如何仅冻结SWT NatTable中可见的列？

Question

我现在让列/行冻结工作到可以右键单击列/行标题，然后单击“冻结”，它将冻结我单击的列和左边的所有列。问题是，如果我向右滚动，然后单击如列索引20 (实际上是任何隐藏了左侧索引的索引)，它将冻结该索引以下的所有列，这将导致表恢复到索引0，而不允许我滚动(因为冻结的列比显示的列多)。如何只冻结我单击的列左边的可见列？我偶然发现了IFreezeCoordinatesProvider，并试图用它做一些厚颜无耻的事情，但没有结果。下面是我创建右键菜单的自定义配置，其中包含冻结命令。任何帮助都是非常感谢的！

public class ColumnHeaderRightClickConfiguration extends AbstractUiBindingConfiguration{

private final ViewportLayer viewportLayer;
private final CompositeFreezeLayer freezeLayer;
private Menu rightClickMenu;

private int localColumnIndex;
private int columnIndex;

private FreezeColumnCommand freezeCommand;

public ColumnHeaderRightClickConfiguration(final NatTable natTable, ViewportLayer viewportLayer, CompositeFreezeLayer freezeLayer){
    this.viewportLayer = viewportLayer;
    this.freezeLayer = freezeLayer;
    this.rightClickMenu = createRightClickMenu(natTable).build();

    natTable.addDisposeListener(new DisposeListener(){
        @Override
        public void widgetDisposed(DisposeEvent e) {
            rightClickMenu.dispose();
        }

    });
}

private PopupMenuBuilder createRightClickMenu(NatTable natTable){

    Menu menu = new Menu(natTable);

    MenuItem freezeLeft = new MenuItem(menu, SWT.NONE);
    freezeLeft.setText("Freeze");

    MenuItem unfreeze = new MenuItem(menu, SWT.NONE);
    unfreeze.setText("Unfreeze");
    unfreeze.setEnabled(false);

    freezeLeft.addSelectionListener(new SelectionListener(){
        @Override
        public void widgetSelected(SelectionEvent e) {
            System.out.println(columnIndex);
            freezeCommand = new FreezeColumnCommand(freezeLayer, columnIndex-1, true);
            natTable.doCommand(freezeCommand);

            freezeLeft.setEnabled(false);
            unfreeze.setEnabled(true);
        }
        @Override
        public void widgetDefaultSelected(SelectionEvent e){}
    });

    unfreeze.addSelectionListener(new SelectionListener(){
        @Override
        public void widgetSelected(SelectionEvent e) {
            natTable.doCommand(freezeCommand);

            unfreeze.setEnabled(false);
            freezeLeft.setEnabled(true);
        }
        @Override
        public void widgetDefaultSelected(SelectionEvent e) {}
    });

    return new PopupMenuBuilder(natTable, menu);
}

@Override
public void configureUiBindings(UiBindingRegistry uiBindingRegistry) {
    MouseEventMatcher matcher = new MouseEventMatcher(SWT.NONE, GridRegion.COLUMN_HEADER, MouseEventMatcher.RIGHT_BUTTON){
        @Override
        public boolean matches(NatTable natTable, MouseEvent event, LabelStack regionLabels){
            if (super.matches(natTable, event, regionLabels)){
                localColumnIndex = natTable.getColumnPositionByX(event.x);
                columnIndex = viewportLayer.localToUnderlyingColumnPosition(localColumnIndex);
                return true;
            }else{
                return false;
            }
        }
    };
    uiBindingRegistry.registerMouseDownBinding(matcher, new ColumnPopupMenuAction(rightClickMenu));
}

}

Answer 1

现在，FreezeColumnCommand不支持所请求的特性。只有FreezeSelectionCommand能够通过移动视图之外不可见的左侧列来执行冻结操作。原因是对应的FreezeColumnStrategy在计算冻结坐标时没有考虑到当前的viewport状态。这肯定是要在NatTable中修复的，我为此创建了一张票证：bug.cgi?id=504489

