从视图拖放到GEF编辑器

Question

我有一个简单的View，上面有一个代表POJO的TreeViewer。我需要将TreeItem从视图中拖放到 GEF 编辑器（在多页编辑器内）。

当我将项目从查看器拖动到编辑器区域时，将在侦听器中调用创建请求、句柄拖动和更新请求方法。但是当我放下该项目时handleDrop/drop没有被调用。

我的View包含：

Transfer[] types = new Transfer[]{TextTransfer.getInstance()};
treeViewer.addDragSupport(DND.DROP_MOVE, types, new InstructionDragListener(treeViewer));

DragListener如下所示：

public class InstructionDragListener implements DragSourceListener {
    private Viewer viewer;
    public InstructionDragListener(Viewer viewer) {
        this.viewer = viewer;
    }
    @Override
    public void dragStart(DragSourceEvent event) {
        System.out.println("start");
        event.doit = true;
    }
    @Override
    public void dragSetData(DragSourceEvent event) {
        IStructuredSelection selection = (IStructuredSelection) viewer.getSelection();
        Instruction ins=null;
        if (selection.getFirstElement() instanceof Instruction)
            ins = (Instruction) selection.getFirstElement();
        event.data= ins.getID();
        System.out.println("data");
    }
    @Override
    public void dragFinished(DragSourceEvent event) {
        System.out.println("end");
    }
}

编辑器是MultiPageEditor的一部分，如下所示：

public class MyGraphicalEditor extends GraphicalEditorWithFlyoutPalette {
    public static String ID = "MyEditorID";
    public MyGraphicalEditor() {
        setEditDomain(new DefaultEditDomain(this));
    }
    @Override
    protected void initializeGraphicalViewer() {
        super.initializeGraphicalViewer();
        getGraphicalViewer().setContents(ProjectManager.getInstance().getTestCaseTest());
    }
    @Override
    protected void configureGraphicalViewer() {
        super.configureGraphicalViewer();
        getGraphicalViewer().setEditPartFactory(new TestCaseEditPartFactory());
        getGraphicalViewer().addDropTargetListener(new MyTransferTargetDropListener(getGraphicalViewer()));
    }
}

DropListener如下所示：

public class MyTransferTargetDropLsitener extends AbstractTransferDropTargetListener {
    private MyTransferTagetDropFactory factory = new MyTransferTagetDropFactory();
    public MyTransferTargetDropLsitener(EditPartViewer viewer, Transfer xfer) {
        super(viewer, xfer);
    }

    @Override
    protected Request createTargetRequest() {
        System.out.println("CREATE REQUEST");
        CreateRequest request = new CreateRequest();
        request.setFactory(factory);
        return request;
    }
    protected void handleDragOver() {
        System.out.println("HANDLE DRAG");
        super.handleDragOver();
    }
    @Override
    protected void updateTargetRequest() {
        System.out.println("UPDATE REQUEST");
        System.out.println(getDropLocation().toString());
        ((CreateRequest)getTargetRequest()).setLocation(getDropLocation());
    }
    @Override
    protected void handleDrop() {
        System.out.println("DROP HANDLED");
        super.handleDrop();
    }
    @Override
    public void drop(DropTargetEvent event) {
        System.out.println("DROPPED");
        super.drop(event);
    }
}

我错过了什么？

Answer 1

我想通了。

问题是，必须有一个 XYPolicy 安装在 特定AbstractGraphicalEditPart .