CompositePageTransformer.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.viewpager2.widget;
import android.view.View;
import androidx.annotation.NonNull;
import androidx.viewpager2.widget.ViewPager2.PageTransformer;
import java.util.ArrayList;
import java.util.List;
/**
* Allows for combining multiple {@link PageTransformer} objects.
*
* @see ViewPager2#setPageTransformer
* @see MarginPageTransformer
*/
public final class CompositePageTransformer implements PageTransformer {
private final List<PageTransformer> mTransformers = new ArrayList<>();
/**
* Adds a page transformer to the list.
* <p>
* Transformers will be executed in the order that they were added.
*/
public void addTransformer(@NonNull PageTransformer transformer) {
mTransformers.add(transformer);
}
/** Removes a page transformer from the list. */
public void removeTransformer(@NonNull PageTransformer transformer) {
mTransformers.remove(transformer);
}
@Override
public void transformPage(@NonNull View page, float position) {
for (PageTransformer transformer : mTransformers) {
transformer.transformPage(page, position);
}
}
}