JavaFX的新手，因此也是TornadoFX的新手，所以请耐心等待。

我有一个简单的Java应用程序，但是想把它移到Kotlin，并且遇到了在TornadoFX中找到相应机制的问题。我有一个ListView持有IStoryItem代表Stories和Chapters的实现。我希望能够将章节移动到一个故事，甚至从一个故事到另一个故事。 Java中的TreeView在其setCellFactory调用中具有以下实现：

    tv.setCellFactory(new Callback<TreeView<IStoryItem>, TreeCell<IStoryItem>>() {
        @Override
        public TreeCell<IStoryItem> call(TreeView<IStoryItem> siTreeView) {
            TreeCell<IStoryItem> cell = new TreeCellStoryEditor();

            cell.setOnDragDetected((MouseEvent event) -> {
                // Don't drag Story nodes.
                if (cell.getItem() instanceof Story) return;

                Dragboard db = cell.startDragAndDrop(TransferMode.MOVE);

                // Put the Part on the dragboard
                // From: https://stackoverflow.com/a/30916660/780350
                ClipboardContent content = new ClipboardContent();
                content.put(objectDataFormat, cell.getItem());
                db.setContent(content);

                event.consume();
            });

            cell.setOnDragOver((DragEvent event) -> {
                if (event.getGestureSource() != cell && event.getDragboard().hasContent(objectDataFormat)) {
                    /* allow for moving */
                    event.acceptTransferModes(TransferMode.MOVE);
                }

                event.consume();
            });

            cell.setOnDragEntered((DragEvent event) -> {
                IStoryItem item = cell.getItem();
                if (item instanceof Story &&
                        event.getGestureSource() != cell &&
                        event.getDragboard().hasContent(objectDataFormat)) {
                    cell.setUnderline(true);
                }

                event.consume();
            });

            cell.setOnDragExited((DragEvent event) -> {
                cell.setUnderline(false);
                event.consume();
            });

            cell.setOnDragDropped((DragEvent event) -> {
                try {
                    Dragboard db = event.getDragboard();
                    boolean success = false;
                    if (db.hasContent(objectDataFormat)) {
                        Part droppedPart = (Part)db.getContent(objectDataFormat);
                        IStoryItem targetStoryItem = cell.getItem();

                        // Question: How to handle drops between leaf items or
                        // before the initial leaf or after the final leaf.
                        if (targetStoryItem instanceof Story) {
                            Story story = (Story) targetStoryItem;

                            updateStoryWith(droppedPart, story);
                            addPartTo(cell.getTreeItem(), droppedPart);
                            success = true;
                        }
                    }

                    event.setDropCompleted(success);
                    event.consume();
                } catch (Exception e) {
                    System.out.println(e.getMessage());
                }
            });

            cell.setOnDragDone((DragEvent event) -> {
                if (event.getTransferMode() == TransferMode.MOVE) {
                    IStoryItem item = cell.getItem();
                    TreeItem<IStoryItem> ti = cell.getTreeItem();
                    TreeItem<IStoryItem> pti = ti.getParent();
                    pti.getChildren().remove(ti);

                    IStoryItem psi = pti.getValue();
                    // Remove the Part/Chapter from its previous Story
                    boolean removed = removePartFrom(psi, item);
                }
                event.consume();
            });

            cell.setEditable(true);

            return cell;
        };
    });

我在TornadoFX中寻找类似的东西，却找不到任何看起来有用的东西。我已经在使用cellFormat构建器，但我无法弄清楚如何在其中添加事件处理程序。我从IntelliJ的intellisense中看到，还有一个cellFactory构建器，但我不知道如何使用它或如何向它添加事件处理程序。

Answer 1

您可以在TornadoFX中使用完全相同的技术。请记住，TornadoFX只是在JavaFX之上应用高级API。您始终可以毫无问题地访问底层JavaFX API。

tv.setCellFactory {
    object : TreeCell<IStoryItem>() {
        init {
            setOnDragOver { event ->

            }
            setOnDragEntered { event ->

            }
            setOnDragExited { event ->

            }
            setOnDragDropped { event ->

            }
        }
    }
}

TornadoFX在TreeView上拖放

1 个答案: