Showing NatTable context menu

问题:

I use NatTable. How to show context menu item on certain condition depending on the content of the cell? And how to select cell over which context menu was called? I bind menu with the following code

uiBindingRegistry.registerMouseDownBinding(
            new MouseEventMatcher(SWT.NONE, null, MouseEventMatcher.RIGHT_BUTTON), new PopupMenuAction(menu));

UPD: I create menu like this, but 'Test' item is visible in spite of isActive always return false. What's wrong with it?

menu = new PopupMenuBuilder(natTable).withMenuItemProvider(ITEM_ID, new IMenuItemProvider() {
        @Override
        public void addMenuItem(final NatTable natTable, final Menu popupMenu) {
            final MenuItem menuItem = new MenuItem(popupMenu, SWT.PUSH);
            menuItem.setText("Test");
            menuItem.setEnabled(true);
            menuItem.addSelectionListener(new SelectionAdapter() {
                @Override
                public void widgetSelected(final SelectionEvent event) {
                    System.out.println("test");
                }
            });
        }
    }).withVisibleState(ITEM_ID, new IMenuItemState() {
        @Override
        public boolean isActive(final NatEventData natEventData) {
            return false;
        }
    }).build();

回答1:

The given answer is correct. Although it can be improved. You don't need the SelectionLayer.

class CellPopupMenuAction implements IMouseAction {

    private final Menu menu;

    public CellPopupMenuAction(Menu menu) {
        this.menu = menu;
    }

    @Override
    public void run(NatTable natTable, MouseEvent event) {
        int columnPosition = natTable.getColumnPositionByX(event.x);
        int rowPosition = natTable.getRowPositionByY(event.y);

        ILayerCell cell = natTable.getCellByPosition(columnPosition, rowPosition);

        if (!cell.getDisplayMode().equals(DisplayMode.SELECT)) {
            natTable.doCommand(
                    new SelectCellCommand(
                            natTable,
                            columnPosition,
                            rowPosition,
                            false,
                            false));
        }

        menu.setData(MenuItemProviders.NAT_EVENT_DATA_KEY, event.data);
        menu.setVisible(true);
    }
}

This way you completely remove the need to reference the SelectionLayer and even improve the functionality because the SelectCellCommand is never fired if you right click on a selected cell.

回答2:

You need IMouseAction to select cell. An example code from here and some additional code added inside it to select call added over it below :

nattable.addConfiguration( new AbstractUiBindingConfiguration()

    uiBindingRegistry.registerMouseDownBinding( new MouseEventMatcher( SWT.NONE, GridRegion.BODY,
                            MouseEventMatcher.RIGHT_BUTTON ), new CellPopupMenuAction(menu, selectionLayer) );


});

class CellPopupMenuAction implements IMouseAction {

                private final Menu menu;
                private final SelectionLayer selectionLayer;

                public CellPopupMenuAction(Menu menu, SelectionLayer selectionLayer) {
                    this.menu = menu;
                    this.selectionLayer = selectionLayer;
                }

                @Override
                public void run(NatTable natTable, MouseEvent event) 
                {
                    if( selectionLayer.getSelectedRowCount() <= 1 )
                            {
                                int colPosition = LayerUtil.convertColumnPosition( natTable,
                                        natTable.getColumnPositionByX( event.x ), selectionLayer );
                                int rowPosition = LayerUtil.convertRowPosition( natTable,
                                        natTable.getRowPositionByY( event.y ), selectionLayer );

                                natTable.doCommand( new SelectCellCommand( selectionLayer, colPosition, rowPosition, false,
                                        false ) );
                            }
                    menu.setData(event.data);
                    menu.setVisible(true);
                }
            }

I assume you have the selectionLayer as a private variable in your code.

回答3:

I used SomeDude's answer above and it worked but the menu item was displaying before the selection which looked odd. I moved the menu display to a UI thread asyncExec call and selection occurs first then the menu appears on top of it -

@Override
public void run(NatTable natTable, MouseEvent event) {

    if (selectionLayer.getSelectedRowCount() <= 1) {

        int colPosition = LayerUtil.convertColumnPosition(natTable, natTable.getColumnPositionByX(event.x),
                selectionLayer);

        int rowPosition = LayerUtil.convertRowPosition(natTable, natTable.getRowPositionByY(event.y),
                selectionLayer);

        natTable.doCommand(new SelectCellCommand(selectionLayer, colPosition, rowPosition, false, false));

    }

    Display.getDefault().asyncExec(new Runnable() {
        public void run() {
            menu.setData(event.data);
            menu.setVisible(true);
        }
    });

}