why does View.setLayoutParams can call ViewGroup.onSetLayoutParams which is protected?

Question

when i was searching the android source code, i have found something i can not understand or bear. you can see all onSetLayoutParams in the frameworks source code bellow:

./base/core/java/android/widget/Toolbar.java: protected void onSetLayoutParams(View child, ViewGroup.LayoutParams lp) {

./base/core/java/android/widget/GridLayout.java: protected void onSetLayoutParams(View child, ViewGroup.LayoutParams layoutParams) {

./base/core/java/android/widget/GridLayout.java: super.onSetLayoutParams(child, layoutParams);

./base/core/java/android/view/View.java: ((ViewGroup) mParent).onSetLayoutParams(this, params);

./base/core/java/android/view/ViewGroup.java: protected void onSetLayoutParams(View child, LayoutParams layoutParams) {

every define of onSetLayoutParams is proected, yet View.setLayoutParams cast its parent to a ViewGroup, then call ViewGroup's onSetLayoutParams. i don not think this is right in java, but all android seems running very well.

sorry for my poor english.

The method is protected, but I can't access it from a inherited class. =/ — Eduardo Reis, Aug 25 '17 at 17:44
Because it's marked @hide it's not included in the SDK and not included in android.jar (so you cannot override or call it). — Mark Renouf, Aug 30 '17 at 19:33

score 0 · Accepted Answer · edited May 23 '17 at 12:14

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somehow i found my answer from this page: In Java, difference between default, public, protected, and private

Java protected seems making the method not visible to classes out of this package, within the same package, its a public method.

edited May 23 '17 at 12:14

Community

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answered Jun 04 '15 at 09:30

Zion

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why does View.setLayoutParams can call ViewGroup.onSetLayoutParams which is protected?

1 Answers1