我怎样才能分辨出Gxt引发了什么事件?

也许有人会发现这很有用,我已经创建了实用程序类来查看什么样的事件会上升。这个想法当然是在公认的答案中提出的。

import java.util.HashMap;
import java.util.Map;

import com.extjs.gxt.ui.client.event.BaseEvent;
import com.extjs.gxt.ui.client.event.EventType;
import com.extjs.gxt.ui.client.event.Events;
import com.extjs.gxt.ui.client.event.Listener;
import com.extjs.gxt.ui.client.widget.Component;

/**
 * Class for debugging purposes. Sometimes it is hard to tell what type of event
 * is invoked and when. During debug process you can just do:
 * 
 * EventUtils.attachDebugListeners(c);
 * EventUtils.attachDebugListeners(c, "NAME");
 * 
 * You'll then get information about events as they are invoked.
 * 
 * List of events copied from {@link Events} class.
 * 
 */
public class EventUtils {

    public static void attachDebugListeners(final Component c) {
        attachDebugListeners(c, null);
    }

    public static void attachDebugListeners(final Component c, final String msg) {
        for (final EventType type : eventTypeNames.keySet()) {
            c.addListener(type, new Listener<BaseEvent>() {
                @Override
                public void handleEvent(BaseEvent be) {
                    String typeName = eventTypeNames.get(type);
                    if (msg != null)
                        System.out.print(msg + " -> ");
                    System.out.println(typeName);
                }
            });
        }
    }

