在CellTable單元格中添加雙擊事件 - GWT

Question

我無法弄清楚如何將雙擊事件添加到CellTable的單元格中。

GWT CellTable可能嗎？

有任何解決方法

謝謝你..

人

BTW，我看到了這個帖子，但沒有迴應... http://www.devcomments.com/Adding-DoubleClicks-and-OnContextMenu-to-CellTable-at1066168.htm

Answer 1

如果你想要一個文本你可以使用這個：

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); 
     } 
    } 
} 

然後，你實例化它：

new EventfulTextCell("click", "dblclick") 

然後覆蓋onBrowserEvent（）方法來處理您的事件。

Answer 2

我製作不同的東西，只是適合我的需要：

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 3

cellTable.addDomHandler(new DoubleClickHandler() { 

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

Answer 4

因爲CellPreview接口本身不捕捉雙擊事件，你將需要添加事件邏輯到重寫onCellPreview方法。首先你會認爲最好的辦法是檢查點擊時間差異。但是，使用狀態機和點擊次數會更加高效和優雅。這更強大，可以處理多個事件 - 例如鼠標懸停，單擊和雙擊。代碼非常簡單。所以享受！

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"); 
    } 

優化：隨意將計數，計時器和延遲作爲靜態類成員或全局成員來重用。在創建新實例之前，還要檢查計時器是否爲空。爲簡單起見，我忽略了這一點。與許多其他技術不同，這種方式仍然可以讓您輕鬆直接訪問單元格事件。重載AbstractCell的技術也很有效，但是有時候你實際上沒有定製單元，或者想要定製單元來處理單元上的事件。

Answer 5

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 6

對於小區列表，此代碼的工作確定：

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

我不知道有關表格單元格