FragmentContainerView.java
/*
* Copyright 2019 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.fragment.app;
import static androidx.annotation.RestrictTo.Scope.LIBRARY;
import android.animation.LayoutTransition;
import android.content.Context;
import android.util.AttributeSet;
import android.widget.FrameLayout;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RestrictTo;
/**
* FragmentContainerView is a customized Layout designed specifically for Fragments. It extends
* {@link FrameLayout}, so it can reliably handle Fragment Transactions, and it also has additional
* features to coordinate with fragment behavior.
*
* <p>Layout animations and transitions are disabled for FragmentContainerView. Animations should be
* done through {@link FragmentTransaction#setCustomAnimations(int, int, int, int)}. If
* animateLayoutChanges is set to <code>true</code> or
* {@link #setLayoutTransition(LayoutTransition)} is called directly an
* {@link UnsupportedOperationException} will be thrown.
*
* @hide -- remove once z ordering is implemented.
*/
@RestrictTo(LIBRARY)
public final class FragmentContainerView extends FrameLayout {
public FragmentContainerView(@NonNull Context context) {
super(context);
}
public FragmentContainerView(@NonNull Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
public FragmentContainerView(
@NonNull Context context,
@Nullable AttributeSet attrs,
int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
/**
* When called, this method throws a {@link UnsupportedOperationException}. This can be called
* either explicitly, or implicitly by setting animateLayoutChanges to <code>true</code>.
*
* <p>View animations and transitions are disabled for FragmentContainerView. Use
* {@link FragmentTransaction#setCustomAnimations(int, int, int, int)} and
* {@link FragmentTransaction#setTransition(int)}.
*
* @param transition The LayoutTransition object that will animated changes in layout. A value
* of <code>null</code> means no transition will run on layout changes.
* @attr ref android.R.styleable#ViewGroup_animateLayoutChanges
*/
@Override
public void setLayoutTransition(@Nullable LayoutTransition transition) {
throw new UnsupportedOperationException(
"FragmentContainerView does not support Layout Transitions or "
+ "animateLayoutChanges=\"true\".");
}
}