使用openGL在android中绘制一个圆(drawing a circle in android with openGL)

 更新：这是固定在Mosby 3.0.1。 
 
 
 这只是Mosby的一个Android工具问题。 android布局编辑器实际上实例化了一个MvpConstraintLayout实例，以在Android Studio中预览它。 然而，Android Studio并不是通过将一个像MvpContraintLayout这样的View MvpContraintLayout到一个真实的Activity MvpContraintLayout实现的，而是在内部使用了一些MvpContraintLayout “上下文”的东西。 Mosby的PresenterManager内部试图为你的MvpConstraintLayout找到一个Activity，但在Android Studio中没有使用真正的Activity（ MvpConstraintLayout ），因此UI编辑器会显示此错误消息，并且在手机上安装时它会正常工作（因为有真正使用的活动）。 
 
 要解决这个问题，您必须在调用委托之前使用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);
    }
}
 
 实际上， ViewGroupMvpDelegate应该在内部处理。 这应该与Mosby 3.0.1修复。 
 
 请参阅https://github.com/sockeqwe/mosby/issues/229 

UPDATE: This is fixed in Mosby 3.0.1.
 
 
This is just a android tooling issue with Mosby. The android layout editor actually instantiates a Instance of MvpConstraintLayout to preview it in Android Studio. However, Android Studio doesn't do that by attaching a View like MvpContraintLayout to a real Activity, but internally uses some mocked "context" alike thing. Mosby's PresenterManager internally tries to find an Activity for your MvpConstraintLayout, but in Android Studio there is no real Activity used (as already explained) and therefore the UI editor displays this error message and when installed on the phone it works properly (because there is a real Activity used).
 
To fix that you have to use view.isInEditMode() before calling the delegate like this:
 
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);
    }
}
 
This is actually something ViewGroupMvpDelegate should take care of internally. This should be fixed with Mosby 3.0.1.
 
See https://github.com/sockeqwe/mosby/issues/229