    final static Map<EventType, String> eventTypeNames = new HashMap<EventType, String>();
    static {
        eventTypeNames.put(Events.Activate, "Events.Activate");
        eventTypeNames.put(Events.Add, "Events.Add");
        eventTypeNames.put(Events.Adopt, "Events.Adopt");
        eventTypeNames.put(Events.AfterEdit, "Events.AfterEdit");
        eventTypeNames.put(Events.AfterLayout, "Events.AfterLayout");
        eventTypeNames.put(Events.ArrowClick, "Events.ArrowClick");
        eventTypeNames.put(Events.Attach, "Events.Attach");
        eventTypeNames.put(Events.AutoHide, "Events.AutoHide");
        eventTypeNames.put(Events.BeforeAdd, "Events.BeforeAdd");
        eventTypeNames.put(Events.BeforeAdopt, "Events.BeforeAdopt");
        eventTypeNames.put(Events.BeforeBind, "Events.BeforeBind");
        eventTypeNames.put(Events.BeforeCancelEdit, "Events.BeforeCancelEdit");
        eventTypeNames.put(Events.BeforeChange, "Events.BeforeChange");
        eventTypeNames
                .put(Events.BeforeCheckChange, "Events.BeforeCheckChange");
        eventTypeNames.put(Events.BeforeClose, "Events.BeforeClose");
        eventTypeNames.put(Events.BeforeCollapse, "Events.BeforeCollapse");
        eventTypeNames.put(Events.BeforeComplete, "Events.BeforeComplete");
        eventTypeNames.put(Events.BeforeEdit, "Events.BeforeEdit");
        eventTypeNames.put(Events.BeforeExpand, "Events.BeforeExpand");
        eventTypeNames.put(Events.BeforeHide, "Events.BeforeHide");
        eventTypeNames.put(Events.BeforeLayout, "Events.BeforeLayout");
        eventTypeNames.put(Events.BeforeOpen, "Events.BeforeOpen");
        eventTypeNames.put(Events.BeforeOrphan, "Events.BeforeOrphan");
        eventTypeNames.put(Events.BeforeQuery, "Events.BeforeQuery");
        eventTypeNames.put(Events.BeforeRemove, "Events.BeforeRemove");
        eventTypeNames.put(Events.BeforeRender, "Events.BeforeRender");
        eventTypeNames.put(Events.BeforeSelect, "Events.BeforeSelect");
        eventTypeNames.put(Events.BeforeShow, "Events.BeforeShow");
        eventTypeNames.put(Events.BeforeStartEdit, "Events.BeforeStartEdit");
        eventTypeNames.put(Events.BeforeStateRestore,
                "Events.BeforeStateRestore");
        eventTypeNames.put(Events.BeforeStateSave, "Events.BeforeStateSave");
        eventTypeNames.put(Events.BeforeSubmit, "Events.BeforeSubmit");
        eventTypeNames.put(Events.Bind, "Events.Bind");
        eventTypeNames.put(Events.Blur, "Events.Blur");
        eventTypeNames.put(Events.BodyScroll, "Events.BodyScroll");
        eventTypeNames.put(Events.BrowserEvent, "Events.BrowserEvent");
        eventTypeNames.put(Events.CancelEdit, "Events.CancelEdit");
        eventTypeNames.put(Events.CellClick, "Events.CellClick");
        eventTypeNames.put(Events.CellDoubleClick, "Events.CellDoubleClick");
        eventTypeNames.put(Events.CellMouseDown, "Events.CellMouseDown");
        eventTypeNames.put(Events.CellMouseUp, "Events.CellMouseUp");
        eventTypeNames.put(Events.Change, "Events.Change");
        eventTypeNames.put(Events.CheckChange, "Events.CheckChange");
        eventTypeNames.put(Events.CheckChanged, "Events.CheckChanged");
        eventTypeNames.put(Events.Clear, "Events.Clear");
        eventTypeNames.put(Events.Close, "Events.Close");
        eventTypeNames.put(Events.Collapse, "Events.Collapse");
        eventTypeNames.put(Events.ColumnClick, "Events.ColumnClick");
        eventTypeNames.put(Events.ColumnResize, "Events.ColumnResize");
        eventTypeNames.put(Events.Complete, "Events.Complete");
        eventTypeNames.put(Events.ContextMenu, "Events.ContextMenu");
        eventTypeNames.put(Events.Deactivate, "Events.Deactivate");
        eventTypeNames.put(Events.Detach, "Events.Detach");
        eventTypeNames.put(Events.Disable, "Events.Disable");
        eventTypeNames.put(Events.DoubleClick, "Events.DoubleClick");
        eventTypeNames.put(Events.DragCancel, "Events.DragCancel");
        eventTypeNames.put(Events.DragEnd, "Events.DragEnd");
        eventTypeNames.put(Events.DragEnter, "Events.DragEnter");
        eventTypeNames.put(Events.DragFail, "Events.DragFail");
        eventTypeNames.put(Events.DragLeave, "Events.DragLeave");
        eventTypeNames.put(Events.DragMove, "Events.DragMove");
        eventTypeNames.put(Events.DragStart, "Events.DragStart");
        eventTypeNames.put(Events.Drop, "Events.Drop");
        eventTypeNames.put(Events.EffectCancel, "Events.EffectCancel");
        eventTypeNames.put(Events.EffectComplete, "Events.EffectComplete");
        eventTypeNames.put(Events.EffectStart, "Events.EffectStart");
        eventTypeNames.put(Events.Enable, "Events.Enable");
        eventTypeNames.put(Events.Exception, "Events.Exception");
        eventTypeNames.put(Events.Expand, "Events.Expand");
        eventTypeNames.put(Events.Focus, "Events.Focus");
