如何:UiBinder + GWT MVP +多个独立显示区域

Question

我正在使用GWT MVP和UiBinder来创建一个带有DockLayoutPanel的应用程序.我希望南北码头是静态的,包含按钮和链接.我希望在中心和东部码头的两个不同区域拥有动态视图.由于这些动态区域应该彼此独立,我为每个动态显示区域设置不同的ActivityMapper和ActivityManager; 中心,东顶和东底.

如何在加载应用程序时独立初始化这3个不同的显示区域？如何在一个显示区域中从一个Activity切换到另一个Activity而不影响其他区域？

当我使用PlaceController的goTo在一个区域中从一个地方切换到另一个地方时,另一个区域的活动停止.

五月天,请帮忙,五月天!

以下是我的一些代码:

AppViewImpl.ui.xml

<g:DockLayoutPanel styleName="{style.dockPanel}" unit="PX" width="975px" height="100%">

    <!-- DOCK PANEL EAST -->
    <g:east size="220">
        <g:LayoutPanel styleName="{style.eastPanel}">
            <g:layer left="0px" width="220px" top="0px" height="105px">
                <g:SimpleLayoutPanel ui:field="topRightPanel"/>
            </g:layer>

            <g:layer left="0px" width="220px" top="110px" height="340px">
                    <g:InlineLabel styleName="{style.label}" text="ANOTHER DISPLAY AREA"/>
            </g:layer>
        </g:LayoutPanel>
    </g:east>

    <!-- DOCK PANEL NORTH -->
    <g:north size="110">
        <g:LayoutPanel styleName="{style.northPanel}">
            <g:layer left="0px" width="755px" top="0px" height="105px">
                    <g:InlineLabel styleName="{style.label}" text="NORTH PANEL"/>
            </g:layer>
        </g:LayoutPanel>
    </g:north>

    <!-- DOCK PANEL SOUTH -->
    <g:south size="20">
        <g:LayoutPanel styleName="{style.southPanel}">
            <g:layer left="0px" width="755px" top="0px" height="20px">
                    <g:InlineLabel styleName="{style.label}" text="SOUTH PANEL"/>
            </g:layer>
        </g:LayoutPanel>
    </g:south>

    <!-- DOCK PANEL CENTER -->
    <g:center>
        <g:SimpleLayoutPanel ui:field="mainPanel" />
    </g:center>
</g:DockLayoutPanel>

MyModule.java

公共类MyModule实现了EntryPoint {

private Place defaultPlace = new DefaultPlace("");

public void onModuleLoad() {
    // Create ClientFactory using deferred binding so we can replace with 
    // different impls in gwt.xml
    ClientFactory clientFactory = GWT.create(ClientFactory.class);
    EventBus eventBus = clientFactory.getEventBus();
    PlaceController placeController = clientFactory.getPlaceController();

    // Start ActivityManager for the main widget with our ActivityMapper
    ActivityMapper topRightActivityMapper = new TopRightActivityMapper(clientFactory);
    ActivityManager topRightActivityManager = new ActivityManager(topRightActivityMapper, eventBus);
    topRightActivityManager.setDisplay(clientFactory.getAppView().getTopRightPanel());

    // Start ActivityManager for the main widget with our ActivityMapper
    ActivityMapper mainActivityMapper = new AppActivityMapper(clientFactory);
    ActivityManager mainActivityManager = new ActivityManager(mainActivityMapper, eventBus);
    mainActivityManager.setDisplay(clientFactory.getAppView().getMainPanel());

    // Start PlaceHistoryHandler with our PlaceHistoryMapper
    AppPlaceHistoryMapper historyMapper = GWT .create(AppPlaceHistoryMapper.class);
    PlaceHistoryHandler historyHandler = new PlaceHistoryHandler(historyMapper);
    historyHandler.register(placeController, eventBus, defaultPlace);
    RootLayoutPanel.get().add(clientFactory.getAppView());

    // Goes to place represented on URL or default place
    historyHandler.handleCurrentHistory();

    new AppController(clientFactory);
}

}

AppController.java

public class AppController implements AppView.Presenter {

    private ClientFactory clientFactory;

    AppController(ClientFactory clientFactory){
        this.clientFactory = clientFactory;
        goTo(new TopRightAPlace(""));
    }

    @Override
    public void goTo(Place place) {
        clientFactory.getPlaceController().goTo(place);
    }

}

TopRightAViewImpl.java

public class TopRightAViewImpl extends Composite implements TopRightAView {

    interface Binder extends UiBinder<Widget, TopRightAViewImpl> {
    }

    private static final Binder binder = GWT.create(Binder.class);

    private Presenter listener;
    @UiField
    Button button;

    public TopRightAViewImpl() {
        initWidget(binder.createAndBindUi(this));
    }

    @Override
    public void setName(String name) {
        button.setHTML(name);
    }

    @Override
    public void setPresenter(Presenter listener) {
        this.listener = listener;
    }

    @UiHandler("button")
    void onButtonClick(ClickEvent event) {
        listener.goTo(some other place);
    }
}

Answer 1

GWT PlaceS,PlaceController以及PlaceHistoryMapper使您能够创建应用程序,使浏览器的后退按钮和书签的工作正如人们所预料之内可收藏的URL.这就是GWT Place的设计目标.因此,Place在任何时间点在应用程序中激活多个是没有意义的,因为您有一个整个应用程序的URL.

PlaceController的goTo()方法确实通知了已注册的ActivityManager,它在收到PlaceChangeEvent时停止当前的Activity.

我建议你不要在你东边的两个区域使用Places和PlaceChangeEvents DockLayoutPanel.将Places用于应用程序的主屏幕,这可能是您的主屏幕的中心DockLayoutPanel.当您需要更新它们时,为东侧区域触发不同GwtEvent类型(通用事件类型之一(即.ValueChangeEvent)或自定义事件类型).您仍然可以Activitie在东侧使用s,但是您需要创建自己的ActivityManager,实际上并不那么难.您所要做的就是复制GWT ActivityManager,重命名它,并将处理PlaceChangeEvents和PlaceChangeRequestEvents 的方法的名称替换为处理自己事件的方法.