Vaadin Grid的進入/離開編輯模式的監聽器？

Question

我想在vaadin網格進入編輯模式時啓用/禁用某些複選框。

不幸的是我找不到正確的鉤子。我得到的最接近的是SelectionListener，但它與編輯模式不匹配。

grid.addSelectionListener(new SelectionListener() { ... }); 

當網格進入編輯模式時，有沒有什麼辦法讓事件發生？

Answer 1

對於Vaadin 8

對於Vaadin 8你可以擴展Grid，並返回一個自定義Editor（據我所看到的，目前還沒有用於捕獲啓動事件實現監聽器）。

此外，您可以添加取消&保存監聽器（已由框架實現）以查看編輯器是否已關閉。

---

CustomEditor.java

public class CustomEditor<T> extends EditorImpl<T> { 

    private EventRouter eventRouter = new EventRouter(); 

    public CustomEditor(PropertySet<T> propertySet) { 
    super(propertySet); 
    } 

    public Registration addStartListener(EditorStartListener<T> listener) { 
    return eventRouter.addListener(EditorStartEvent.class, listener, 
            EditorStartListener.class.getDeclaredMethods()[0]); 
    } 

    @Override 
    protected void doEdit(T bean) { 
    super.doEdit(bean); 
    fireToggleEvent(bean); 
    } 

    private void fireToggleEvent(T bean) { 
    eventRouter.fireEvent(new EditorStartEvent<>(this, bean)); 
    } 
} 

---

EditorStartListener.java

@FunctionalInterface 
public interface EditorStartListener<T> extends Serializable { 

    void onEditorStart(EditorStartEvent<T> event); 
} 

---

EditorStartEvent.java

public class EditorStartEvent<T> extends EventObject { 

    private T bean; 

    public EditorStartEvent(Editor<T> editor, T bean) { 
    super(editor); 
    this.bean = bean; 
    } 

    @SuppressWarnings("unchecked") 
    @Override 
    public Editor<T> getSource() { 
    return (Editor<T>) super.getSource(); 
    } 

    public Grid<T> getGrid() { 
    return getSource().getGrid(); 
    } 

    public T getBean() { 
    return bean; 
    } 
} 

---

CustomGrid.java

public class CustomGrid<T> extends Grid<T> { 

    private PropertySet<T> propertySet; 

    public CustomGrid() { 
    super(); 
    } 

    // Other constructors omitted for clarity 

    @Override 
    protected void setPropertySet(PropertySet<T> propertySet) { 
    this.propertySet = propertySet; 
    super.setPropertySet(propertySet); 
    } 

    @Override 
    protected Editor<T> createEditor() { 
    return new CustomEditor<T>(propertySet); 
    } 
} 

---

用法：

Grid<Person> grid = new CustomGrid<>(); 
CustomEditor<Person> editor = (CustomEditor<Person>) grid.getEditor(); 
editor.setEnabled(true); 
editor.addStartListener(event -> System.out.println("Editor started!")); 

對於Vaadin 7

對於Vaadin 7你可以覆蓋的方法doEditItem()，並使用與上述相同的方法來添加這裏聽衆：

---

EditStartListener.java

public interface EditStartListener extends Serializable { 

    public static final Method EDIT_START_METHOD = ReflectTools.findMethod(EditStartListener.class, "editStart", EditStartEvent.class); 

    public void editStart(EditStartEvent event); 

} 

---

EditStartEvent.java

public class EditStartEvent extends Component.Event { 

    public EditStartEvent(Component source) { 
     super(source); 
    } 

    public Grid getGrid() { 
     return (Grid) getSource(); 
    } 
} 

---

CustomGrid。java

public class CustomGrid extends Grid { 

    public void addEditStartListener(EditStartListener listener) { 
     addListener(EditStartEvent.class, listener, EditStartListener.EDIT_START_METHOD); 
    } 

    @Override 
    protected void doEditItem() { 
     super.doEditItem(); 
     fireEvent(new EditStartEvent(this)); 
    } 
}