        eventTypeNames.put(Events.HeaderChange, "Events.HeaderChange");
        eventTypeNames.put(Events.HeaderClick, "Events.HeaderClick");
        eventTypeNames
                .put(Events.HeaderContextMenu, "Events.HeaderContextMenu");
        eventTypeNames
                .put(Events.HeaderDoubleClick, "Events.HeaderDoubleClick");
        eventTypeNames.put(Events.HeaderMouseDown, "Events.HeaderMouseDown");
        eventTypeNames.put(Events.HiddenChange, "Events.HiddenChange");
        eventTypeNames.put(Events.Hide, "Events.Hide");
        eventTypeNames.put(Events.Invalid, "Events.Invalid");
        eventTypeNames.put(Events.KeyDown, "Events.KeyDown");
        eventTypeNames.put(Events.KeyPress, "Events.KeyPress");
        eventTypeNames.put(Events.KeyUp, "Events.KeyUp");
        eventTypeNames.put(Events.LiveGridViewUpdate,
                "Events.LiveGridViewUpdate");
        eventTypeNames.put(Events.Maximize, "Events.Maximize");
        eventTypeNames.put(Events.MenuHide, "Events.MenuHide");
        eventTypeNames.put(Events.MenuShow, "Events.MenuShow");
        eventTypeNames.put(Events.Minimize, "Events.Minimize");
        eventTypeNames.put(Events.Move, "Events.Move");
        eventTypeNames.put(Events.OnBlur, "Events.OnBlur");
        eventTypeNames.put(Events.OnChange, "Events.OnChange");
        eventTypeNames.put(Events.OnClick, "Events.OnClick");
        eventTypeNames.put(Events.OnContextMenu, "Events.OnContextMenu");
        eventTypeNames.put(Events.OnDoubleClick, "Events.OnDoubleClick");
        eventTypeNames.put(Events.OnError, "Events.OnError");
        eventTypeNames.put(Events.OnFocus, "Events.OnFocus");
        eventTypeNames.put(Events.OnKeyDown, "Events.OnKeyDown");
        eventTypeNames.put(Events.OnKeyPress, "Events.OnKeyPress");
        eventTypeNames.put(Events.OnKeyUp, "Events.OnKeyUp");
        eventTypeNames.put(Events.OnLoad, "Events.OnLoad");
        eventTypeNames.put(Events.OnLoseCapture, "Events.OnLoseCapture");
        eventTypeNames.put(Events.OnMouseDown, "Events.OnMouseDown");
        eventTypeNames.put(Events.OnMouseMove, "Events.OnMouseMove");
        eventTypeNames.put(Events.OnMouseOut, "Events.OnMouseOut");
        eventTypeNames.put(Events.OnMouseOver, "Events.OnMouseOver");
        eventTypeNames.put(Events.OnMouseUp, "Events.OnMouseUp");
        eventTypeNames.put(Events.OnMouseWheel, "Events.OnMouseWheel");
        eventTypeNames.put(Events.OnScroll, "Events.OnScroll");
        eventTypeNames.put(Events.Open, "Events.Open");
        eventTypeNames.put(Events.Orphan, "Events.Orphan");
        eventTypeNames.put(Events.Ready, "Events.Ready");
        eventTypeNames.put(Events.Refresh, "Events.Refresh");
        eventTypeNames.put(Events.Register, "Events.Register");
        eventTypeNames.put(Events.Remove, "Events.Remove");
        eventTypeNames.put(Events.Render, "Events.Render");
        eventTypeNames.put(Events.Resize, "Events.Resize");
        eventTypeNames.put(Events.ResizeEnd, "Events.ResizeEnd");
        eventTypeNames.put(Events.ResizeStart, "Events.ResizeStart");
        eventTypeNames.put(Events.Restore, "Events.Restore");
        eventTypeNames.put(Events.RowClick, "Events.RowClick");
        eventTypeNames.put(Events.RowDoubleClick, "Events.RowDoubleClick");
        eventTypeNames.put(Events.RowMouseDown, "Events.RowMouseDown");
        eventTypeNames.put(Events.RowMouseUp, "Events.RowMouseUp");
        eventTypeNames.put(Events.RowUpdated, "Events.RowUpdated");
        eventTypeNames.put(Events.Scroll, "Events.Scroll");
        eventTypeNames.put(Events.Select, "Events.Select");
        eventTypeNames.put(Events.SelectionChange, "Events.SelectionChange");
        eventTypeNames.put(Events.Show, "Events.Show");
        eventTypeNames.put(Events.SortChange, "Events.SortChange");
        eventTypeNames.put(Events.SpecialKey, "Events.SpecialKey");
        eventTypeNames.put(Events.StartEdit, "Events.StartEdit");
        eventTypeNames.put(Events.StateChange, "Events.StateChange");
        eventTypeNames.put(Events.StateRestore, "Events.StateRestore");
        eventTypeNames.put(Events.StateSave, "Events.StateSave");
        eventTypeNames.put(Events.Submit, "Events.Submit");
        eventTypeNames.put(Events.Toggle, "Events.Toggle");
        eventTypeNames.put(Events.TriggerClick, "Events.TriggerClick");
        eventTypeNames.put(Events.TwinTriggerClick, "Events.TwinTriggerClick");
        eventTypeNames.put(Events.UnBind, "Events.UnBind");
        eventTypeNames.put(Events.Unregister, "Events.Unregister");
        eventTypeNames.put(Events.Update, "Events.Update");
        eventTypeNames.put(Events.Valid, "Events.Valid");
        eventTypeNames.put(Events.ValidateDrop, "Events.ValidateDrop");
        eventTypeNames.put(Events.ValidateEdit, "Events.ValidateEdit");
        eventTypeNames.put(Events.ViewReady, "Events.ViewReady");
    }
}

