支持 Mvp ConstraintLayout

Question

我自己尝试支持MvpConstraintLayout，直接从MvpLinearLayout复制代码

public abstract class MvpConstraintLayout<V extends MvpView, P extends MvpPresenter<V>>
        extends ConstraintLayout implements MvpView, ViewGroupDelegateCallback<V, P> {
    protected P presenter;
    protected ViewGroupMvpDelegate<V, P> mvpDelegate;

    public MvpConstraintLayout(Context context) {
        super(context);
    }

    public MvpConstraintLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public MvpConstraintLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    /**
     * Get the mvp delegate. This is internally used for creating presenter, attaching and detaching
     * view from presenter etc.
     *
     * <p><b>Please note that only one instance of mvp delegate should be used per android.view.View
     * instance</b>.
     * </p>
     *
     * <p>
     * Only override this method if you really know what you are doing.
     * </p>
     *
     * @return {@link ViewGroupMvpDelegate}
     */
    @NonNull
    protected ViewGroupMvpDelegate<V, P> getMvpDelegate() {
        if (mvpDelegate == null) {
            mvpDelegate = new ViewGroupMvpDelegateImpl<>(this, true);
        }

        return mvpDelegate;
    }

    @Override protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        getMvpDelegate().onAttachedToWindow();
    }

    @Override protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        getMvpDelegate().onDetachedFromWindow();
    }

    @SuppressLint("MissingSuperCall") @Override protected Parcelable onSaveInstanceState() {
        return getMvpDelegate().onSaveInstanceState();
    }

    @SuppressLint("MissingSuperCall") @Override
    protected void onRestoreInstanceState(Parcelable state) {
        getMvpDelegate().onRestoreInstanceState(state);
    }

    /**
     * Instantiate a presenter instance
     *
     * @return The {@link MvpPresenter} for this view
     */
    public abstract P createPresenter();

    @Override public P getPresenter() {
        return presenter;
    }

    @Override public void setPresenter(P presenter) {
        this.presenter = presenter;
    }

    @Override public V getMvpView() {
        return (V) this;
    }

    @Override public final Parcelable superOnSaveInstanceState() {
        return super.onSaveInstanceState();
    }

    @Override public final void superOnRestoreInstanceState(Parcelable state) {
        super.onRestoreInstanceState(state);
    }
}

然后，在代码中使用它

public class StatusBarLayout extends MvpConstraintLayout<StatusView, StatusPresenter>
        implements StatusView {

    public StatusBarLayout(Context context) {
        super(context);

        init();
    }

    public StatusBarLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public StatusBarLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        ButterKnife.bind(this, this);
    }

    @Override
    public StatusPresenter createPresenter() {
        return DaggerStatusBarLayoutComponent.builder().build().presenter();
    }

    private void init() {
        View.inflate(getContext(), R.layout.layout_status, this);
    }
}

在预览中，IDE 表示

java.lang.IllegalStateException: Could not find the surrounding Activity
    at com.hannesdorfmann.mosby3.PresenterManager.getActivity(PresenterManager.java:231)
    at com.hannesdorfmann.mosby3.mvp.delegate.ViewGroupMvpDelegateImpl.<init>(ViewGroupMvpDelegateImpl.java:70)
    at com.skybornecn.ifdive.widgets.MvpConstraintLayout.getMvpDelegate(MvpConstraintLayout.java:55)
    at com.skybornecn.ifdive.widgets.MvpConstraintLayout.onAttachedToWindow(MvpConstraintLayout.java:63)
    at android.view.View.dispatchAttachedToWindow(View.java:15395)
    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2953)
    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2960)
    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2960)
    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2960)
    at android.view.AttachInfo_Accessor.setAttachInfo(AttachInfo_Accessor.java:42)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:333)
    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:429)
    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:368)
    at com.android.tools.idea.rendering.RenderTask.compute(RenderTask.java:567)
    at com.android.tools.idea.rendering.RenderTask.compute(RenderTask.java:549)
    at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:863)
    at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:549)
    at com.android.tools.idea.rendering.RenderTask.lambda$inflate(RenderTask.java:680)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

mosby PresenterManager我看过了，但还是不知道为什么。另外，安装到phone，布局显示就ok了。

Answer 1

更新：这在 Mosby 3.0.1 中已修复。

这只是 Mosby 的 android 工具问题。 android 布局编辑器实际上实例化了 MvpConstraintLayout 的实例，以便在 Android Studio 中预览它。但是，Android Studio 不会通过将 MvpContraintLayout 之类的视图附加到真实的 Activity 来做到这一点，而是在内部使用一些模拟的 "context" 类似的东西。 Mosby 的 PresenterManager 在内部尝试为您的 MvpConstraintLayout 找到一个 Activity，但是在 Android Studio 中没有使用真正的 Activity（如前所述），因此 UI 编辑器显示此错误消息，当安装在 phone 上时它工作正常（因为使用了真正的 Activity）。

要解决这个问题，您必须在像这样调用委托之前使用 view.isInEditMode()：

public abstract class MvpConstraintLayout<V extends MvpView, P extends MvpPresenter<V>>
        extends ConstraintLayout implements MvpView, ViewGroupDelegateCallback<V, P> {
    ...

    @Override protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        if (!isInEditMode()) getMvpDelegate().onAttachedToWindow();
    }

    @Override protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        if (!isInEditMode()) getMvpDelegate().onDetachedFromWindow();
    }

    @SuppressLint("MissingSuperCall") @Override protected Parcelable onSaveInstanceState() {
       if (!isInEditMode()) return getMvpDelegate().onSaveInstanceState();
       return super.onSaveInstanceState();
    }

    @SuppressLint("MissingSuperCall") @Override
    protected void onRestoreInstanceState(Parcelable state) {
        if (!isInEditMode()) getMvpDelegate().onRestoreInstanceState(state);
    }

    /**
     * Instantiate a presenter instance
     *
     * @return The {@link MvpPresenter} for this view
     */
    public abstract P createPresenter();

    @Override public P getPresenter() {
        return presenter;
    }

    @Override public void setPresenter(P presenter) {
        this.presenter = presenter;
    }

    @Override public V getMvpView() {
        return (V) this;
    }

    @Override public final Parcelable superOnSaveInstanceState() {
        return super.onSaveInstanceState();
    }

    @Override public final void superOnRestoreInstanceState(Parcelable state) {
        super.onRestoreInstanceState(state);
    }
}

这实际上是 ViewGroupMvpDelegate 应该在内部处理的事情。这应该用 Mosby 3.0.1 修复。

见https://github.com/sockeqwe/mosby/issues/229

支持 Mvp ConstraintLayout

Support MvpConstraintLayout

mosby