在NatTable中修复之前，您可以直接使用FreezeHelper。这会将冻结的内部计算和处理暴露在通常应该避免的代码中，但现在这将是一个解决办法。

此外，您的菜单配置不遵循NatTable准则。您正在做的许多事情都不合适，例如创建自己的菜单，但使用PopupMenuBuilder。下面是使用NatTable 1.4的代码。

public class ColumnHeaderRightClickConfiguration extends AbstractUiBindingConfiguration {

    private Menu rightClickMenu;

    private boolean frozen = false;

    public ColumnHeaderRightClickConfiguration(
            NatTable natTable,
            CompositeFreezeLayer compositeFreezeLayer,
            FreezeLayer freezeLayer,
            ViewportLayer viewportLayer,
            SelectionLayer selectionLayer) {
        this.rightClickMenu = new PopupMenuBuilder(natTable)
                .withMenuItemProvider("freeze", new IMenuItemProvider() {

                    @Override
                    public void addMenuItem(NatTable natTable, Menu popupMenu) {
                        MenuItem freezeLeft = new MenuItem(popupMenu, SWT.NONE);
                        freezeLeft.setText("Freeze");

                        freezeLeft.addSelectionListener(new SelectionAdapter() {
                            @Override
                            public void widgetSelected(SelectionEvent event) {
                                int columnPosition = MenuItemProviders.getNatEventData(event).getColumnPosition();
                                int pos = LayerUtil.convertColumnPosition(natTable, columnPosition, selectionLayer);
                                // this should be the solution
                                // if (compositeFreezeLayer.doCommand(new FreezeColumnCommand(compositeFreezeLayer, pos, true))) {
                                //     ColumnHeaderRightClickConfiguration.this.frozen = true;
                                // }

                                int coordCol = 0;
                                coordCol = viewportLayer.getScrollableLayer()
                                        .getColumnPositionByX(viewportLayer.getOrigin().getX());
                                if (coordCol > 0
                                        && coordCol >= pos) {
                                    coordCol = pos;
                                }

                                PositionCoordinate topLeftPosition = new PositionCoordinate(freezeLayer, coordCol, -1);
                                PositionCoordinate bottomRightPosition = new PositionCoordinate(freezeLayer, pos, -1);

                                FreezeHelper.freeze(freezeLayer, viewportLayer, topLeftPosition, bottomRightPosition);
                                ColumnHeaderRightClickConfiguration.this.frozen = true;
                            }
                        });

                    }
                })
                .withMenuItemProvider("unfreeze", new IMenuItemProvider() {

                    @Override
                    public void addMenuItem(NatTable natTable, Menu popupMenu) {
                        MenuItem unfreeze = new MenuItem(popupMenu, SWT.NONE);
                        unfreeze.setText("Unfreeze");

                        unfreeze.addSelectionListener(new SelectionAdapter() {
                            @Override
                            public void widgetSelected(SelectionEvent event) {
                                natTable.doCommand(new UnFreezeGridCommand());
                                ColumnHeaderRightClickConfiguration.this.frozen = false;
                            }
                        });
                    }
                })
                .withEnabledState("freeze", new IMenuItemState() {

                    @Override
                    public boolean isActive(NatEventData natEventData) {
                        return !ColumnHeaderRightClickConfiguration.this.frozen;
                    }
                })
                .withEnabledState("unfreeze", new IMenuItemState() {

                    @Override
                    public boolean isActive(NatEventData natEventData) {
                        return ColumnHeaderRightClickConfiguration.this.frozen;
                    }
                })
                .build();

        natTable.addDisposeListener(new DisposeListener() {
            @Override
            public void widgetDisposed(DisposeEvent e) {
                ColumnHeaderRightClickConfiguration.this.rightClickMenu.dispose();
            }

        });
    }

    @Override
    public void configureUiBindings(UiBindingRegistry uiBindingRegistry) {
        MouseEventMatcher matcher = new MouseEventMatcher(
                SWT.NONE,
                GridRegion.COLUMN_HEADER,
                MouseEventMatcher.RIGHT_BUTTON);
        uiBindingRegistry.registerMouseDownBinding(
                matcher,
                new PopupMenuAction(this.rightClickMenu));
    }
}