java - 如何使用特定的小部件注入(inject)GWT Activity＃start？

我有以下父容器：

public class ParentContainer extends Composite {
    // Contains a bunch of TextButtons (RedButton, GreenButton, etc.).
    private LayoutPanel buttonPanel;

    // When user clicks a TextButton inside the buttonPanel,
    // it changes the content of this contentPanel.
    private LayoutPanel contentPanel;
}

因此，当用户单击buttonPanel内的一个TextButtons时，contentPanel的内容就会更改。我正在尝试使用“活动/位置”框架使每个TextButton单击在历史中被记住。因此，如果用户分别单击“红色”，“绿色”和“蓝色”按钮，则contentPanel将更改3次，然后他们可以单击“后退/前进”浏览器历史记录按钮并在历史记录中来回移动（然后“重播”按钮一遍又一遍地点击等等）。

我也有以下课程：

com.mywebapp
    MainModule.gwt.xml
com.mywebapp.client
    MainModule
com.mywebapp.client.places
    RedButtonPlace
    GreenButtonPlace
    BlueButtonPlace
    ... 1 place for all buttons
com.mywebapp.client.activities
    RedButtonActivity
    GreenButtonActivity
    BlueButtonActivity
    ... 1 activity for all buttons
com.mywebapp.client.ui
    ParentContainer
    RedButton
    GreenButton
    BlueButton
    BlackButton
    PurpleButton
    OrangeButton

我正计划将其连接起来，以便：


PlaceController.goTo(new RedButtonPlace())最终路由到RedButtonActivity
PlaceController.goTo(new GreenButtonPlace())最终路由到GreenButtonActivity
等等（每个按钮的颜色都有其位置和活动）


我遇到的问题是：如果我从PlaceController.goTo(new RedButtonPlace())单击处理程序中调用RedButton，我该如何指示RedButtonActivity更新contentPanel的位置？例如：

public class RedButton extends TextButton {
    // ... bunch of stuff, nevermind why I am extending TextButton
    // this is just to help me connect all the major dots of GWT!

    public RedButton() {
        this.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent event) {
                // If the RedButton is clicked, we want all the content in RedButtonActivity#RedButtonView
                // to go inside ParentContainer#contentPanel.
                PlaceController.goto(new RedButtonPlace());
            }
        });
    }
}

public class RedButtonActivity extends AbstractActivity {
    public interface RedButtonView extends IsWidget {
        // Whatever the RedButton expects to be able to display.
    }

    private RedButtonView view;

    @Override
    public void start(AcceptsOneWidget panel, EventBus eventBus) {
        // Probably injected via GIN.
        view = somehowInjectTheView();

        panel.setWidget(view);
    }
}

最后一行是这里的关键：panel.setWidget(view)。我们如何确定panel是ParentContainer#contentPanel？提前致谢！

编辑：每个答案表明，这是代码更新：

public class ParentContainer extends Composite {
    // All the stuff that's up above in the first parent container.

    public ParentContainer() {
        super();

        // Again, via GIN.
        ActivityManager redButtonActivityManager = getSomehow();
        redButtonActivityManager.setDisplay(contentPanel);
    }
}

如果这是正确的方法，那么我假设在调用start(AcceptsOneWidget panel, EventBus eventBus)方法时，redButtonActivityManager知道为panel参数注入正确的显示吗？

最佳答案

您将ParentContainer#contentPanel传递给setDisplay()的ActivityManager方法，作为管理器初始化的一部分。