我最终使用了蛮力:创建了一个事件类型和名称的映射,然后为组件可以接收的每种类型的事件附加一个侦听器。然后我在监听器中设置了一个断点,我可以看到当发生任何事情时接收到了什么事件。

如果不是被丢弃的代码,我会把它清理成一个实用程序类,而不是使用匿名侦听器类等。

    final Map<EventType, String> eventTypeNames = new HashMap<EventType, String>();
    eventTypeNames.put(Events.BeforeExpand, "BeforeExpand");
    eventTypeNames.put(Events.Expand, "Expand");
    ...
    eventTypeNames.put(Events.BeforeStateSave, "BeforeStateSave");
    eventTypeNames.put(Events.StateSave, "StateSave");

    for (EventType eventType : Arrays.asList(
            Events.BeforeExpand,
            Events.Expand,
            ...
            Events.BeforeStateSave,
            Events.StateSave
    )) {
        this.addListener(eventType, new Listener<BaseEvent>() {
            public void handleEvent(final BaseEvent be) {
                String type = eventTypeNames.get(be.getType());
                String ev = be.toString();
            }
        });
    }

各种小部件的API文档描述了什么事件将触发以及何时触发。例如,假设我们希望在用户选择新的 TabItem 在一个 TabPanel .

面板 的API文档(位于 http://extjs.com/deploy/gxtdocs/com/extjs/gxt/ui/client/widget/TabPanel.html )显示了几个事件;我们对 Select :

选择:tabpanelevent(容器,项)

在选择项后激发。

• 容器:这个
• 项:所选的项

因此,为了捕获事件(您似乎理解,但为了完整起见,我将包括),过程是将一个侦听器添加到 面板 特别关注 Events.Select 事件:

tp.addListener(Events.Select, new Listener<TabPanelEvent>(){
  public void handleEvent(TabPanelEvent be)
  {
    MessageBox.alert("Test", be.item.getText(), null);
  }
});

请注意,许多事件都有一个名为 doit 您可以将其设置为false以取消事件。

完整的代码列表:

package edu.fresno.client;

import com.extjs.gxt.ui.client.Events;
import com.extjs.gxt.ui.client.event.Listener;
import com.extjs.gxt.ui.client.event.TabPanelEvent;
import com.extjs.gxt.ui.client.widget.ContentPanel;
import com.extjs.gxt.ui.client.widget.MessageBox;
import com.extjs.gxt.ui.client.widget.TabItem;
import com.extjs.gxt.ui.client.widget.TabPanel;
import com.extjs.gxt.ui.client.widget.layout.FitLayout;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.RootPanel;

public class GWTSandbox implements EntryPoint {
  public void onModuleLoad() {

      TabPanel tp = new TabPanel();

      TabItem ti1 = new TabItem("TabItem1");
      TabItem ti2 = new TabItem("TabItem2");

      tp.add(ti1);
      tp.add(ti2);

      tp.addListener(Events.Select, new Listener<TabPanelEvent>(){
            public void handleEvent(TabPanelEvent be)
            {
                MessageBox.alert("Test", be.item.getText(), null);
            }
      });


      ContentPanel panel = new ContentPanel();
      panel.setLayout(new FitLayout());
      panel.add(tp);
      RootPanel.get().add(panel);

  }
}

可以为构造函数添加以下代码:

    ContentPanel  panel =new ContentPanel(){
      public boolean fireEvent(EventType type) {
          System.out.println(type.getEventCode());
          return super.fireEvent(type);
      }
      public boolean fireEvent(EventType eventType, BaseEvent be) {
          System.out.println(eventType.getEventCode());
          return super.fireEvent(eventType, be);
      }
      public boolean fireEvent(EventType type, ComponentEvent ce) {
          System.out.println(type.getEventCode());
          return super.fireEvent(type, ce);
      }
    };

然后它将打印该组件可以接收的任何事件。