ViewGroup's clipChildren

当子View的内容超出其layout的位置时，是否会被栽剪掉超出的部分。
即子View的内容能否显示在其layout的外部。

源码跟踪：

public void setClipChildren(boolean clipChildren) {
    boolean previousValue = (mGroupFlags & FLAG_CLIP_CHILDREN) == FLAG_CLIP_CHILDREN;
    if (clipChildren != previousValue) {
        setBooleanFlag(FLAG_CLIP_CHILDREN, clipChildren);
        for (int i = 0; i < mChildrenCount; ++i) {
            View child = getChildAt(i);
            if (child.mRenderNode != null) {
                child.mRenderNode.setClipToBounds(clipChildren);
            }
        }
        invalidate(true);
    }
}

public class View implements Drawable.Callback, KeyEvent.Callback,
    AccessibilityEventSource {
    ...
    final RenderNode mRenderNode;
    ....
}

 public boolean setClipToBounds(boolean clipToBounds) {
      return nSetClipToBounds(mNativeRenderNode, clipToBounds);//目前至JNI层
}

工具类：

 public static void disableParentsClip(@NonNull View view) {
    while (view.getParent() != null && view.getParent() instanceof ViewGroup) {
        ViewGroup viewGroup = (ViewGroup) view.getParent();
        viewGroup.setClipChildren(false);
        viewGroup.setClipToPadding(false);
        view = viewGroup;
    }
}

public static void enableParentsClip(@NonNull View view) {
    while (view.getParent() != null && view.getParent() instanceof ViewGroup) {
        ViewGroup viewGroup = (ViewGroup) view.getParent();
        viewGroup.setClipChildren(true);
        viewGroup.setClipToPadding(true);
        view = viewGroup;
    }
}

来源 Smoke & Mirrors: The Magic Behind Wonderful UI in Android