Question

我无法弄清楚如何将双击事件添加到CellTable的单元格中。

是否可以使用GWT CellTable？

有没有解决方法

谢谢..

人

顺便说一句，我看过这篇文章，但没有回复...... http://www.devcomments.com/Adding-DoubleClicks-and-OnContextMenu-to-CellTable-at1066168.htm

Answer 1

我精心制作了一些符合我需求的东西：

cellTable.addCellPreviewHandler(new Handler<TitoloProxy>() {

           long lastClick=-1000;

           @Override
           public void onCellPreview(CellPreviewEvent<TitoloProxy> event) {
               long clictAt = System.currentTimeMillis();
               GWT.log("clickAt: "+(clictAt));
               GWT.log("lastClick: "+(lastClick));
               if(event.getNativeEvent().getType().contains("click")){
                   GWT.log(""+(clictAt-lastClick));
                   if(clictAt-lastClick < 300) { // dblclick on 2 clicks detected within 300 ms
                       Window.alert("I am a double click crafted event!");

                   }
                   lastClick = System.currentTimeMillis();
               }
           }
       });

Answer 2

    cellTable.addDomHandler(new DoubleClickHandler() {

        @Override
        public void onDoubleClick(DoubleClickEvent event) {
            Window.alert("That's it!");
        }
    }, DoubleClickEvent.getType());

Answer 3

Integer row=0;// to hold row index
Integer column=0;// to hold column index 
_Grid.addCellPreviewHandler(new CellPreviewEvent.Handler<Model>() {
// this is to handle row id
        @Override
        public void onCellPreview(final CellPreviewEvent<Model> event) {

            if (BrowserEvents.CLICK.equalsIgnoreCase(event.getNativeEvent().getType())) {
                row = event.getIndex();
                column=event.getColumn();
            }

        }
    });

// because Doubleclick handler doesn't give row index or column index we will use addCellPreviewHandler to return row index or column index.
_Grid.addDomHandler(new DoubleClickHandler() {

        @Override
        public void onDoubleClick(final DoubleClickEvent event) {
            System.out.println(" You clicked row = " + row);
            System.out.println(" You clicked column = " + column);

        }
    }, DoubleClickEvent.getType());

Answer 4

由于CellPreview接口本身不捕获双击事件，因此您需要在Overriden onCellPreview方法中添加事件逻辑。首先，您会认为最好的方法是检查点击时间差异。但是，使用状态机并计算点击次数会更加高效和优雅。这更加强大，允许您处理多个事件案例 - 例如鼠标悬停，单击和双击。代码非常简单。所以尽情享受！

public class CellHoverHandler implements Handler<T> {

    Timer singleClickTimer;
    int clickCount = 0;
    int clickDelay = 300;

    @Override
    public void onCellPreview(final CellPreviewEvent<T> event) {
        if (Event.getTypeInt(event.getNativeEvent().getType()) == Event.ONMOUSEOVER) {
            handleOnMouseOver(event);
        } else if (Event.getTypeInt(event.getNativeEvent().getType()) == Event.ONCLICK) {
            clickCount++;
            if (clickCount == 1) {
                singleClickTimer = new Timer() {

                    @Override
                    public void run() {
                        clickCount = 0;
                        handleOnClick(event);
                    }
                };
                singleClickTimer.schedule(clickDelay);
            } else if (clickCount == 2) {
                singleClickTimer.cancel();
                clickCount = 0;
                handleOnDblClick(event);
            }
        }
    }

    private void handleOnMouseOver(CellPreviewEvent<T> event) {
        Element cell = event.getNativeEvent().getEventTarget().cast();
        GWT.log("mouse over event");
    }

    private void handleOnClick(CellPreviewEvent<T> event) {
        Element cell = event.getNativeEvent().getEventTarget().cast();
        GWT.log("click event");
    }

    private void handleOnDblClick(CellPreviewEvent<T> event) {
        Element cell = event.getNativeEvent().getEventTarget().cast();            
        GWT.log("double click event");
    }

优化：随意将计数，计时器和延迟作为静态类成员或全局成员重用。在创建新实例之前，还要检查计时器是否为null。为简单起见，我省略了这一点。与许多其他技术不同，这种方式仍然可以让您轻松直接地访问单元格事件。重载AbstractCell的技术也很有效，但有时候你真的没有自定义单元格，或者想让自定义单元格只处理单元格上的事件。

Answer 5

对于单元格列表，此代码可以正常工作：

  cellList.addDomHandler(new DoubleClickHandler() {
    @Override
    public void onDoubleClick(DoubleClickEvent event) {
      // do the stuff
    }
  }, DoubleClickEvent.getType());

我不确定表格单元格

Answer 6

将此留在此处以供将来参考

    private Set<GenericEventHandler<T>> dblClickHandlers = new HashSet<>(4);

dblClickHandlers只需映射我选择的接口实现

    table.addCellPreviewHandler(event -> {
        if (BrowserEvents.DBLCLICK.equalsIgnoreCase(event.getNativeEvent().getType())) {
            LOGGER.info("dblclick (native) " + event.getIndex() + "  " + event.getColumn() + "; " + event.getValue());
            dblClickHandlers.forEach(handler -> {
                handler.onEvent(event.getValue());
            });
        }
    });
    table.sinkBitlessEvent(BrowserEvents.DBLCLICK);

诀窍是消除“ dblclick”事件。

Answer 7

如果您想要一个允许您支持自己选择的事件列表的文本单元格，可以使用：

public class EventfulTextCell extends AbstractSafeHtmlCell`<String`> {

    private static final String[] NO_CONSUMED_EVENTS = null; 

    public EventfulTextCell() {
        this(NO_CONSUMED_EVENTS);
    }

    public EventfulTextCell(String... consumedEvents) {
        super(SimpleSafeHtmlRenderer.getInstance(), consumedEvents);
    }

    @Override
    public void render(Context context, SafeHtml value, SafeHtmlBuilder sb) {
        if (value != null) {
            sb.append(value);
        }
    }
}

然后你实例化它：

new EventfulTextCell("click", "dblclick")

然后覆盖onBrowserEvent（）方法来处理你的事件。

在CellTable单元格中添加双击事件 - GWT

7 个答案: